16 research outputs found
NEW GEOCHEMICAL DATA OF BASALTS IN THE TSOROIDOG AREA, CENTRAL MONGOLIA
At present, geochemical data are widely used for reconstructing geodynamic settings, especially, volcanic rocks of mafic composition, i.e., basalts, because they are widespread in many orogenic belts and are indicative of different geodynamic environments. In general, we propose the reconstruction of the tectonic settings of basalts according to their relationships with associated ocean plate stratigraphy (OPS) sediments, their petrogenesis and their geochemical features.At present, geochemical data are widely used for reconstructing geodynamic settings, especially, volcanic rocks of mafic composition, i.e., basalts, because they are widespread in many orogenic belts and are indicative of different geodynamic environments. In general, we propose the reconstruction of the tectonic settings of basalts according to their relationships with associated ocean plate stratigraphy (OPS) sediments, their petrogenesis and their geochemical features
THE EARLY-MIDDLE PALEOZOIC VOLCANISM AND GEODYNAMIC EVOLUTION OF THE HERLEN MASSIF, CENTRAL PART OF THE CAOB: CONSTRAINS FROM GEOCHEMISTRY, U-PB GEOCHRONOLOGY, LU-HF AND RB-SR ISOTOPES OF VOLCANIC ROCKS
Mongolia lies in the central part of the Central Asian Orogenic Belt [Mossakovsky et al., 1994; Zorin, 1999; Jahn, 2004; Khain et al., 2003; Badarch et al., 2002; Windley et al., 2007; Zhang et al, 2008], or Altaids [Şengör et al., 1993; Şengör, Natal’in, 1996; Wilhem et al., 2012], which is fringed by the Siberian craton in the north and by the Tarim and Sino-Korean Cratons in the south. According to the recent tectonic subdivision, the territory of Mongolia is subdivided into Northern and Southern domains which are separated by the so called Mid Mongolian Tectonic Line [Tomurtogoo, 2012]. The Herlen Massif is one of the important tectonic units of the South Mongolian domain in the Argun-Idermeg super terrane extending through the territories of Russia and China [Parfenov et al., 2009; Tomurtogoo, 2014b]. The Herlen massif, also known as Herlen superterrane [Tomurtogoo, 2012] or Idermeg terrane [Tomurtogoo, 2014a] is composed of Ereendavaa, Undur-Khaan, Idermeg and Gobian Altay-Baruun Urt terranes converged at the end of the Cambrianbeginning of the Ordovician [Badarch et al., 2002; Tomurtogoo, 2014b].Mongolia lies in the central part of the Central Asian Orogenic Belt [Mossakovsky et al., 1994; Zorin, 1999; Jahn, 2004; Khain et al., 2003; Badarch et al., 2002; Windley et al., 2007; Zhang et al, 2008], or Altaids [Şengör et al., 1993; Şengör, Natal’in, 1996; Wilhem et al., 2012], which is fringed by the Siberian craton in the north and by the Tarim and Sino-Korean Cratons in the south. According to the recent tectonic subdivision, the territory of Mongolia is subdivided into Northern and Southern domains which are separated by the so called Mid Mongolian Tectonic Line [Tomurtogoo, 2012]. The Herlen Massif is one of the important tectonic units of the South Mongolian domain in the Argun-Idermeg super terrane extending through the territories of Russia and China [Parfenov et al., 2009; Tomurtogoo, 2014b]. The Herlen massif, also known as Herlen superterrane [Tomurtogoo, 2012] or Idermeg terrane [Tomurtogoo, 2014a] is composed of Ereendavaa, Undur-Khaan, Idermeg and Gobian Altay-Baruun Urt terranes converged at the end of the Cambrianbeginning of the Ordovician [Badarch et al., 2002; Tomurtogoo, 2014b]
Geochemistry and geochronology of the Paleozoic sedimentary rocks in the Shar Khutul area, Central Mongolia
The study area is located in the central part of Tsetserleg terrane in the southwestern margin of the Khangai-Khentey orogenic system. The paper presents new data on geochemistry and geochronology of sedimentary rocks from the Shar Khutul area, where the Tsetserleg terrane consists of Silurian-Devonian oceanic plate stratigraphic unit and Carboniferous shallow water sediment. The Upper Silurian to Middle Devonian Erdenetsogt Formation (S3-D2er), which is an oceanic plate stratigraphic unit, is mainly composed of siliceous siltstone, volcanites, tuffs, quartzite, and cherts. The shallow water sediments are divided into Upper Devonian to Lower Carboniferous Tsetserleg Formation (D3-C1cc) and Lower–Middle Carboniferous Dzargalant Formation (C1-2dz). The Tsetserleg Formation (D3-C1cc) consists of only sedimentary rocks such as bluish-grey sandstones and siltstones, and Lower–Middle Carboniferous Dzargalant Formation (C1-2dz) is principally composed of medium- to coarse-grained, brown-greenish grey sandstones with thin-layers of dark siltstones and gravelites.
