Geochemical Characteristics of Elements and Their Geological Significance in the Boundary between Yanjiahe Formation and Shuijingtuo Formation of the Early Cambrian in Yichang area
-
摘要: 为揭示宜昌地区早寒武世岩家河组-水井沱组转换时期的沉积环境、物源及构造背景，本文对宜昌暮阳溪剖面岩家河组-水井沱组界线上下采集的样品进行了元素地球化学分析。结果表明：排除成岩作用和陆缘碎屑影响后，对比稀土元素北美页岩标准化配分曲线、(La/Sm)N、(Gd/Yb) N特征，岩家河组-水井沱组轻、重稀土元素存在一定程度分异，且水井沱组轻、重稀土元素分异程度较岩家河组强；U、V、Ni、Co、Cr、Cu富集系数，Mo EF -UEF协变图及V/(V+Ni)、δU表明岩家河组-水井沱组界线上下沉积时期总体处在缺氧还原环境中，但局部还原程度不一；La/Yb-ΣREE图解、Eu/ΣREE-ΣLREE/ΣHREE散点图和(K2O/Na2O)-SiO2图解特征显示岩家河组-水井沱组界线附近源岩主要为上地壳沉积岩类-玄武岩类，源区构造背景为被动大陆边缘。Abstract: In order to reveal the depositional environment, provenance and structural setting of the Early Cambrian Yanjiahe Formation-Shuijingtuo Formation transition period in Yichang area, this paper analyzed the element geochemistry of samples collected from above and below the Yanjiahe Formation-Shuijingtuo Formation boundary in Muyangxi Section, Yichang. The results show that: Excluding diagenetic and marginal clastic influences, the comparison of NASC standardized partition curve, (La/Sm) N and (Gd/Yb) N characteristics of rare earth elements shows that the light rare earth elements of Yanjiahe Formation and Shuijingtuo Formation have mild to moderate differentiation, while the heavy rare earth elements have weak differentiation, and the light and heavy rare earth elements of Shuijingtuo Formation have stronger differentiation than that of Yanjiahe Formation. The enrichment coefficients of U, V, Ni, Co, Cr, Cu, Mo EF -UEF covariant diagram and value of V/(V+Ni) and δU indicate that the sedimentary period above and below the boundary of Yanjiahe Formation and Shuijingtuo Formation was generally in anoxic reduction environment, but the local reduction degree was different. La/Yb-ΣREE、Eu/ΣREE-ΣLREE/ΣHREE and (K2O/Na2O)-SiO2 suggest that there may be a mixture source of sedimentary rocks and basalt from upper crust near the Yanjiahe Formation – Shuijingtuo Formation boundary. The tectonic setting of the source area is the passive continental margin.
-
Key words:
- element geochemistry /
- Yanjiahe Formation /
- Shuijingtuo Formation /
- Early Cambrian /
- Yichang, Hubei
-
-
[1] 陈孝红,危凯,张保民,李培军,李海,刘安,罗胜元.2018.湖北宜昌寒武系水井沱组页岩气藏主控地质因素和富集模式[J].中国地质,45(2):207-226.
[2] 常华进,储雪蕾,冯连君,黄晶,张启锐.2009.氧化还原敏感微量元素对古海洋沉积环境的指示意义[J].地质论评,55(1):91-99.
[3] 杜洋,樊太亮,高志前.2016.塔里木盆地中下奥陶统碳酸盐岩地球化学特征及其对成岩环境的指示—以巴楚大板塔格剖面和阿克苏蓬莱坝剖面为例[J].天然气地球科学,27(8):1509-1523.
[4] 郭俊锋,强亚琴,宋祖晨,郑亚娟,姚肖永,肖良,李相传.2017.寒武纪早期岩家河生物群:研究进展和展望[J].古生物学报,56(4):461-475.
[5] 胡亚,陈孝红.2017.三峡地区前寒武纪－寒武纪转折期黑色页岩地球化学特征及其环境意义[J]．地质科技情报,36(1):61-71.
