scholarly journals Morphology of Khorgo Volcano Crater in the Khangai Mountains in Central Mongolia

2020 ◽  
pp. 19-35
Author(s):  
Altanbold Enkhbold ◽  
Ulambadrakh Khukhuudei ◽  
Sanchir Dorjgochoo ◽  
Byambabayar Ganbold
Keyword(s):  
Lava Dome ◽  
Morphological Form ◽  
Basic Composition ◽  
Central Mongolia ◽  
Tectonic Faults ◽  
Central Asian ◽  
Cenozoic Volcanism ◽  
Morphometric Methods ◽  
Cenozoic Basalt ◽  
Basalt Composition

Cenozoic basalt, which is widespread in Mongolia, has been attracting the attention of Central Asian researchers since the beginning of the last century. This study identified the geomorphological shape of the Khorgo volcano. The main purpose of the study is to determine the origin and morphological form of Khorgo volcano, a key representative of Cenozoic volcanism. In general, there are several types of morphological forms associated with lava overflow, and it is important to determine which types are the most common and also to establish a link between them. Geomorphological studies in this area have not been conducted in Mongolia. Spatial improvement and morphometric methods satellite imagery had identified Khorgo volcanic faults.Khangai magmatism had thinned its crust to 45 km during the Tariat-Chuluut volcanic activity. It can be concluded that this was due to the thinning of the continental crust in the Khangai Mountains because of mantle plume. During this time, tectonic faults formed were formed, which had broken through the earth's crust. Part of this fault was formed in the vicinity of Khorgo Mountain from northwest to southeast, and lava flowed with the basic composition, which led to the formation of the current morphological form of Khorgo volcano. The lava flow was less than 45% silica and potassium-dominated, which blocked the Suman River valley and formed the present-day Terkhiin Tsagaan Lake. The morphometric analysis compared the morphology of a typical volcano, which showed that the mouth of the crater of the Khorgo volcano has a slope slanting about 45 degrees, it is about 100 meters in depth, with a diameter of about 500 meters. By comparing the basalt composition of the Khorgo volcano and its morphometric characteristics with other standard volcanoes, it has been determined that it is in the form of a lava dome.

NEOPROTEROZOIC TECTONIC EVOLUTION OF THE OPHIOLITIC BAYANKHONGOR SUTURE ZONE, CENTRAL ASIAN OROGENIC BELT (CENTRAL MONGOLIA)

2019 ◽  
Author(s):  
James R. Worthington ◽  
◽  
Claire E. Bucholz ◽  
Uyanga Bold ◽  
Francis A. Macdonald ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Suture Zone ◽  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Central Mongolia ◽  
Central Asian

scholarly journals Cenozoic Volcanism on the Hangai Dome, Central Mongolia: Geochemical Evidence for Changing Melt Sources and Implications for Mechanisms of Melting

2012 ◽  
Vol 53 (9) ◽  
pp. 1913-1942 ◽  
Author(s):  
A. C. Hunt ◽  
I. J. Parkinson ◽  
N. B. W. Harris ◽  
T. L. Barry ◽  
N. W. Rogers ◽  
...  
Keyword(s):  
Central Mongolia ◽  
Geochemical Evidence ◽  
Cenozoic Volcanism

scholarly journals Late Cenozoic Uguumur and Bod-Uul Volcanic Centers in Northern Mongolia: Mineralogy, Geochemistry, and Magma Sources

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 612
Author(s):  
Alexander Perepelov ◽  
Mikhail Kuzmin ◽  
Svetlana Tsypukova ◽  
Yuri Shcherbakov ◽  
Sergey Dril ◽  
...  
Keyword(s):  
Basaltic Magma ◽  
Magma Source ◽  
Depth Range ◽  
Late Cenozoic ◽  
Central Mongolia ◽  
Cenozoic Volcanism ◽  
Northern Mongolia ◽  
Magma Sources ◽  
Response To Stress ◽  
Isotope Systematics

