Occurrence of recent dedolomite crust on pedogenic calcrete in Al-Jabal Al-Akhdar, Northern Oman

Authors

  • Fikry Ibrahim Khalaf Kuwait University
  • Abdullah Al-Zamel

Keywords:

Al-Jabal Al-Akhdar, calcrete, crust, dedolomite, Oman.

Abstract

Rusty dedolomitized crust occurs in fractured pedogeniccalcrete horizon within terra rossa soil contained in shallow phytokarstic cavities in the calcareous rocks exposed at Al-Jabal Al-Akhdar Mountain, Oman. Two lithotypes were recognized: (a) dedolomitizeddetrital dolomite and (b) dedolomitizedauthigenic dolomite. The first is light brownish, has an undulating
sharp contact with the nodular calcretes and consists of euhedral to subhedral moderately to poorly sorted dolomite grains floating in a micritic groundmass. The second is relatively thicker, dark brown, and consists of idiotopic mosaic of moderately sorted well euhedral dolomite crystals that reach up to 200 um in size. Microscopic examination of stained thin sections indicated that most of both detrital and authigenic dolomite crusts have been partially or completely dedolomitized. XRD analysis indicated that both types of crusts mostly consist of calcite and dolomite with traces of quartz, where abundance of
calcite reflects their dedolomitization. The chemical composition of these crusts reflects their mineralogy. The paragenetic events of the crust formation are discussed. The availability of dolomitic source rocks and the present prevailed semiarid climate characterized by intermittent wet and dry periods have played a significant role in its development. This work presents a unique mode of occurrence of dedolomitized dolomite associated with recent pedogeniccalcretes.

Author Biography

Fikry Ibrahim Khalaf, Kuwait University

Department of Earth & Environmental Sciences

Faculty of Science

Kuwait University

References

Al-Busaidi, M. (2012). The struggle between nature and

development: Linking local knowledge with sustainable

natural resources management in Al-Jabal Al-Akhdar

Region, Oman. PhD thesis, University of Glasgow, School

of Geographical and Earth Sciences. P 433.

Al-Hashimi, W.S. &Hemingway, J. E.(1973). Recent

dedolomitization and the origin of the rusty crusts of

Northumberland.Journal of Sedimentary Petrology, 43:82 -91.

Arakel, A.V. (1986). Evolution of calcrete in palaeodrainages

of the lake Napper Area, central Australia. Palaeogeography

Palaeoclimatology Paleoecology, 54:283 -303.

Back, W., Hanshaw, B.B., Plummer, L.N., Rahn,

P.H., Rightmire, C.T.et al.(1983). Process and rate of

dedolomitization: Mass transfer and 14C dating in a regional

carbonate aquifer.Geol. Soc. Amer. Bull., 94:1415- 1429.

Baud, A.& Richoz, S. (2013). Permian–Triassic Transition

and the Saiq/Mahil Boundary in the Oman Mountains:

Proposed correction for lithostratigraphic nomenclature.

GeoArabia, 18:87- 98.

Budai, J.M., Lohmann, K.C.& Owen, R.M. (1984).

Burial dedolomite in the Mississippian Madison Limestone,

Wyoming and Utah thrust belt. Journal of Sedimentary

Petrology, 54: 276- 288.

Burns, S.J., Fleitmann, D., Mudelsee, M., Neff,

U., Matter, A.et al. (2001). Speleothem evidence from

Oman for continental Pluvial events during Interglacia

l Periods. Geology, 29(7):623 -626.

Cantrell, D.L., Al-Khammash, A.& Jenden, P.D. (2007).

Characterization and significance of dedolomite in Wadi

Nisah, central Saudi Arabia. GeoArabia, 12 (3):15–30.

Carlisle, D. (1983). Concentration of uranium and vanadium

in calcretes and gypcretes. In: Residual Deposits (Ed. by

R. C. L. Wilson). Geological Society of London, Special

Publication, 11:185- 195.

Carpenter, A.B., Trout, M.L.& Pickett, E.E. (1974).

