B Ghasemshirazi; M.R Majidifard; A Kheradmand; T Mohtat
Abstract
In this research, the Campanian -Maastrichtian deposits in Jupar section, Central Iran have been studied to determine biozonation and Paleobathymetry of the deposits. The planktonic and benthic foraminifera were studied in order to assign palaeobathymetry of the Campanian- Maastrichtian deposits. A depth ...
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In this research, the Campanian -Maastrichtian deposits in Jupar section, Central Iran have been studied to determine biozonation and Paleobathymetry of the deposits. The planktonic and benthic foraminifera were studied in order to assign palaeobathymetry of the Campanian- Maastrichtian deposits. A depth of 490- 650 m was assigned for most parts of the sediments according to planktonic/epibenthic ratio and the regression equation D = e (3.58718+ (0.03534 × %P*)). In the present investigation, 58 planktonic species of 27 genera have been identified. The Campanian -Maastrichtian deposits is divided into 7 biozones on the basis of planktonic foraminifera, which are cosmopolitan and consist of biozone1-Globotruncanita elevata Partial Range Zone, Biozone2- Globotruncana ventricosa Interval Zone, Biozone3- Globotruncanita calcarata Interval Zone, Biozone4- Globotruncanella havanensis Partial range zone , Biozone5- Globotruncana aegyptiaca Interval zone, Biozone6- Gansserina gansseri Interval zone, and Biozone7- Contusotruncana contusa Interval Zone.
R. Moussavi-Harami; A. Mahboubi; A. Kheradmand; H. Zandmoghadam
Abstract
For interpretation of paragenetic sequence and post depositional history of siliciclastic sediments of Dahu Formation (Late Camberian), two stratigraphy sections were measured at Dahuieh (type section) and Gazuieh in the NE and E of Zarand, with the thickness of 240 and 227 meters, respectively. The ...
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For interpretation of paragenetic sequence and post depositional history of siliciclastic sediments of Dahu Formation (Late Camberian), two stratigraphy sections were measured at Dahuieh (type section) and Gazuieh in the NE and E of Zarand, with the thickness of 240 and 227 meters, respectively. The diagenetic processes affected these sediments, during three stages eogenesis, mesogenesis and telogenesis, including compaction, cementation, alteration, dissolution, fracturing and vein filling. Clay mineral study within sandstone and mud rocks of Dahu Formation led to identification of two groups of clay as illite and cholerite. Illite form 90% of clay minerals in these sediments that are mostly formed during burials and clay mineral diagenesis as well as alteration and dissolution of potassium feldspar. The interpreted paragenetic sequence shows that a large number of diagenetic processes act in the mesogenetic stage. Physical compaction and hematite cement have operated in eogenetic stage, while other processes such as chemical compaction, silica and dolomite cement, feldspar alteration, sericitization, ilitization and chloritization, dissolution of feldspars and cherts have occurred in mesogenetic stage. The fractures and calcite vein filling have formed in telogenetic stage during uplifting. We hope that this information can be used for evaluation of post depositional and burial history of similar sediments in local and regional scale.
