Evaluation of depositional environment conditions of middle Pliocene-Pleistocene clastic deposits (Bakhtiyari Formation) based on the characteristics of lithofacies the southeastern folded Zagros, north of Bandar Abbas city
Subject Areas : Sedimentology and analysis of sedimentary basins
پيمان رضائي
1
,
سیده اکرم جویباری
2
,
شهربان محمدزاده شمیلی
3
1 -
2 -
3 -
Keywords:
Abstract :
The Bakhtiari Formation represents the Middle Pliocene-Pleistocene time period in the folded Zagros structural sedimentary zone. Debris deposits of this formation have wide outcrops in the northern area of Bandar Abbas city. In order to study the Bakhtiari formation from the point of view of sedimentary geology, three sections of this formation were selected in the northwest of Bandar Abbas city (Genow Power Plant, South of town Down Tazeyan, South of town Morvarid). From these sections, 50 samples were taken for microscopic examination and 6 samples were taken to identify heavy minerals. In all three sections, the Bakhtiari Formation includes an interval of conglomerate, sandstone and some mudstones. In the studied area, this formation is placed on the Aghajari formation with an erosional discontinuity boundary. The upper border of the Bakhtiari Formation with Quaternary deposits is also of erosional discontinuity. Field and laboratory investigations led to the identification of coarse-grained petrofacies (mud-supported conglomerate and grain-supported), medium-grained (calclitite sandstone), fine-grained (mudstone) and five structural elements (GB, CH, SB, GH, FF) has been. The results of this research show that the deposits of the Bakhtiari Formation in the north west of Bandar Abbas has been deposit in a braided river far from origin at the end of an alluvial fan. The set of heavy minerals identified in this sequence have two origins, Hormuz Salt Series and Sanandaj-Sirjan Zone, which have been affected by several sedimentary cycles. The set of petrofacies features of the Bakhtiari Formation is a confirmation of the tectonic dynamics of the end of the Cenozoic era in the middle Pliocene-Pleistocene time frame, especially the Bakhtyari tectonic event, which has led to the intensification of continental conditions in the studied area.