[6] 何佳伟,谢渊,侯明才,刘建清,何利,芦云飞.2021.川西南盐津地区志留系龙马溪组页岩地球化学特征及地质意义[J].古地理学报,23(6):1174-1191.
[7] 罗胜元,陈孝红,李培军,唐协华.2020.鄂西宜昌地区寒武系常规、非常规天然气显示及勘探意义[J].地质通报,39(4):538-551.
[8] 罗胜元,李培军,陈孝红,倪方杰,李海,刘安.2022.鄂西宜昌地区寒武系页岩测井评价及优质储层识别[J].华南地质,38(3):417-430.
[9] 李琪琪,蓝宝锋,李刚权,徐尚,刘婷,苟启洋,王雨轩.2021.黔中隆起北缘五峰-龙马溪组页岩元素地球化学特征及其地质意义[J].地球科学,46(9):3172-3188.
[10] 李娟,于炳松,郭峰.2013.黔北地区下寒武统底部黑色页岩沉积环境条件与源区构造背景分析[J].沉积学报,31(1):20-31.
[11] 潘时妹,冯庆来,常珊.2018.湖北宜昌寒武系纽芬兰统岩家河组小壳化石[J].微体古生物学报,35(1):30-40.
[12] 田兴磊,雒昆利,王少彬,倪润祥.2014.长江三峡地区成冰纪—埃迪卡拉纪转换时期微量元素和稀土元素地球化学特征[J].古地理学报,16(4):483-502.
[13] 田兴磊,雒昆利.2017.三峡地区埃迪卡拉系至下寒武统地层中硒的含量分布富集规律[J].中国科学:地球科学,47(8):881-898.
[14] 田洋,赵小明,王令占,涂兵,谢国刚,曾波夫.2015.鄂西南利川三叠纪须家河组地球化学特征及其对风化、物源与构造背景的指示[J].岩石学报,31(1):261-272.
[15] 闫斌,朱祥坤,张飞飞,唐索寒.2014.峡东地区埃迪卡拉系黑色页岩的微量元素和Fe 同位素特征及其古环境意义[J].地质学报,88(8):1603-1615.
[16] 危凯,李旭兵,刘安,李继涛,白云山,周鹏,陈孝红.2015.湖南慈利溪口剖面埃迪卡拉系陡山沱组碳酸盐岩微量元素特征及其古环境意义[J].古地理学报,17(3):297-308.
[17] 吴朝东,杨承运,陈其英.1999.湘西黑色岩系地球化学特征和成因意义[J].岩石矿物学杂志,18(1):28-29.
[18] 曾雄伟,王志宏.2022.湖北宜昌樟村坪陡山沱组沉积的氧化还原环境及其成磷意义——来自微量元素的约束[J].华南地质,38(3):533-541.
[19] 赵坤,李婷婷,朱光有,张志遥,李婧菲,王鹏举,闫慧慧,陈永进.2020.下寒武统优质烃源岩的地球化学特征与形成机制—以鄂西地区天柱山剖面为例[J].石油学报,41(1):13-26.
[20] 张克信,何卫红,徐亚东,骆满生,宋博文,张智勇,潘桂棠,王永和, 赵小明, 邢光福.2014. 沉积大地构造相划分与鉴别[J].地球科学——中国地质大学学报,39(8):915-928.
[21] 张沛,郑建平,张瑞生,余淳梅.2005.塔里木盆地塔北隆起奥陶系—侏罗系泥岩稀土元素地球化学特征[J].沉积学报,23(4):740-746.
[22] 张晓潼,袁华茂,宋金明,段丽琴.2022.海洋Re、Mo和U对氧化还原环境的指示作用[J]. 地球科学进展,37(4):358-369.
[23] Allègre C J, Minster J F. 1978. Quantitative models of trace element behavior in magmatic processes[J]. Earth and Planetary Science Letters, 38(1):1-25.
[24] Algeo T J, Tribovillard N. 2009. Environmental analysis of paleoceanographic systems based on molybdenum-uranium covariation[J]. Chemical Geology, 268(3/4): 211-225.
