AGE AND SOURCES OF DETRITAL MATERIAL FOR THE METASEDIMENTARY ROCKS OF THE NILAN TERRANE OF THE MONGOL-OKHOTSK OROGENIC BELT

Abstract

The paper presents the first results of U-Th-Pb (LA-ICP-MS) isotopic dating of detrital zircons from the Paleozoic (?) metasedimentary rocks of the Nilan Terrane of the Mongol-Okhotsk orogenic belt to refine the age estimates and determine their probable correlation with earlier dated sediments of this belt. It has been stated that the metasedimentary rocks of the Olga, Salarin and Rovnen formations and of the Sivak formation of the Nilan terrane are characterized by the almost complete absence of the Early Precambrian zircons, slightly negative εNd(t) values, and Mesoproterozoic tNd(DM) and tNd(С) values. The isotope dataset obtained shows that most of the detrital sediments were carried from continental massifs of the Amur superterrane.

Keywords

• mongol-okhotsk belt
• u-pb geochronology
• sm-nd isotopic-geochemical studies
• nilan terrane
• detrital zircons
• source area