Preliminary report on the origin and chemical evolution of

lead- and zinc-rich oil field brines in central Mississippi.

Economic Geology, 69:1191- 1206.

Chafetz, H.S. (1972). Surface diagenesis of limestone.

Journal of Sedimentary Petrology, 42: 325 -329.

Chilingar, G.V. (1956). Dedolomitization: A review.

American Association of Petroleum Geologists Bulletin,40:

- 778.

Clemens, S.C., Murray, D.W.& Prell, W.L. (1996).

Nonstationary phase of the Plio-Pleistocene Asian monsoon.

Science, 274:943 -948.

Coniglio, M. (2003). Dedolomitization. In: Encyclopedia of

Earth Science. Part 4: Sedimentology, pp 300 -303.

De Groot, K. (1967). Experimental dedolomitization.Journal

of Sedimentary Petrology, 37: 1216- 1220.

Dickson, J.A.D. (1966). Carbonate identification and genesis

as revealed by staining. Journal of Sedimentary Petrology,

:491- 505.

Dixon, J.C. (2010). Origin of calcrete and dolocrete in

the carbonate mantle of St Vincent Basin, southern South

Australia. Cadernos Lab. Xeoloxico de Laxe Coruna,

:109 -122.

Escorcia, L.C., Gomez-Rivas, E., Daniele, L.& Corbella,

M. (2013). Dedolomitization and reservoir quality: insights

from reactive transport modelling, Geofluids, 13: 221–231.

Evamy B.D.(1967). Dedolomitization and the development

of rhombohedral pores in limestones.Journal of Sedimentary

Petrology, 37:1204 -1215

Goldberg, M. (1967). Supratidal dolomitization and

dedolomitization in Jurassic rocks of Hamakhtesh Haqatan,

Israel. Journal of Sedimentary Petrology, 37: 760 -773.

Holail H., Lohmann K.C.& Sanderson, I. (1988).

Dolomitization and dedolomitization of Upper Cretaceous

carbonates; Babariya Oasis, Egypt, In: V. Shukla and

P.A, Baker (Editors), Sedimentology and Geochemistry

of Dolostones. Soc. Eeon. Paleontol. Mineral. Special

Publication, 43:191- 207.

Hutton, J.T.& Dixon, J.C. (1981). The chemistry and

mineralogy of some South Australian calcretes and associated

soft carbonates and their dolomitization. Geological Society

of Australia, 28:71 -79.

Jacobson, G., Arakel, A.V.& Yijian, Ch. (1988). The

central Australian groundwater discharge zone: Evolution of

associated calcrete and gypcrete deposits. Australian Journal

of Earth Science, 35:549- 565.

James, N.P., Bone, Y.& Kyser, T.K.(1993). Shallow burial

dolomitization and dedolomitization of mid-Cenozoic, coolwater,

calcitic, deep-shelf limestones, southern Australia.

Journal of Sedimentary Petrology, 63:528 -538.

Jones, B., Pleydell, S.M., Ng, K.C.& Longstaffe, F.J.(1989).

Formation of poikilotopic calcite-dolomite fabrics in the Oligocene-

Miocene Bluff formation of Grand Cayman, British West Indies.

Bulletin of Canadian Petroleum Geology, 37:255 -265.

Katz, A. (1968). Calcian dolomites and dedolomitization.

Nature, 217:439 -440

Kenny, R. (1992). Origin of disconformity dedolomite in

the Martin Formation (Late Devonian, northern Arizona).

Sedimentary Geology, 78:137- 146.

Khalaf, F.I.& Abdal, M.S. (1993). Dedolomitization of

dolocrete deposits in Kuwait, Arabian Gulf. Geologische

Rundschay, 82:741 -749

Khalaf, F.I.& Al-Zamel, A. (2016). Petrography,

micromorphology and genesis of Holocene pedogenic

calcrete in Al-Jabal Al-Akhdar, Sultanate of Oman. Catena,

: 496–510.

Khalaf, F.I., Al-Ajmi, D.& Al-Dousari, A.(1994).Detrital

palygorskite in recent terrestrial and marine sediments of

Kuwait. Egyptian Journal of Geology, 38 (2): 537- 554.

