H Ghaderi Fijani; M Khanehbad; R Moussavi Harami; A. Mahboubi
Abstract
The elongated Elyato River catchment, covering about 52.89 Km2 areas, is located in southwestern Fariman. To understand the grain size variation and effective factors in downstream fining, 35 samples from central axis of Longitudinal Bars have been collected and analyzed. The results indicate that the ...
Read More
The elongated Elyato River catchment, covering about 52.89 Km2 areas, is located in southwestern Fariman. To understand the grain size variation and effective factors in downstream fining, 35 samples from central axis of Longitudinal Bars have been collected and analyzed. The results indicate that the grain size decreases downstream as exponential. The lithological and geomorphological changes and faulting are effective in the slope percentage changes downstream. Based on petrographic studies, sediments on the river’s substrate are igneous rock fragments such as gabbro and serpentine group. However, based on sedimentological studies, we show that the sediments of Longitudinal Bars are mostly poorly and very poorly sorted, near symmetrical to very positive skewness and mesokurtic and platy kurtic kurtosis. Six sedimentary facies including grain supported gravel (Gcm), matrix supported gravel (Gmm), grain supported gravel with horizontal bedding (Gh), massive sand (Sm), laminated mud (Fl) and massive mud (Fm) are recognized along the wall of the studied river. These sedimentary facies have formed in 3 architectural elements including channel (CH), Gravel bars and bed form (GB) and fine grain clastic deposits (FF). Based on sedimentary facies and architectural elements, sedimentary model for this river is proposed as gravelly braided river system.
Stratigraphy and Palaeontology
M. Allameh; A. Mahboubi; R. Moussavi-Harami; M. Khanehbad
Abstract
The Aitamir Formation (Albian-Cenomanian) composed of siliciclastic rocks and several carbonate horizons. In order to study depositional environment and sequence stratigraghy, two stratigraghic sections studied in east Koppeht Dagh basin near the Baghak and Shurijeh villages. Field and petrograghic studies ...
Read More
The Aitamir Formation (Albian-Cenomanian) composed of siliciclastic rocks and several carbonate horizons. In order to study depositional environment and sequence stratigraghy, two stratigraghic sections studied in east Koppeht Dagh basin near the Baghak and Shurijeh villages. Field and petrograghic studies led to siliciclastic and carbonate facies that deposited in lagoon, barrier, shoreface and open marine environments. Sequence stratigraghy analysis led to identification of three depositional sequences in both sections. Comparision of interpreted sea level curves at studied area with Albian-Cenomanian global curve shows similarities and differences that can be relatedto tectonic setting and sedimentation rate.
M Badpa; K Khaksar; A Ashouri; M Khanehbad
Abstract
Rich assemblages of Carboniferous corals exist in the Zaladu stratigraphic section. After the identification of the corals, more than of 200 thin sections of coral fossils and microfacies were selected and studied for environmental parameters. This association belonging to Bashkirian age (the oldest ...
Read More
Rich assemblages of Carboniferous corals exist in the Zaladu stratigraphic section. After the identification of the corals, more than of 200 thin sections of coral fossils and microfacies were selected and studied for environmental parameters. This association belonging to Bashkirian age (the oldest stage of Late Carboniferous) and were found in two horizons. Based on the colonies geometry, the distance between them, the abundance and distribution of corals and microfacies study, the habitats of lower horizon is “ Coral meadows (subtype B1) “. The upper horizon made a “polyspecific Coral biostrome (subtype C2) “. These corals existed in a lagoon toward barrier and open marine toward barrier belonging to a shallow carbonate ramp environment. This association favored a shallow, warm, and clear marine environment with normal salinity and high oxygen, within the photic zone. The fasciculate rugose of Fomichevella and Heintzella, have the most abundance, and these colonies made main builders of the coral association. Colonial rugose corals of Fomichevella and Minatoa have maximum diversity. Michelinia tabulate corals, has the least abundance and diversity.
