dating the ancient dam of ma'rib (yemen)

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  • ali

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    ral

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    ancarnano

    f thortance of the locality as a caravan station are proposed as

    rogeological system. 14C analysis confirms that the earliestthe late 4th millennium or early 3rd millennium .

    DA

    aus dem Yemen (ABADY), published by theIndeed, dressed stones of an already mature form arefound in South Arabia in archaeological contexts inTDeutsches Archaologisches Institut ana

    (DAIS), gives an exhaustive treatment of the topic ofirrigation in the ancient Marib oases (Figures 1 & 2).Nevertheless, ABADY leaves some unexplored andunsettled points. In any case, researchers of DAIS getfull credit for showing how a multidisciplinaryapproach can be used to tackle a complex problemsuch as irrigation in the ancient Marib oases, of greatimportance for an understanding of the history of theSouth Arabian peoples, and above all for havinggrasped the basic mechanisms on which the Sabaeanhydraulic systems in South Arabia were based.

    P. Gentelle of the French Archaeological Mission inYemen (MAFRAY) was able to uncover the mechan-ism on which the irrigation systems in the Shabwah (orS{ibwa) area were based (Figure 1).

    Working independently, U.S. archaeologists arrivedat similar conclusions after analysing ancient irrigationcrops in the Timna area in the Wad al-Jubah (Figure2) (Toplyn, 19841986).

    The present author, a member of the ItalianArchaeological Mission in Yemen (MAIRAY), appliedand tested the same principles to the ancient irrigationsystems of Barraqish (Francaviglia, 1994, 2000),

    which no traces of material culture of comparablerichness have so far been found. At the same time,there is no known civilisation in the ancient NearEast that succeeded in building hydraulic structurescomparable to those of South Arabia.

    The Marib DamThe ancient Sabaean dam of Marib, with its basin, itssluices and its canals, is the best example of controlledirrigation in the entire Ancient World. It allowed anarea of over 9600 ha, divided into two oases, to beirrigated.

    Researchers of DAIS have described a sophisticatedmethod for the relative dating of the irrigation sedi-ments produced by thousands of years of activity bythe ancient Marib dams. It is based on the observationthat every annual irrigation cycle deposited a thin layerof silt (78 mm/year) onto the tilled fields. As theseaccumulated thin layers ultimately raised the level ofthe irrigated fields, every few decades the bottoms ofthe sluices regulating the distribution of the irrigationwater had to be raised to ensure the minimum slopeJournal of Archaeological Science (2000) 27, 645653doi:10.1006/jasc.1999.0518, available online at http://www.ide

    Dating the Ancient Dam of Ma

    Vincenzo M. Francaviglia

    CNR-Istituto per Le Tecnologie Applicate ai Beni CultuItalia

    (Received 9 November 1998, revised manuscript accepted

    It has been shown that extremely accurate absolute dates cof Marib (Yemen) by means of AMS assay of the radioobtained indicate that the silty sediments relating to the fiare no earlier than the beginning of the Christian era anddisagrees with historical sources, which give the collapse osilting up of the water storage basin and the declining impthe main causes of the decline of the entire Marib hydirrigation systems in the Wad Danah probably date from

    Keywords: YEMEN, SABAEANS, MAz RIB DAM, 14CDESERT FARMING.

    Introductionhe monumental volume Archaologische Berichteanother of the ancient cities of South Arabia.The irrigation systems in the four cases mentioned

    were found to be variations of a single model that wasFax: +39-06-90-67-23-73; Email: vincenzo.francaviglia@mlib.cnr.it

    64503054403/00/070645+09 $35.00/0 2000 Academic Press

    TING, SEDIMENTS, IRRIGATION, ARID LANDS,

    adapted to suit dierent environments, the origin ofwhich is, however, dicult to situate in time and space.brary.com on

    ib (Yemen)

    i, C.P. 10,00016 MONTEROTONDO ST. (Roma),

    1 October 1999)

    be obtained for the silty sediments from the ancient basinbon contained in detrital charcoal fragments. The resultsl period of activity of the ancient Sabaean dam of Marib

    later than the end of the 3rd century. This new evidencee famous Sabaean dam a much later date. The inexorablerequired to reach the fields, which had now becomehigher (Wagner, 1993).

    As the overall particle size distribution of thesediment layer occurring between two activity cycles

    2000 Academic Press

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    (separated by an increase in the sluice level) displays aconstant gradual increase in particle diameter followedby a sharp decreasing size, it was possible to estimatethe duration of the entire period of activity of the greatMarib dam. Six periods have been identified, rangingfrom VI (the earliest, believed to have begun in themid-3rd millennium) to I (corresponding to the 6th or7th century ). Assuming a sedimentation rate of8 mm/year, and dividing the thickness of the sedimentlayer corresponding to a given period by this rate, it ispossible to estimate the activity of the period itself.The total duration of irrigation activity at Marib isobtained by summing the duration of the single periods(Wagner, 1993).

