柴北缘平台地区下干柴沟组下段元素地球化学特征及意义
|
摘要
为查明柴北缘平台地区下干柴沟组下段古沉积环境演化及其对油气勘探的指示意义,综合运用对沉积环境反应敏感的主微量元素和碳氧同位素数据,对研究区的古气候、古盐度、氧化还原环境等古环境参数进行了综合研究。结果表明:气候指数表明研究区沉积时期干热和温湿气候共存,但整体上气候偏温暖湿润;锶、钡含量及δ~(13)C_(VPDB)与δ~(18)O_(VPDB)数据分析表明,沉积水体为盐度较高的淡水沉积;利用钒、镍、铬、钴等氧化还原判定指标的分析,反映研究区可能存在贫氧亚还原环境和富氧环境,但X衍射数据中仅出现反映氧化环境的赤铁矿,且利用钴元素估算的古水体深度大部分低于26 m;结合岩心数据分析,表明研究区主要发育以氧化环境为主的辫状河浅水沉积体系;基于元素地球化学分析的古环境演化结果可知,干湿气候交替出现,造成湖平面升降频繁,粗粒心滩相与细粒河漫滩相可呈互层状分布,为有利的储盖组合发育创造了条件。该研究结果对指导研究区油气勘探具有重要意义。
In order to find out the evolution of palaeosedimentary environment in the lower member of lower Ganchaigou Formation in the platform area on the north margin of Qaidam Basin and its indicative significance for oil and gas exploration,the main trace element and carbon-oxygen isotopic data sensitive to the sedimentary environment were used to study the paleoenvironment parameters like paleoclimate,paleosalinity and redox environment of the study area. The climate index showed that the arid and warm humid climates coexisted in the sedimentary period of the study area,but the climate was warm and humid on the whole. The analysis of strontium and barium contents as well as δ~(13)C_(VPDB) and δ~(18)O_(VPDB) data showed that the sedimentary water was freshwater deposit with high salinity.The analysis of redox indexes such as vanadium,nickel,chromium and cobalt showed that there might be oxygenpoor subreduction environment and oxygen-rich environment in the study area,but only hematite reflecting oxidation environment was found in X-ray diffraction data,moreover,the depth of fossil water depth estimated by cobalt element was less than 26 m; combined with the analysis of core data,it was judged that the shallow water sedimentary system of braided river dominated by oxidation environment was mainly developed in the study area. The paleoenvironmental evolution results obtained from element geochemistry analysis showed that the dry and wet climates occurred alternately,resulting in frequent fluctuation of lake level,and the coarse-grained channel bar facies and fine-grained alluvial flat facies exhibited interbedded distribution,which created conditions for the development of favorable reservoir-caprock assemblage. The study results are of great significance for guiding oil and gas exploration in the study area.
In order to find out the evolution of palaeosedimentary environment in the lower member of lower Ganchaigou Formation in the platform area on the north margin of Qaidam Basin and its indicative significance for oil and gas exploration,the main trace element and carbon-oxygen isotopic data sensitive to the sedimentary environment were used to study the paleoenvironment parameters like paleoclimate,paleosalinity and redox environment of the study area. The climate index showed that the arid and warm humid climates coexisted in the sedimentary period of the study area,but the climate was warm and humid on the whole. The analysis of strontium and barium contents as well as δ~(13)C_(VPDB) and δ~(18)O_(VPDB) data showed that the sedimentary water was freshwater deposit with high salinity.The analysis of redox indexes such as vanadium,nickel,chromium and cobalt showed that there might be oxygenpoor subreduction environment and oxygen-rich environment in the study area,but only hematite reflecting oxidation environment was found in X-ray diffraction data,moreover,the depth of fossil water depth estimated by cobalt element was less than 26 m; combined with the analysis of core data,it was judged that the shallow water sedimentary system of braided river dominated by oxidation environment was mainly developed in the study area. The paleoenvironmental evolution results obtained from element geochemistry analysis showed that the dry and wet climates occurred alternately,resulting in frequent fluctuation of lake level,and the coarse-grained channel bar facies and fine-grained alluvial flat facies exhibited interbedded distribution,which created conditions for the development of favorable reservoir-caprock assemblage. The study results are of great significance for guiding oil and gas exploration in the study area.
引文
[1]邓宏文,钱凯.沉积地球化学与环境分析[M].兰州:甘肃科学技术出版社,1993:5-6.
[2]刘刚,周东升.微量元素分析在判别沉积环境中的应用---以江汉盆地潜江组为例[J].石油实验地质,2007,29(3):307-310.
