Massive Sulfide Deposit Kidd Creek Mine, Timmins, Ontario

By Rex A. Crouch

Copyright © 2008 by Rex A. Crouch

Abstract

This is an overview of the Kidd Creek Mine identifying the location of the deposit, geologic

origin, the structural geology of the deposit, geochemistry that makes the deposit unique but relates it to nearby sulfide deposits, and an examination of the minerals from the MTU Kidd Creek Suite. The major sulfide minerals in the deposit are mainly pyrite, chalcopyrite, and

sphalerite. Other minerals are bornite, covellite, digenite, stromeyerite, pyrrhotite, marcasite, galena, aresenopyrite, and silver. X-ray diffraction was conducted on several samples in the suite and results presented herein. One sulfide in the suite was breaking down into a sulfate

and was addressed in more detail. Several reflected light images of polished sections are reviewed to emphasize the complexity of the deposit.

Geographic Location: The Kidd Creek Mine is located 22 kilometers north of

Timmins, Ontario, Canada at latitude 48°41’23.70” N and longitude 81°22’17.96 W at an elevation of 917 feet above sea level. [1]

Map 1. Kidd Creek Mine regional map [2]

Image 1. Kidd Creek Mine satellite imagery [3]

Genetic Type: Archean, volcanogenic massive sulfide (VMS) with metavolcanic and

komatiitic rocks and high silica rhyolites under tholeiitic basalt in an Abitibi greenstone belt consisting of high-grade Zn, Cu, and Ag ore. [4][5] Geological Origin: An overview of the region shows thick eugeosynclinal successions

of metavolcanic and metasedimentary structures intruded by felsic and mafic plutonic rocks. These successions formed a belt that has a general strike to the east but demonstrates various levels of complicated folding. This belt extends to the east from the Timmins area, through Noranda and Val d’Or, and ending in the Bourlamaque, Quebec area. [6] The Kidd Creek deposit is a VMS Archean lens with a rhyolite volcaniclastic pile, felsic flows, and a thick sequence of mafic flows with dikes and sill throughout located in the Abitibi greenstone belt. The lens has been overturned between 70 and 80 degrees with profound structural deformation to include at least three phases of folding and north trending of the structural body. The initial folds were isoclinals and have been refolded and partially obscured by a set of northwest trending shear folds. The mentioned north trending reopened previous folds but resulted in a deformation of the two fold phases. The shearing, in addition to faults had a significant affect on the distribution and redistribution of the sulfides. Hydrothermal fluids were also responsible in the mineral deposition as defined by elevated MgO, Fe2O3, and Cu which transect both the footwall which is predominately rhyolite and the ultramafic rocks of the lens. [5] Significance: Kidd Creek Mine is one of the largest VMS deposits descending more than 10000 feet, and the lateral extents of the VMS deposit are 6 times as large as the main deposit itself. It is estimated that 138 million tons are in reserve with grades of 2.35% Cu, 6.5% Zn, 0.23% Pb, and 89 g/ton of Ag. Many other metals are present (such as Au) but not in economic concentrations. [5] Other minerals recovered in the deposit include: bornite, covellite, digenite, stromeyerite, pyrrhotite, marcasite, galena, and aresenopyrite. [6]