The SiO2 content of the Shar Khutul area sandstones ranges from 63.85 to 67.95 wt.% and the average content of TiO2 is 0.72 wt.% and Al2O3 content is 14.38 wt.%. The Chemical Index of Alteration (CIA) value ranges from 48.71 to 56.94 and the range of Index of compositional variations (ICV) is from 0.98 to 1.24. Moreover, the samples studied show that most of the sandstones are generally immature and were derived from weakly weathered source rocks.
The ratios of Eu/Eu* (0.83), La/Sc (3.81), La/Co (5.30), and Cr/Th (13.81) indicate that the derivation of the Shar Khutul area sandstones from felsic rock sources and confirm the signatures of a felsic igneous provenance and suggest an active continental margin tectonic setting of the source area.
The clastic zircons from the medium grained sandstone (Erdenetsogt formation) yield ages between 2.5 Ga and 236 Ma and the detrital zircons exhibit four peak ages at 1.7-2.5 Ga (n = 13), 455-499 Ma (n = 6), 337-382 Ma (n = 13) and 236–250 Ma (n = 5)
NEW GEOCHEMICAL DATA OF BASALTS IN THE TSOROIDOG AREA, CENTRAL MONGOLIA
At present, geochemical data are widely used for reconstructing geodynamic settings, especially, volcanic rocks of mafic composition, i.e., basalts, because they are widespread in many orogenic belts and are indicative of different geodynamic environments. In general, we propose the reconstruction of the tectonic settings of basalts according to their relationships with associated ocean plate stratigraphy (OPS) sediments, their petrogenesis and their geochemical features
The Gravitational Model of the Mongolian Foreign Trade
The article presents an analysis of Mongolia's foreign trade using econometric gravity modeling tools as a popular tool for analyzing International trade flows. To create a model for the development of the Mongolian economy in the context of modern globalization processes, the authors studied exogenous and endogenous models of economic growth. To develop the gravity model of the Mongolian Economy, the current state of Mongolia's foreign trade was studied in the context of the economic situation of the 10 countries of Mongolia's trading partners that most strongly influence the gross trade of Mongolia. The statistics of the Customs Administration and the National Statistical Committee of Mongolia are used, as well as macroeconomic indicators of the countries of the world. When building the model, the main assumptions of the gravitational theory were used, that trade flows positively depend on the size of the GDP of the countries of foreign trade partners, therefore, for the regression analysis, the GDP sizes of 10 active partners of Mongolia are taken. Alternative methods of resistance to foreign trade are also considered, in particular the distance indicator
Effects of the parasitic ichthyoxenus amurensis on the amur ide (leuciscus waleckii)
The survey on the Amur ide, Leuciscus waleckii, conducted between May to October, 2015 along Kherlen River in Khentii province, Mongolia. Ichthyoxenus amurensis was found in the body cavity of the Amur ide. A total of 12 individuals of Ichthyoxenus amurensis were collected from eight of 25 fish specimens (prevalence=32.0%). In the body cavity of the Amur ide, Leuciscus waleckii was found within a thin-walled membranous sac, an orifice near the ventral region of the pectoral fin. Ichthyoxenus amurensis caused deleterious effects in fish, such as decreases in mean weight and growth. This is the first report about detecting of Ichthyoxenus amurensis parasite from the Amur ide, Leuciscus waleckii, in Kherlen river, Mongolia.
Амарын сугас (leuciscus waleckii) загасанд ichthyoxenus amurensis шимэгчийн үзүүлэх нөлөө
Хураангуй: Загас нь хүнс тэжээлийн бас нэг баялаг бөгөөд олон зуун жилийн турш тэдгээрийг судалж, хамгаалан, ашиглаж ирсэн. Манай орны 3 ай савын гол, мөрөн, нуурт 2 анги, 8 баг, 13 овог, 44 төрөлд хамаарах 70 гаруй зүйл загас тархжээ. Хэрлэн голын дагуу хийгдсэн загасны паразитын судалгаагаар 3 зүйлийн загас илэрч байв. Судалгаанд хамрагдсан n=25 загасанд өвчний шинжилгээ хийхэд 8 тооны Амарын сугас (Leuciscus waleckii) загас Ichthyoxenus amurensis паразитаар халдварласан байв. Ichthyoxenus amurensis нь сугас загасны цээжний сэлүүрийн хоорондын болон хэвлийн арьсыг цоолон хэвлийн хөндийд нэвтэрдэг болох нь тогтоогдов. Ichthyoxenus amurensis зүйл шимэгчээр халдварласан загасны өсөлт удааширч, бие давжаарах, биеийн жин буурдаг болох нь батлагдав. Мөн Ichthyoxenus amurensis нь эм загасанд илүү шимэгчилж буйг судалгаагаар илрүүлэв. Хэрлэн голын сав газар дахь Амарын сугас загасанд Ichthyoxenus amurensis зүйл шимэгчилж буйг анх тутам илрүүлсэн болно.
