Carbon isotope excursion and its genetic mechanism during the Sinian to Cambrian transition in the northern Tarim Basi

doi:10.13745/j.esf.sf.2020.7.5

Abstract

Abstract:

The Sinian to Cambrian transition is a time node for the Earth evolution, yet carbon and oxygen isotopes, which are well preserved in the Tarim Basin during this period, are barely studied. Here, based on the measurements of the Sugaitebulake outcrop, a comprehensive analysis of paleontology, microscopic identification, and carbon isotope excursions is carried out, and the genetic mechanism of the N1 (BACE) and P1 (ZHUCE) excursion events is explained. The correlation coefficient between δ ¹³C_carb and δ¹⁸O_carb (R²= 0.05) or δ ¹⁸O_carb and Mn/Sr (R²= 0.09), as well as microscopic characteristics, shows that the later diagenesis did not lead to fractionation of carbon and oxygen isotopes significantly, and the original carbon isotopic characteristics are basically preserved. Six carbon excursions were detected from the bottom to the top of the formation, which comprise, respectively, excursions P-1 with δ ¹³C_carb between 1.9‰ and 2.4‰, N1 with δ¹³C_carbbetween -6.8‰ and -10.3‰, P1 with δ¹³C_carb between 1.4‰ and 4.1‰, N2a-c with δ¹³C_carb between -0.4‰ and -2.8‰, P2a-c with δ¹³C_carb between 0.2‰ and 0.6‰, and N3 with δ¹³C_carb peaked at -3.4‰. Together with paleontological and chronological constraints, the interface between silica-phosphorus shale of the bottom Yuertusi Formation and algal-dolomite of the top Qigebulake Formation is confirmed as the boundary of the Sinian to Cambrian of the northern Tarim Basin. Also completed is a structural correlation framework comparing the northern Tarim with Tabei, Laolin, Xiaotan, Three Gorges, Siberia, Oman, and Morocco plates. It reveals the carbon isotope excursions during the Sinian to Cambrian transition in northern Tarim are more controlled by the fluctuation of carbon fixation rate (f_org) due to paleo-marine redox changes. The decreased productivity and carbon fixation, caused by large-scale anoxic events in the transgression of the Yuertusi Formation, is the main reason for the N1 excursion; then the recovered productivity and carbon fixation from oxygen increase during regression forms the P1 excursion. The above results are beneficial for the further study of the Cambrian paleo-environments and evaluation of the deep to ultra-deep resources in the Tarim Basin.

Key words: Tarim, Sinian, Cambrian, carbon isotope, excursion, carbon fixation

CLC Number:

FAN Qi, FAN Tailiang, LI Qingping, ZHANG Yan, GU Yu, SHANG Yaxin. Carbon isotope excursion and its genetic mechanism during the Sinian to Cambrian transition in the northern Tarim Basi[J]. Earth Science Frontiers, 2021, 28(5): 436-447.

