Tectonics
Golnaz Abbasi; Ali Solgi; Mohsen Pourkermani; Hosein Motamedi; alireza farrokhnia; Keivan Orang
Abstract
We used 2D seismic profiles, field observation and well data to constrain the structural evolution of the Saveh basin during the late-lower Miocene to late Pliocene. During this time period almost 8-9 kilometers of Upper Red Formation (URF) and the Pliocene conglomerates were deposited in the basin depocenter. ...
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We used 2D seismic profiles, field observation and well data to constrain the structural evolution of the Saveh basin during the late-lower Miocene to late Pliocene. During this time period almost 8-9 kilometers of Upper Red Formation (URF) and the Pliocene conglomerates were deposited in the basin depocenter. During the late- lower Miocene (to early- middle Miocene ?), Syn-depositional activity of west-east-northwest-southeast trending high-angle fault zones, with an extensional component, created accommodation space for deposition of lower Upper Red Formation. Since the late- middle Miocene (or late Miocene), initiation of a compressional phase has resulted in regional deformation.The deposition of upper part of the URF and the Pliocene conglomerates was contemporaneous with compressional deformation. During this stage, the middle part of the URF acted as an effective detachment horizon and detachment folds, such as the Saveh and Taraz Naeen anticlines, were formed. The thinning of the Pliocene conglomerates towards the crestal point of these folds indicates late structural growth. According to the top Qom depth map, there are no traps with fault independent closure within the Saveh basin. The top of the Qom Formation is estimated at -4250 m in the Taraz Naeen anticline.
K. Orang; Mohammad Mohajjel; F. Mousivand; E. Rastad
Abstract
The Chah Gaz Zn-Pb-Cu volcanogenic massive sulfide (VMS) deposit is a polydeformed, polymetamorphosed ore body in southern part of the Sanandaj-Sirjan zone. The ore bodies are comprised predominantly of stratiform, tabular and lenticular massive sulfide lenses and are elongated in 0600-0700 orientation. ...
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The Chah Gaz Zn-Pb-Cu volcanogenic massive sulfide (VMS) deposit is a polydeformed, polymetamorphosed ore body in southern part of the Sanandaj-Sirjan zone. The ore bodies are comprised predominantly of stratiform, tabular and lenticular massive sulfide lenses and are elongated in 0600-0700 orientation. The host rocks and massive sulfides have been complexly deformed during three deformation stages (D1, D2, D3) and two associated episodes of green schist facies metamorphism (M1, M2) that all events occurred after middle Jurassic. The earliest structural elements in the mine area are bedding and continuous foliation (S1) that are preserved in the host rocks; include phyllites, slates and schists. F1 folds have not been identified in the ore bodies, Although they do recognized as shallowly to moderately plunging to NW and isoclinal folds within the Chah Gaz area. Geometry of ore bodies was mainly controlled by D2 structures (include folds and foliations). F2 plunge shallowly to NE or SW. F2 are close to open and their axial planes dip steeply to S and N. Ore bodies are commonly transposed from S0-S1 and show rearrangement parallel to axial planar foliation (AS2) and composite foliation (ST2). ST2 is vertical and strikes NE-SW. Sulfide minerals in the ore bodies have undergone extensive deformation, remobilization and dynamic recrystallisation during D2 tectono-thermal stage. D3 structures are locally controller of ore bodies and include folds and shear zones.
