Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by KHORMALI, F. Articles by OWLIAIE, H. R. Search for Related Content GeoRef GeoRef Citation

Late Mesozoic—Cenozoic clay mineral successions of southern Iran and their palaeoclimatic implications

¹ Department of Soil Science, College of Agriculture, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran, and ² Department of Soil Science, College of Agriculture, Shiraz University, Shiraz, Iran

^* E-mail: khormali{at}gau.ac.ir

(Received 13 November 2003; revised 25 October 2004)

Clay minerals of calcareous sedimentary rocks of southern Iran, part of the old Tethys area, were investigated in order to determine their origin and distribution, and to reconstruct the palaeoclimate of the area. Chemical analysis, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and thin-section studies were performed on the 16 major sedimentary rocks of the Fars and Kuhgiluyeh Boyerahmad Provinces.

Kaolinite, smectite, chlorite, illite, palygorskite and illite-smectite interstratified minerals were detected in the rocks studied. The results revealed that detrital input is possibly the main source of kaolinite, smectite, chlorite and illite, while in situ neoformation during the Tertiary shallow saline and alkaline environment could be the dominant cause of palygorskite occurrences in the sedimentary rocks.

The presence of a large amount of kaolinite in the Lower Cretaceous sediments and the absence or rare occurrence of chlorite, smectite, palygorskite and illite are in accordance with the warm and humid climate of that period. Smaller amounts of kaolinite and the occurrence of smectite in Upper Cretaceous sediments indicate the gradual shift from warm and humid to more seasonal climate. The occurrence of palygorskite and smectite and the disappearance of kaolinite in the late Palaeocene sediments indicate the increase in aridity which has probably continued to the present time.

KEYWORDS: clay minerals, palaeoclimate, sedimentary rocks, Iran

This article has been cited by other articles:

				K. NABIOLLAHY, F. KHORMALI, K. BAZARGAN, and SH. AYOUBI Forms of K as a function of clay mineralogy and soil development Clay Minerals, September 1, 2006; 41(3): 739 - 749. [Abstract] [Full Text] [PDF]