Figures/Tables 9

References 31

[1]	BAMHACH R K. Phanerozoic biodiversity mass extinctions[J]. Annual Review of Earth and Planetary Sciences, 2006, 34(1):127-155. DOI URL
[2]	ZHU M Y, STRAUSS H, SHIELDS G A. From snowball earth to the Cambrian bioradiation: calibration of Ediacaran-Cambrian Earth history in South China[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2007, 254(1/2):1-6. DOI URL
[3]	史晓颖, 李一良, 曹长群. 生命起源、早期演化阶段与海洋环境演变[J]. 地学前缘, 2016, 23(6):128-139.
[4]	陈斐然, 张颖, 徐祖新, 等. 全球前寒武—寒武系含油气盆地石油地质特征及成藏主控因素[J]. 吉林大学学报(地球科学版), 2017, 47(4):974-989.
[5]	许效松, 汪正江, 万方, 等. 塔里木盆地早古生代构造古地理演化与烃源岩[J]. 地学前缘, 2005, 12(3):49-57.
[6]	贾建忠, 万晓樵, 张翼翼, 等. 白垩纪中期海相富有机碳沉积的地球生物学背景[J]. 地学前缘, 2009, 16(5):143-152.
[7]	钱建新, 肖兵. 新疆阿克苏—乌什地区早寒武世小壳动物群[G]//地层古生物论文集. 北京: 地质出版社, 1984: 65-90.
[8]	肖兵, 段承华. 新疆早寒武世玉尔吐斯小壳动物群再研究[J]. 新疆地质, 1992(3):212-232.
[9]	肖兵. 化石Anabarites的发现及再论玉尔吐斯组的时代归属[J]. 新疆地质, 1989(4):35-39.
[10]	钱逸, 冯伟民, 李国祥, 等. 新疆寒武纪早期单壳类软体动物化石分类学与生物地层学[J]. 微体古生物学报, 2009, 26(3):193-210.
[11]	张光亚, 刘伟, 张磊, 等. 塔里木克拉通寒武纪—奥陶纪原型盆地、岩相古地理与油气[J]. 地学前缘, 2015, 22(3):269-276.
[12]	李日俊, 张洪安, 钱一雄, 等. 关于南天山碰撞造山时代的讨论[J]. 地质科学, 2010, 45(1):57-65.
[13]	陆松年, 李怀坤, 陈志宏. 塔里木与扬子新元古代热-构造事件特征、序列和时代: 扬子与塔里木连接(YZ-TAR)假设[J]. 地学前缘, 2003, 10(4):321-326.
[14]	樊奇, 樊太亮, 李一凡, 等. 塔里木地台北缘早寒武世古海洋氧化-还原环境与优质海相烃源岩发育模式[J]. 地球科学, 2020, 45(1):285-302.
[15]	樊茹, 邓胜徽, 张学磊. 寒武系碳同位素漂移事件的全球对比性分析[J]. 中国科学: D辑, 2011, 41(12):1829-1839.
[16]	GUO Q J, DENG Y N, HU J, et al. Carbonate carbon isotope evolution of seawater across the Ediacaran-Cambrian transition: evidence from the Keping area, Tarim Basin, NW China[J]. Geological Magazine, 2017, 154(6):1244-1256. DOI URL
[17]	WANG X L, HU W X, YAO S P, et al. Carbon and strontium isotopes and global correlation of Cambrian Series 2 to Series 3 carbonate rocks in the Keping area of the northwestern Tarim Basin, NW China[J]. Marine and Petroleum Geology, 2011, 28(5):992-1002. DOI URL
[18]	ISHIKAWA T, UENO Y, KOMIYA T, et al. 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, 2008, 14(1/2):193-208. DOI URL