The paper presents new data on mineralogy, geochemistry, and Sr-Nd-Pb isotope systematics of Late Cenozoic eruption products of Uguumur and Bod-Uul volcanoes in the Tesiingol field of Northern Mongolia, with implications for the magma generation conditions, magma sources, and geodynamic causes of volcanism. The lavas and pyroclastics of the two volcanic centers are composed of basanite, phonotephrite, basaltic trachyandesite, and trachyandesite, which enclose spinel and garnet peridotite and garnet-bearing pyroxenite xenoliths; megacrysts of Na-sanidine, Ca-Na pyroxene, ilmenite, and almandine-grossular-pyrope garnets; and carbonate phases. The rocks are enriched in LILE and HFSE, show strongly fractioned REE spectra, and are relatively depleted in U and Th. The low contents of U and Th in Late Cenozoic volcanics from Northern and Central Mongolia represent the composition of a magma source. The presence of carbonate phases in subliquidus minerals and mantle rocks indicates that carbon-bearing fluids were important agents in metasomatism of subcontinental lithospheric mantle. The silicate-carbonate melts were apparently released from eclogitizied slabs during the Paleo-Asian and Mongol-Okhotsk subduction. The parent alkali-basaltic magma may be derived as a result from partial melting of Grt-bearing pyroxenite or eclogite-like material or carobantized peridotite. The sources of alkali-basaltic magmas from the Northern and Central Mongolia plot different isotope trends corresponding to two different provinces. The isotope signatures of megacrysts are similar to those of studied volcanic centers rocks. The P-T conditions inferred for the crystallization of pyroxene and garnet megacrysts correspond to a depth range from the Grt-Sp phase transition to the lower crust. Late Cenozoic volcanism in Northern and Central Mongolia may be a response to stress propagation and gravity instability in the mantle associated with the India-Asia collision.

scholarly journals New orogenic type gold occurrences in the Uyanga ore knot (Central Mongolia)

2019 ◽  
Vol 98 ◽  
pp. 08020
Author(s):  
Ariunbileg Sodov ◽  
Olga Gaskova ◽  
Altansukh Gankhuyag ◽  
Dagva-Ochir Lkhagvasuren ◽  
Otgonbaatar Dorjsuren ◽  
...  
Keyword(s):  
Microprobe Analysis ◽  
Gold Deposits ◽  
Gold Content ◽  
Rock Interaction ◽  
Central Mongolia ◽  
Quartz Veins ◽  
Central Asian ◽  
Mineral Assemblages ◽  
Metallogenic Zone ◽  
Water Rock Interaction

The Khangay-Khentey belt is located in central Mongolia (Central Asian Orogenic Belt). The Uyanga ore knot district of the Khangay metallogenic zone are hosted by the lower-middle Devonian volcanogenic-sedimentary Erdenetsogt formation. The new Burgetei, Ult and Senjit gold occurrences were studied. The rocks of the Erdenetsogt formation have an irregular gold content: 0.96 g/t Au is determined in quartz vein (BG-7/16), Au content is highest up to 3.5 g/t in the quartzite-jasper (Ult-7/16 and Ult-9/16) cut by quartz veins in the Ult occurrence. The Senjit occurrence represents Au-Hg-Sb epizonal level of orogenic gold deposits structure with highest Hgand Sb content up to 8.5 ppm and 39 ppm respectively. The Au content of arsenic pyrite of the Burgetei and Ult is below the detection limit by electron microprobe analysis. The Au content of arsenopyrite of the Ult occurrence is highest (up to 238 ppm). The ore-mineral assemblages in the new gold occurrences reflect the differences between three explored sites, formed in the course of fluid evolution during the water-rock interaction. Variable concentrations of indicative elements (As, Te, Sb, Hg) and their ratios confirm this fact.

scholarly journals Zircon U–Pb geochronology and geochemistry of granitic rocks in central Mongolia

