age and geological significance of anatexis within the ......of crustal materials. two-stage hf...

Running title: Age and geological significance of anatexis of Madgascar

Age and Geological Significance of Anatexis within the Berere HTHP Complex

Belt of Maevatanana Area, North-central Madgascar

LI Peng1, LIU Shanbao

1,*, LI Jiankang

1, SHI Guanghai

2, LIU Xiang

3

1 Key Laboratory of Metallogeny and Mineral Resource Assessment, Institute of Mineral Resources, Chinese Academy of

Geological Sciences, Beijing 100037, Beijing, China 2State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing

100083, Beijing, China 3Hunan Nuclear Geology, Changsha 410011, Hunan, China

Abstract: The Berere HTHP Complex belt in Maevatanana area of north–central Madagascar formed in the ~ 2.5

Ga orogeny and underwent high temperature (up to 1050ºC) and high pressure (up to 11.5 kbar) granulite facies

metamorphism. Then a widespread anatexis took place and numerous widely distributed felsic leucosomes formed.

The majority of these leucosomes are parallel to the schistosity of the complex or are present as stockworks, as

thin layers, or as lenses at different scales in the host rocks. Here, we report new petrographic data, zircon

LA–ICP–MS U–Pb ages, and Lu–Hf isotopic data for felsic leucosomes within this complex. Anatexis, as identified

by the petrological study of felsic leucosomes in the field and in thin sections, involved initial ternary feldspar

exsolving to produce antiperthite and a quartz + plagioclase ± K-feldspar + sericite mineral assemblage around

feldspar grain boundaries. Dissolution is apparent along muscovite grain boundaries, and residual sericite is

present around the margins of feldspar and quartz, all suggesting that anatexis was driven by reactions involving

muscovite. Zircon U–Pb dating indicates that the felsic leucosomes within the complex formed at 2467–2369 Ma.

The majority of samples have positive Hf(t) values, although a few have negative values, suggesting their formation

from magmas predominantly sourced from the depleted mantle, possibly with the involvement of minor amounts

of crustal materials. Two-stage Hf model ages and Hf(t) values for these samples are consistent with those for

gneisses of the basement, indicating that the felsic leucosomes were formed by the anatexis of gneisses and both of

their protolith formed during the formation of continental crust in Meso-Neoarchean (ca. 3.1–2.7 Ga). As such,

the crystallization age of the felsic leucosome (~2.4 Ga) represents the timing of regional anatexis and a change to

post-orogenic tectonism. And this anatexis is also corresponds to the thermal event in Dharwar craton in India

which has a pronounced similar Precambrian geology with Madagascar, providing an important constraints on

the correlation of the two continental fragments.

Key words: anatexis, felsic leucosome, U–Pb zircon dating, Lu-Hf isotope, Madagascar.

E-mail: [email protected]

1. Introduction Orogenesis at plate convergent margins, including crustal shortening and extensional thinning, is always accompanied

by the deformation, metamorphism, and partial melting of crustal material (e.g., Teyssier and Whitney, 2002; Gordon et

al., 2008, 2013; Labrousse et al., 2011; Cui Yinliang et al., 2017; Li Yong et al., 2018; Li Leilei et al., 2018). Anatexis is

commonly observed in high-grade metamorphic rocks within orogenic belts, and the complex melting reactions involved

in this process are important for the migration of crustal material and the redistribution of chemical elements, meaning

that anatexis is closely related to the evolution of orogenic events. Consequently, many studies have focused on the

timing and genesis of anatexis, and the associated effects of material migration on mineralizing processes (e.g., Sawyer,

1999, 2001; Kriegsman, 2001; Vanderhaeghe and Teyssier, 2001; Brown, 2007; Gregory et al., 2009, 2012; Zeng et al.,

2011; Lackey et al., 2012; McLeod et al., 2012).

Precambrian basement material is widely exposed along the eastern two-thirds of Madagascar, which is an area

containing abundant mineral resources. Identifying the major magmatic and metamorphic events, and the tectonic

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evolution of basement material is a key part of understanding the geological history of the early Precambrian. Tucker et

al. (2011) suggested that metamorphic rocks of the Fenoarivo Group in the Antongil–Masora area of east Madagascar

records polyphase deformation, metamorphism, and partial melting at ca. 2.55 Ga. A Neoarchean age has also been

obtained for the mafic gneisses and schists of the Tsaratanana Complex, an area that also underwent latest Neoarchean

granulite- and amphibolite-facies metamorphism (Nicollet, 1990; Tucker et al., 1999, 2011; Goncalves et al., 2004;

Kabete et al., 2006). Relict high-Al–Mg granulites in this area also preserve ultrahigh-temperature

garnet–sapphirine–quartz and orthopyroxene–sillimanite–quartz assemblages that suggest pressure–temperature (P–T)

conditions of at least 11 kbar and 1050°C at around 2.5 Ga, as identified using electron microprobe dating of monazite

(Nicollet, 1990; Nicollet et al., 1997; Paquette et al., 2004). Anatexis is commonly recorded within the Precambrian

basement of Madagascar and can provide evidence of the tectonic history of this area, the timing of significant tectonic

changes, and the influence of the migration of anatexis-related material on mineralization. However, the research in this

region has focused on the northern Antongil and north–central Andriamena areas, in addition to other areas of

Madagascar (e.g., Nicollet, 1990; Tucker et al., 1999, 2011, 2014; Collins et al., 2003; Paquette et al., 2004; Schofield et

al., 2010; Sajeev et al., 2014), meaning that the Maevatanana greenstone belt has remained relatively understudied.

Here, we constrain the age and discuss the geological significance of anatexis within the Berere Complex, which is

located in the Maevatanana area of north–central Madagascar. The anatexis in this area may provide useful insights for

mineral exploration as well as outlining the relationship between anatexis and the thermal and tectonic evolution of the

region. Here, we use petrographic data and laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS)

zircon U–Pb and Lu–Hf isotopic data for felsic leucosomes in the study area to determine the timing and genetic

processes of anatexis, the nature of the protolith, and make a comparison with India to discuss the correlation of the two

continental fragments.

2. Geological Setting The bedrock geology of Madagascar is divided into distinct western and eastern provinces. Sedimentary and minor

amounts of volcanic rocks underlie the western third of the island and were deposited during the separation of

Madagascar and Greater India from East Africa, a process that began in the late Paleozoic (Reeves and de Wit, 2000). In

comparison, the eastern two-thirds of the island are underlain by Precambrian rocks that vary widely in age (3187–536

Ma; Tucker et al., 1999), metamorphic grade (greenschist to granulite), and possible tectonic affinity (Kröner et al., 2000).

This Precambrian basement is divided by tectonic location and lithology into the Antongil, Antananarivo, Betsimisaraka,

Tsaratanana, Itremo, Ikalamavony, Tolagnaro, Ampanihy, and Vohibory units (e.g., Collins and Windley, 2002). The

Precambrian basement records multi-period deformation, metamorphism, and magmatism that can be divided into three

stages: Archean cratonization, Proterozoic–early Paleozoic intracratonic orogenesis, and taphrogeny that post-dates the

late Paleozoic (Guerrot et al., 1993; Handke et al., 1997; Ito et al., 1997; Cox et al., 1998; Kröner et al., 1999a;

Goncalves et al., 2003).


The Tsaratanana thrust sheet is divided from west to east into the Maevatanana, Andriamena, and Beforona–Alaotra

greenstone belts (Collins et al., 2000). This study focuses on the Berere Complex (Fig. 1), which is located within the

Maevatanana greenstone belt. The Berere Complex forms part of the Maevatanana Series of the Neoarchean Vohibory

system and is subdivided into a lower formation containing biotite and augen migmatites, a middle formation dominated

by two-mica gneiss, amphibolite, and magnetite quartzite units, and an upper formation containing two-mica and

biotite–plagioclase gneisses intercalated with mica and talc schist, tremolite–actinolite amphibolite, and quartz pegmatite

(Besairie, 1969). The main rock types exposed in study area are biotite–(hornblende)–plagioclase gneiss, granitic gneiss,

and granitic/mafic intrusions. The area around the Berere Complex also contains NNE–SSW trending folds and faults,

NNE–SSW to N–S trending tectonic belts, and minor NW–SW to NNW–SSW, NE–SW, and E–W trending tectonic

zones that are located within the NNE–SSW trending tectonic belts (Li Peng et al., 2015). The complex also contains

widespread felsic leucosomes that have trends generally parallel to the schistosity, range in color from white to pale red,

and have widths of 0.5–15 cm, with other leucosomes being present as stockworks (2–35 cm wide), thin layers, or lenses

within the host rocks (including all types of gneisses and the most schistose granitoids in this area). Some of these

Fig. 1. Regional geological map of Maevatanana (modified after 1:100,000 geological maps of Maevatanana and Kamakama–Mahazoma;

Besairie, 1969).

1, Quaternary alluvium; 2, T3–J2 Marine carbonate, schist, lignite, gypsum, and transitional sedimentary rocks; 3, Isalo I (T2–3) sandstone and mudstone; 4–6,

Maevatanana Group of the Vohibory system: 4, Upper group containing two-mica gneiss, mica schist, talc schist, tremolite–actinolite amphibolite, and quartz pegmatite

units; 5, Middle group containing two-mica gneiss, amphibolite, and magnetite quartzite units; 6, Lower group containing biotite and augen migmatites; 7, Andriba

Group of the Graphite System, containing two-mica and epidotized pyroxene gneisses; 8, Migmatitic granite; 9, Monzonitic granite; 10, Meta-ultramafic rocks (talc

schist, tremolite–actinolite amphibolite, hornblendite, and serpentine units); 11, Quartz and pegmatite veins; 12, Charnockite; 13, Quartz diorite; 14, Basalt; 15, Fault and

mylonite zones.


leucosomes have fabrics in the shape of ‘M’ or ‘S’ as a result of later tectonism (Fig. 2).

Fig. 2. Field photographs showing representative examples of host rocks and felsic leucosomes within the Berere Complex.

3. Petrography The felsic leucosome samples analyzed during this study were obtained from drillholes ZK6-6, ZK35-3, and ZK43-2

within the Berere Complex (Fig. 1). These samples cover a variety of felsic leucosomes that range in color from white to

pale red and have widths of 2–5 cm, some of which are cross-cut by quartz or carbonate veinlets.

Sample ZK6-6-B2 was collected from a depth of 580.75–583.7 m in drillhole ZK6-6, is a pale red felsic leucosome

with a transitional boundary to the surrounding rock, and has undergone brecciation and recrystallization. White banded

felsic leucosome sample ZK35-3-B6 is from a silicified banded gneiss at a depth of 520–527 m in drillhole ZK35-3, and

sample ZK35-3-B10 is a pale red banded felsic leucosome from a potassic-altered banded gneiss at a depth of

95.47–96.47 m in drillhole ZK35-3. Sample ZK35-3-B9 was collected from a depth of 165.55–166.39 m and is a pale red

felsic leucosome with a width of about 1 m, and sample ZK35-3-B11 was collected from a depth of 197.12–200.27 m and

is a red felsic leucosome with a sharp boundary with the surrounding rock. Finally, sample ZK43-2-B2 was obtained

from a depth of 41–41.95 m within drillhole ZK43-2 and is a red felsic leucosome that has undergone brecciation and

recrystallization, and has a transitional boundary with the surrounding rock.

The samples appear similar to each other under the microscope, and the color of the leucosomes is dependent on

variations in the proportions of plagioclase and K-feldspar. The felsic leucosomes contain brecciated and recrystallized

felsic material (50%), quartz (20%), K-feldspar (5%–15%), plagioclase (5%–15%), muscovite/sericite (10%), and minor

amounts of biotite and calcite. The plagioclase within these leucosomes shows polysynthetic twinning and the K-feldspar

shows tartan twining, with both feldspars altered to sericite. Muscovite dissolution is evident in the form of serrated grain

boundaries, and massive quartz grains have a shape-preferred orientation that is parallel to the schistosity of the

surrounding rock, suggesting that both the veins and the surrounding rocks have undergone significant tectonic

compression. The quartz and carbonate veinlets that cross-cut the leucosomes also provide evidence that this area has

undergone at least two stages of alteration.