Relation to Other Similar Deposits Worldwide: Moving along the eugeosynclinal

successions of metavolcanic and metasedimentary structures where the Kidd Creek Mine is found, other deposits such as the Kotia, Jamieson, and Genex share similar geochemistry in terms of sulfides but the nearby McIntyre deposit was unusual being a dissemination of chalcopyrite with tennantite and molybdenite in a quartz-feldspar porphyry plus gold. On the flanks of the structure where the sulfide mines are found, there are large bodies of diorite and gabbro. Going about 12 miles south from the Kidd Creek deposit you encounter large gold deposits. Looking past sulfides and other precious metals found in the Kidd Creek deposit and focusing on oxygen isotope ratios a different story may be told. The oxygen isotope ratios in Zircons from rhyolites found in the Kidd Creek VMS are 18O = 5.4 ‰ which is typically what is found throughout the Superior Province. What is uncommon is that 18O = 14.2 ‰ to 16.1 ‰ in primary quartz phenocrysts. The 18O content from the zircons are believed to be from partial melting of a tholeiite source but the variation in the 18O for the quartz in the Kidd Creek deposit serve as an additional indicator that Kidd Creek had a high degree of hydrothermal exchange. [7] In relation to other similar deposits worldwide, the Kidd Creek deposit is considered unique geologically but based on geochemistry with at least one noted exception being the 18O content, otherwise it does share some similarities with deposits of close proximity. [6] The discrete differences in geochemistry indicate that Kidd Creek was probably more hydrothermally active than other VMS deposits

Map and/or cross-section The below stratigraphic column is a very simplified version of the actual strata.

Figure 1 Kidd Mine Stratigraphic Column [4]

The below image represents a side view of the Kidd Creek deposit showing how the lens has been tilted to the mentioned 70 to 80 degree angle. The pit it shown on the top as well as the larger shaft houses. In the description of the specimens from the Kidd Creek Suite found in the next section of this paper, I will identify the location (whenever possible) where the sample was retrieved such as North or South ore body or hanging wall or foot wall thus allowing the reader to visualize types of rocks and minerals throughout the mine as they relate to this profile.

Figure 2. Kidd Mine ore-bodies viewed from west [4]

Various views inside the mine:

This photo depicts a contact point between rhyolite lapillistone and coarser rhyolite breccias at the top of the photo (photo is from the 2300 level; roof bolt for scale). The matrix of the lapillistone is completely replaced by pyrite [8]

This is a 1 cm thick sulfide turbidite layer in

the hanging wall. [8]

This is a stringer of bornite in massive chalcopyrite immediately overlying the bornite zone. The field of view in this photo is 1 meter wide. [8]

The above photos are to assist the reader in understanding the ores as they are found in this deposit. An overview of some of the specimens found in the deposit follows:

Description of Specimens: The following specimens are property of Michigan Technological University Geological and Mining Engineering Department and represent the ore samples found at the Kidd Creek deposit:

Specimen 20-3-456 Pyrite-Zinc ore from North Zone ore body Massive bronze colored ore with a sub-metallic luster

Specimen 20-3-461 Diorite Aphanitic smooth textured dull dark grey colored rock

Specimen 20-3-459 Chalcopyrite from South Zone ore body Massive dull brassy yellow colored mineral with a sub-metallic luster.

Specimen 3463 Vaguely banded Sphalerite Pyrite Bands of massive dark brown sphalerite and brassy metallic-luster pyrite

Specimen 3444 Massive Andesite – Diorite from the hanging wall Aphanitic smooth textured gray vitreous luster rock

Specimen 3469 Chert banded in massive Pyrite Aphanitic very smooth textured rock with varying degrees of dull to sub-metallic luster in the pyrite

Specimen 3477 Massive banded Chalcopyrite Massive mineral ore with a consistent metallic luster

Specimen 3459 Cherty Breccia Aphanitic smooth textured rock

Specimen 3437 Highly sericitized Rhyolite from the footwall Aphanitic glassy smooth textured rock in various shades of green/tan with white streaks.

Specimen 3453 Carbonaceous Horizon Aphanitic greasy textured sub-metallic rock

Specimen 3464 Carbonaceous Sedimentary rock from the hanging wall Aphanitic resinous dull dark gray greasy luster rock with obvious layering sedimentary features in shades of brown.

