Response of nitrogen isotopes to paleo-environment and organic carbon accumulation in a Late Paleozoic alkaline lake, Junggar Basin

Behavior of Nitrogen Contents and Isotopes during Thermal Evolution and Hydrocarbon Generation in Shale: Insights from Hydrothermal Experiments in a Semiopen System

“…Nitrogen is an important element in ancient sedimentary rocks and crude oil, but the field has developed slowly due to the technical difficulty of obtaining measurements from these N-poor samples. ,, However, recent technical advances have opened the door to carrying out rapid and reliable analyses of minute quantities of N, and the application of this proxy has thus accelerated. , A series of achievements have been made in the reconstruction of ancient sedimentary environments and oil-source correlation. ,,− First, nitrogen is redox-sensitive in the field of liquid water stability. The oxygenation of Earth’s atmosphere and oceans has played a major role in the evolution of the global biogeochemical nitrogen cycle, and the isotopic composition of nitrogen in oceans is preserved in sedimentary rocks (δ 15 N sed ) during depositional processes, which makes δ 15 N a meaningful tool for paleoenvironmental reconstruction. ,− Moreover, reconstructing the biogeochemical nitrogen cycle in deep time is also important for deciphering the evolution of life over Earth’s history and major geological events. , And some research in the petroleum system reported that the δ 15 N of crude oil is correlated with δ 15 N of source rock so the δ 15 N can be expected to become a new oil-source comparative analysis index. ,, …”

Cyclostratigraphy of Lower Permian alkaline lacustrine deposits in the Mahu Sag, Junggar basin and its stratigraphic implication

“…The formation of such an alkaline lake is jointly controlled by favorable paleoclimatic, paleotectonic, and paleogeographic conditions (Cao et al, 2020). Alkaline lakes have been proven to be favorable environments for organic matter accumulation and preservation and have been recognized as having high hydrocarbon (Burton et al, 2014;Xia et al, 2022). Therefore, alkaline lacustrine deposits are of great environmental and economic significance in paleoclimatic reconstruction and shale oil exploration (e.g., Smith and Carroll, 2015;Yu et al, 2019) and are characterized by the deposition of alkaline minerals (sodium carbonate minerals) and fine-grained organic-rich sediments (Warren, 2010;Pecoraino et al, 2015).…”