Analyses of thin sections revealed information on the anatexis, including: 1) some plagioclase crystals with clear


polysynthetic twins have antiperthite structures (Fig. 3a), and poikilitic K-feldspars with fuzzy boundaries are present as

inclusions within these plagioclase grains; 2) a quartz + plagioclase ± K-feldspar + sericite mineral assemblage is present

around feldspar grain boundaries (Fig. 3b); 3) dissolution of muscovite is evidenced by the presence of serrated grain

boundaries, suggesting that the anatexis was closely related to muscovite dissolution (Fig. 3c); and 4) residual sericite

occurs along feldspar and quartz grain boundaries and in fractures within feldspar, again suggesting that muscovite was

the main reactive phase during anatexis (Fig. 3d).

Fig. 3. Photomicrographs showing representative examples of felsic leucosome samples from the Berere Complex.

4. Analytical Techniques All samples were collected from drilling cores, and the whole–rock geochemical analyses were performed at the

National Research Center of Geoanalysis in Beijing, China. Zircon separation, cathodoluminescence (CL) imaging and

U–Th–Pb isotope measurements were all carried out at the Beijing SHRIMP Center, Chinese Academy of Geological

Sciences (CAGS). Zircon grains were extracted from rock samples using the conventional procedures including rock

crushing, sieving, elutriating, drying, dressing by magnetic separation, electromagnetic selection, heavy liquid separation

and hand picking under a binocular microscope. Zircon grains were then mounted onto a double-sided adhesive tape and

enclosed in an epoxy resin disk with a diameter of 2.5 cm. The morphology of zircon crystals was examined in both

transmitted and reflected light, and images were taken using an optical microscope and a CL imaging system. Procedures

were identical to those described by Liu et al. (2015) and Li Peng et al. (2017).

U-Pb dating analyses were conducted by LA-ICP-MS at the Institute of Mineral Resources, Chinese Academy of

Geological Sciences, Beijing, China. Laser sampling was performed using a Newwave UP 213 laser ablation system. A

Bruker M90 ICP-MS instrument was used to acquire ion-signal intensities. Helium was applied as a carrier gas. Argon

was used as the make-up gas and mixed with the carrier gas via a T-connector before entering the ICP. Each analysis

incorporated a background acquisition of approximately 15s (gas blank) followed by 45s data acquisition from the

sample. Off-line raw data selection and integration of background and analyte signals, and time-drift correction and

quantitative calibration for U-Pb dating was performed by ICPMSDataCal (Liu et al., 2010). For the analyses we used a

spot size of 25 m, and the time–dependent elemental fractionation was minimized by using a laser frequency of 10 Hz.


Zircon GJ1(601.0 ± 1.7 Ma, 2, Elhlou et al., 2006) was used as external standard for U-Pb dating, and was analyzed

twice every 5-10 analyses. Time-dependent drifts of U-Th-Pb isotopic ratios were corrected using a linear interpolation

(with time) for every 5-10 analyses according to the variations of GJ1. Uncertainty of preferred values (0.5%) for the

external standard GJ1 was propagated to the ultimate results of the samples. In all analyzed zircon grains the common Pb

correction was not necessary due to the low signal of common 204

Pb and high 206

Pb/204

Pb. U, Th and Pb concentration

was calibrated by NIST 610. Concordia diagrams and weighted mean calculations were made using Isoplot/Ex_ver3. The

zircon Plesovice is dated as unkown samples and yielded weighted mean 206

Pb/238

U age of 337 ± 2 Ma (2SD, n = 12),

which is in good agreement with the recommended 206

Pb/238

U age of 337.13 ± 0.37 Ma (2SD) (Sláma et al., 2008). The

determination of the ages for zircons (>1000 Ma) has to be based primary on their 207

Pb/206

Pb ages.

Zircon Hf isotope measurements were generally obtained from spots previously used for U–Pb dating, and using a

Finnigan Neptune MC–ICP–MS equipped with a Newwave UP 213 LA system at the Ministry of Land and Resources

Key Laboratory of Metallogeny and Mineral Assessment, Chinese Academy of Geological Sciences, Beijing, China. The

Hf isotope analyses used a 55 m spot size and a 2 min scanning time. A GJ–1 standard zircon was used for external

standardization during Hf isotopic analysis, and it yielded an average 176

Hf/177

Hf value of 0.282008 ± 28 (2). All other

analytical and correction procedures were identical to those described by Hou Kejun et al. (2007). The single-stage Hf

model ages (TMD1) and two-stage Hf model ages (TMD2) were calculated in same way as those described by Xia Jinglong

et al. (2015).

5. Results 5.1. Zircon morphology

Zircons within felsic leucosomes in the study area have been classified using CL imaging into the following

morphological classes: 1) euhedral stumpy or granular zircons with clear growth zones (Fig. 4; e.g., ZK6-6-B2,

ZK35-3-B6, and ZK43-2-B2-6); 2) euhedral stumpy or granular zircons with weakly visible growth zoning and weakly

luminescent cores (Fig. 4; e.g., ZK35-3-B10-18 and ZK35-3-B11-17); and 3) xenomorphic granular zircons with clear

growth zoning (Fig. 4; e.g., ZK35-3-B9-16,18). The growth zones identified during this study are similar to the growth

characteristics of anatectic zircon (Liati and Gebauer, 1999; Zeh et al., 2010).

Fig. 4. Cathodoluminescence images of zircons from the felsic leucosome samples of the Berere complex.

5.2. Zircon U-Pb dating


The results of zircon U–Pb dating are given in Supplementary Table 1. The majority of analyses are concordant, with the few discordant points having t207/206 > t207/235 > t206/238 characteristics indicative of variable radiogenic lead loss. The high Th/U ratios of these zircons are probably related to the influence of paragenetic minerals, zircon growth rates, and a lack of aqueous fluids during crystallization.

Table 1. Zircon LA–ICP–MS U–Pb data for felsic leucosome samples from the Berere complex.

Grain Spot Th(ppm) U(ppm) Th/U 207

Pb/206

Pb (1σ) 207

Pb/235

U (1σ) 206

Pb/238

U (1σ) Age (Ma)

207Pb/

206Pb (1σ)

207Pb/

235U (1σ)

206Pb/

238U (1σ)

