Start |Author Index | View Uploaded Presentations | Meeting Information

GSA Annual Meeting in Indianapolis, Indiana, USA - 2018

Paper No. 23-21
Presentation Time: 9:00 AM-5:30 PM

ORIGIN OF THE URANIUM ELEMENT IN THE EARLY CAMBRIAN AND ITS GEOLOGICAL SIGNIFICANCE IN SHALE GAS EXPLORATION: A CASE STUDY OF THE LOWER CAMBRIAN SHALES IN THE YANGTZE AREA IN SOUTH CHINA


LIU, Xiaoxue1, JIANG, Zhenxue1, ZHANG, Kun2, WEI, Lin3, HUANG, Yizhou1, WEN, Ming1, WANG, Xin1, XUAN, Qixiang1, LIU, Tianlin1 and XIE, Xuelian4, (1)Unconventional Natural Gas Institute, China University of Petroleum (Beijing), No.18, Road Fuxue, District Changping, Beijing, 102249, China, (2)Unconventional Natural Gas Institute, University of Petroleum (Beijing), No.18, Road Fuxue, District Changping, Beijing, 102249, China, (3)institute of unconventional natural gas, Beijing, 102200, China, (4)Guangzhou Marine Geological survey, Guangzhou, 510760, China

The Lower Cambrian shales have always been the main target of marine shale gas exploration in South China. However, there are a number of low production wells and even failed wells. A large reason is the lack of material basis in the shale gas reservoir process; therefore finding the organic rich shale (i.e., TOC content > 2%) development area is an important issue that needs to be solved.

Considering that the Lower Cambrian shales in the Yangtze area contain many elements such as silicon, calcium, aluminum, uranium, thorium, potassium, iron and manganese, In this study, U, Si and Al log data, the total organic carbon (i.e., TOC) content, which come from three typical wells with different distances from the boundary line between the Yangtze plate and the Cathaysian plate, as well as the analysis of a lithofacies element in the Jiang ye-1 well, are selected as the basic data. Based on the Si and Al log data from the three wells, the excess siliceous mineral content from a non-terrigenous clastic source is calculated, and the siliceous source with excess siliceous mineral layers is analyzed with a Al-Fe-Mn ternary plot. Through further analysis of the relationship between excess silicon and uranium, the source of uranium in the Lower Cambrian shale is clarified, the tectonic setting of uranium and its relationship with the enrichment of organic matter is elucidated.

The results show that both uranium and excess silicon come from a hydrothermal solution at the junction of the Yangtze plate and the Cathaysian plate. Radioactive uranium can enhance biological productivity, which is conducive to the enrichment of sedimentary organic matter. For the exploration of shale gas in the Lower Cambrian, it is necessary to conduct exploration among target areas near the junction of the two plates that have moderate maturity and good preservation conditions.

Session No. 23--Booth# 43

T34. Unconventional Energy Resources (Posters)
Sunday, 4 November 2018: 9:00 AM-5:30 PM
Halls J-K (Indiana Convention Center)
Geological Society of America Abstracts with Programs. Vol. 50, No. 6
doi: 10.1130/abs/2018AM-321995
© Copyright 2018 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.
Back to: T34. Unconventional Energy Resources (Posters)
<< Previous Abstract | Next Abstract >>