GEOCHEMICAL HETEROGENEITY OF BASITES OF AN OPHIOLITE ASSOCIATION FROM THE KUZNETSK ALATAU (SOUTH-WESTERN SIBERIA)

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7105-98-8 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 11, 27-34 pp, DOI: 10.5593/sgem2017/11/S01.004

ABSTRACT

Ophiolites from the northern slope of the Kuznetsk Alatau (north-western sector of the Altay-Sayan folded area) are the most typical fragments of suboceanic crust, which was formed in the Riphean. This investigation presents and interprets the results of petrochemical and geochemical studies the composition of basite rocks of these ophiolite paragenesis from the Severnaya, Zelenaya, Barkhatnaya mountains and Semenovsky massif. The contents of petrogenic oxides and trace elements were measured by X-ray fluorescence on instrument OXFORD ED-2000 and ICP-MS (high-resolution mass spectrometer Agilent 7500cx) respectively.
Petrochemical parameters of rocks vary within wide limits and show a possible vertical sequence of magmatic complexes in the ophiolitic section. And these rocks are the products of sodium tholeitic petrochemical series. Based on the geochemical features the studied rocks can be divided into 4 groups and also their geodynamic conditions of formation were determined. In the result obtained petrochemical and geochemical heterogeneities indicate the present of tectonic association of different type fragments of oceanic crust from ancient sea basins in the folded belt structures.

Keywords: basites, ophiolite association, mid-ocean ridge, supra-subduction zone