scholarly journals Investigation of paleosol in Shurijeh Formation; Example from the Ghorghoreh section in the eastern Kopet- Dagh sedimentary basin

2021 ◽  
Vol 29 (3) ◽  
pp. 547-562
Author(s):  
مهناز Keshmiri ◽  
محمدحسین Mahmudy Gharaie ◽  
سیدرضا Moussavi-Harami ◽  
اسداله Mahboubi ◽  
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2019 ◽  
Vol 80 (2) ◽  
pp. 39-51
Author(s):  
Morteza Taherpour-Khalil-Abad ◽  
Jafar Taheri ◽  
Mahmoud Rezamajidifard ◽  
Zinat Hassanzadeh ◽  
Ivana Carevic

during micropaleontological investigations on the lower cretaceous successions of the tirgan Formation in Kopet-dagh sedimentary basin, some new achievements are yielded. in this regards, the first occurrence of Bispiraloconulus serbicus Schlagintweit, Bucur & Sudar in close association with Torremiroella hispanica Brun & canerot is reported for the first time from the upper Barremian of Kopet-dagh sedimentary basin (ne iran). the biostratigraphic investigations were carried out on a 197.5 m thick gelian stratigraphic succession cropping out along the tirgan Formation located 35 km southwest of Shirvan town. this study reviews the palaeogeographical distribution and age of Bispiraloconulus serbicus Schlagintweit, Bucur & Sudar and Torremiroella hispanica Brun & canerot along the northern tethyan margins and extends its pal?eobiogeographical existence.


2016 ◽  
Vol 87 (3) ◽  
pp. 631-647 ◽  
Author(s):  
Gail M. Atkinson ◽  
David W. Eaton ◽  
Hadi Ghofrani ◽  
Dan Walker ◽  
Burns Cheadle ◽  
...  

2021 ◽  
pp. 1-14
Author(s):  
Adrian W. A. Rushton ◽  
Mansoureh Ghobadi Pour ◽  
Leonid E. Popov ◽  
Hadi Jahangir ◽  
Arash Amini

Abstract Graptolites have been collected from sections through Lower Ordovician strata in northern Iran. At the Saluk Mountains, in the Kopet–Dagh region, mudrocks yielded fragmentary tubaria of Rhabdinopora sp. cf. R. flabelliformis, indicating the presence of lower Tremadocian strata there; stratigraphically, they lie between two limestone beds with the euconodont Cordylodus lindstromi. At Simeh–Kuh in the eastern Alborz Mountains (Semnan Province), upper Tremadocian – lower Floian strata include laminated dark mudstones that contain restricted graptolite faunas, mainly of small declined didymograptids; these are thought to represent incursions of plankton during periods of marine highstands. The lower major flooding surface in Simeh–Kuh coincides with an invasion of the graptolite biofacies and an incursion of Hunnegraptus? sp.; the second major flooding surface is associated with an incursion of Baltograptus geometricus. They were most probably synchronous with those in the lower part of the Hunnegraptus copiosus Biozone and at the base of the Cymatograptus protobalticus Biozone in the of the Tøyen Shale Formation succession of Västergötland, Scandinavia, suggesting that observed characters of sedimentation were eustatically controlled.


Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 682
Author(s):  
Anatoliy Petrovich Sorokin ◽  
Andrey Alexeyevich Konyushok ◽  
Valeriy Mikhailovich Kuz’minykh ◽  
Sergey Vadimovich Dugin

The primary sources and the conditions for the formation of the Paleogene–Neogene coal-bearing deposits in the Zeya–Bureya sedimentary basin were identified and studied with the help of paleogeographic reconstructions and geochemical analyses. Based on the results obtained, we suggest a new basic model of element transfer into the coal, involving two mutually complementary processes to account for the introduction and concentration of gold and other trace elements in the sequences investigated. The first process reflects the system in which peatlands were concentrated along the basin’s junction zone and the passive internal residual mountain ranges. The second reflects the junction’s contrast-type (sharp-type) forms conditions along the external mobile mountain-fold frame. The eroded gold particles were transported over 10–20 km as complex compounds, colloids, dispersed particles, and nanoparticles, and remobilized into clastogenic and dissolved forms along the first few kilometers. The release of gold in the primary sources occurred due to weathering of gold-bearing ore zones, followed by transportation of gold by minor rivers to the areas of peat accumulation. This study considered the probability of the accumulation of high concentrations of gold and rare earth elements (REE) in coal due to the introduction of organic and inorganic materials during floods, with episodes of catastrophic events, and volcano–hydrothermal activities.


2020 ◽  
Vol 12 (1) ◽  
pp. 25-43
Author(s):  
Yuan Peng ◽  
Yongsheng Zhang ◽  
Eenyuan Xing ◽  
Linlin Wang

AbstractThe Zhongwunongshan Structural Belt (ZWSB) locates between the Olongbruk Microblock of North Qaidam and the South Qilian Block in China, and it has important implication for understanding the tectonic significance of North Qaidam. Nowadays, there are few discussion on the Caledonian tectonothermal events of the Zhongwunongshan Structural Belt, and there exist different opinions on provenance and tectonic environment of the Zhongwunongshan Group in the ZWSB and its adjacent North Qaidam. In this study, a comprehensive analysis of the detrital zircon geochronological research was carried out on the Zhongwunongshan Group. The detrital zircon U-Pb dating results showed two major populations. The first was Neoproterozoic (966-725 Ma) with a ∈Hf(t) = −15.9 to 9.5, and the other was late Early Paleozoic (460-434Ma) with a ∈Hf(t) = −9.6 to −3.1. In combination with previous research, the dominated provenances were found to be the Neoproterozoic granitic gneiss of the Yuqia-Shaliuhe HP-UHP metamorphic belt and the late Early Paleozoic granite of the Tanjianshan ophiolite-volcanic arc belt in North Qaidam. The Zhongwunongshan Group was deposited in the back-arc sedimentary basin related to the Caledonian collisional orogeny during Middle Silurian-Early Devonian (434-407.9 Ma).


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