ZK6-6-B2-1 135.51 100 1.35 0.1541 0.0009 9.90941 0.119 0.466 0.005 2392 9.4 2426 11 2466 22

ZK6-6-B2-2 366.96 367.4 1 0.1546 0.0009 10.0997 0.0895 0.4743 0.0037 2398 11 2444 8.2 2502 16

ZK6-6-B2-3 246.9 156.2 1.58 0.1511 0.0008 9.92463 0.0933 0.4761 0.0038 2358 9.3 2428 8.7 2510 17

ZK6-6-B2-4 173.68 139.1 1.25 0.1501 0.0008 9.41751 0.074 0.4547 0.0028 2347 14 2380 7.2 2416 12

ZK6-6-B2-5 163.71 146.8 1.12 0.1511 0.0008 9.71899 0.0663 0.466 0.0022 2359 9.3 2409 6.3 2466 9.8

ZK6-6-B2-6 251.46 224.8 1.12 0.1507 0.0008 9.98571 0.1006 0.4802 0.0042 2354 9.3 2433 9.3 2528 18

ZK6-6-B2-7 295.21 285.5 1.03 0.151 0.0009 9.97486 0.0856 0.4787 0.0032 2357 11 2432 7.9 2522 14

ZK6-6-B2-8 177.03 157.3 1.13 0.1505 0.001 9.43388 0.1461 0.4543 0.0065 2352 10 2381 14 2414 29

ZK6-6-B2-9 79.16 82.23 0.96 0.1501 0.001 9.66909 0.1488 0.4667 0.0065 2347 12 2404 14 2469 28

ZK6-6-B2-10 255.34 167 1.53 0.1519 0.0011 10.1061 0.1314 0.482 0.0053 2369 13 2445 12 2536 23

ZK6-6-B2-11 176.72 121 1.46 0.1532 0.0011 10.0613 0.1108 0.4757 0.0041 2383 12 2440 10 2509 18

ZK6-6-B2-12 115.77 131.2 0.88 0.1517 0.001 9.98504 0.1009 0.4771 0.0038 2365 11 2433 9.3 2515 17

ZK6-6-B2-13 186.15 140.5 1.32 0.1544 0.001 10.3116 0.094 0.484 0.0031 2395 12 2463 8.4 2545 13

ZK6-6-B2-14 91.39 96.47 0.95 0.1547 0.0011 9.33961 0.0924 0.4371 0.003 2398 12 2372 9.1 2338 13

ZK6-6-B2-15 131.03 135.4 0.97 0.154 0.001 9.85095 0.0822 0.4635 0.0024 2391 11 2421 7.7 2455 10

ZK6-6-B2-16 93.69 118.8 0.79 0.1578 0.0011 9.51078 0.089 0.4368 0.0028 2432 12 2389 8.6 2336 13

ZK6-6-B2-17 77.96 119.7 0.65 0.1568 0.0012 9.42063 0.0833 0.4353 0.0021 2422 13 2380 8.1 2330 9.6

ZK6-6-B2-18 151.06 139.1 1.09 0.1526 0.0013 8.12423 0.0953 0.3858 0.0031 2376 15 2245 11 2103 14

ZK6-6-B2-19 77.43 88.92 0.87 0.1542 0.0013 9.3162 0.0989 0.4376 0.0025 2394 10 2370 9.7 2340 11

ZK6-6-B2-20 77.1 81.84 0.94 0.1482 0.0014 9.3979 0.1425 0.4599 0.0058 2325 17 2378 14 2439 25

ZK6-6-B2-21 65.72 66.41 0.99 0.1476 0.0015 9.31105 0.1412 0.4573 0.0053 2318 17 2369 14 2428 23

ZK35-3-B6-1 62.31 227.46 0.27 0.153 0.0007 9.33565 0.0737 0.4421 0.0031 2380 7.7 2372 7.2 2360 14

ZK35-3-B6-2 18.54 225.43 0.08 0.1707 0.0009 9.7274 0.1003 0.4128 0.0036 2564 2.9 2409 9.5 2228 16

ZK35-3-B6-3 47.24 50.54 0.93 0.164 0.0008 9.88277 0.0875 0.4366 0.0034 2498 2.9 2424 8.2 2335 15

ZK35-3-B6-4 65.03 122.3 0.53 0.1723 0.0007 10.8627 0.0966 0.4568 0.0038 2581 7.1 2511 8.3 2425 17

ZK35-3-B6-5 264.86 128.45 2.06 0.1647 0.0008 10.6577 0.1339 0.4689 0.0057 2506 6.9 2494 12 2479 25

ZK35-3-B6-6 216.2 191.52 1.13 0.1609 0.0007 10.6159 0.1232 0.478 0.0052 2465 7.1 2490 11 2518 23

ZK35-3-B6-7 126.15 70.44 1.79 0.1633 0.0008 10.1187 0.1609 0.4494 0.007 2500 6.9 2446 15 2393 31

ZK35-3-B6-8 544.04 380.91 1.43 0.176 0.0019 11.2176 0.1432 0.4676 0.0066 2616 18 2541 12 2473 29

ZK35-3-B6-9 121.94 430.09 0.28 0.1555 0.0009 9.62803 0.1611 0.4487 0.0074 2409 9.6 2400 15 2390 33

ZK35-3-B6-10 244.83 234.09 1.05 0.1551 0.0008 9.82959 0.0761 0.4591 0.0028 2403 9.3 2419 7.1 2436 12

ZK35-3-B6-11 39.7 43.28 0.92 0.1513 0.001 8.9935 0.0857 0.4307 0.0032 2361 11 2337 8.7 2309 14

ZK35-3-B6-12 145.78 126.98 1.15 0.1511 0.0011 9.77625 0.1038 0.4689 0.004 2359 12 2414 9.8 2479 18

ZK35-3-B6-13 126.45 397.33 0.32 0.1456 0.0012 8.85468 0.092 0.4418 0.0032 2295 15 2323 9.5 2359 14

ZK35-3-B6-14 149.83 198.6 0.75 0.14 0.0013 8.786 0.1229 0.455 0.0045 2227 16 2316 13 2417 20

ZK35-3-B6-15 130.76 267.53 0.49 0.1452 0.0016 9.71078 0.1472 0.4851 0.0048 2290 19 2408 14 2549 21

ZK35-3-B6-16 99.37 124.33 0.8 0.1506 0.002 10.1316 0.1606 0.4883 0.0039 2354 22 2447 15 2563 17


ZK35-3-B6-17 129.16 131.26 0.98 0.1371 0.0021 8.50928 0.1485 0.4507 0.0033 2191 26 2287 16 2398 15

ZK35-3-B6-18 47.02 321.53 0.15 0.1507 0.0027 8.89728 0.1742 0.4294 0.0032 2353 29 2328 18 2303 14

ZK35-3-B6-19 66.31 263.81 0.25 0.1434 0.0028 7.56989 0.1655 0.3842 0.0029 2268 33 2181 20 2096 14

ZK35-3-B10-1 229.82 158.20 1.45 0.1592 0.0006 10.2795 0.0812 0.4682 0.0035 2447 5.1 2460 7.3 2475 15

ZK35-3-B10-2 139.52 337.35 0.41 0.1705 0.0013 10.1629 0.0898 0.4342 0.0039 2563 13 2450 8.2 2325 18

ZK35-3-B10-3 151.27 62.99 2.4 0.1675 0.0009 10.2585 0.0917 0.4443 0.0035 2533 8.6 2458 8.3 2370 16

ZK35-3-B10-4 221.01 53.75 4.11 0.1669 0.0008 10.519 0.0917 0.4568 0.0034 2527 7.3 2482 8.1 2425 15

ZK35-3-B10-5 137.43 46.19 2.98 0.1705 0.0012 10.7574 0.1144 0.4578 0.004 2562 11 2502 9.9 2430 18

ZK35-3-B10-6 274.22 133.68 2.05 0.1589 0.0005 10.2819 0.1293 0.4692 0.0057 2444 5.4 2460 12 2480 25

ZK35-3-B10-7 328.42 193.51 1.7 0.1562 0.0005 10.1727 0.1388 0.4722 0.0063 2415 5.6 2451 13 2493 27

ZK35-3-B10-8 305.76 412.45 0.74 0.1705 0.0019 10.4556 0.162 0.4485 0.0073 2565 20 2476 14 2388 32

ZK35-3-B10-9 529.09 98.86 5.35 0.157 0.0006 9.71058 0.0702 0.4485 0.0028 2423 7.3 2408 6.7 2389 13

ZK35-3-B10-10 335.98 333.24 1.01 0.1576 0.0006 9.84735 0.0811 0.453 0.0032 2431 1.7 2421 7.6 2409 14

ZK35-3-B10-11 292.81 101.7 2.88 0.1545 0.0007 10.1252 0.0635 0.475 0.0023 2396 6.3 2446 5.8 2506 10

ZK35-3-B10-12 208.8 329.02 0.63 0.1581 0.0008 10.624 0.1202 0.4873 0.0052 2435 7.9 2491 10 2559 23

ZK35-3-B10-13 230.78 274.58 0.84 0.1577 0.0008 10.377 0.0989 0.477 0.0042 2432 3.5 2469 8.8 2514 18

ZK35-3-B10-14 305.07 160.5 1.9 0.1527 0.0008 10.091 0.0793 0.4786 0.0029 2376 9.3 2443 7.3 2521 13

ZK35-3-B10-15 187.99 243.21 0.77 0.1599 0.001 9.92468 0.082 0.4496 0.0028 2455 11 2428 7.6 2393 12

ZK35-3-B10-16 163.77 384 0.43 0.1698 0.0017 9.40173 0.0843 0.4026 0.0031 2555 17 2378 8.2 2181 14

ZK35-3-B10-17 109.28 201.62 0.54 0.1573 0.0013 10.2566 0.0972 0.4723 0.0031 2428 14 2458 8.8 2494 14

ZK35-3-B10-18 274.79 318.48 0.86 0.1582 0.0015 10.0805 0.1009 0.4619 0.0031 2436 17 2442 9.2 2448 14

ZK35-3-B10-19 176.49 264.89 0.67 0.1512 0.0016 9.97013 0.1423 0.4776 0.0054 2361 17 2432 13 2517 24

ZK35-3-B10-20 543.87 64.48 8.44 0.1497 0.0017 9.27621 0.1096 0.448 0.0024 2343 19 2366 11 2386 10

ZK35-3-B9-1 54.78 40.43 1.35 0.1602 0.0014 9.74757 0.1355 0.4413 0.0043 2458 15 2411 13 2357 19

ZK35-3-B9-2 106.91 72.74 1.47 0.1613 0.0015 9.54225 0.1336 0.429 0.0039 2469 15 2392 13 2301 18

ZK35-3-B9-3 103.61 73.3 1.41 0.1603 0.0014 9.62706 0.1303 0.4355 0.0041 2458 15 2400 12 2330 18

ZK35-3-B9-4 104.2 86.96 1.2 0.1604 0.0012 10.3254 0.1298 0.4665 0.0042 2461 13 2464 12 2468 18

ZK35-3-B9-5 66.41 57.62 1.15 0.1726 0.0015 10.5086 0.1326 0.441 0.0037 2582 15 2481 12 2355 16

ZK35-3-B9-6 75.64 63.99 1.18 0.1729 0.0015 10.7095 0.1697 0.4474 0.0048 2587 14 2498 15 2384 21

ZK35-3-B9-7 79.49 61.72 1.29 0.1624 0.0015 9.91186 0.1455 0.4411 0.0039 2481 17 2427 14 2356 18

ZK35-3-B9-8 96.98 57.82 1.68 0.1541 0.001 9.53064 0.1396 0.4482 0.0059 2392 11 2391 13 2387 26

ZK35-3-B9-9 96.46 57.63 1.67 0.1554 0.0011 9.66797 0.1181 0.4512 0.0048 2406 12 2404 11 2401 21

ZK35-3-B9-10 135.36 85.1 1.59 0.1542 0.0011 9.51479 0.1301 0.4472 0.0053 2392 13 2389 13 2383 24

ZK35-3-B9-11 59.42 44.91 1.32 0.1597 0.0013 9.88716 0.1554 0.4488 0.0065 2454 14 2424 14 2390 29

ZK35-3-B9-12 72.13 66.2 1.09 0.161 0.0015 9.8676 0.1531 0.4425 0.0043 2466 17 2422 14 2362 19