Khalaf, F.I. (1990). Occurrence of phreatic dolocrete

within Tertiary clastic deposits of Kuwait. Arabian Gulf.

Sedimentary Geology, 68: 223- 239.

Kharaka, Y.K., Callender, E.& Wallace, R.H. (1977).

Geochemistry of geopressured geothermal waters from

the Frio Clay in the Gulf Coast region of Texas.Geology,

: 241- 244.

Koehrer, B., Zeller, M., Aigner, T., Poeppelreiter, M.,

Milroy, P., Forke, H.& Al-Kindi, S. (2010). Facies and

stratigraphic framework of a Khuff outcrop equivalent:

Saiq and Mahil formations, Al Jabal al-Akhdar, Sultanate of

Oman. GeoArabia, 15: 91- 156.

Land, L.S.& Prezbindowski, D.R. (1981). The origin

and evolution of saline formation water, Lower Cretaceous

carbonates, south-central Texas, U.S.A.Journal of Hydrology,

: 51 -74.

Mann, A.W.& Horwitz, R.C. (1979). Groundwater calcrete

deposits in Australia: some observations from Western

Australia. Journal of the Geological Society of Australia,

:293- 303.

Nader, F.H., Swennen, R.& Keppens, E. (2008).

Calcitization/dedolomitization of Jurassic dolostones

(Lebanon): results from petrographic and sequential

geochemical analyses. Sedimentology, 55:1467–1485.

Neff, U., Bums, S.G., Mangini, A., Mudelsee, M.,

Fleitmann, D.&Matter, A. (2001). Strong coherence

between solar variability and the monsoon in Oman between

and 6 kyr ago. Nature,4111: 290- 293.

Netterberg, F. (1980). Geology of Southern African calcretes:

Terminology, description, macrofeatures, and classification.

South African Journal of Geology, 83:255- 283.

Phillips, S.E.& Milnes, A.R. (1988). The Pleistocene

terrestrial carbonate mantle on the southeastern margin of

the St. Vincent Basin, South Australia. Australian Journal of

Earth Science, 35:463- 481.

Rameil, N. (2008). Early diagenetic dolomitization and

dedolomitization of Late Jurassic and earliest Cretaceous platform

carbonates: A case study from the Jura Mountains (NW Switzerland,

E France). Sedimentary Geology, 212(1 -4): 70- 85.

Saddiqi, O., Michard, A., Goffe, B., Poupeau, G.&

Oberhansli, R. (2006). Fission- track thermochronology

of the Oman Mountains continental windows, and current

problems of tectonic interpretation: Societe Geologique de

France Bulletin, 177: 127- 134.

Stoessell,R.K., Klimentidis, R.E.& Prezbindowski,

D.R.(1987). Dedolomitization in Na-Ca-Cl brines from 100°

to 200°C at 300 bars.Geochimica et Cosmochimica Acta, 51:

-855.

Theriault, F.& Hutcheon, L. (1987). Dolomitization and

calcitization of the Devonian Grosmont Formation, Northern

Alberta.Journal of Sedimentary Petrology, 6: 955- 966.

Vandeginste, V.& John, C.M. (2012). Influence of climate

and dolomite composition on dedolomitization: insights

from a multi-proxy study in the Central Oman Mountains.

Journal of Sedimentary Research, 82: 177- 195.

Von Morlot, A. (1847). Veber Dolomit und seine Kunstliche

Darstelling aus Kalkstein: Naturwissenschaftliche

Abhandlungen, gesammelt und durch Subscription lursg:

Von Wilhelm Haidinger, 1:305 -315.

Warrak, M.(1974). The petrology and origin of dedolomitized

veined or brecciated carbonated rocks, the cornieules, in the

Frejus region, French Alps. Journal of Geological Society,

: 229 -247.

Watts, N.L. (1980). Quaternary pedogenic calcretes from

the Kalahari (Southern Africa): Mineralogy, genesis and

diagenesis.Sedimentology, 27:661- 686.

Downloads

Published

24-01-2018