    This is the theory, although it is not always possible

    during which irrigation was performed exclusively orpartially with well water. Some uncertainty also sur-rounds the annual rate of sedimentation estimated inthe irrigated fields. This is believed to vary from 7 to8 mm/year, a variation that can lead to significantlong-term dierences. Nevertheless, the principles ofsedimentary deposits occurring in annual cycles,their continuous variation within a single periodand of the repeatability of the periods themselvesremain valid.

    The present work is aimed at seeking answers to thedoubts and unsolved questions arising out of the DAISreconstruction of the entire activity of the Marib damby:

    Taima

    Mada'in Salih (Hegra)

    al- Ula (Dedan)

    Haybar

    Medina (Yatrib)

    Mecca

    HIGIAZ

    Berenice

    TIHAMAH

    Nagran`

    `

    al-Fau

    Ma'in

    WQatif

    al-Nagar

    Umm al-Nar

    OMAN

    DHOFAR

    HADRAMAUT`Sibwa

    Timna

    AWSANQATABAN

    Marib`GAWF

    Sana`

    ZafarAxum

    Mar Rosso AL-RUB AL-HALI

    Bahrein (Dilmun)

    Wad

    i al-D

    awas

    ir

    Figure 1. The Arabian Peninsula with the localities mentioned in the text (after Chiesa et al., 1994).i

    Hatra

    Tigri

    Eufrate

    Seleuc

    Hra

    Palmira

    ZebedUgarit

    Biblo

    Damasco

    Aleppo

    Bosra

    GerusalemmeAmman

    Umm al-Gimal

    Petra Ramm Gawf (Dumat al-Gandol) al-Ubayd

    Wadi al-Sirhan

    646 V. M. Francavigliato extrapolate as, for example, it is not possible to takeinto account periods of inactivity of the dam or periods0 km 500

    tesifonte

    mah

    Faylakah(1) testing the use of accelerating mass spectrometry(AMS) in the 14C assay performed on charcoal

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    Hand minute vegetal remains found in the upstreamand downstream sediments of the ancient Maribdam;

    (2) checking the dates handed down to us via historictradition of the beginning of the Marib damactivity and, above all, of its end;

    (3) providing an, albeit indirect, answer to thequestion of the continual increase over thecenturies of the particle diameter of the sedimentsdue to irrigation activity. Researchers of DAIStend to think in terms of geologic (neotectonic)causes while the present author favours causesinherent in the dam-sluice-canal distributionsystem.

    Any artificial lake created by damming a river sooneror later ends up by silting up completely. The lakecreated by the construction of the great Marib damcould not escape this fate due to the large quantities ofmineral matter transported by the wad. The sedimentthat gradually accumulated on its bottom is easy todistinguish as it diers in diameter from that depositedin the fields downstream from the dam.

    According to DAIS workers, the basin constructedby the Sabaeans at Marib should be considered not as

    the violence of the two annual floods of the WadDanah (the two sayls, one in spring and the other insummer).

    This system had two somewhat annoying sideeects: the gradual raising of the level of the arableland and the one of the basin bottom due to thesediment transported by the Wad Danah. To counter-act the gradual rise in the level of the arable land, theSabaeans periodically raised the level of the dam;according to researchers of DAIS, they remedied thegradual silting up of the basin by removing the bottomsediments every 80 years or so. The silting up of theMarib dam, and thus the reduction of its depth,reduced its ability to curb the violence of the floods,which ended up by violently impinging upon the weirs(made of stone and wood), thus increasing the percent-age of large diameter sediment transported into theirrigated fields. This constant increase in the diameterof the sediment deposited in the arable fields ended upby increasing soil permeability and thus its waterretaining capacity.

    There is some indication that the Sabaeans wouldperiodically (completely or partially?) empty the basinupstream from the Marib dam. This was a titanic

    Figure 2. Detail of preceding illustration (after Chiesa et al., 1994)

    T

    A

    Sana`

    Zafar

    Ma'in

    Marib`

    HIMYAR

    al-Masamma

    Gebel Urqub

    SABA

    Sirwah

    Baraqis

    al-Sawda'MA'IN

    W

    adi D

    anah

    W. Yalaa water reservoir from which water was periodicallywithdrawn as required, but rather as a defence againstHADRAMAUT`

    na

    AN

    QATABAN

    agar b. Humayd

    Sabwa

    Raybun

    Qana

    Wadi Hadram

    au