[19]	KIKUMOTOI R, TAHATA M, NISHIZAWA M, et al. Nitrogen isotope chemostratigraphy of the Ediacaran and Early Cambrian platform sequence at Three Gorges, South China[J]. Gondwana Research, 2014, 25(3):1057-1069. DOI URL
[20]	旷红伟, 李家华, 彭楠, 等. 燕山地区1.6~1.0 Ga时期碳酸盐岩碳、氧同位素组成、演化及其地质意义[J]. 地学前缘, 2009, 16(5):118-133.
[21]	VEIZER J, ALA D, AZMY K, et al. ⁸⁷Sr/⁸⁶Sr, δ¹³C and δ¹⁸O evolution of Phanerozoic seawater[J]. Chemical Geology, 1999, 161(1):59-88. DOI URL
[22]	MARSHALL J D. Climatic and oceanographic isotopic signals from the carbonate rock record and their preservation[J]. Geological Magazine, 1992, 129(2):143-160. DOI URL
[23]	PENG S, BABCOOK L E, COOPER R A. The geological time scale, Chapter 19: the Cambrian Period[M]//The Geologic Time Scale 2012. Amsterdam: Elsevier, 2012: 1-52.
[24]	GUO Q, STRAUSS H, ZHU M, et al. High resolution organic carbon isotope stratigraphy from a slope to basinal setting on the Yangtze Platform, South China: implications for the Ediacaran-Cambrian transition[J]. Precambrian Research, 2013, 225:209-217. DOI URL
[25]	LI D, LING H F, SHIELDS-ZHOU G A, et al. Carbon and strontium isotope evolution of seawater across the Ediacaran-Cambrian transition: evidence from the Xiaotan section, NE Yunnan, South China[J]. Precambrian Research, 2013, 225:128-147. DOI URL
[26]	KAUFMAN A J, KNOLL A H, SEMIKHATOV M A, et al. Integrated chronostratigraphy of Proterozoic-Cambrian boundary beds in the western Anabar region, northern Siberia[J]. Geological Magazine, 1996, 133(5):505-553.
[27]	AMTHOR J E, GROTZINGER J P, SCHRODER S, et al. Extinction of Cloudina and Namacalathus at the Precambrian-Cambrian boundary in Oman[J]. Geology, 2003, 31(5):431-434. DOI URL
[28]	何秀彬, 徐备, 袁志云. 新疆柯坪地区新元古代晚期地层碳同位素组成及其对比[J]. 科学通报, 2007, 52(1):107-113.
[29]	GROTZINGER J P, BOWRING S A, SAYLOR B Z, et al. Biostratigraphic and geochronologic constraints on early animal evolution[J]. Science, 1995, 270(5236):598-604. DOI URL
[30]	BOWRING S A, GROTZINGER J P, ISACHSEN C E, et al. Calibrating rates of Early Cambrian evolution[J]. Science, 1993, 261(5126):1293-1298. DOI URL
[31]	杜小弟, 刘万洙, 王东坡. 碳氧同位素与海平面变化: 以新疆柯坪地区上震旦统—奥陶系碳氧同位素剖面为例[J]. 世界地质, 1994, 13(3):120-123.

