Provenance, Sedimentary Environment, Tectonic Setting, and Uranium Mineralization Implications of the Yaojia Formation, SW Songliao Basin, NE China

Abstract

The SW Songliao Basin is an extremely significant part of the giant sandstone uranium metallogenic belt in northern China. The Yaojia Formation is the most significant ore-bearing layer in the region. However, the poorly constrained sedimentology of the Yaojia Formation has substantially hindered the understanding of the basin and the exploration of uranium deposits within it. To determine the sedimentology, provenance, and tectonic setting of the Yaojia Formation in the study area, we conducted petrography, whole-rock geochemical analysis, and electron probe research. Based on the results of the study, it appears that the Yaojia Formation sandstone is predominantly composed of lithic sandstone and feldspar lithic sandstone. Uranium exists in two forms: as independent minerals and as adsorption uranium. Pitchblende is the most common independent uranium mineral, with small amounts of coffinite also occurring. The ratios of Sr/Ba, V/(V+Ni), V/Cr, Ni/Co, and (Cu+Mo)/Zn of the samples indicate that the Yaojia Formation was deposited in a sub- to oxygen-rich freshwater environment with a moderately stratified bottom water body and smooth circulation. The geochemical characteristics of the Yaojia Formation sandstones imply that they are primarily derived from felsic igneous rocks in the upper continental crust in active continental margin and continental island arc environments. According to geochemistry and previous detrital zircon U-Pb chronology studies, the Mesozoic and Late Paleozoic felsic igneous rocks of the southern Great Xing’an Mountains are the principal sources of the Yaojia Formation in the SW Songliao Basin. Besides providing sediments for the study area, the uranium-rich felsic igneous rocks in the source areas also represent a long-term, stable, and ideal source of uranium, suggesting substantial potential for uranium exploration in the study area.

Chemostratigraphic Approach to the Study of Resources’ Deposit in the Upper Silesian Coal Basin (Poland)

“…In a stratigraphic context, differences in mineralogy and/or chemistry can lead to the formation of a geochemical system, which provides valuable information about geological settings, climate, and the processes of sediment production and preservation. The stratigraphic record exhibited changes in the concentration of certain elements over time as a result of geological conditions, such as tectonic, climatic, redox, oceanographic, biotic, and other processes [15][16][17]26,46].…”

“…The origin of the quartz is especially important when analyzing the main determinants of the quality of hydrocarbon reservoirs [19]. Several geochemical criteria have been reported for determining the origin of silicon in sedimentary rocks [10,19,46,49].…”

“…In this study, the relationships between TiO 2 and SiO 2 were analyzed to determine the quartz origin. A strong positive correlation between TiO 2 and SiO 2 suggests that terrigenous quartz is a primary source of silica, while a clear negative relationship indicates a high proportion of biogenic silica [10,19,46,49].…”

“…Trace element composition can potentially provide information regarding the provenance of terrigenous sediments and source-area rock compositions [26,46,[49][50][51][52][53][54][55][56].…”

“…The ratios of Al 2 O 3 /TiO 2 and TiO 2 /Zr as well as the abundance of trace elements, such as Zr, La, Sc, Th, and their elemental ratios (Th/Sc and La/Th), are commonly used in provenance studies (e.g., [18,26,46,[49][50][51][52][53][54][55][56][57][58][59]).…”