ZK35-3-B9-13 60.20 42.06 1.43 0.1607 0.0012 9.301 0.1373 0.4187 0.005 2465 13 2368 14 2255 23

ZK35-3-B9-14 49.92 35.86 1.39 0.1727 0.0014 10.5151 0.1535 0.441 0.0054 2584 13 2481 14 2355 24

ZK35-3-B9-15 46.12 45.36 1.02 0.1715 0.0013 10.3276 0.1665 0.4364 0.0061 2572 13 2465 15 2334 27

ZK35-3-B9-16 69.78 46.67 1.49 0.1635 0.0011 9.83985 0.1085 0.4366 0.0042 2492 11 2420 10 2336 19

ZK35-3-B9-17 30.39 29.15 1.04 0.1709 0.0013 10.3673 0.1473 0.4393 0.0051 2566 13 2468 13 2347 23

ZK35-3-B9-18 54.37 38.45 1.41 0.1604 0.0012 9.91972 0.1456 0.4483 0.0055 2461 13 2427 14 2387 24

ZK35-3-B9-19 48.26 35.88 1.35 0.1605 0.0012 9.64288 0.154 0.4361 0.0065 2461 12 2401 15 2333 29


ZK35-3-B9-20 43.55 35.24 1.24 0.161 0.0014 10.2683 0.2063 0.4609 0.0073 2466 15 2459 19 2444 32

ZK35-3-B9-21 32.21 30.31 1.06 0.1537 0.0011 8.83472 0.1586 0.4173 0.0071 2388 12 2321 16 2248 32

ZK35-3-B11-1 10.83 120.67 0.09 0.1377 0.0019 7.74748 0.1511 0.4096 0.005 2198 30 2202 18 2213 23

ZK35-3-B11-2 28.57 61.73 0.46 0.1422 0.0018 7.14448 0.1193 0.3656 0.0034 2253 22 2130 15 2009 16

ZK35-3-B11-3 44.99 21.39 2.1 0.1422 0.0017 6.94313 0.1285 0.3551 0.0046 2254 20 2104 16 1959 22

ZK35-3-B11-4 48.12 106.83 0.45 0.1537 0.0015 9.58543 0.1304 0.4532 0.0035 2388 17 2396 13 2410 16

ZK35-3-B11-5 11.67 26.98 0.43 0.1583 0.0016 9.69749 0.1491 0.4452 0.0048 2439 17 2406 14 2374 22

ZK35-3-B11-6 42.41 89.52 0.47 0.1524 0.0012 9.98928 0.1303 0.4763 0.005 2373 13 2434 12 2511 22

ZK35-3-B11-7 36.36 70.05 0.52 0.1523 0.001 9.18109 0.1191 0.438 0.005 2372 11 2356 12 2342 22

ZK35-3-B11-8 71.46 125.42 0.57 0.1535 0.0008 9.44647 0.147 0.4467 0.0065 2387 9 2382 14 2381 29

ZK35-3-B11-9 74.48 102.54 0.73 0.1567 0.0007 9.82731 0.1073 0.4551 0.0044 2421 8 2419 10 2418 20

ZK35-3-B11-10 155.66 299.1 0.52 0.1537 0.0006 8.29719 0.1043 0.3914 0.0046 2388 6.8 2264 11 2129 21

ZK35-3-B11-11 40.21 45.3 0.89 0.1571 0.0008 9.89551 0.1193 0.4573 0.0052 2424 8.3 2425 11 2428 23

ZK35-3-B11-12 219 397.77 0.55 0.1538 0.0007 9.89386 0.11 0.4668 0.0048 2391 8.5 2425 10 2470 21

ZK35-3-B11-13 164.98 533.81 0.31 0.1554 0.0009 10.1927 0.0722 0.4764 0.0027 2406 9.3 2452 6.5 2511 12

ZK35-3-B11-14 113.55 126.24 0.9 0.1526 0.0009 7.17888 0.0884 0.3416 0.0038 2376 11 2134 11 1894 18

ZK35-3-B11-15 118.6 372.97 0.32 0.1516 0.0015 9.52535 0.1161 0.4598 0.0054 2365 16 2390 11 2438 24

ZK35-3-B11-16 59.55 106.68 0.56 0.1505 0.0012 9.93897 0.1493 0.4792 0.006 2354 13 2429 14 2524 26

ZK35-3-B11-17 85.21 424.09 0.2 0.1534 0.0015 9.67945 0.1234 0.4599 0.0046 2384 216 2405 12 2439 20

ZK35-3-B11-18 185.99 382.05 0.49 0.154 0.0028 9.6345 0.1356 0.4615 0.0059 2390 30 2400 13 2446 26

ZK35-3-B11-19 246.64 271.41 0.91 0.146 0.0016 8.76363 0.129 0.436 0.0042 2299 19 2314 13 2333 19

ZK35-3-B11-20 51.58 101.65 0.51 0.1459 0.0018 9.1237 0.1319 0.4541 0.0034 2298 21 2350 13 2414 15

ZK35-3-B11-21 75.02 126.91 0.59 0.1434 0.0019 9.21877 0.1401 0.4669 0.0031 2268 18 2360 14 2470 14

ZK43-2-B2-1 172.01 69.69 2.47 0.1568 0.0009 9.06511 0.0609 0.4186 0.0021 2421 9.3 2345 6.1 2254 9.4

ZK43-2-B2-2 123.27 58.44 2.11 0.1562 0.0009 9.6787 0.0687 0.4484 0.0025 2417 9.6 2405 6.5 2388 11

ZK43-2-B2-3 74.64 116.5 0.64 0.154 0.0008 9.51801 0.0632 0.4474 0.0024 2390 9.3 2389 6.1 2384 10

ZK43-2-B2-4 180.95 80.61 2.24 0.154 0.0008 9.48324 0.0633 0.4457 0.0024 2391 8.2 2386 6.1 2376 11

ZK43-2-B2-5 142.36 52.71 2.7 0.1547 0.0009 9.82579 0.0861 0.4594 0.0034 2398 9.3 2419 8.1 2437 15

ZK43-2-B2-6 158.63 197.93 0.8 0.1542 0.001 9.47831 0.1153 0.4447 0.005 2394 11 2385 11 2372 22

ZK43-2-B2-7 76.98 39.22 1.96 0.1553 0.001 9.82327 0.1562 0.4573 0.0068 2406 11 2418 15 2428 30

ZK43-2-B2-8 57.26 89.48 0.64 0.1552 0.001 10.1788 0.1117 0.4744 0.0046 2403 12 2451 10 2503 20

ZK43-2-B2-9 105.12 101.27 1.04 0.1533 0.0011 9.70479 0.1177 0.4577 0.0049 2384 12 2407 11 2429 22

ZK43-2-B2-10 97.95 44.15 2.22 0.1533 0.0013 9.65426 0.1153 0.4556 0.0047 2383 14 2402 11 2420 21

ZK43-2-B2-11 116.01 70.44 1.65 0.1548 0.0012 9.84152 0.1263 0.4601 0.0053 2400 13 2420 12 2440 23

ZK43-2-B2-12 128.96 164.93 0.78 0.1503 0.001 9.94619 0.0733 0.4784 0.0023 2350 11 2430 6.8 2520 10

ZK43-2-B2-13 79.36 37.47 2.12 0.1548 0.001 9.61236 0.1067 0.4492 0.0045 2400 10 2398 10 2392 20

ZK43-2-B2-14 77.56 150.29 0.52 0.1535 0.0009 9.14935 0.1066 0.4313 0.0047 2385 9.9 2353 11 2311 21

ZK43-2-B2-15 58.94 107.67 0.55 0.155 0.0008 9.99734 0.0884 0.4665 0.0036 2402 8.2 2435 8.2 2468 16

ZK43-2-B2-16 46.49 86.37 0.54 0.1546 0.0008 9.80875 0.0767 0.4589 0.003 2398 7.6 2417 7.2 2435 13

ZK43-2-B2-17 145.04 64.86 2.24 0.1546 0.0009 9.09203 0.0666 0.4255 0.0024 2398 9.6 2347 6.7 2286 11

ZK43-2-B2-18 67.27 72.71 0.93 0.1544 0.0007 10.3901 0.1047 0.4872 0.0045 2395 8 2470 9.3 2558 20

ZK43-2-B2-19 63.96 45.85 1.4 0.1583 0.0008 10.5605 0.1159 0.4829 0.0049 2439 8.6 2485 10 2540 21


ZK43-2-B2-20 46.6 37.28 1.25 0.1571 0.0009 10.3521 0.1464 0.477 0.0063 2425 9.1 2467 13 2514 27

Seventeen spot analyses of zircons from sample ZK6-6-B2 yielded a weighted mean 207

Pb/206

Pb age of 2372 ± 9.9 Ma

(N = 17, MSWD = 3.1; Fig. 5a), and 11 spot analyses of zircons from sample ZK35-3-B6 yield three weighted mean 207

Pb/206

Pb ages of 2499 ± 4.9 (N = 3, MSWD = 0.53; Fig. 5b), 2369 ± 10 (N = 5, MSWD = 1.00; Fig. 5b), and 2291 ±

21 Ma (N = 3, MSWD = 0.26; Fig. 5b). The 20 spot analyses of zircons from sample ZK35‒3‒B10 yielded three

weighted mean 207

Pb/206

Pb ages of 2542 ± 12 (N = 6, MSWD = 2.6; Fig. 5c), 2433 ± 5.4 (N = 10, MSWD = 3.3; Fig. 5c),

and 2385 ± 29 Ma (N = 4, MSWD = 3.5; Fig. 5c), and the 21 spot analyses of zircons from sample ZK35‒3‒B9 yielded

three weighted mean 207

Pb/206

Pb ages of 2578 ± 12 (N = 5, MSWD = 0.46; Fig. 5d), 2467 ± 7.7 (N = 12, MSWD = 0.73;

Fig. 5d), and 2394 ± 12 Ma (N = 4, MSWD = 0.45; Fig. 5d). Finally, 18 spot analyses of zircons from sample

ZK35‒3‒B11 yielded three weighted mean 207

Pb/206

Pb ages of 2419 ± 17 (N = 4, MSWD = 1.3; Fig. 5e), 2382 ± 7.1 (N =

9, MSWD = 1.17; Fig. 5e), and 2275 ± 28 Ma (N = 5, MSWD = 1.3; Fig. 5e), and the spot analyses of zircons from

sample ZK43‒2‒B2 yielded a weighted mean 207

Pb/206

Pb age of 2403 ± 7.2 Ma (N = 19, MSWD = 2.4; Fig. 5f).


Fig. 5. Zircon U–Pb concordia diagrams for felsic leucosome samples from the Berere Complex.

5.3. Zircon Hf analysis

The results of zircon Hf isotopic analyses are given in Supplementary Table 2, and the majority of analyses were

located within the same zircon domains as those used for U–Pb dating. All of the analyzed zircons have low 176

Lu/177

Hf

ratios (<0.002), suggesting they contain low amounts of radiogenic Hf, meaning that their initial 176

Lu/177

Hf ratios are

indicative of their Hf isotopic compositions during zircon formation (Wu Fuyuan et al., 2007). All samples have low fLu/Hf

ratios (mean of –0.98), indicating that their two-stage Hf model ages are representative of the residence time of their

source materials within the crust (Amelin et al., 2000; Wu Fuyuan et al., 2007). Table 2. Zircon Lu–Hf isotopic compositions of felsic leucosome samples from the Berere complex.

