Petrology of Ortsog-Uul peridotite-gabbro massif in Western Mongolia

M. Shapovalova, N. Tolstykh, R. Shelepaev, M. Cherdantseva

Research output: Contribution to journalConference articlepeer-review

Abstract

The Ortsog-Uul mafic-ultramafic massif of Western Mongolia is located in a tectonic block with overturned bedding. The massif hosts two intrusions: a rhythmically-layered peridotite-gabbro association (Intrusion 1) and massive Bt-bearing amphibole-olivine gabbro (Intrusion 2). Intrusions 1 and 2 have different petrology features. Early Intrusion 1 (278±2.5Ma) is characterized by lower concentrations of alkalis, titanium and phosphorus than late Intrusion 2 (272±2Ma). The chondrite-normalized REE and primitive mantle-normalized rare elements patterns of Ortsog-Uul intrusions have similar curves of elements distribution. However, Intrusion 2 is characterized higher contents of REE and rare elements. High concentrations of incompatible elements are indicative of strong fractionation process. It has been suggested that Intrusions 1 and 2 derived from compositionally different parental melts. Model calculations (COMAGMAT-3.57) show that parental melts of two intrusions were close to high-Mg picrobasaltic magmas. The concentration of MgO in melt is 16.21 (Intrusion 1) and 16.17 (Intrusion 2). Isotopic data of Ortsog-Uul magmatic rocks exhibit different values of ϵNd (positive and negative) for Intrusion 1 and 2, respectively.

Original languageEnglish
Article number012020
Number of pages6
JournalIOP Conference Series: Earth and Environmental Science
Volume110
Issue number1
DOIs
Publication statusPublished - 3 Jan 2018

Keywords

  • MANTLE
  • EVOLUTION
  • BASALTS

Fingerprint Dive into the research topics of 'Petrology of Ortsog-Uul peridotite-gabbro massif in Western Mongolia'. Together they form a unique fingerprint.

Cite this