https://mongoliajol.info/index.php/MGS/issue/feed Mongolian Geoscientist 2022-07-16T00:00:00+00:00 Bayaraa Batkhishig mongoliangeoscientist@must.edu.mn Open Journal Systems <p>The Mongolian Geoscientist is published by the <a title="MUST" href="http://www.must.edu.mn/" target="_blank" rel="noopener">Mongolian University of Science and Technology </a>with support from <a title="Mongolian Geological Society" href="http://geosociety.mn" target="_blank" rel="noopener">The Geological Society of Mongolia</a>.</p> <p><strong>The Mongolian Geoscientist is included on <a title="Google Scholar" href="https://scholar.google.com" target="_blank" rel="noopener">Google Scholar</a>, <a title="Dimensions" href="https://app.dimensions.ai/discover/publication?and_facet_source_title=jour.1364668" target="_blank" rel="noopener">Dimensions,</a> <a title="DOAJ" href="https://www.doaj.org/toc/2663-5151" target="_blank" rel="noopener">DOAJ</a>, <a title="EBSCO Discovery service" href="https://www.ebscohost.com/discovery" target="_blank" rel="noopener">EBSCO Discovery service</a> and <a title="CNKI" href="https://enscholar.cnki.net/journal/search" target="_blank" rel="noopener">CNKI</a></strong></p> https://mongoliajol.info/index.php/MGS/article/view/1825 The Igneous breccia system of the Shand porphyry Cu-Mo deposit, Northern Mongolia 2022-05-10T09:20:56+00:00 Bayaraa Ganbat ganbat.igmr.mas@gmail.com Dashdorjgochoo Odgerel odgereld@mas.ac.mn Dorjyunden Altankhuyag aataadorj@gmail.com Dorjgochoo Sanchir sanchird@mas.ac.mn Chikalov Altanzul ch.azulaa19@gmail.com Gurdorj Azjargal azaaguree1028@gmail.com <p>The Shand Cu-Mo deposit is located in the Orkhon-Selenge depression, Northern Mongolia. It lies near the Erdenetiin Ovoo porphyry Cu-Mo deposit, which together define one of Northern Mongolian’s most economically significant metallogenic belts. In the Shand Cu-Mo (Au?) deposit, several ore related breccia types are associated with the porphyritic granodiorite intrusions, and they contain pre-, synand post-mineralized porphyry stocks, magmatic-hydrothermal and intrusive breccia. There are genetically at least two type of hydrothermal breccias have recognized in Shand deposit, i.e. magmatic-hydrothermal breccia and intrusive breccia. Magmatichydrothermal breccia is presented spatially associated with intrusions but extending sub vertical which characterized by angular fragments/clasts supported or infilled by minerals commonly indicative of high temperature and salinity (e.g. tourmaline, feldspar), silicas, carbonates and sulphides (Cu, Mo, (Au)) matrix derived from hydrothermal fluids precipitation. May grade downwards into cupolas of intrusive with or without intrusive breccia and pegmatite where occur at approximately deep from 250-1300 m depth. Intrusive breccia is mostly occurred in contact between margin intrusions at shallow depth which is mainly composed by granodiorite porphyry, granodiorite and dacite. Our drillhole relogging and petrographical observations are granodiorite hosted breccia and granodiorite porphyry hosted breccia. Here, we present an integrated study involving detailed drillhole logging, and petrographical observations to elucidate the genetic relationship and evolution of the Shand deposit for magmatic-hydrothermal breccia and intrusive breccia. Also, we propose that the magmatic breccia types indicate emplacement of igneous rocks from initially dacitic magma composition.</p> 2022-07-20T00:00:00+00:00 Copyright (c) 2022 Bayaraa Ganbat, Dashdorjgochoo Odgerel, Dorjyunden Altankhuyag, Dorjgochoo Sanchir, Chikalov Altanzul, Gurdorj Azjargal https://mongoliajol.info/index.php/MGS/article/view/1810 Investigation of the electrical resistivity structure of the subsurface at Mogod valley in central Mongolia: Insight is using 1D Magnetotelluric inversion 2022-07-15T13:05:42+00:00 Bayartogtokh Enkhzul enkhzul@iag.ac.mn Erdenechimeg Batmagnai enkhzul@iag.ac.mn Shoovdor Tserendug enkhzul@iag.ac.mn Gendenpuntsag Bayanjargal enkhzul@iag.ac.mn <p>In this paper, we report a preliminary result of the Magnetotelluric investigation of the Mogod area. The Mogod region is one of the most prominent fields for geophysical study since the region includes young and active faults and geothermal activities. We conducted magnetotelluric measurements at 20 sites during geophysical field seasons in 2018-2021 as a pilot survey to understand data property and the electromagnetic noise level for the detailed electromagnetic studies. During the fieldwork, we used Lemi Magnetotelluric instruments and measured all three orthogonal components of the magnetic field and the horizontal components of the electric field. For the data processing, we used Matlab code by using the M-estimate regression method, and estimated the magnetotelluric transfer function with a lownoise level. The electrical resistivity model of the subsurface of survey layout shows us the existing resistivity anomalies at shallow-depth, and thickness of the upper crust approximately 11-17 km. Here, suggest that the thickness of the upper crust is 17 km and crust is 40 km with local magnetotelluric measurements. Additionally, the electric conductor appears in the southwest of Mogod region, we interpret that conductor play as a source of geological activity of Mogod region, and it might be the signature of a remanent fluid.</p> 2022-07-16T00:00:00+00:00 Copyright (c) 2022 Bayartogtokh Enkhzul, Erdenechimeg Batmagnai, Shoovdor Tserendug, Gendenpuntsag Bayanjargal