Specimen 3447 Magnesite with Cr-Mica altered ultramafic rock Aphanitic sandy textured rock intermixed with green chrome mica

Specimen 3445 Andesite – Diorite from the footwall Aphanitic smooth textured dull dark gray rock

Specimen 3455 Sericitized Rhyolite from the North Zone ore body footwall Aphanitic silky textured and is a bright gray color. The rock has a wavy surface with a sub-metallic luster

Specimen 3454 Carbonaceous Horizon Sulfides along the bedding Aphanitic smooth textured dull dark gray rock

Specimen 3450 Altered Rhyolite from the South Zone ore body footwall Aphanitic glassy smooth textured with greasy luster rock

Specimen 3480 Sphalerite – Galena ore Massive grey to silver mineral ore with sub-metallic to metallic luster

Specimen 3472 Rhyolite from footwall Aphanitic glassy smooth textured dull dark gray rock

.

Specimen 3470 Fine-grained massive Sphalerite Pyrite ore with thin folds of pyrite Massive sub-metallic mineral ore with varying colors of bronze pyrite to dark bronze sphalerite

Specimen 3473 Pyrite in Carbonaceous Horizon Aphanitic smooth textured dull gray colored rock with some intermixed brassy colored pyrite

Specimen 3456 Cherty Rhyolite from footwall Aphanitic very smooth rolling textured sub-metallic luster rock

Specimen 20-3-453 Graphite Agillite with Pyrite crystals Aphanitic smooth textured mineral with euhedral pyrite crystals intermixed

Specimen 3460 Stringer ore in Rhyolite from footwall Aphanitic smooth textured dull ore with copper colored sub-metallic luster bands of chalcopyrite throughout

Specimen 3474 Pyrite – Sphalerite ore Massive mineral with varying degree of dull to metallic luster in which the pyrite displays a bright brassy luster and the sphalerite is a dull brownish color luster.

Specimen 20-3-452 Rhyolite Agglomerate with Quartz Eyes Aphanitic smooth textured dull gray rock with small phaneritic quartz pieces

Specimen 3466 Pyrite ore with Slate in Carbonaceous Horizon Aphanitic very smooth textured sub-metallic rock with varying shades of dark gray with sporadic bronze colored pyrite specimens throughout

Specimen 20-3-457 Massive Chalcopyrite Massive bronze colored metal bearing saw marks

Specimen 3475 Chalcopyrite from South Zone ore body Massive ore with bronze colored sub-metallic luster to dull dark grey rock

Specimen 3452 Carbonaceous Horizon Aphanitic smooth textured sub-metallic luster rock

Specimen 20-3-455 Massive Sphalerite and Galena Massive sugary textured grey sub-metallic luster with dark brown dull luster ore

Specimen 3408 Disseminated Sulfides in Carbonaceous Horizon Aphanitic ripple smooth textured blue-white-grey colored sample

Specimen 20-3-454 Siliceous Chalcopyrite in Cherty Breccia Aphanitic semi-smooth textured mineral with bronze colored sub-metallic luster

Specimen 3448 Sericitized Rhyolite cut by chrome mica (altered) Aphanitic semi-smooth textured rock

A closer inspection of some of the above samples: Three samples were studied in greater detail by x-ray diffraction for the below-indicated reasons. One of the samples in the suite was breaking down from a sulfide into a sulfate and was lacking an identification labels. A second was reviewed to insure the accuracy of the cards that came with the sample. A third was inspected as the name given on the card was vague. Sample which was missing its identification card: About ⅓ of this sample was breaking down from a sulfide to a sulfate. As mentioned, this is the only sample in the suite that is breaking down. It had the odor of battery acid.

In the image to the left you can see the cracks forming and a white powder beginning to form near the top of the rock in the photo. I initially conducted a pH test on this sample and found it to have a pH level of 2.65 – (the upper quarter of the pH spectrum) being acidic.

This acidic pH level suggested possible electric conductivity. A 2.43 gram sample was removed from the affected area of the ore. The resistance was first determined to be 763 Ohms/cm on the surface of the sample. The sample was then immersed in 10 ml of H2O. With the voltage probes 1 cm apart and in contact with the immersed sample, the voltage produced was 0.058 volts varying by 0.003 volts as the water turned a pale blue green color. The H2O used was left with 380 ppm total dissolved solids. The process of this sample breaking down into a sulfate is producing about 76 microwatts per cm so we can assume that the sample is producing its own heat and to some degree can easily break down in solution. A more introspective question outside of the scope of this paper may ask how the heat formed during the chemical reaction may affect the surrounding rocks?