[3]程岳宏,于兴河,韩宝清,等.东濮凹陷北部古近系沙三段地球化学特征及地质意义[J].中国地质,2010,37(2):357-366.
[4]MURRAY R W.Chemical criteria to identify the depositional environment of chert:general principles and applications[J].Sedimentary Geology,1994,90(3):213-232.
[5]孙国强,刘伟明,王波,等.柴北缘平台地区路乐河组砂岩储层特征[J].沉积学报,2016,34(2):356-363.
[6]吕婧文,李远,王鹏,等.柴达木盆地平台地区路乐河组沉积微相研究[J].沉积与特提斯地质,2016,36(2):55-61.
[7]田继先,孙平,张林,等.柴达木盆地北缘山前带平台地区天然气成藏条件及勘探方向[J].天然气地球科学,2014,25(4):526-531.
[8]仵宗涛,孙国强,王锋,等.柴北缘平台地区下干柴沟组下段碳酸盐胶结物特征及意义[J].沉积与特提斯地质,2016,36(4):30-36.
[9]张运周,徐胜林,陈洪德,等.川东北旺苍地区栖霞组地球化学特征及其古环境意义[J].石油实验地质,40(2):210-217.
[10]陈志鹏,任战利,于春勇,等.银额盆地哈日凹陷下白垩统热水沉积岩特征及成因.[J].地球科学,2018,43(4):1-21.
[11]范玉海,屈红军,王辉,等.微量元素分析在判别沉积介质环境中的应用---以鄂尔多斯盆地西部中区晚三叠世为例[J].中国地质,2012,39(2):382-389.
[12]李浩,陆建林,李瑞磊,等.长岭断陷下白垩统湖相烃源岩形成古环境及主控因素[J].地球科学---中国地质大学学报,2017,42(10):1774-1786.
[13]张文伟.基于主(微)量元素分析法的细粒沉积岩沉积环境判别---以大民屯凹陷安福屯地区沈352井沙四下亚段为例[J].东北石油大学学报,2017,41(4):99-106.
[14]周长勇,张启跃,吕涛,等.云南中三叠世罗平生物群产出地层的地球化学特征和沉积环境[J].地质论评,2014,60(2):285-298.
[15]张妮,林春明,周健,等.苏北盆地高邮凹陷古近系戴南组一段元素地球化学特征及其地质意义[J].地质学报,2012,86(2):269-279.
[16]MCCULLOCH M,CAPPO M,AUMEND J,et al.Tracing the life history of individual barramundi using laser ablation MC-ICP-MS Sr-isotopic and Sr/Ba ratios in otoliths[J].Marine&Freshwater Research,2005,56(5):637-644.
[17]王峰,刘玄春,邓秀芹,等.鄂尔多斯盆地纸坊组微量元素地球化学特征及沉积环境指示意义[J].沉积学报,2017,35(6):1265-1273.
[18]李俊花,白光勇,张谊理.孤东油田上第三系馆陶组上段微量元素的分布特征及沉积环境分析[J].石油大学学报(自然科学版),1993,17(3):114-117.
[19]KEITH M L,WEBER J N.Carbon and oxygen isotopic composition of selected limestones and fossils[J].Geochimica Et Cosmochimica Acta,1964,28(S1):1787-1816.
[20]孙建伟,付永涛,兰朝利.青岛八仙墩碎屑岩微量元素地球化学特征及沉积环境意义[J].海洋科学,2014,38(8):75-81.
[21]吴智平,周瑶琪.一种计算沉积速率的新方法---宇宙尘埃特征元素法[J].沉积学报,2000,18(3):395-399.
[22]孟苗苗,康志宏,樊太亮,等.痕量元素和碳氧同位素在塔里木盆地西南缘棋盘组沉积环境研究中的应用[J].成都理工大学学报(自然科学版),2016,43(1):77-85.
[23]陈建强,周洪瑞,王训练.沉积学及古地理学教程[M].北京:地质出版社,2004:84.
[24]贾艳艳,邢学军,孙国强,等.柴北缘西段古-新近纪古气候演化[J].地球科学---中国地质大学学报,2015,40(12):1955-1967.
[25]施辉,刘震,连良达.高原咸化湖盆岩性油气藏富集规律---以柴达木盆地西南区为例[J].天然气地球科学,2013,24(4),701-710.
[26]胡晓峰,刘招君,柳蓉,等.抚顺盆地始新统军屯组微量元素特征及油页岩的有利成矿条件[J].吉林大学学报(自然科学版),2012,42(3),60-70.
[2]刘刚,周东升.微量元素分析在判别沉积环境中的应用---以江汉盆地潜江组为例[J].石油实验地质,2007,29(3):307-310.