[25] Bhatia M R, Taylor S R. 1981. Trace-element geochemistry and sedimentary provinces: A study from the Tasman Geosyncline, Australia[J]. Chemical Geology, 33(1-4): 115-125.
[26] Bhatia M R. 1985. Rare earth element geochemistry of Australian Paleozoic graywackes and mudrocks: Provenance and tectonic control[J]. Sedimentary Geology, 45(1-2): 97-113.
[27] Boynton W V. 1984. Cosmochemistry of the rare earth element[A].// In: Henderson P (ed). Rare Earth Element Geochemistry: Developments in Geochemistry[M]. Amsterdam: Elsevier, 63-114.
[28] Condie K C. 1989. Geochemical changes in basalts and andesites across the Archean-Proterozoic boundary: Identification and significance[J]. Lithos, 23(1-2):1-18.
[29] HaskinMA, Haskin LA. 1966. Rare earths in European shales: a redetermination[J]. Science, 154(3748): 507-509.
[30] Hatch J R, Leventhal J S. 1992. Relationship between inferred redox potential of the depositional environment and geochemistry of the Upper Pennsylvanian (Missourian) Stark Shale Member of the Dennis Limestone, Wabaunsee County, Kansas, U.S.A[J]. Chemical Geology, 99(1-3):65-82.
[31] Holland H D. 1978. The Chemistry of the Atmosphere and Oceans[J]. New York:Wiley, 351-373.
[32] Ishikawa T, Ueno Y, Komiya T, Sawaki Y, Jian H, Shu D, Yong L, Maruyama S, Yoshida N. 2008. Carbon isotope chemostratigraphy of a Precambrian / Cambrian boundary section in the Three Gorge area, South China: Prominent global-scale isotope excursions just before the Cambrian Explosion[J]. Gondwana Research, 14(1-2): 193-208.
[33] Ishikawa T, Ueno Y, Shu D, Yong L, Jian H, Guo J, Yoshida N, Komiya T. 2013. Irreversible change of the oceanic carbon cycle in the earliest Cambrian: High-resolution organic and inorganic carbon chemostratigraphy in the Three Gorges area, South China[J]. Precambrian Research, 225: 190-208.
[34] Jones B J, Manning A C. 1994. Comparison of geochemical indices used for the interpretation of palaeoredox conditions in ancient mudstones[J]. Palaeogepgrphy Palaeoclimatology Palaeoecology, 111(1-4):111-129.
[35] McLennan S M. 1989. Rare earth elements in sedimentary rocks: influence of provenance and sedimentary processes[J].Reviews in Mineralogy and Geochemistry, 21(1): 169-200.
[36] Piper D Z, Perkins R B. 2004. A modern vs Permian black shale: The hydrograph, primary productivity, and water-column chemistry of deposition[J]. Chemical Geology, 206(3-4): 177-197.
[37] Roser B P, Korsch R J. 1988. Provenance signatures of sandstone-mudstone suites determined using discriminant function analysis of major-element data[J]. Chemical Geology, 67(1-2):119-139.
[38] Shields G, Stille P. 2001. Diagenetic constraints on the use of cerium anomalies as palaeoseawater redox proxies: an isotopic and REE study of Cambrian phosphorites[J]. Chemical Geology, 175(1): 29-48.
[39] Tawfik H A, Ghandour I M, MaejimaW, Armstrong A J S, Hameed A A. 2017. Petrography and geochemistry of the siliciclastic Araba Formation (Cambrian), east Sinai, Egypt: implications for provenance, tectonic setting and source weathering[J]. Geological Magazine,154(1): 1-23.
[40] Tribovillard N, Algeo T J, Lyons T, Riboulleau A. 2006. Trace metals as paleoredox and paleoproductivity proxies: An update[J]. Chemical Geology, 232:12-32.
[41] Webb G E, Kamber B S. 2000. Rare earth elements in Holocene reefal microbialites: a new shallow seawater proxy[J]. Geochimica et Cosmochimica Acta, 64(9): 1557-1565.
-
计量
- 文章访问数: 758
- PDF下载数: 183
- 施引文献: 0
下载: