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Paleoclimatic Reconstruction in Northern Oman Based on Carbonates from Hyperalkaline Groundwaters

Published online by Cambridge University Press:  20 January 2017

Ian D. Clark  and
Jean-Charles Fontes
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Abstract

A paleoclimatic reconstruction for the past 35,000 years for northern Oman is based on an unusual approach using travertines and fracture calcites associated with hyperalkaline springs. High-pH groundwaters (pH up to 11.9) discharge from the mantle sequence of the Oman Ophiolite as the product of modern, low-temperature serpentinization. Under arid climatic conditions, hyperalkaline discharge occurs at the surface. Uptake of atmospheric CO2 precipitates characteristic laminated travertines, accompanied by strong kinetic depletion of 13C and 18O. Pluvial climates supporting a shallow bicarbonate-groundwater flow system and vegetation are recorded by fracture calcites with equilibrium stable isotope contents and calcite-replaced roots and stems. All such carbonates have modern initial 14C contents, allowing radiocarbon dating and paleoclimatic reconstruction for the late Pleistocene and Holocene. Our reconstruction shows a dominantly wet late Pleistocene up to 19,000 yr B.P., when a phase of climatic deterioration began, leading to a period of hyperaridity which dominated from ca. 16,300 to 13,000 yr B.P. The early Holocene pluvial occurred from 12,500 to ca. 6500 yr B.P. and was followed by renewed climatic deterioration and the current phase of hyperaridity. Comparison of this paleoclimatic reconstruction with that for lacustrine deposits from the A'Rub al Khali of central Saudi Arabia and the summer insolation-driven monsoon record of east Africa and the Arabian Sea is remarkably good.

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Articles
Information
Quaternary Research , Volume 33 , Issue 3 , May 1990 , pp. 320 - 336
Copyright
University of Washington

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References

Barnes, I. O'Neil, J. R. The relationship between fluids in some fresh alpine-type ultramafics and some possible modern serpentinization, western United States. Geological Society of America Bulletin 80 1969 1947 1960 CrossRefGoogle Scholar
Barnes, I. O'Neil, J. R. Trescases, J. J. Present day serpentinization in New Caledonia, Oman and Yugoslavia. Geochimica et Cosmochimia Acta 42 1978 144 145 CrossRefGoogle Scholar
Causse, C. Conrad, G. Fontes, J.-Ch. Gasse, F. Gibert, E. Kassir, A. Le dernier “Humide” Pleistocène du Sahara nord-occidental daterait de 80–100,000 ans. Comptes Rendus de l'Académie des Sciences, Paris 306 1988 1459 1469 II Google Scholar
Clark, I. D. Groundwater Resources in the Sultanate of Oman: Origin, Circulation Times, Recharge Processes and Paleoclimatology. Isotopic and Geochemical Approaches. Thesis 1987 Université de Paris-Sud Orsay, France 264 Google Scholar
Clark, I. D. Fontes, J.-Ch. Fritz, P. Hyperalkaline springs and travertines in Oman: isotope disequilibria and 14C dating 1990 Submitted for publication Google Scholar
Clark, I. D. Fritz, P. Souther, J. G. Geochemistry and isotope hydrogeology of the Mount Edziza Geothermal area. Canadian Journal of Earth Science 26 1989 1160 1171 CrossRefGoogle Scholar
Felber, H. Hötzl, H. Maurin, V. Moser, H. Rauert, W. Zötl, J. G. Sea level fluctuations in the Quaternary Al-Sayari, S. S. Zötl, J. G. Quaternary Period in Saudi Arabia 1978 Springer-Verlag Vienna 50 57 Google Scholar
Fontes, J.-Ch. Gasse, F. Callot, Y. Plaziat, J.Ch. Carbonel, P. Dupeuble, P. A. Kaczmarska, I. Freshwater to marine-like environments from Holocene lakes in northern Sahara. Nature (London) 317 6038 1985 608 610 CrossRefGoogle Scholar
Fontes, J.-Ch. Gasse, F. Ben Khelifa, L. Zouari, K. Ben Ouezdou, H. Zaouali, J. Carbonel, P. Causse, C. Programme PALHYDAF: État d'avancement, janvier 1987. Premier méridien: Sud Tunisie-Sud Niger. Séminaire “Paléolacs-Paléoclimats” ORSTOM Bondy. Géodynamique 2 2 1987 139 142 Google Scholar
Gass, I. G. Lippard, S. J. Shelton, A. W. Ophiolite in Oman: The Open University Project. Episodes 8 1 1985 13 20 CrossRefGoogle Scholar
Gasse, F. Fontes, J.-Ch. Palaeoenvironments and palaeohydrology of a tropical closed lake (L. Asal, Djibouti) since 10,000 yr B.P.. Palaeogeography, Palaeoclimatology, Palaeoecology 69 1989 67 102 CrossRefGoogle Scholar
Glennie, K. W. Hughes Clark, M. W. Moody-Stuart, M. Pilaar, W. F. M. Reinhardt, B. M. Geology of the Oman Mountains 1974 Report by Exploration Research Shell Oil Google Scholar
Kutzbach, J. E. Street-Perrott, F. A. Milankovitch forcing of fluctuations in the level of tropical lakes from 18 to 0 kyr B.P.. Nature (London) 317 12 1985 130 134 CrossRefGoogle Scholar
Launay, J. Fontes, J.-Ch. Les source thermales de Prony (Nouvelle Calédonie) et leurs précipités chimiques: Exemple de formation de brucite primaire. Géologie de la France 1 1985 83 100 Google Scholar
McClure, H. A. Radiocarbon chronology of Late Quaternary lakes in the Arabian Peninsula. Nature (London) 263 1976 755 756 CrossRefGoogle Scholar
Mook, W. G. Bommerson, J. C. Staverman, W. H. Carbon isotope fractionation between dissolved bicarbonate and gaseous carbon dioxide. Earth and Planetary Science Letters 22 1974 169 176 CrossRefGoogle Scholar
Neal, C. Stanger, G. Hydrogen generation from mantle source rocks in Oman. Earth and Planetary Science Letters 66 1983 315 320 CrossRefGoogle Scholar
O'Neil, J. R. Clayton, R. N. Mayeda, T. K. Oxygen isotope fractionation in divalent metal carbonates. Journal of Chemical Physics 51 12 1969 5547 5558 CrossRefGoogle Scholar
O'Neil, J. R. Barnes, I. C13 and O18 compositions in some fresh-water carbonates associated with ultramafic rocks and serpentinites: Western United States. Geochimica et Cosmochimica Acta 35 1971 687 697 CrossRefGoogle Scholar
Roberts, N. Lake levels as an indicator of near eastern palaeoclimates: A preliminary appraisal Bintliff, J. L. Van Zeist, W. Palaeoclomates, Palaeoenvironments and Human Communities in the Eastern Mediterranean Region in Later Prehistory 1982 BAR International Series, 133 Oxford 235 267 Google Scholar
Rossignol-Strick, M. African monsoons, an immediate climatic response to orbital insolation. Nature (London) 304 7 1983 46 49 CrossRefGoogle Scholar
Saliège, J. F. Fontes, J.-Ch. Essai de détermination expérimentale du fractionnement des isotopes 13C et 14C du carbone au cours des processus naturels. International Journal of Applied Radiation and Isotopes 35 1 1982 55 62 CrossRefGoogle Scholar
Street, F. A. Grove, A. T. Global maps of lake-level fluctuations since 30,000 B.P.. Quaternary Research 12 1979 83 118 CrossRefGoogle Scholar
Street-Perrott, F. A. Roberts, N. Fluctuations in closed-basin lakes as an indicator of past atmospheric circulation patterns Street-Perrot, A. et al. Variations in the Global Water Budget 1983 Reidel Dordrecht 331 345 Google Scholar
Turi, B. Stable isotope geochemistry of travertines Fritz, B. P. Fontes, J.Ch. Handbook of Environmental Isotope Geochemistry Vol. 2 1986 Elsevier Amsterdam/New York 207 235 Google Scholar
Zouari, K. Géochimie et sédimentologie des dépots continentaux d'origine aquatique du sud Tunisien: Interprétations paléohydrologiques et paléoclimatiques. Unpublished Ph.D. thesis 1988 Université de Paris-Sud Orsay, France Google Scholar