地质学报（英文版）2006，Vol.80Issue(4)：550-556,7.
B, Sr, O and H Isotopic Compositions of Formation Waters from the Bachu Bulge in the Tarim Basin
B, Sr, O and H Isotopic Compositions of Formation Waters from the Bachu Bulge in the Tarim Basin
摘要
Abstract
In order to elucidate the origin and migration of basinal brines in the Bachu Bulge, Tarim Basin, we have carried out analyses on chemical composition, and boron, hydrogen and oxygen isotopes of formation waters together with the XRD of clay minerals from the Paleozoic strata. The waters show Ca, B, Li and Sr enrichment and SO4 depletion in the Carboniferous and Ordovician and K enrichment in part of the Ordovician relative to seawater. The relationship between δD and δ18O shows that all the data of the waters decline towards the Global Meteoric Water Line with the intersection of them close to the present-day local meteoric water, suggesting that modern meteoric water has mixed with evaporated seawater. The 87Sr/86Sr ratios range from 0.7090 to 0.7011, significantly higher than those of the contemporary seawater. The δ11B values range from +19.7 to +32.3‰, showing a decrease with the depth and B concentrations. The results suggest that isotopically distinct B and Sr were derived from external sources. However, since the percentages of illite are shown to increase with depth among clay minerals in the study area, i.e., illite is due to precipitation rather than leaching during deeper burial, it is unlikely for illite to have contributed a significant amount of B to the waters. Thus, B with low δ11B values is interpreted to have been added mainly from thermal degradation of kerogen or the basalts in the Cambrian and Lower Ordovician.关键词
δ11B, formation water, water-rock interaction, Tarim BasinKey words
δ11B, formation water, water-rock interaction, Tarim Basin分类
天文与地球科学引用本文复制引用
CAI Chunfang,PENG Licai,MEI Bowen ,XIAO Yingkai..B, Sr, O and H Isotopic Compositions of Formation Waters from the Bachu Bulge in the Tarim Basin[J].地质学报（英文版）,2006,80(4):550-556,7.基金项目
The research was financially supported by the National Natural Science Foundation of China (Grant Nos.40573034 and 40173023) and China National Major Basic Development Program "973" (2003CB214605). （Grant Nos.40573034 and 40173023）
