M. R. Bakhshi Mohebbi; A. A. Moridi farimani; R. Moezzi nasab
Abstract
Among the sedimentary units of the east flysch basin in the Nosrat-Abad area, where in the 105km northwest of Zahedan, there is a sandstone-conglomerate unit with an Oligo-Miocene age. The depositional environment of this deposit was fluvial which has been morphologically dissected in several portions; ...
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Among the sedimentary units of the east flysch basin in the Nosrat-Abad area, where in the 105km northwest of Zahedan, there is a sandstone-conglomerate unit with an Oligo-Miocene age. The depositional environment of this deposit was fluvial which has been morphologically dissected in several portions; this unit covers the Eocene sandstone-shale deposits by an angular unconformity about 30 degrees. The measured thickness is about 2650 meters. The composed particles and pebbles are in various grain size. On the other hand, sandstone, siltstone, and mudstone accompany the conglomerate unit. Field observations document the unit was formed in a fluvial depositional environment. Imbrication and cross, smooth, and lens-shaped bedding are the main recognizable sedimentary structures. Moreover, the caved and filled structure are seen. Note that there is difference between the lithology of the pebbles in the conglomerate and the rocks composing the flysch zone, the pebbles could be originated from the west side, where in the Lut block. The recognized fossils from limestone pebbles are belong to the families such as Orbitolina, Alveolina, Nummulite, and Miliolid, consequently, the age of conglomerate-sandstone unit must be younger than Eocene and cover by Conglomarate Quaternary probably could be Oilgo-Miocene.
Stratigraphy and Palaeontology
Reza Moezzi nasab; Mohammad Nabi Gorgij; Mohammad Reza Bakhshi mohebbi
Abstract
Hormak Section consist of alternation of Oligomictic conglomerate with mainly Alveolinids and Nummulitid bearing calcareous pebbles and afew andesits, basalt and rhyolitic tuff pebbles, Pebbly Sandstone and red shale. The Sourse of red continental - clastic Hormak formation conglomerate probably was ...
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Hormak Section consist of alternation of Oligomictic conglomerate with mainly Alveolinids and Nummulitid bearing calcareous pebbles and afew andesits, basalt and rhyolitic tuff pebbles, Pebbly Sandstone and red shale. The Sourse of red continental - clastic Hormak formation conglomerate probably was Debil formation and Equvaleut Late Paleocene – Early Eocene deposits. Approxmalty 80% of Debil formation foraminifer contents very resemble to that are identified in the Hormak Section conglomerate. In the studied area based on identified species such as A.canavarii, A.elliptica nuttalli, A.pasticillata, A.decipiens, A.fornasinii, A.globula, A.solida Early Eocene age are suggested.
M Daryapeyma Hormozi; H Biabangard; S Bagheri; M.R Bakhshi Mohebi
Abstract
Dasht Kuh volcanic complex is located to ~75 km to the north of Iranshahr. It consists of two parts: A (main body) and B (the isolated part in the northern Dasht Kuh). Based on the geological maps of the area, the volcanic bodies intruded the flysch type rocks of the East Iran in Cretaceous; the rocks ...
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Dasht Kuh volcanic complex is located to ~75 km to the north of Iranshahr. It consists of two parts: A (main body) and B (the isolated part in the northern Dasht Kuh). Based on the geological maps of the area, the volcanic bodies intruded the flysch type rocks of the East Iran in Cretaceous; the rocks are separated from Eocene conglomerate across a fault zone. The Dasht Kuh volcanic complex essentially consists of basalt, andesite, basaltic andesite and trachybasalt. The main rock-forming minerals are plagioclase, pyroxene, hornblende, and sanidine with dominant porphyritic texture. Minor pyroclastic materials occur in the lower parts of the complex.Samples rocks from of Dasht Kuh in the rare earth elements diagram relative to abundance of these elements in the Chondrite, shows a significant negative slope observed that the samples are enriched in light rare earth elements (LREE) and depletion of heavy earth elements (HREE). Different chemical composition, Tectono-magmatic and origin digrams shows that rocks in these bodies have alkaline nature of mantle origin and were formed in continental volcanic arc. It seems Dasht Kuh volcanic comlex are part of island arc that wide arc from northern Pakistan to Iran that have been separated from their origin by younger tectonic events.