Grain Spot Age(Ma) 176

Yb/177

Hf 176

Lu/177

Hf 176

Hf/177

Hf 2σ εHf(t) 2σ tDM1 tDM2 fLu/Hf

ZK6-6-B2-1 2372 0.021606 0.000595 0.281388 0.000024 5.5 0.858565 2575 2640 -0.982067

ZK6-6-B2-2 2372 0.022542 0.000616 0.281372 0.000021 4.8 0.756648 2598 2679 -0.981441

ZK6-6-B2-3 2372 0.026516 0.000694 0.281314 0.000021 2.8 0.756220 2682 2809 -0.979085

ZK6-6-B2-4 2372 0.021952 0.000739 0.281554 0.000026 10.2 0.937629 2359 2318 -0.977753

ZK6-6-B2-5 2372 0.022950 0.000598 0.281319 0.000018 1.8 0.639943 2668 2825 -0.982001

ZK6-6-B2-6 2372 0.035823 0.000933 0.281326 0.000017 3.2 0.588610 2683 2798 -0.971895

ZK6-6-B2-7 2372 0.024697 0.000714 0.281314 0.000022 2.8 0.773230 2683 2809 -0.978493

ZK6-6-B2-8 2372 0.024912 0.000629 0.281271 0.000021 0.3 0.733967 2736 2926 -0.981056

ZK6-6-B2-9 2372 0.027858 0.000723 0.281375 0.000019 6.4 0.689088 2602 2638 -0.978235

ZK6-6-B2-10 2372 0.026787 0.000695 0.281377 0.000020 4.0 0.708079 2597 2702 -0.979053

ZK6-6-B2-11 2372 0.032843 0.000891 0.281375 0.000021 3.7 0.743699 2613 2721 -0.973167

ZK6-6-B2-12 2372 0.019083 0.000492 0.281298 0.000019 2.9 0.661000 2689 2815 -0.985183

ZK6-6-B2-13 2372 0.025254 0.000645 0.281347 0.000021 5.3 0.746085 2635 2699 -0.980580

ZK6-6-B2-14 2372 0.024028 0.000635 0.281376 0.000022 4.1 0.765392 2594 2694 -0.980878

ZK6-6-B2-15 2372 0.026490 0.000707 0.281336 0.000023 3.3 0.815950 2652 2768 -0.978704

ZK6-6-B2-16 2372 0.019998 0.000520 0.281278 0.000018 0.7 0.647513 2718 2900 -0.984323

ZK6-6-B2-17 2372 0.023906 0.000623 0.281322 0.000020 2.3 0.696528 2666 2808 -0.981236

ZK6-6-B2-18 2372 0.024292 0.000622 0.281300 0.000018 -0.2 0.646933 2696 2905 -0.981273

ZK6-6-B2-19 2372 0.027082 0.000678 0.281306 0.000018 -0.1 0.654621 2691 2895 -0.979571

ZK6-6-B2-20 2372 0.023117 0.000571 0.281313 0.000017 1.2 0.592490 2675 2848 -0.982794

ZK6-6-B2-21 2372 0.023880 0.000659 0.281279 0.000019 -0.7 0.680360 2727 2945 -0.980145

ZK35-3-B6-1 2369 0.002707 0.000066 0.281237 0.000018 -1.3 0.636584 2741 2980 -0.998027


ZK35-3-B6-2 2369 0.007640 0.000174 0.281233 0.000020 -2.9 0.706707 2754 3033 -0.994745

ZK35-3-B6-3 2369 0.039054 0.000977 0.281217 0.000024 -4.1 0.866561 2833 3129 -0.970583

ZK35-3-B6-4 2369 0.037448 0.000920 0.281195 0.000022 -3.1 0.780258 2859 3125 -0.972301

ZK35-3-B6-5 2369 0.030258 0.000735 0.281238 0.000022 -0.1 0.768798 2787 2981 -0.977875

ZK35-3-B6-6 2369 0.022109 0.000550 0.281204 0.000022 -1.0 0.777520 2819 3037 -0.983433

ZK35-3-B6-7 2369 0.019993 0.000527 0.281258 0.000015 -1.5 0.550449 2745 2983 -0.984112

ZK35-3-B6-8 2369 0.058650 0.001380 0.281307 0.000021 1.1 0.733725 2740 2902 -0.958431

ZK35-3-B6-9 2369 0.003689 0.000068 0.281286 0.000016 -0.4 0.566512 2676 2897 -0.997950

ZK35-3-B6-10 2369 0.032684 0.000967 0.281287 0.000020 0.2 0.715335 2738 2927 -0.970872

ZK35-3-B6-11 2369 0.019102 0.000545 0.281239 0.000019 -2.7 0.677756 2773 3041 -0.983589

ZK35-3-B6-12 2369 0.038285 0.001096 0.281280 0.000019 0.6 0.676901 2757 2933 -0.966977

ZK35-3-B6-13 2369 0.018429 0.000686 0.281231 0.000014 -2.1 0.506561 2793 3041 -0.979333

ZK35-3-B6-14 2369 0.000445 0.000009 0.281291 0.000017 1.2 0.596457 2666 2843 -0.999722

ZK35-3-B6-15 2369 0.099034 0.002200 0.281539 0.000028 8.3 1.007330 2474 2474 -0.933746

ZK35-3-B6-16 2369 0.078817 0.001948 0.281380 0.000021 3.6 0.733899 2679 2779 -0.941331

ZK35-3-B6-17 2369 0.028568 0.000785 0.281265 0.000020 -0.8 0.712238 2754 2970 -0.976356

ZK35-3-B6-18 2369 0.028206 0.000700 0.281308 0.000020 3.1 0.707023 2690 2807 -0.978915

ZK35-3-B10-1 2433 0.011817 0.000309 0.281265 0.000023 1.2 0.823483 2721 2890 -0.990690

ZK35-3-B10-2 2433 0.015256 0.000414 0.281297 0.000024 0.8 0.843656 2685 2869 -0.987532

ZK35-3-B10-3 2433 0.009552 0.000263 0.281312 0.000018 1.8 0.634163 2655 2814 -0.992070

ZK35-3-B10-4 2433 0.010000 0.000265 0.281312 0.000017 2.3 0.587072 2655 2802 -0.992013

ZK35-3-B10-5 2433 0.005860 0.000158 0.281293 0.000020 1.5 0.716995 2674 2841 -0.995255

ZK35-3-B10-6 2433 0.010385 0.000259 0.281279 0.000018 1.3 0.625865 2699 2867 -0.992205

ZK35-3-B10-7 2433 0.017248 0.000433 0.281278 0.000015 1.2 0.542174 2712 2883 -0.986962

ZK35-3-B10-8 2433 0.026351 0.000554 0.281329 0.000018 2.7 0.652224 2652 2786 -0.983311

ZK35-3-B10-9 2433 0.012132 0.000318 0.281270 0.000017 0.0 0.620904 2715 2917 -0.990413

ZK35-3-B10-10 2433 0.014654 0.000347 0.281287 0.000017 0.5 0.590987 2694 2884 -0.989540

ZK35-3-B10-11 2433 0.014051 0.000373 0.281286 0.000015 2.7 0.524748 2697 2828 -0.988770

ZK35-3-B10-12 2433 0.013692 0.000375 0.281299 0.000018 3.1 0.636699 2680 2801 -0.988706

ZK35-3-B10-13 2433 0.030797 0.000787 0.281327 0.000019 3.3 0.692406 2670 2786 -0.976291

ZK35-3-B10-14 2433 0.012365 0.000323 0.281304 0.000016 3.2 0.581046 2670 2790 -0.990262

ZK35-3-B10-15 2433 0.023010 0.000607 0.281277 0.000019 -0.1 0.661496 2726 2927 -0.981724

ZK35-3-B10-16 2433 0.010631 0.000288 0.281357 0.000015 3.4 0.542481 2597 2718 -0.991337

ZK35-3-B10-17 2433 0.018940 0.000513 0.281307 0.000020 3.0 0.710223 2679 2801 -0.984555

ZK35-3-B10-18 2433 0.014269 0.000364 0.281266 0.000016 1.6 0.569623 2724 2882 -0.989023

ZK35-3-B10-19 2433 0.012953 0.000350 0.281276 0.000019 2.0 0.664878 2709 2856 -0.989461

ZK35-3-B10-20 2433 0.009175 0.000271 0.281304 0.000017 1.3 0.614969 2666 2838 -0.991837

ZK35-3-B9-1 2467 0.014569 0.000399 0.281289 0.000020 0.3 0.719433 2695 2889 -0.987991

ZK35-3-B9-2 2467 0.015351 0.000416 0.281239 0.000020 -2.2 0.700300 2763 3020 -0.987460

ZK35-3-B9-3 2467 0.014020 0.000385 0.281276 0.000021 -0.8 0.749343 2712 2935 -0.988401

ZK35-3-B9-4 2467 0.016696 0.000445 0.281358 0.000021 3.3 0.730756 2606 2727 -0.986604

ZK35-3-B9-5 2467 0.015213 0.000420 0.281237 0.000023 -2.9 0.807838 2767 3041 -0.987359


ZK35-3-B9-6 2467 0.013892 0.000377 0.281257 0.000021 -1.6 0.762752 2736 2980 -0.988633

ZK35-3-B9-7 2467 0.015721 0.000412 0.281285 0.000021 -1.1 0.759079 2701 2935 -0.987579

ZK35-3-B9-8 2467 0.021480 0.000544 0.281346 0.000020 1.6 0.712216 2629 2796 -0.983604

ZK35-3-B9-9 2467 0.013578 0.000352 0.281267 0.000019 0.2 0.667782 2721 2918 -0.989412

ZK35-3-B9-10 2467 0.011460 0.000294 0.281311 0.000017 1.8 0.593303 2658 2816 -0.991157

ZK35-3-B9-11 2467 0.012193 0.000310 0.281247 0.000021 -2.5 0.757325 2745 3013 -0.990652

ZK35-3-B9-12 2467 0.012943 0.000328 0.281244 0.000019 -1.9 0.664946 2750 3001 -0.990117

ZK35-3-B9-13 2467 0.016846 0.000420 0.281229 0.000019 -2.0 0.680612 2776 3026 -0.987349

ZK35-3-B9-14 2467 0.017091 0.000419 0.281290 0.000020 0.5 0.724357 2695 2886 -0.987374

ZK35-3-B9-15 2467 0.015326 0.000385 0.281306 0.000020 -0.5 0.721434 2671 2892 -0.988394

ZK35-3-B9-16 2467 0.013899 0.000348 0.281241 0.000022 -1.9 0.798811 2756 3005 -0.989526

ZK35-3-B9-17 2467 0.013410 0.000341 0.281249 0.000020 -1.5 0.699266 2744 2984 -0.989743

ZK35-3-B9-18 2467 0.016832 0.000415 0.281256 0.000019 -0.3 0.661887 2740 2948 -0.987488

ZK35-3-B9-19 2467 0.018131 0.000443 0.281290 0.000022 0.5 0.772933 2696 2887 -0.986653

ZK35-3-B9-20 2467 0.013824 0.000350 0.281231 0.000020 -0.6 0.699415 2769 2981 -0.989467

ZK35-3-B9-21 2467 0.010693 0.000277 0.281270 0.000019 -2.7 0.690732 2712 2988 -0.991661

ZK35-3-B11-1 2419 0.035617 0.000975 0.281310 0.000023 -0.5 0.812889 2707 2917 -0.970621

ZK35-3-B11-4 2419 0.049077 0.001167 0.281297 0.000027 -1.0 0.962510 2738 2958 -0.964859

ZK35-3-B11-5 2419 0.031843 0.000756 0.281208 0.000026 -3.3 0.915289 2829 3105 -0.977215

ZK35-3-B11-6 2419 0.036279 0.000854 0.281345 0.000020 1.4 0.693489 2651 2819 -0.974268

ZK35-3-B11-7 2419 0.035709 0.000896 0.281322 0.000022 -0.7 0.767682 2685 2905 -0.973013

ZK35-3-B11-8 2419 0.037004 0.001018 0.281273 0.000023 -1.2 0.822947 2760 2983 -0.969341

ZK35-3-B11-9 2419 0.032850 0.000806 0.281306 0.000023 0.0 0.830947 2701 2901 -0.975727

ZK35-3-B11-10 2419 0.028212 0.000716 0.281275 0.000020 -1.8 0.696821 2736 2981 -0.978421

ZK35-3-B11-11 2419 0.034261 0.000852 0.281329 0.000020 1.4 0.715901 2673 2837 -0.974338

ZK35-3-B11-12 2419 0.033179 0.000820 0.281290 0.000020 0.1 0.696867 2724 2919 -0.975295

ZK35-3-B11-13 2419 0.047511 0.001145 0.281327 0.000018 0.7 0.654550 2696 2876 -0.965511

ZK35-3-B11-15 2419 0.040382 0.001018 0.281316 0.000024 -0.7 0.840505 2702 2919 -0.969335

ZK35-3-B11-16 2419 0.031364 0.000792 0.281297 0.000025 0.5 0.885693 2712 2898 -0.976136

ZK35-3-B11-17 2419 0.035738 0.000934 0.281276 0.000023 -0.8 0.806805 2751 2967 -0.971871

ZK35-3-B11-18 2419 0.032636 0.000840 0.281321 0.000020 0.7 0.725470 2682 2863 -0.974687

ZK35-3-B11-19 2419 0.042947 0.001091 0.281327 0.000021 0.1 0.755915 2692 2889 -0.967128

ZK35-3-B11-20 2419 0.034726 0.000857 0.281387 0.000019 3.5 0.686285 2594 2710 -0.974176

ZK35-3-B11-21 2419 0.030565 0.000748 0.281297 0.000015 0.6 0.548575 2708 2892 -0.977472

ZK43-2-B2-1 2392 0.011404 0.000300 0.281366 0.000019 0.5 0.669880 2585 2786 -0.990972

ZK43-2-B2-2 2392 0.012849 0.000339 0.281281 0.000021 0.1 0.764325 2701 2902 -0.989795

ZK43-2-B2-3 2392 0.014014 0.000362 0.281318 0.000020 1.5 0.697584 2654 2820 -0.989095

ZK43-2-B2-4 2392 0.017928 0.000453 0.281274 0.000017 -0.3 0.615071 2718 2926 -0.986370

ZK43-2-B2-5 2392 0.011930 0.000300 0.281237 0.000018 -0.7 0.649417 2758 2974 -0.990953

ZK43-2-B2-6 2392 0.024305 0.000584 0.281288 0.000018 0.1 0.643826 2709 2908 -0.982398

ZK43-2-B2-7 2392 0.015869 0.000376 0.281250 0.000017 -0.6 0.596747 2745 2960 -0.988676

ZK43-2-B2-8 2392 0.011340 0.000276 0.281235 0.000021 -0.5 0.737100 2759 2971 -0.991696


ZK43-2-B2-9 2392 0.021645 0.000514 0.281299 0.000017 0.4 0.593913 2690 2882 -0.984518

ZK43-2-B2-10 2392 0.013633 0.000317 0.281251 0.000018 -0.8 0.627135 2741 2963 -0.990441

ZK43-2-B2-12 2392 0.022767 0.000559 0.281339 0.000018 2.7 0.647964 2639 2775 -0.983168

ZK43-2-B2-13 2392 0.019004 0.000497 0.281316 0.000018 1.2 0.657463 2666 2840 -0.985043

ZK43-2-B2-14 2392 0.018331 0.000452 0.281267 0.000017 -0.9 0.604618 2728 2953 -0.986400

ZK43-2-B2-15 2392 0.014624 0.000344 0.281248 0.000016 -0.2 0.554963 2746 2952 -0.989654

ZK43-2-B2-16 2392 0.017595 0.000485 0.281262 0.000022 -1.1 0.774190 2738 2968 -0.985385

ZK43-2-B2-17 2392 0.018152 0.000468 0.281282 0.000019 -0.3 0.683682 2710 2919 -0.985891

ZK43-2-B2-18 2392 0.013883 0.000346 0.281257 0.000017 -0.2 0.609825 2735 2939 -0.989577

ZK43-2-B2-19 2392 0.012060 0.000309 0.281283 0.000016 0.0 0.586549 2697 2901 -0.990695

ZK43-2-B2-20 2392 0.014910 0.000366 0.281242 0.000015 -0.8 0.539354 2755 2976 -0.988964

The 176

Hf/177

Hf and 176

Lu/177

Hf ratios of present-day chondrite and depleted mantle reservoirs are 0.282772 and 0.0332, and 0.28325 and 0.0384, respectively (Blichert-Toft

and Albarède, 1997; Griffin et al., 2000). = 1.865 10–11

a–1

(Scherer et al., 2001), (176

Lu/177

Hf)C = 0.015.

Twenty of the 21 zircon Lu–Hf analyses from sample ZK6-6-B2 (1 analysis has a large uncertainty) have 176

Hf/177

Hf

ratios of 0.281271–0.281338 (weighted mean of 0.281329), yielding Hf(t) values between –0.739 and 6.437 (weighted

mean of 2.699) and two-stage Hf model ages of 2736–2575 Ma. Two groups of zircons with different U–Pb ages have no

significant difference in Lu–Hf isotopic compositions.

Seventeen of the 18 zircon Lu–Hf analyses from sample ZK35-3-B6 (spot 15 has a large uncertainty) have 176

Hf/177

Hf

ratios of 0.281195–0.281380 (weighted mean of 0.281262), yielding Hf(t) values from –4.138 to 3.600 (weighted mean

–0.596) and two-stage Hf model ages of 3129–2779 Ma. Two groups of zircons with different U–Pb ages have no

significant difference in Lu–Hf isotopic compositions.

Twenty zircon Lu–Hf analyses from sample ZK35-3-B10 have 176

Hf/177

Hf ratios of 0.281265–0.281357 (weighted

mean of 0.281296), yielding Hf(t) values between –0.068 and 3.414 (weighted mean of 1.828) and two-stage Hf model

ages of 2927–2718 Ma. Two groups of zircons with different U–Pb ages have no significant difference in Lu–Hf isotopic

compositions

Twenty-one zircon Lu–Hf analyses from sample ZK35-3-B9 have 176

Hf/177


mean of 0.281272), yielding Hf(t) values between –2.873 and 3.325 (weighted mean of –0.683) and two-stage Hf model

ages of 3041–2727 Ma.

Sixteen of 18 zircon Lu–Hf analyses from sample ZK35-3-B11 (spots 5 and 20 have large uncertainties) have 176

Hf/177

Hf ratios of 0.281273–0.281345 (weighted mean of 0.281307), corresponding to Hf(t) values between –1.770 and

1.436 (weighted mean of –0.071) and two-stage Hf model ages of 2983–2819 Ma.

Nineteen zircon Lu–Hf analyses from sample ZK43-2-B2 have 176

Hf/177


mean of 0.281279), yielding Hf(tt) values between –1.140 and 2.681 (weighted mean of 0.09) and two-stage Hf model

ages of 2876–2775 Ma.

Histograms the two-stage Hf model ages (tDM2) and Hf(t) values of zircons from the Berere Complex felsic leucosome

samples are given in Fig. 6, indicating that these samples all have similar Lu–isotopic characteristics, with tDM2 values of

3000–2800 Ma and generally positive Hf(t) values that range between –2 and 4.


Fig. 6. Histograms showing the distribution of two-stage Hf model ages and Hf(t) values for felsic leucosome samples and

gneisses from the Berere Complex (Lu–Hf isotopic compositions of gneisses are from Li Pneg et al., 2017).

6. Discussion 6.1. Age interpretation and timing of anatexis

Anatectic zircons generally have the form (idiomorphic columnar) and structure (dense oscillatory zoning) expected

for magmatic zircons but have lower Th/U ratios than the latter. This is primarily because anatectic zircons crystallize in

a liquid dominated environment rather than a true magmatic environment as a result of the different degrees of influence

of anatexis-related hydrous fluids (Keay et al., 2001). The majority of the anatectic zircons within the samples from the

study area, which crystallized from a felsic melt generated by the partial melting of metamorphic basement material, are

intact and euhedral, and contain clear oscillatory zoning from the core to the edge of the crystal. Previous research

suggests that anatectic zircons that crystallized during partial melting form in one of three ways: 1) dissolution and

reprecipitation of metamorphic or magmatic zircons from the host rock (Keay et al., 2001; Rubatto et al., 2001;

Andersson et al., 2002); 2) decomposition of other Zr-containing minerals excluding zircon (Fraser et al., 1997;

Flowerdew et al., 2006); or 3) crystallization of zircon from extraneous Zr-bearing fluids or melts (Foster et al., 2001;

Flowerdew et al., 2006). The Paleoproterozoic metabasite, gneiss, and granite units in the study area are free of inherited

magmatic or metamorphic zircons and other Zr-containing minerals (Li, 2015), indicating that models 1 and 2 are not

applicable. Therefore, it is inferred that the anatectic zircons within the felsic leucosomes in the Maevatanana area

crystallized from extraneous Zr-containing fluids.

The Zircon U–Pb analyses yielded three groups of ages at ~2.5, ~2.4, and ~2.28 Ga. The field, petrographic,

geochronological, and isotopic characteristics of these leucosomes indicate that they all formed during the same

geological event. The ages of the six samples (2467–2369 Ma) represent the timing of felsic leucosome formation as well

as the timing of regional anatexis within the Berere Complex. The few zircons with ages of ~2.5 Ga which is consistent

with the diagenetic age of gneisses in the basement (Paquette et al., 2004; Li Peng et al., 2017) are captured zircons.

Zircons with ages ~2.28 Ga within these leucosomes formed by later regional tectonic metamorphism after leucosome

crystallization, an event that caused Pb loss in some of the discordant zircons described above.

Paquette et al. (2004) suggested that regional granulite-facies ultrahigh-temperature metamorphism in Andriamena

greenstone belt occurred at ~2.5 Ga, as inferred from the dating of garnet-bearing monazite. The fact that the three

greenstone belts in this area were amalgamated before 600 Ma (e.g., Nédélec et al., 1994; Windley et al., 1997; Kröner et

al., 1999b; Collins et al., 2001; Wit, 2003) means that this timing of peak metamorphism can also be applied to the


http://dict.cnki.net/dict_result.aspx?searchword=%e6%8d%95%e8%8e%b7%e9%94%86%e7%9f%b3&tjType=sentence&style=&t=captured+zircon

Berere Complex. The dates obtained during our study are younger than the granulite-facies ultrahigh-temperature

metamorphic event, suggesting that regional anatexis occurred during decompression following the peak metamorphism.

Combining the mineral assemblages and formation temperatures of amphibolite-facies gneisses in this area (details in

another unpublished article) with the petrographic characteristics of felsic leucosomes within the Berere Complex

suggests that regional anatexis occurred during retrograde metamorphism associated with decreasing temperatures and

pressures, mainly as a result of the dehydration melting of muscovite and the partial melting of felsic minerals, both of

which acted as sources for the leucosomes within the complex.

Anatexis is associated with the evolution of orogenic belts from extrusion and shortening to extension and thinning

(Gordon et al., 2008), with the latter being associated with crustal thinning and increased heat flux, both of which can

cause partial melting (Brown, 2001; Foster et al., 2001). A late Archean paleocontinent formed at about 2.5 Ga as a result

of collision of the Madagascar microcontinent with other microcontinents in a tectonic event that was associated with

subduction, collision, and accretion (Tucker et al., 1999; Collins et al., 2001; Kabete et al., 2006). The tectonic regime in

this region changed to extension and thinning at about 2.4 Ga, causing an increase in crustal thinning and heat flux, a

process that in turn provided the heat source for anatexis. This indicates that regional anatexis in the Maevatanana area

occurred during a period of post-collisional extension and thinning at ~2.4 Ga, coincident with a change in the tectonic

regime in this area.

6.2. Constraints on leucosome protolith compositions

The zircon Lu–Hf isotopic system has a high closure temperature and is relatively resistant to resetting during

hydrothermal fluid or thermal activity compared with the zircon U–Pb isotopic system. This means that zircons can

preserve initial Hf isotopic compositions even during granulite-facies metamorphism (Wu Fuyuan et al., 2007);

consequently, this technique is useful for protolith identification. Felsic leucosomes from the Maevatanana area plot near

the chondrite line on 176

Hf/177

Hf–t and Hf(t)–t diagrams (Fig.7), and there is no significant difference in composition

between zircons with different ages, indicating that all of these Paleoarchean felsic leucosome samples have similar

protolith magma source characteristics. They formed from a mantle-derived magmatic protolith that assimilated crustal

material during ascent, differentiation, and emplacement. The presence of samples with both positive and negative Hf(t)

values is a result of crust–mantle interaction, providing evidence that the magmatic protoliths of these samples were

contamination by crustal material. In addition, the two-stage Hf model ages of these felsic leucosomes (3.0–2.6 Ga) are

much older than their crystallization ages, indicating that the protoliths formed during the Archean.

Two-stage Hf model ages and Hf(t) values for these samples are consistent with those for gneisses of the basement

(Fig.6; Li Peng et al., 2017), suggesting both of their protolith formed during the formation of continental crust in

Meso-Neoarchean (ca. 3.1–2.7 Ga). As such, the Lu–Hf isotopic characteristics of the felsic leucosomes in the Berere

Complex formed by the partial melting of gneisses that form part of the early Precambrian metamorphic crystalline

basement in this region.


Fig. 7. Hf(t)–t and 176Hf/177Hf–t diagrams for felsic leucosome samples from the Berere

Complex.

6.3. Implications for the genesis of anatexis

The field, petrographic, and Lu–Hf isotopic data discussed above indicate that the leucosomes in the study area were

generated by the partial melting of early Precambrian metamorphic crystalline basement gneisses. This model is

supported by the following evidence. 1) The leucosomes are present as stockworks, thin layers, veinlets, or lenses within

the host rocks and the majority have transitional boundaries (Fig. 2b-d), all of which are indicative of migmatization and

are consistent with the structures expected to form during in situ anatexis. 2) The petrography, geochronological and

Lu–Hf isotopic data, and geochemical compositions (unpublished data) of felsic bands within the banded gneisses in the

study area are similar to the features of the felsic leucosomes described above, indicating that a late-stage injection model

for these leucosomes can be ruled out. 3) An anatexis model for the felsic leucosomes in the study area is supported by

the petrological data presented here (Fig. 3), as the presence of typical granitic textures, similar amounts of alkali and

plagioclase feldspars, and antiperthitic plagioclase are all consistent with the characteristics of typical felsic leucosome

generated by the partial melting of meta-argillaceous rocks (Gilotti and Elvevold, 2002; Lang and Gilotti, 2007). The

presence of antiperthite textures is indicative of the crystallization of K-rich plagioclase from a felsic melt under

high-temperature conditions (Godard et al., 1996; Gilotti and Elvevold, 2002). 4) The felsic leucosomes and gneissic

matrix (unpublished data) in the study area have similar two-stage Hf model ages and Hf(t) values to each other,

indicating that both of these units formed from protoliths generated at the same time and from the same magmatic source.

Previous experimental petrology and phase balance simulations suggest that mica, epidote, and hornblende are hydrous

minerals that play an important role in the initiation of (ultra-)high pressure metamorphic anatexis, even though all of

these hydrous minerals require quite different P–T conditions for the initiation of dehydration partial melting and produce

melts with different chemical compositions (Liati and Gebauer, 2001; Douce, 2005). The following microstructural

characteristics of the samples in the study area indicate that muscovite decomposition was the main process that initiated

anatexis within the Berere Complex. 1) The presence of a quartz + plagioclase ± K-feldspar + sericite mineral

assemblage, and the evidence of dissolution in the form of irregular jagged boundaries of individual muscovite crystals

(Fig. 3c) indicates that the decomposition of muscovite and the generation of felsic melts was simultaneous, ruling out a

hydrothermal metasomatic origin for the dissolution of muscovite in these samples. 2) Sericite is also present around

quartz and feldspar grain boundaries and in fractures in feldspar, suggesting that muscovite was the main reactive phase

during anatexis (Fig. 3d).

6.4. Juxtaposition of Madagascar and India in Archean and Palo-Proterozoic

The juxtaposition of Madagascar and India in Neo-Proterozoic is always a focus research to understand the

Gondwanaland tectonics, especially the assembly of this mega-continent during the Pan-African period. But in Archean


and Palo-Proterozoic, the continental correlation is more difficult to define due to the lack of geological information

carriers. Fortunately, the HTHP metamorphic complex belts in north-central Madgascar and Dharwar craton of India have

persisted a large numbers of clues in understanding the possible Palo-Proterozoic supercontinent tectonics.

Corresponding to north-central Madagascar, the Dharwar Craton in north-central India is also composed of granulite

gneisses, Archaean granitic to intermediate plutonic rocks, migmatites and greenstone belts (e.g., Yoshida et al., 1999;

Jayananda et al., 2013). According to geochronology data gaven by Jayananda et al. (2000, 2006, 2013), Neoarchean

greenstone volcanism, TTG accretion and calc-alkaline magmatism in Dharwar Craton corresponds to two major peaks

(U-Pb zircon ages, 2.7 – 2.65 Ga and 2.58 – 2.52 Ga) of mantle differentiation and continental growth. Granulite-facies

metamorphism took place at ca. 2.5 Ga (e.g., Jayananda and Peucat, 1996; Jayananda et al., 2013), which is consistent

with the timing of peak metamorphism in Berere HTHP complex belt. And also, a widespread thermal event took place in

Dharwar craton at ca. 2.4 Ga, which corresponded to the timing of regional anatexis within the Berere Complex.

Besides the lithological similarity of Precambrian basement and the similarity of thermal events ages, the close structural

features and comparable distribution of metamorphic grade also show a pronounced Precambrian geology similarity

between Madagascar and India (Li Peng et al., 2017). Both India and Madagascar are characterized by N–S

trending Archaean granite-greenstone terrains to the north and the Proterozoic granulite terrains to the south, which

are dissected by several Proterozoic shear zones. In Madagascar, Metamorphic grade of the basement rocks

generally increases towards south and southwest, except for the Itremo Group cover sequence (Windley et al.,1994),

ranging from greenschist facies in the north and north-eastern areas to low amphibolite–medium granulite facies in

the central and southern areas (e.g., Nicollet, 1990; Yoshida et al., 1999). This distribution is conformable to that of

India where the lower grade rocks occur in the northwest and the higher grade rocks in the south (Fig. 8).


Fig.8 Madagascar and India within East Gondwana (cited after Yosliida and Santosh, 1996; Li Peng et al., 2017; with minor modifications). The Pan-African magmatic-metamorphic events are excluded, showing possible pre-Pan-African signatures.

AF: Africa. ANT: East Antarctica. CITZ: Central Indian Tectonic Zone. EDL: Enderby Land. LHB: Lutzow Holm Bay. MD: Madagascar. DC: Dharwar craton.

MOZ: Mozambique. NIS: North Indian Shield. SIS: South Indian Shield. SL: Sri Lanka.

As the above descriptions, Madagascar and India are well comparable in various aspects in Archean and

Palo-Proterozoic, which implies that the juxtaposition of Madagascar and India was also exsited in Archean. This provide

significative clues in constrainting on the correlation of the continental fragments.

7. Conclusions (1) Felsic leucosomes within the Berere Complex, located in the Maevatanana area of Madagascar, record

microstructural evidence of anatexis. The petrography, zircon U–Pb ages, and characteristics of regional metamorphism

in this area suggest that anatexis occurred during retrograde metamorphism and resulted in the dehydration melting of

muscovite and partial melting of felsic minerals.

(2) Regional anatexis within the Maevatanana area occurred during post-collision extension and thinning at 2467–2369

Ma, representing the timing of anatexis and a change in the tectonic regime of the area.

(3) Zircon Lu–Hf isotopic analysis indicates that the felsic leucosomes formed from Archean protoliths generated by

mantle-derived magmas that assimilated crustal material.

(4) Anatectic zircons within felsic leucosomes in the Berere Complex formed from extraneous Zr-containing fluids.


Acknowledgments We thank Academician Pei Rongfu for constructive and thoughtful reviews that considerably improved an earlier

version of this manuscript. Drs Huang fan and Wang Chenghui provided valuable input during this study, and Dr. Wang

Ping’an provided generous support during fieldwork. This study was funded by Geological Survey Project grants from

the China Geological Survey (grant numbers 12120113102100, DD20160056), Research Program of Department of Land

and Resources of Hunan Province (grant number 2018-02), and Science Foundation of Hunan Nuclear Geology (grant

number KY2016-311-01)..


References

Andersson, J., Möller, C., and Johansson, L., 2002. Zircon geochronology of migmatite gneisses along the Mylonite Zone (S Sweden):

a major Sveconorwegian terrane boundary in the Baltic Shield. Precambrian Research, 114(1): 121-147.

Amelin, Y., Lee, D.C., and Halliday, A.N., 2000. Early–middle Archean crustal evolution deduced from Lu–Hf and U–Pb isotopic

studies of single zircon grains. Geochimica et Cosmochimica Acta, 64: 4205-4225.

Besairie, H., 1969. Feuille Morondava N 6, 1/500 000. Madagascar Geological Survey.

Blichert-Toft, J., and Albarède, F., 1997. The Lu-Hf isotope geochemistry of chondrites and the evolution of the mantle-crust

system. Earth and Planetary Science Letters, 148(1): 243-258.

Brown, M, 2001. Crustal melting and granite magmatism: key issues. Physics and Chemistry of the Earth, Part A. Solid Earth and

Geodesy, 26(4): 201-212.

Brown, M, 2007. Crustal melting and melt extraction, ascent and emplacement in orogens: Mechanisms and consequences. Journal of

the Geological Society, 164: 709-730.

Collins, A.S., Razakamanana, T., and Windley, B.F., 2000. Neoproterozoic extensional detachment in central Madagascar:

implications for the collapse of the East African Orogen. Geological Magazine, 137(01): 39-51.

Collins, A.S., Fitzsimons, I.C., Kinny, P.D., Razakamanana, T., Brewer, T.S., Windley, B.F., and Kröner, A., 2001. The Archaean

rocks of central Madagascar: their place in Gondwana. In: 4th International Archaean Symposium, 294-296.

Collins, A.S., and Windley, B.F., 2002. The tectonic evolution of central and northern Madagascar and its place in the final assembly

of Gondwana. The Journal of geology, 110(3): 325-339.

Collins, A.S., Fitzsimons, I.C., Hulscher, B., and Razakamanana, T., 2003. Structure of the eastern margin of the East African Orogen

in central Madagascar. Precambrian Research, 123(2): 111-133.

Cox, R, Armstrong, R.A., and Ashwal, L.D., 1998. Sedimentology, geochronology and provenance of the Proterozoic Itremo Group,

central Madagascar, and implications for pre-Gondwana paleogeography. Journal of the Geological Society, 155: 1009-1024.

Cui Yinliang, Xu Heng, Zhou Jiaxi, Zhang Miaohong, Jiang Yongguo and Zeng Min, 2017. Alkaline prophyries in the

Chenghai-Binchuan tectono-magmatic belt, western Yunnan province, SW China. Acta Geologica Sinica (English Edition), (S1):

88-89.

Douce, A.E.P., 2005. Vapor-absent melting of tonalite at 15~32 kbar. Journal of Petrology, 46(2): 275-290.

Flowerdew, M.J., Millar, I.L., Vaughan, A.P.M., Horstwood, M.S.A., and Fanning, C.M., 2006. The source of granitic gneisses and

migmatites in the Antarctic Peninsula: A combined U-Pb SHRIMP and laser ablation Hf isotope study of complex zircons.

Contributions to Mineralogy and Petrology, 151(6): 751- 768.

Foster, D.A., Schafer, C., Fanning, C.M., and Hyndman, D.W., 2001. Relationships between crustal partial melting, plutonism,

orogeny, and exhumation: Idaho-Bitterroot batholith. Tectonophysics, 342(3-4): 313-350.

Fraser, G., Ellis, D., and Eggins, S., 1997. Zirconium abundance in granulite facies minerals, with implications for zircon

geochronology in highgrade rocks. Geology, 25: 607-610.

Gilotti, J.A., and Elvevold, S., 2002. Extensional exhumation of a high-pressure granulite terrane in Payer Land, Greenland

Caledonides: structural, petrologic, and geochronologic evidence from metapelites. Canadian Journal of Earth Sciences, 39(8):

1169-1187.

Godard, G., Martin, S., Prosser, G., Kienast, J.R., and Morten, J.R., 1996. Variscan migmatites, eclogites and garnet peridotites of the

Ulten zone, Eastern Austroalpine system. Tectonophysics, 259: 313-341.

Goncalves, P., Nicollet, C., and Lardeaux, J.M., 2003. Finite strain pattern in Andriamena unit (north-central Madagascar): evidence

for late Neoproterozoic–Cambrian thrusting during continental convergence. Precambrian Research, 123(2): 135-157.

Goncalves, P., Nicollet, C., and Montel, J.M., 2004. Petrology and in situ U-Th-Pb monazite geochronology of ultrahigh-temperature

metamorphism from the Andriamena mafic unit, north-central Madagascar. Significance of a petrographical P–T path in a

polymetamorphic context. Journal of Petrology, 45(10): 1923-1957.

Gordon, S.M., Whitney, D.L., Teyssier, C, Grove, M., and Dunlap, W.J., 2008. Timescales of migmatization, melt crystallization, and

cooling in a Cordilleran gneiss dome: Valhalla complex, southeastern British Columbia. Tectonics, 27(4): 1-28.

Gordon, S.M., Whitney, D.L., Teyssier, C., and Fossen, H., 2013. U-Pb dates and trace-element geochemistry of zircon from

migmatite, Western Gneiss Region, Norway: significance for history of partial melting in continental subduction. Lithos, 170:

35-53.

Gregory, C.J., Buick, I.S., Hermann, J., and Rubatto, D., 2009. Mineral-scale trace element and U-Th-Pb age constraints on

metamorphism and melting during the Petermann Orogeny (Central Australia). Journal of petrology, 50: 251-287.

Gregory, C.J., Rubatto, D., Hermann, J., Berger, A., and Engi, M., 2012. Allanite behaviour during incipient melting in the southern

Central Alps. Geochimica et Cosmochimica Acta, 84: 433-458.

Griffin, W.L., Pearson, N.J., Belousova, E., Jackson, S.E., Van Achterbergh, E., O’Reilly, S.Y., and Shee, S.R., 2000. The Hf isotope

composition of cratonic mantle: LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites. Geochimica et Cosmochimica Acta,

64(1): 133-147.

Guerrot, C., Cocherie, A. and Ohnenstetter, M., 1993. Origin and evolution of the West Andriamena Pan-African mafic-ultramafic

complex in Madagascar as shown by U-Pb, Nd isotopes and trace element constraints. Terra Abstracts, 5: 387.

Handke, M.J., Tucker, R.D., and Ashwal, L.D., 1999. Neoproterozoic continental arc magmatism in west-central

Madagascar. Geology, 27(4): 351-354.

Hou Kejun, Li Yanhe, Zou Tianren, Qu Xiaoming, Shi Yuruo, and Xie Guiqing, 2007. Laser ablation-MC-ICP-MS technique for Hf

isotope microanalysis of zircon and its geological applications. Acta Petrologica Sinica, 23(10): 2595-2604 (in Chinese with

English abstract).

Hou Kejun, Li Yanhe, and Tian Yourong, 2009. In situ U-Pb zircon dating using laser ablation-multi ion counting-ICP-MS. Mineral


Deposits, 28(4): 481-492 (in Chinese with English abstract).

Ito, M., Suzuki, K., and Yogo, S., 1997. Cambrian granulite to upper amphibolite facies metamorphism of post-797 Ma sediments in

Madagascar. Journal of Earth and Planetary Sciences, Nagoya University, 44: 89-102.

Jayananda, M. and Peucat, J.J., 1996. Geochronological framework of southern India. In: Santosh, M. and Yoshida, M. (Eds.), The

Archaean and Proterozoic terrains of Southern India within East Gondwana, Gondwana Research Group Mem.3, Field Science

Public, Osaka, 53-75.

Jayananda, M., Moyen, J.-F., Martin, H., Peucat, J.J., Auvray, B., and Mahabaleswar, B., 2000. Late Archean (2550-2520 Ma) juvenile

Magmatism in the Eastern Dharwar craton, southern India: constraints from geochronology, Nd–Sr isotopes and whole rock

geochemistry. Precambrian Research, 99: 225- 254.

Jayananda, M., Chardon, D., Peucat, J.J., and Capdevila, R., 2006. 2.61 Ga potassic granites and crustal reworking in the western

Dharwar craton, southern India: tectonic, geochronologic and geochemical constraints. Precambrian Research, 150: 1-26.

Jayananda, M., Tsutsumi, Y., Miyazaki, T., Gireesh, R.V., Kapfo, K., Tushipokla, Hidaka, H., and Kano, T., 2013. Geochronological

constraints on Meso- and Neoarchean regional metamorphism and magmatism in the Dharwar craton, southern India. Journal of

Asian Earth Sciences, 78 (10): 18-38.

Kabete, J., Groves, D., McNaughton, N., and Dunphy, J., 2006. The geology, SHRIMP U-Pb geochronology and metallogenic

significance of the Ankisatra-Besakay District, Andriamena belt, northern Madagascar. Journal of African Earth Sciences, 45(1):

87-122.