地层	样品号	岩性	深度/ cm	TC含量/ %	TOC含量/ %	δ¹³C_carb/ ‰	δ¹⁸O_carb/ ‰	w(Fe)/ %	Mn/Sr	Mg/Ca	U/Al	Th/U
奇格布拉克组	SG8-1	白云岩	2 020.00	12.16	0.33	1.90	-5.20	0.39	0.01	0.59	7.35	0.35
奇格布拉克组	SG8-2	白云岩	1 975.00	12.08	0.30	2.40	-6.00	0.39	0.01	0.60	1.82	1.41
玉尔吐斯组	SG8-3	磷块岩	1 957.00	5.03	2.87	1.40	-8.90	4.22	0.00	0.50	5.33	0.25
	SG8-4	磷块岩	1 947.00	0.11	0.08	—	—	1.82	0.00	0.35	5.08	0.29
	SG8-5	磷块岩	1 920.00	0.40	0.21	-10.30	-6.00	4.90	0.00	0.39	96.66	0.00
	SG8-6	页岩	1 872.00	1.28	1.11	-6.90	-7.20	7.35	0.00	0.15	44.47	0.02
	SG8-7	页岩	1 847.00	3.87	3.70	-6.80	-9.20	6.93	0.00	0.31	29.67	0.04
	SG8-8	磷块岩	1 841.00	0.16	0.12	-7.80	-11.80	6.05	0.00	1.03	3.88	0.36
	SG8-9	泥灰岩	1 826.00	10.80	0.32	3.20	-7.50	1.69	0.01	0.52	7.74	0.45
	SG8-10	砂屑灰岩	1 808.00	5.96	0.25	2.70	-8.20	0.98	0.00	0.23	12.38	0.15
	SG8-11	白云岩	1 786.00	12.40	0.24	4.10	-8.30	1.19	0.02	0.57	1.92	1.28
	SG8-12	白云岩	1 594.00	12.00	0.23	1.40	-7.40	3.29	0.01	0.54	4.11	0.77
	SG8-13	白云岩	1 575.00	6.37	0.18	0.20	-5.00	1.77	0.01	0.38	2.46	0.81
	SG8-14	石膏	1 544.00	8.28	0.09	-1.90	-5.20	6.15	0.06	0.26	3.45	0.74
	SG8-15	泥灰岩	1 530.00	7.42	0.18	-1.00	-7.00	3.44	0.01	0.33	11.86	0.39
	SG8-16	泥灰岩	1 495.00	2.19	0.52	-0.40	-5.40	3.85	0.07	0.63	0.86	2.10
	SG8-17	重晶石	1 452.00	11.36	0.10	-2.70	-7.20	0.81	0.02	0.03	3.11	0.56
	SG8-18	泥灰岩	1 420.00	2.03	0.89	0.30	-4.40	3.03	0.02	0.59	0.42	0.56
	SG8-19	粉砂岩	1 387.00	10.50	0.12	-2.70	-7.30	0.69	0.02	0.02	11.09	1.22
	SG8-20	页岩	1 360.00	1.67	1.29	0.20	-6.00	3.67	0.02	0.33	1.88	0.96
	SG8-21	重晶石	1 317.00	10.10	0.11	-2.50	-6.60	2.67	0.01	0.04	2.72	0.72
	SG8-22	页岩	1 295.00	2.34	0.60	0.60	-3.10	3.70	0.02	0.41	2.66	0.82
	SG8-23	泥灰岩	1 255.00	10.90	0.14	-2.80	-7.20	0.92	0.01	0.02	6.19	0.26
	SG8-24	重晶石	1 100.00	11.00	0.02	-2.10	-7.40	1.10	0.02	0.02	1.51	1.31
	SG8-25	泥灰岩	1 075.00	11.60	0.04	-1.60	-6.80	1.16	0.01	0.03	3.74	0.51
	SG8-26	云灰岩	978.00	11.50	0.02	-0.50	-7.30	1.96	0.03	0.06	2.92	0.88
	SG8-27	云灰岩	864.00	2.72	0.14	0.40	-5.50	3.54	0.08	0.36	0.69	3.23
	SG8-28	泥灰岩	810.00	11.10	0.08	0.30	-6.40	2.81	0.07	0.17	1.42	2.33
	SG8-29	灰岩	762.00	10.40	0.06	0.70	-6.70	2.05	0.05	0.09	0.75	3.56
	SG8-30	白云岩	714.00	11.10	0.07	0.40	-7.40	1.59	0.01	0.03	2.49	1.28
	SG8-31	页岩	694.00	4.28	0.79	0.40	-6.80	3.68	0.10	0.37	1.78	1.35
	SG8-32	泥灰岩	575.00	11.10	0.09	0.10	-7.70	1.18	0.02	0.03	1.32	1.84
	SG8-33	云灰岩	544.00	11.00	0.12	-0.10	-7.40	1.15	0.03	0.08	1.23	2.27
	SG8-34	云灰岩	496.00	10.10	0.09	0.20	-6.80	2.11	0.07	0.15	0.77	3.91
	SG8-35	白云岩	396.00	11.00	0.19	-1.00	-7.20	1.40	0.10	0.49	0.97	2.67
	SG8-36	白云岩	326.00	10.70	0.12	-1.00	-7.40	1.03	0.04	0.56	1.79	1.52
	SG8-37	云灰岩	251.00	8.74	0.18	-2.00	-7.90	3.65	0.01	0.41	18.11	0.44
	SG8-38	白云岩	216.00	12.30	0.24	-1.70	-7.80	0.25	0.02	0.55	7.67	0.38
肖尔布拉克组	SG8-39	硅质岩	116.00	6.64	0.98	-1.10	-8.00	1.62	0.02	0.58	17.10	0.17
肖尔布拉克组	SG8-40	白云岩	47.00	12.90	0.63	-3.40	-7.50	0.08	0.00	0.60	109.93	0.04