An x-ray diffraction was conducted on the sample as presented below:

This trace was difficult to interpret. There was a lot of noise at the beginning of the trace that could not be smoothed out but there were peaks that positively identified pyrite and iron sulfate hydrate (Szomolnokite) FeSO4*H2O in the sample. The Szomolnokite confirmed the suspicion that the sample was becoming a sulfate. One peak remained unidentified.

Examining sample 3466. In confirming that the identification labels that came with the samples were correct one piece was selected to be scrutinized. A small silver colored piece of metallic mix was removed from the larger sample 3466 which is shown in the above sequence of photos. This sample is said to be pyrite ore with slate in a carbonaceous horizon. X-ray diffraction was conducted on the sample and Dr. George Robinson and myself found that chlorite and quartz were present in the sample as well as a very clean pyrite FeS2. Below is a trace of the x-ray powder diffraction pattern:

Quartz

Chlorite

Pyrite

The last specimen to be scrutinized is sample 3408 which has a very non-descriptive label which states: “Disseminated Sulfides in Carbonaceous Horizon”.

The above trace indicates that sample 3408 is predominately sphalerite and quartz

A microscopic look at the complexity of ore textures from the Kidd Creek deposit:

In this magnified photo we see disseminated, euhedral pyrite which developed in sphalerite at the top of the bornite zone – all surrounded by chalcopyrite. The field of view is 1 cm across. [8]

Atoll structures Pyrite which apparently resulted from corrosion of the porous cores of earlier pyrite in a bornite matrix. It is also noted that there is a grain of mawsonite in the bornite. The field of view is 1 cm across. [8]

In this photo we see the corroded remnants of early, Ni-carrollite located in the core of a much larger pyrite atoll structure. The field of view is 2 mm. [8]

In this image we see traces of digenite throughout the massive bornite. In the bottom left hand corner is a large grain of mawsonite. Field of view is 5 mm. [8]

Summary: At the macro level, the Kidd Creek deposit is a geologically unique VMS with strong evidence of hydrothermal alterations with geochemistry that shares some commonalities with local deposits but is unique to the area. At the microscopic level there are complex replacement series which required detailed study and explanation. Economically, the deposit is very rich allowing for penetration past the 10,000 foot level involving the advancement of mining technologies at all levels.

Works Cited:

[1] Info Mine (2006). “Regional Map of Kidd Creek Mine location” [2] Info Mine (2006). “Kidd Creek” [3] Terra Metrics. (2007). "Image of Kidd Creek Mine." [4] Gibson, R., Hannington, Gibbins, DeWolfe, and Duff (2003). "The Kidd Creek Volcanogenic Massive Sulfide Deposit: A Growing Giant, After Fortyt Years of Mining, Exploration, and Research." The Gangue(78): 18. [5] David M. Richardson (1998), "An Alteration Study of the Archean Kidd Creek Volcanogenic Massive Sulphide Deposit, Abitibi Greenstone Belt, Canada for the Department of Geology, Laurentian University Sudbury, Ontario, Canada [6] Geology and Economic Minerals of Canada (1972), Geologic Survey of Canada, Economic Geology Report Number 1 [7] King, Barrie, and Valley (1997), “Hydrothermal Alteration of Oxygen Isotope Ratios in Quartz Phenocrysts, Kidd Creek Mine, Ontario” Geology, v. 25, n. 12, p 1079-108 [8] Mineral Deposits of Canada (2006), Photo library: Giant Kidd Creek Volcanogenic Massive Sulfide deposit, Western Abitibi Subprovince, Timmins, Ontario, Canada. http://gsc.nrcan.gc.ca/mindep/photolib/vms/kidd_creek/index_e.php

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