MINERALOGY, GEOCHEMISTRY AND THE NATURE OF LIGHTNING OF LUMINESCENT LAYERS IN THE BAZHENOV FORMATION OF THE WEST SIBERIAN SEDIMENTARY BASIN

Известия Томского политехнического университета: Инжиниринг георесурсов

Elena S. Kondrashova¹ 

[1] NationalResearchTomskPolytechnicUniversity;

关键词: west siberia;    the bazhenov formation;    petrography;    geochemistry;    volcanogenic material;   

DOI  :  10.18799/24131830/2020/8/2774

来源: DOAJ

【 摘 要 】

Relevance. The study of mineralogical and geochemical features of luminescent layers in the Bazhenov formation of West Siberian sedimentary basin (Tomsk region and adjacent regions) will allow clarifying their mineral composition and nature of formation, as well as the opportunity of their use as additional regional horizon to restore the paleogeographic history of the Bazhenov formation. The main aim of the research is to study the mineralogical and geochemical features and determine the origin of luminescent layers in the deposits of the Bazhenov formation. Objects: sedimentary rocks, luminescent layers and enclosing rocks of the Bazhenov formation. Methods: X-ray diffractometry, petrographic analysis, scanning electron microscopy, inductively coupled plasma mass spectrometry, inductively coupled plasma atomic emission spectrometry, instrumental neutron activation analysis, x-ray luminescence. Results. The luminescent layers in ultraviolet light were detected in the distribution area of the Bazhenov formation in the central and south-eastern part of the West Siberian sedimentary basin. Thickness of layers varies from 2 mm to 15 cm. The study of the mineral composition made it possible to divide the separated layers into two groups according to the main mineral phases. The study of layers of the I group showed that they are composed mainly of clay minerals with an admixture of clastic silty material. The main clay minerals in them are kaolinite and mixed-layer minerals of the illite-smectite series. Layers with a predominantly siliceous (quartz) composition correspond to the II group. When analyzing chemical composition data it was identified that the studied layers as a whole have lower element contents (Co, Ni, Cu, Zn, Moand others) compared to the «ordinary» rocks of the Bazhenov formation due to the low content of buried organic matter, which is traditionally associated with the accumulation of some microelements. The elevated concentrations of thorium in the samples of the studied layers are noted. The study shown the signs of the presence of volcanic material. It is assumed that studied layers are of volcanic origin and were formed as a result of the dia- and catagenetic transformation of the volcanoclastic material of tuff sediments in the presence of a large amount of organic matter.

【 授权许可】

Unknown