2020 ◽  
Vol 50 ◽  
pp. 23-44
Author(s):  
Boldbaatar Dolzodmaa ◽  
Yasuhito Osanai ◽  
Nobuhiko Nakano ◽  
Tatsuro Adachi
Keyword(s):  
Tectonic Setting ◽  
Granitic Rocks ◽  
Metamorphic Rocks ◽  
Calc Alkaline ◽  
Volcanic Arc ◽  
Central Mongolia ◽  
Central Asian ◽  
High K ◽  
Three Stages ◽  
Late Neoproterozoic

The Central Asian Orogenic Belt had been formed by amalgamation of voluminous subduction–accretionary complexes during the Late Neoproterozoic to the Mesozoic period. Mongolia is situated in the center of this belt. This study presents new zircon U–Pb geochronological, whole-rock major and trace element data for granitoids within central Mongolia and discusses the tectonic setting and evolution of these granitic magmas during their formation and emplacement. The zircon U–Pb ages indicate that the magmatism can be divided into three stages: the 564–532 Ma Baidrag granitoids, the 269–248 and 238–237 Ma Khangai granitoids. The 564–532 Ma Baidrag granitoids are adakitic, have an I-type affinity, and were emplaced into metamorphic rocks. In comparison, the 269–248 Ma granitoids have high-K, calc-alkaline, granodioritic compositions and are I-type granites, whereas the associated the 238–237 Ma granites have an A-type affinity. The 564–532 Ma Baidrag and 269–248 Ma Khangai granitoids also both have volcanic arc-type affinities, whereas the 238–237 Ma granites formed in a post-collisional tectonic setting. These geochronological and geochemical results suggest that arc magmatism occurred at the 564–532 Ma which might be the oldest magmatic activity in central Mongolia. Between the Baidrag and the Khangai, there might be paleo-ocean and the oceanic plate subducted beneath the Khangai and produced voluminous granite bodies during the 269–248 Ma. After the closure of the paleo-ocean, the post collisional granitoids were formed at the 238–237 Ma based on the result of later granitoids in the Khangai area.

scholarly journals Detrital Zircon Provenance Analysis in the Central Asian Orogenic Belt of Central and Southeastern Mongolia—A Palaeotectonic Model for the Mongolian Collage

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 880
Author(s):  
Wilfried Winkler ◽  
Denise Bussien ◽  
Munktsengel Baatar ◽  
Chimedtseren Anaad ◽  
Albrecht von Quadt
Keyword(s):  
Orogenic Belt ◽  
Detrital Zircons ◽  
Central Asian Orogenic Belt ◽  
Provenance Analysis ◽  
The South ◽  
Central Mongolia ◽  
Basin Inversion ◽  
The North ◽  
Central Asian ◽  
Sandstone Provenance

Our study is aimed at reconstructing the Palaeozoic–early Mesozoic plate tectonic development of the Central Asian Orogenic Belt in central and southeast Mongolia (Gobi). We use sandstone provenance signatures including laser ablation U-Pb ages of detrital zircons, their epsilon hafnium isotope signatures, and detrital framework grain analyses. We adopt a well-established terran subdivision of central and southeastern Mongolia. However, according to their affinity and tectonic assemblage we group them into three larger units consisting of continental basement, rift-passive continental margin and arc elements, respectively. These are in today’s coordinates: (i) in the north the late Cambrian collage from which the later Mongol-Okhotsk and the Central Mongolia-Erguna mountain ranges resulted, (ii) in the south a heterogeneous block from which the South Mongolia-Xin’gan and Inner Mongolia-Xilin belts developed, and (iii) in between we still distinguish the intra-oceanic volcanic arc of the Gurvansayhan terrane. We present a model for paleotectonic development for the period from Cambrian to Jurassic, which also integrates findings from the Central Asian Orogenic Belt in China and Russia. This mobilistic model implies an interplay of rift and drift processes, ocean formation, oceanic subduction, basin inversion, collision and suture formation in space and time. The final assemblage of the Central Asian Orogenic Belt occurred in Early Jurassic.

Sign in / Sign up

Export Citation Format

Share Document