Open AccessTYPES OF RIVERS FEEDING SEDIMENTARY BASINS ON THE SOUTHEASTERN EDGE OF THE SIBERIAN PLATFORM DURING THE RIPHEAN: SKETCH OF RECONSTRUCTION
Author(s) -
А. В. Маслов,
В. Н. Подковыров
Publication year - 2021
Publication title -
tihookeanskaâ geologiâ
Language(s) - English
Resource type - Journals
ISSN - 0207-4028
DOI - 10.30911/0207-4028-2021-40-4-99-117
Subject(s) - geology , riphean , sedimentary rock , metamorphic rock , clastic rock , geochemistry , terrane , detritus , geomorphology , paleontology , tectonics
Some geochemical features of fine-grained clastic/clay rocks of a number of Riphean formations of the Yudoma-Maya region of southeastern Yakutia are considered. A comparison of the distribution character of the data points of individual and average samples of clay rocks in the (La/Yb)N–Eu/Eu* and (La/Yb)N–Th diagrams, which show the composition of the bottom sediments of the estuarine parts of modern rivers of various categories, allowed us to make a number of conclusions. Thus, individual data points on the (La/Yb)N–Eu/Eu* diagram are concentrated mainly in the fields of bottom sediments of rivers feeding on erosion products of mainly sedimentary (categories 1 and 2) and volcanic rocks (category 4), as well as their overlapping zones. The average data point of the clay rocks of the Trekhgorka Formation in this diagram is located in the field of bottom sediments of rivers draining magmatic/metamorphic terranes (category 3). The average data points of shales of the Dim, Talyn, and Svetly formations are located in the zone of overlapping fields of bottom sediments of rivers of categories 1, 2, and 3, i.e., they contain erosion products of both sedimentary formations and magmatic and metamorphic complexes. This is quite well consistent with the real geological situation. At the same time, in the composition of clayey rocks of higher stratigraphic levels of Riphean, erosion products of magmatic/metamorphic terranes are either absent or their proportion is very small. On the (La/Yb)N–Th graph, most of the individual data points of Riphean clayey rocks tend to be in the fields 1, 2, and 4. Their average data points are mainly confined to the overlapping zone of the fields of bottom sediments of rivers of categories 1 and 2. The average data point of clay rocks of Ust-Kirba Formation is located in the field of bottom sediments of rivers that feed on products of erosion from rocks of volcanic provinces. It also does not contradict the real geological situation.