Differences between Fluid Activities in the Central and North Tarim Basin
详细信息
- 责任者：Zhu Dongya (Laboratory of Structural and Sedimentological Reservoir Geology ; Petroleum Production and Research Institute ; SINOPEC ; Beijing 100083 ; China) ; Meng Qingqiang
- 刊名：Geochimica
- 出版年：2013
- 卷期：42(1)
- 关键词：方解石 ; calcite ; 流体包裹体 ; fluid inclusions ; 塔里木盆地 ; Tarim Basin
- 页码：p.82-94
- 图表：illus., 2 tables, 40 refs.
- 分类号：0600
- issnNo：ISSN0379-1726
- isbnNo：CN44-1398/P
摘要
Homogenization temperatures(HTs) of fluid inclusion,carbon,oxygen and strontium isotopes and rare earth elements(REEs) werenanlyzed for calcites filled in vugs and fractures in Ordovician limestones in the North and Central Tarim Basin.Most of the calcite samples in the North Tarim Basin are related to meteoric water,indicated by relatively low HT,light oxygen isotope composition and high 87Sr/86Sr values.Their average HTs range from 66.6 to 105.8 ℃,δ18OPDB from –18.9‰ to –10.8‰,and 87Sr/86Sr from 0.709190 to 0.709989.Five of the other calcite samples in the North Tarim Basin are related to formation water,and two related to hydrothermal water.The calcite samples in Central Tarim Basin are related to hydrothermal water,with higher HTs than burial temperature of the surround rocks,light oxygen isotope composition,high 87Sr/86Sr values,REE distribution pattern remarkably different from surround limestone and considerable positive Eu anomaly.Their average HTs range from 139.2 to 180.0 ℃,δ18OPDBfrom –7.9‰ to –14.3‰,87Sr/86Sr from 709049 to 0.719503,and δEu from 1.39 to 76.03.It can be summarized from the above that fluids in the Ordovician limestone are mainly meteoric ZHU Dong-ya et al.: Differences between fluid activities in the Central and North Tarim Basin water with minor formation and hydrothermal waters in the North Tarim Basin,whereas fluids are dominantly hydrothermal in the Central Tarim Basin.The differences in fluid activities in the North and Central Tarim Basin can be attributed to the difference in geological environments such as tectonic evolution,magma-volcano activities and so on.The Ordovician limestone in the North Tarim Basin had suffered strong meteoric alteration for several times because of multiple-stage tectonic uplifts.In contrast,The dominant fluids are hydrothermal in the Central Tarim Basin due to intensive and extensive magma-volcano activities in the Permian.