S. Hemati; M. Taherpour Khalil Abad; A. Ghaderi; A. R. Ashouri
Abstract
Micropaleontological study on the carbonate successions of the Tirgan Formation at the Taherabad village and Eshlir anticline stratigraphic sections is led to identification of various taxa of the calcareous algae belong to the families Dasycladaceae, Triploporellaceae, Udoteaceae, Solenoporaceae and ...
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Micropaleontological study on the carbonate successions of the Tirgan Formation at the Taherabad village and Eshlir anticline stratigraphic sections is led to identification of various taxa of the calcareous algae belong to the families Dasycladaceae, Triploporellaceae, Udoteaceae, Solenoporaceae and Gymnocodiaceae and also some specimens of small Gorgonacea. Based on the biometric measurements of morphological features, 16 genera and 20 species from the Taherabad section and 12 genera and 16 species from the Eshlir section have been recognized. Moreover, Permocalculus minutus and Permocalculus? halimedaformis have been found for the first time in the Tirgan Formation. Permocalculus? halimedaformis was introduced from the Minis Valley in Romania for the first time and its finding in this research is the second report around the world. According to this new finding, its geographic distribution is being extended more than 2800 km eastward on the northern margin of the Tethys ocean.
M Sadeghi; K Rashidi; R Shabanian
Abstract
Succession of Permian system in Pir-Eshagh stratigraphic section has been mesured totally about 1400 m, which it's base consists mainly of Dorud formation with thickness of about 100 m which in turn has been overlain by Ruteh and Nesen formations with thickness of 1100 and 200 m respectively. Lower boundary ...
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Succession of Permian system in Pir-Eshagh stratigraphic section has been mesured totally about 1400 m, which it's base consists mainly of Dorud formation with thickness of about 100 m which in turn has been overlain by Ruteh and Nesen formations with thickness of 1100 and 200 m respectively. Lower boundary of this succession overlay unconformablyon the Devonian volcanic rocks and the upper parts continuously and concordantly is changed to yellow lamellar limestone, Elika formation that deposited in lower and middle Triassic. For identification of various calcareous genus and species of algae in these sediments,we systematically selected 220 thin sections from the lower bound up to the upper bound based on the lithological changes perpendicular to the strike of layers. In this study, we identified 7 genus and 9 types of dasycladaceae green algae Mizzia sp., Mizzia velebitana, Mizzia cornuta,Macroporella cf. nuda, Macroporella sp., Epimastopora sp., Epimastopora symetrica, Paraepimastopora longutuba, Epimastopora likana, Epimastoporella japonica, Tabasoporella tulipaformis, Gyroporella sp., Gyroporella nipponica, and 2 genus and 5 types of gymnocodiacea algae family Permocalculus sp., Permocalculus cf. dikenliderensis, Permocalculus fragilis, Permocalculus plumosus, Permocalculus tenellus, Gymnocodium sp., Gymnocodiumbellerophontis at Ruteh and Nesen formations. Also, Tabasoporella tulipaformis algae belonging to the dasycladaceae family which has been introduced from the Jamal formation, for the first time was identified and reported from the carbonated units in the northwest of Iran.
H. Mosadegh; M. Lankarani
Abstract
The carbonate facies of Permian in Gaduk area (Central Alborz) are dominated by calcareous algae. Study of the facies resulted in recognition of several species of Cyanobacteria, Dasycladacean and Gymnocodiacean green algae and also Phylloid algae. In the studied succession, Phylloid algae are identified ...
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The carbonate facies of Permian in Gaduk area (Central Alborz) are dominated by calcareous algae. Study of the facies resulted in recognition of several species of Cyanobacteria, Dasycladacean and Gymnocodiacean green algae and also Phylloid algae. In the studied succession, Phylloid algae are identified in carbonate shoal facies. Cyanobacteria mostly occurred in tidal to lagoonal facies, as encrusters. Dasycladacean and Gymnocodiacean green algae mostly occurred in inner ramp facies. Gymnocodiaceans were found in deeper parts in comparison to Dasycladaceans. Occurrence of Cyanobacteria in depositional sequences coincides with type-one sequence boundaries. Phylloid algae are identified in the facies related to transgressive surfaces and maximum abundance of Dasycladaceans and Gymnocodiaceans was found around maximum flooding surfaces and in highstand systems tracts. Abundance of the calcareous algae shows an increasing trend from the base to the top of carbonate parasequences. Proliferation of the calcareous algae was found in close relationship to climate warming and ice-house to green-house transition in Permian of Alborz.
