Paleogeographic reconstruction of a late Paleozoic arc collision zone, southern Mongolia

Abstract

Paleogeographic reconstruction of a late Paleozoic arc collision zone, Email alerting services articles cite this article to receive free e-mail alerts when new www.gsapubs.org/cgi/alerts click Subscribe America Bulletin to subscribe to Geological Society of www.gsapubs.org/subscriptions/ click Permission request to contact GSA http://www.geosociety.org/pubs/copyrt.htm#gsa click official positions of the Society. citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect presentation of diverse opinions and positions by scientists worldwide, regardless of their race, includes a reference to the article's full citation. GSA provides this and other forums for the the abstracts only of their articles on their own or their organization's Web site providing the posting to further education and science. This file may not be posted to any Web site, but authors may post works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent their employment. Individual scientists are hereby granted permission, without fees or further Copyright not claimed on content prepared wholly by U.S. government employees within scope of Notes articles must include the digital object identifier (DOIs) and date of initial publication.

The Lost South Gobi Microcontinent: Protolith Studies of Metamorphic Tectonites and Implications for the Evolution of Continental Crust in Southeastern Mongolia

“…The zircon age populations in 08OH-04D are strikingly similar to age populations constrained from Permian sandstone samples collected from the region surrounding Yagan-Onch Hayrhan that were presented in a combined detrital zircon/basin analysis study by Heumann et al [43]. The work of Heumann et al contained age populations between ~262-295 Ma, ~420-500 Ma, and zircons as old as ~2500 Ma [43]; whereas our study constrained zircon populations at ~270-300 Ma and ~450 Ma and sampled Precambrian grains with ages of ~1250 Ma and ~2500 Ma.…”

“…The work of Heumann et al contained age populations between ~262-295 Ma, ~420-500 Ma, and zircons as old as ~2500 Ma [43]; whereas our study constrained zircon populations at ~270-300 Ma and ~450 Ma and sampled Precambrian grains with ages of ~1250 Ma and ~2500 Ma. We cannot make a more quantitative comparison of the relative age distributions because our study used a zircon sampling strategy of selecting only inclusion-free zircons, which contrasts with the sampling strategy of Heumann et al [43], which did not exclude zircons due to the presence of inclusions. A Permian protolith is also consistent with previous work that documented a gradual transition from undeformed Permian sedimentary rocks to greenschist-grade metasediments at Yagan-Onch Hayrhan in the region surrounding the metamorphic core complex [29].…”

“…All of the units described above are intruded by younger Late Permian-Early Triassic granitoids [6,19,23,38,39]. Devonian-Carboniferous age rocks in the southernmost portion of Mongolia, near the border with China, are overlain by Upper Permian-Lower Triassic clastic sedimentary rocks derived from the collision between the South Mongolia arc and the North China and Tarim cratons [19,37,43]. In the northern portion of the study region, metamorphic tectonites record deformation at upper amphibolite to greenschist-facies conditions, mainly during the Late Triassic [26].…”

Tracking deep crust by zircon xenocrysts within igneous rocks from the northern Alxa, China: Constraints on the southern boundary of the Central Asian Orogenic Belt

“…The southern Mongolian domain is dominated by Silurian, Devonian and Carboniferous accretionary complexes and arc-related volcanic and volcanoclastic rocks (Badarch et al, 2002;Rojas-Agramonte et al, 2011;Dolgopolova et al, 2013;Guy et al, 2014;Jian et al, 2014). Many Paleozoic intrusions (mainly 525-277 Ma) are exposed in the southern Dalanzadgad area (Khashgerel et al, 2006;Demoux et al, 2009a;Dolgopolova et al, 2013;Wainwright et al, 2011a,b;Heumann et al, 2012). Most of these are granitoids with positive e Nd (t) and e Hf (t) values (e.g., Jahn et al, 2000Jahn et al, , 2004Hong et al, 2004;Kovalenko et al, 2004;Helo et al, 2006;Yarmolyuk et al, 2007;Wainwright et al, 2011b;Kröner et al, 2014;Tong et al, 2015; in press), indicating that they were derived from juvenile crust.…”

Folded Basinal Compartments of the Southern Mongolian Borderland: A Structural Archive of the Final Consolidation of the Central Asian Orogenic Belt

“…The Permian collision marked the end of marine sedimentation in the Mongolian borderland region and the onset of terrestrial sedimentation. Permian sediments from the Tien Shan through the Beishan to southern and eastern Mongolia and adjacent regions of China record the marine-terrestrial transition [23,24] and were affected by crustal shortening due to terminal closure of the final Paleo-Asian ocean seaway [5,7,18,25]. Collision-related crustal shortening likely persisted into the Triassic [5,8,18].…”