Түлхүүр үг: Ichthyoxenus amurensis, паразит, биеийн өсөлт, тарга авалт
Cancer incidence and mortality in Mongolia - National registry data
site of liver, stomach and esophagus, for which cases fatality rates are high in all populations. Emphasis is given in the National Cancer Control Program (NCCP) to limiting treatment for these and other high-fatality cancers to the small sub-set of potentially curable cases, while focusing on palliative care and patient support for the remainder. Meanwhile opportunities are being pursued to prevent liver cancer through hepatitis B vaccination and lung cancer through tobacco control, and to reduce cervical cancer mortality by finding lesions at a pre-malignant or early invasive stage.
THE EARLY-MIDDLE PALEOZOIC VOLCANISM AND GEODYNAMIC EVOLUTION OF THE HERLEN MASSIF, CENTRAL PART OF THE CAOB: CONSTRAINS FROM GEOCHEMISTRY, U-PB GEOCHRONOLOGY, LU-HF AND RB-SR ISOTOPES OF VOLCANIC ROCKS
Mongolia lies in the central part of the Central Asian Orogenic Belt [Mossakovsky et al., 1994; Zorin, 1999; Jahn, 2004; Khain et al., 2003; Badarch et al., 2002; Windley et al., 2007; Zhang et al, 2008], or Altaids [Şengör et al., 1993; Şengör, Natal’in, 1996; Wilhem et al., 2012], which is fringed by the Siberian craton in the north and by the Tarim and Sino-Korean Cratons in the south. According to the recent tectonic subdivision, the territory of Mongolia is subdivided into Northern and Southern domains which are separated by the so called Mid Mongolian Tectonic Line [Tomurtogoo, 2012]. The Herlen Massif is one of the important tectonic units of the South Mongolian domain in the Argun-Idermeg super terrane extending through the territories of Russia and China [Parfenov et al., 2009; Tomurtogoo, 2014b]. The Herlen massif, also known as Herlen superterrane [Tomurtogoo, 2012] or Idermeg terrane [Tomurtogoo, 2014a] is composed of Ereendavaa, Undur-Khaan, Idermeg and Gobian Altay-Baruun Urt terranes converged at the end of the Cambrianbeginning of the Ordovician [Badarch et al., 2002; Tomurtogoo, 2014b]
Changes in the volume and salinity of Lake Khubsugul (Mongolia) in response to global climate changes in the upper Pleistocene and the Holocene
Two gravity cores (1.1 and 2.2 m long) of deep-water bottom sediments from Lake Khubsugul (Mongolia) were studied. The Holocene, biogenic silica and organic matter-rich part of the first core was subjected to AMS radiocarbon dating which placed the date of dramatic increase of pelagic diatoms (40 cm below sediment surface) at a calendar age of 11.5 cal ky BP. ICP-MS analysis of weak nitric acid extracts revealed that the upper Pleistocene, compared to the Holocene samples, were enriched in Ca, Cinorg, Sr, Mg and depleted of U, W, Sb, V and some other elements. Transition to the Holocene resulted in an increase of total diatoms from 0 to 108 g 1, of BiSi from 1% to 20%, of organic matter from 6%. The Bølling–Allerød–Younger Dryas–Holocene abrupt climate oscillations manifested themselves in oscillations of geochemical proxies. A remarkable oscillation also occurred at 22 cm (ca. 5.5 ky BP). The Pleistocene section of the second, longer core was enriched in carbonate CO2 (up to 10%) and water-extractable SO4 2 (up to 300 times greater than that in Holocene pore waters). All this evidence is in an accord with the earlier finding of drowned paleo-deltas at ca. 170 m below the modern lake surface of the lake [Dokl. Akad. Nauk 382 (2002) 261] and suggests that, due to low (ca. 110 mm) regional precipitation at the end of the Pleistocene, Lake Khubsugul was only 100 m deep, and that its volume was ca. 10 times less than today