Keay, S., Lister, G., and Buick, I., 2001. The timing of partial melting, Barrovian metamorphism and granite intrusion in the Naxos

metamorphic core complex, Cyclades, Aegean Sea, Greece. Tectonophysics, 342(3): 275-312.

Kröner, A., Windley, B.F., Jaeckelt, P., Brewer, T.S., and Razakamanana, T., 1999a. New zircon ages and regional significance for the

evolution of the Pan-African orogen in Madagascar. Journal of the Geological Society, 156(6): 1125-1135.

Kröner, A., Windley, B. F., Jaecke, P., Collins, A. S., Brewer, T. S., Nemchin, A., and Razakamanana, T., 1999b. New zircon ages for

Precambrian granites, gneisses and granulites from central and southern Madagascar: significance for correlations in East

Gondwana. Gondwana Research, 2(3): 351-352.

Kröner, A., Hegner E., Collins, A.S., Windley, B.F., Brewer, T.S., Razakamanana, T., and Pidgeon, R.T., 2000. Age and magmatic

history of Antananarivo block, Central Madagascar, as derived from zircon geochronology and Nd isotopic systematics. American

Journal of Science, 300(4): 251-288.

Kriegsman, L.M., 2001. Partial melting, partial melt extraction and partial back reaction in anatectic migmatites. Lithos, 56(1): 75-96.

Labrousse, L., Prouteau, G., and Ganzhorn, A.C., 2011. Continental exhumation triggered by partial melting at ultrahigh pressure.

Geology, 39(12): 1171-1174.

Lackey, J.S., Romero, G.A., Bouvier, A. S., and Valley, J.W., 2012. Dynamic growth of garnet in granitic magmas. Geology, 40:

171-174.

Lang, H.M., and Gilotti, J.A., 2007. Partial melting of metapelites at ultrahigh-pressure conditions, Greenland Caledonides. Journal of

Metamorphic Geology, 25(2): 129-147.

Li Leileil, Wang Zongxiu, Li Chunlin, Gao Wanli, Tan Yuanlong, Qian Tao, Hu Junjie, and Li Huijun, 2018. Ductile shearing

deformation and geochronological characteristics of the Huanghua-Tiejueshan areas in the northwestern margin of the Sulu Orogen.

Acta Geologica Sinica, 92(4): 722-746 (in Chinese with English abstract).

Li Peng, Liu Shanbao, Shi Guanghai, and Zhang Shude, 2015. Zircon U-Pb ages and Hf isotopic characteristics of granites in the

Maevatanana gold field, Madagascar and geological significance. Acta Petrologica Sinica, 31(4): 1153-1170 (in Chinese with

English abstract).

Li Peng, 2015. Magmatic activities and their evolution of Maevatanana greenstone belt, Madagascar. China University of

Geosciences, Beijing (Ph. D thesis): 1-221. (in Chinese with English abstract).

Li Peng, Li Jiankang, Liu Shanbao, Pei Rongfu, and Shi Guanghai, 2017. Origin and Geological Significance of TTG Gneisses from

the Maevatanana Greenstone Belt in North-Central Madagascar, and A Comparison with India. Acta Geologica Sinica (English

Edition), 91(3): 1003-1024.

Li Yong, Yan Zhaokun, Zhou Rongjun, Yan Liang, Dong Shunli, Shao Chongjian and Laurence Svirchev, 2018. Crustal uplift in the

Longmenshan mountains revealed by isostatic gravity anomalies along the eastern margin of the Tibetan Plateau. Acta Geologica

Sinica (English Edition), 92(1): 56-73.

Liati, A., and Gebauer, D., 1999. Constraining the prograde and retrograde PTt path of Eocene HP rocks by SHRIMP dating of

different zircon domains: inferred rates of heating, burial, cooling and exhumation for central Rhodope, northern

Greece. Contributions to Mineralogy and Petrology, 135(4): 340-354.

Liu, Y.S., Gao, S., Hu, Z.C., Gao, C.G., Zong, K.Q. and Wang, D.B., 2010. Continental and oceanic crust recycling-induced

melt-peridotite interactions in the Trans-North China Orogen: U-Pb dating, Hf isotopes and trace elements in zircons from mantle

xenoliths. Journal of Petrology, 51: 537-571.

Liu, Y., Hou, Z., Tian, S., Zhang, Q., Zhu, Z., and Liu, J., 2015a. Zircon U-Pb ages of the mianning–dechang syenites, sichuan

province, southwestern china: constraints on the giant REE mineralization belt and its regional geological setting. Ore Geology

Reviews, 64(8): 554-568.

Lopez, S., and Castro, A., 2001. Determination of the fluid-absent solidus and supersolidus phase relationships of MORB-derived

amphibolites in the range 4~14kbar. American Mineralogist, 86: 1396-1403.

McLeod, C.L., Davidson, J.P., Nowell, G.M., and de Silva, S.L., 2012. Disequilibrium melting during crustal anatexis and implications

for modeling open magmatic systems. Geology, 40: 435-438.

Nédélec, A., Paquette, J.L., Bouchez, J.L., Olivier, P., and Ralison, B., 1994. Stratoid granites of Madagascar: structure and position in

the Panafrican orogeny. Geodinamica Acta, 7(1): 48-56.


Nicollet, C., 1990. Crustal evolution of the granulites of Madagascar. In Granulites and crustal evolution. Granulites and Crustal

Evolution, 291-310.

Nicollet, C., Montel, J.M., Foret, S., Martelat, J.E., Rakotondrazafy, R., and Lardeaux, J.M., 1997. E-Probe monazite dating in

Madagascar: a good example of the usefulness of the in-situ dating method. UNESCO-IUGS-IGCP, 348(368): 65.

Paquette, J.L., Goncalves, P., Devouard, B., and Nicollet, C., 2004. Micro-drilling ID-TIMS U-Pb dating of single monazites: A new

method to unravel complex poly-metamorphic evolutions. Application to the UHT granulites of Andriamena (North-Central

Madagascar). Contributions to Mineralogy and Petrology, 147(1): 110-122.

Reeves, C. and De Wit, M., 2000. Making ends meet in Gondwana: retracing the transforms of the Indian Ocean and reconnecting

continental shear zones. Terra Nova, 12(6): 272-280.

Rubatto, D., Williams, I.S., and Buick, I.S., 2001. Zircon and monazite response to prograde metamorphism in the Reynolds Range,

central Australia. Contributions to Mineralogy and Petrology, 140(4): 458-468.

Sajeev, K., Ishwar-Kumar, C., Ratheesh-Kumar, R.T., and Satish-Kumar, M., 2014. Geological correlations between India and

Madagascar in a Gondwanan perspective. Science reports of Niigata University, 29: 9-10.

Sawyer, E.W., Brown, M.G., and Kotkova, J., 1999. Criteria for the recognition of partial melting. Physics & Chemistry of the Earth

Part A Solid Earth & Geodesy, 24(99): 269-279.

Scherer, E., Münker, C., and Mezger, K., 2001. Calibration of the lutetium-hafnium clock. Science, 293(5530): 683-687.

Schofield, D.I., Thomas, R.J., Goodenough, K.M., De Waele, B., Pitfield, P.E.J., Key, R.M., Bauer, W., Walsh, G.J., Lidke, D.J.,

Ralison, A.V., Rabarimanana, M., Rafahatelo, J.M., and Rabarimanana, M., 2010. Geological evolution of the Antongil craton, NE

Madagascar. Precambrian Research, 182(3): 187-203.

Sláma, J., Kosler, J., Condon, D.J., Crowley, J.L., Gerde,s A., Hanchar, J.M., Horstwood, M.S.A., Morris, G.A., Nasdala, L., Norberg,

N., Schaltegger, U., Schoene, B., Tubrett, M.N., and Whitehouse, M.J., 2008. Plesovice zircon – A new natural reference material

for U–Pb and Hf isotopic microanalysis. Chemical Geology, 249: 1-35.

Teyssier, C., and Whitney, D.L., 2002. Gneiss domes and orogeny. Geology, 30(12): 1139-1142.

Tucker, R.D., Ashwal, L.D., Handke, M.J., Hamilton, M.A., Le Grange, M., and Rambeloson, R.A., 1999. U-Pb geochronology and

isotope geochemistry of the Archean and Proterozoic rocks of north-central Madagascar. The Journal of Geology, 107(2): 135-153

Tucker, R.D., Roig, J.Y., Delor, C., Amelin, Y., Goncalves, P., Rabarimanana, M.H., Ralison, A.V., and Belcher, R.W., 2011.

Neoproterozoic extension in the Greater Dharwar Craton: a reevaluation of the "Betsimisaraka suture" in Madagascar. This article is

one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh. Canadian Journal

of Earth Sciences, 48(2): 389-417.

Tucker, R.D., Roig, J.Y., Moine, B., Delor, C., and Peters, S.G., 2014. A geological synthesis of the Precambrian shield in Madagascar.

Journal of African Earth Sciences, 94: 9-30.

Vanderhaeghe, O., and Teyssier, C., 2001. Partial melting and flow of orogens. Tectonophysics, 342(3): 451-472.

Windley, B.F., Razafiniparany, A., Razakamanana, T., and Ackermand, D., 1994. Tectonic framework o f the Precambrian of

Madagascar and its Gondwana connections: A review and reappraisal. Geologische Rundschau, 83: 642-659.

Windley, B.F., Brewer, T.S., Collins, A., Kröner, A., Jaeckel, P., and Razakamanana, T., 1997. The Pan-African orogen of

Madagascar. In: Abstracts to UNESCO-IUGS-IGCP-348/368 International Field Workshop on Proterozoic geology of Madagascar.

Gondwana Research Group, 5: 104.

Wit, M.J.D., 2003. Madagascar: Heads it's a continent, tails it's an island. Annual Review of Earth and Planetary Sciences, 31:

213-248.

Wu Fuyuan, Li Xianhua, Zheng Yongfei, and Gao Shan, 2007. Lu-Hf isotopic systematics and their applications in petrology. Acta

Sinica, 23(2): 185-220 (in Chinese with English abstract).

Xia Jinglong, Huang Guicheng, Ding Lixue and Cheng Shunbo, 2015. In Situ Analyses of Trace Elements, U-Pb and Lu-Hf Isotopes

in Zircons from the Tongshankou Granodiorite Porphyry in Southeast Hubei Province, Middle-Lower Yangtze River Metallogenic

Belt, China. Acta Geologica Sinica (English Edition), 89(5): 1588-1600.

Yoshida, M., Rajesh, H.M., and Santosh, M., 1999. Juxtaposition of India and Madagascar: a perspective. Gondwana Research, 2(3):

449-462.

Zeh, A., Gerdes, A., Barton, J., and Klemd, R., 2010. U–Th–Pb and Lu–Hf systematics of zircon from TTG's, leucosomes,

meta-anorthosites and quartzites of the Limpopo Belt (South Africa): constraints for the formation, recycling and metamorphism of

Palaeoarchaean crust. Precambrian Research, 179(1): 50-68.

Zeng, L., Gao, L.E., Xie, K., and Jing, L.Z., 2011. Mid-Eocene high Sr/Y granites in the Northern Himalayan Gneiss Domes: Melting

thickened lower continental crust. Earth Planet. Science Letters, 303(3-4): 251-266.

About the first author LI Peng, male, born in 1988 in Taiyuan City, Shanxi province; Doctor; graduated from China University of Geosciences, Beijing;

research assistant of Institute of Mineral Resources, Chinese Academy of Geological Sciences. He is now interested in the study

on mineralogy and petrology. Email: [email protected].

About the corresponding author LIU Shanbao, male, born in 1970 in Shandong province; Doctor; graduated from Institute of Mineral Resources, Chinese Academy of

Geological Sciences; associate research fellow of Institute of Mineral Resources, Chinese Academy of Geological Sciences. He is

now interested in the study on petrology and mineral exploration. Email: [email protected].


age and geological significance of anatexis within the ......of crustal materials. two-stage hf...

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