地层	样品号	岩性	深度/ cm	TC含量/ %	TOC含量/ %	δ¹³C_carb/ ‰	δ¹⁸O_carb/ ‰	w(Fe)/ %	Mn/Sr	Mg/Ca	U/Al	Th/U
奇格布拉克组	SG8-1	白云岩	2 020.00	12.16	0.33	1.90	-5.20	0.39	0.01	0.59	7.35	0.35
奇格布拉克组	SG8-2	白云岩	1 975.00	12.08	0.30	2.40	-6.00	0.39	0.01	0.60	1.82	1.41
玉尔吐斯组	SG8-3	磷块岩	1 957.00	5.03	2.87	1.40	-8.90	4.22	0.00	0.50	5.33	0.25
	SG8-4	磷块岩	1 947.00	0.11	0.08	—	—	1.82	0.00	0.35	5.08	0.29
	SG8-5	磷块岩	1 920.00	0.40	0.21	-10.30	-6.00	4.90	0.00	0.39	96.66	0.00
	SG8-6	页岩	1 872.00	1.28	1.11	-6.90	-7.20	7.35	0.00	0.15	44.47	0.02
	SG8-7	页岩	1 847.00	3.87	3.70	-6.80	-9.20	6.93	0.00	0.31	29.67	0.04
	SG8-8	磷块岩	1 841.00	0.16	0.12	-7.80	-11.80	6.05	0.00	1.03	3.88	0.36
	SG8-9	泥灰岩	1 826.00	10.80	0.32	3.20	-7.50	1.69	0.01	0.52	7.74	0.45
	SG8-10	砂屑灰岩	1 808.00	5.96	0.25	2.70	-8.20	0.98	0.00	0.23	12.38	0.15
	SG8-11	白云岩	1 786.00	12.40	0.24	4.10	-8.30	1.19	0.02	0.57	1.92	1.28
	SG8-12	白云岩	1 594.00	12.00	0.23	1.40	-7.40	3.29	0.01	0.54	4.11	0.77
	SG8-13	白云岩	1 575.00	6.37	0.18	0.20	-5.00	1.77	0.01	0.38	2.46	0.81
	SG8-14	石膏	1 544.00	8.28	0.09	-1.90	-5.20	6.15	0.06	0.26	3.45	0.74
	SG8-15	泥灰岩	1 530.00	7.42	0.18	-1.00	-7.00	3.44	0.01	0.33	11.86	0.39
	SG8-16	泥灰岩	1 495.00	2.19	0.52	-0.40	-5.40	3.85	0.07	0.63	0.86	2.10
	SG8-17	重晶石	1 452.00	11.36	0.10	-2.70	-7.20	0.81	0.02	0.03	3.11	0.56
	SG8-18	泥灰岩	1 420.00	2.03	0.89	0.30	-4.40	3.03	0.02	0.59	0.42	0.56
	SG8-19	粉砂岩	1 387.00	10.50	0.12	-2.70	-7.30	0.69	0.02	0.02	11.09	1.22
	SG8-20	页岩	1 360.00	1.67	1.29	0.20	-6.00	3.67	0.02	0.33	1.88	0.96
	SG8-21	重晶石	1 317.00	10.10	0.11	-2.50	-6.60	2.67	0.01	0.04	2.72	0.72
	SG8-22	页岩	1 295.00	2.34	0.60	0.60	-3.10	3.70	0.02	0.41	2.66	0.82
	SG8-23	泥灰岩	1 255.00	10.90	0.14	-2.80	-7.20	0.92	0.01	0.02	6.19	0.26
	SG8-24	重晶石	1 100.00	11.00	0.02	-2.10	-7.40	1.10	0.02	0.02	1.51	1.31
	SG8-25	泥灰岩	1 075.00	11.60	0.04	-1.60	-6.80	1.16	0.01	0.03	3.74	0.51
	SG8-26	云灰岩	978.00	11.50	0.02	-0.50	-7.30	1.96	0.03	0.06	2.92	0.88
	SG8-27	云灰岩	864.00	2.72	0.14	0.40	-5.50	3.54	0.08	0.36	0.69	3.23
	SG8-28	泥灰岩	810.00	11.10	0.08	0.30	-6.40	2.81	0.07	0.17	1.42	2.33
	SG8-29	灰岩	762.00	10.40	0.06	0.70	-6.70	2.05	0.05	0.09	0.75	3.56
	SG8-30	白云岩	714.00	11.10	0.07	0.40	-7.40	1.59	0.01	0.03	2.49	1.28
	SG8-31	页岩	694.00	4.28	0.79	0.40	-6.80	3.68	0.10	0.37	1.78	1.35
	SG8-32	泥灰岩	575.00	11.10	0.09	0.10	-7.70	1.18	0.02	0.03	1.32	1.84
	SG8-33	云灰岩	544.00	11.00	0.12	-0.10	-7.40	1.15	0.03	0.08	1.23	2.27
	SG8-34	云灰岩	496.00	10.10	0.09	0.20	-6.80	2.11	0.07	0.15	0.77	3.91
	SG8-35	白云岩	396.00	11.00	0.19	-1.00	-7.20	1.40	0.10	0.49	0.97	2.67
	SG8-36	白云岩	326.00	10.70	0.12	-1.00	-7.40	1.03	0.04	0.56	1.79	1.52
	SG8-37	云灰岩	251.00	8.74	0.18	-2.00	-7.90	3.65	0.01	0.41	18.11	0.44
	SG8-38	白云岩	216.00	12.30	0.24	-1.70	-7.80	0.25	0.02	0.55	7.67	0.38
肖尔布拉克组	SG8-39	硅质岩	116.00	6.64	0.98	-1.10	-8.00	1.62	0.02	0.58	17.10	0.17
肖尔布拉克组	SG8-40	白云岩	47.00	12.90	0.63	-3.40	-7.50	0.08	0.00	0.60	109.93	0.04