[3]程岳宏,于兴河,韩宝清,等.东濮凹陷北部古近系沙三段地球化学特征及地质意义[J].中国地质,2010,37(2):357-366.
[4]MURRAY R W.Chemical criteria to identify the depositional environment of chert:general principles and applications[J].Sedimentary Geology,1994,90(3):213-232.
[5]孙国强,刘伟明,王波,等.柴北缘平台地区路乐河组砂岩储层特征[J].沉积学报,2016,34(2):356-363.
[6]吕婧文,李远,王鹏,等.柴达木盆地平台地区路乐河组沉积微相研究[J].沉积与特提斯地质,2016,36(2):55-61.
[7]田继先,孙平,张林,等.柴达木盆地北缘山前带平台地区天然气成藏条件及勘探方向[J].天然气地球科学,2014,25(4):526-531.
[8]仵宗涛,孙国强,王锋,等.柴北缘平台地区下干柴沟组下段碳酸盐胶结物特征及意义[J].沉积与特提斯地质,2016,36(4):30-36.
[9]张运周,徐胜林,陈洪德,等.川东北旺苍地区栖霞组地球化学特征及其古环境意义[J].石油实验地质,40(2):210-217.
[10]陈志鹏,任战利,于春勇,等.银额盆地哈日凹陷下白垩统热水沉积岩特征及成因.[J].地球科学,2018,43(4):1-21.
[11]范玉海,屈红军,王辉,等.微量元素分析在判别沉积介质环境中的应用---以鄂尔多斯盆地西部中区晚三叠世为例[J].中国地质,2012,39(2):382-389.
[12]李浩,陆建林,李瑞磊,等.长岭断陷下白垩统湖相烃源岩形成古环境及主控因素[J].地球科学---中国地质大学学报,2017,42(10):1774-1786.
[13]张文伟.基于主(微)量元素分析法的细粒沉积岩沉积环境判别---以大民屯凹陷安福屯地区沈352井沙四下亚段为例[J].东北石油大学学报,2017,41(4):99-106.
[14]周长勇,张启跃,吕涛,等.云南中三叠世罗平生物群产出地层的地球化学特征和沉积环境[J].地质论评,2014,60(2):285-298.
[15]张妮,林春明,周健,等.苏北盆地高邮凹陷古近系戴南组一段元素地球化学特征及其地质意义[J].地质学报,2012,86(2):269-279.
[16]MCCULLOCH M,CAPPO M,AUMEND J,et al.Tracing the life history of individual barramundi using laser ablation MC-ICP-MS Sr-isotopic and Sr/Ba ratios in otoliths[J].Marine&Freshwater Research,2005,56(5):637-644.
[17]王峰,刘玄春,邓秀芹,等.鄂尔多斯盆地纸坊组微量元素地球化学特征及沉积环境指示意义[J].沉积学报,2017,35(6):1265-1273.
[18]李俊花,白光勇,张谊理.孤东油田上第三系馆陶组上段微量元素的分布特征及沉积环境分析[J].石油大学学报(自然科学版),1993,17(3):114-117.
[19]KEITH M L,WEBER J N.Carbon and oxygen isotopic composition of selected limestones and fossils[J].Geochimica Et Cosmochimica Acta,1964,28(S1):1787-1816.
[20]孙建伟,付永涛,兰朝利.青岛八仙墩碎屑岩微量元素地球化学特征及沉积环境意义[J].海洋科学,2014,38(8):75-81.
[21]吴智平,周瑶琪.一种计算沉积速率的新方法---宇宙尘埃特征元素法[J].沉积学报,2000,18(3):395-399.
[22]孟苗苗,康志宏,樊太亮,等.痕量元素和碳氧同位素在塔里木盆地西南缘棋盘组沉积环境研究中的应用[J].成都理工大学学报(自然科学版),2016,43(1):77-85.
[23]陈建强,周洪瑞,王训练.沉积学及古地理学教程[M].北京:地质出版社,2004:84.
[24]贾艳艳,邢学军,孙国强,等.柴北缘西段古-新近纪古气候演化[J].地球科学---中国地质大学学报,2015,40(12):1955-1967.
[25]施辉,刘震,连良达.高原咸化湖盆岩性油气藏富集规律---以柴达木盆地西南区为例[J].天然气地球科学,2013,24(4),701-710.
[26]胡晓峰,刘招君,柳蓉,等.抚顺盆地始新统军屯组微量元素特征及油页岩的有利成矿条件[J].吉林大学学报(自然科学版),2012,42(3),60-70.