安徽巢湖平顶山西坡剖面下三叠统殷坑组沉积及地球化学特征
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摘要
本文在对安徽巢湖平顶山西坡剖面下三叠统殷坑组解剖的基础上,着重对其内部赋存的碳酸盐岩的矿物组成、结构构造、化学成分及碳氧同位素特征等方面做了系统研究,探讨了其沉积环境和成岩环境,以及与海平面变化的关系等。研究表明,下三叠统殷坑组是在海水不断变深的背景下沉积的,经历了较浅水开阔台地、较深水的上斜坡和下斜坡,最后到深水盆地的4个演化过程。瘤状灰岩在殷坑组极其发育,由瘤体和基质两部分组成,瘤体多为灰色、浅灰色或灰白色微晶灰岩、泥晶微晶灰岩和微晶泥晶灰岩;基质颜色较深,以黄色、褐黄色和黄灰色钙质泥岩为主。条带状、断续状和杂乱状瘤状灰岩在剖面上呈规律性分布,与其所处的沉积环境和后期成岩作用强度密切相关,它们分别发育在下斜坡、上斜坡和深水盆地环境,溶蚀作用依次增强。殷坑组碳酸盐岩δ13 C处于负值区,自下而上,由-5.97‰变为-1.17‰,记录了一个明显的δ13 C正向大漂移,幅度达到4.80‰,这可能与生物复苏、有机质大量埋藏,以及海平面上升和沉积环境的改变有关。
In this paper,we discussed the sedimentary and diagenetic environments of the Early Triassic Yinkeng Formation at the west Pingdingshan section,Chaohu,Anhui Province,based on the detailed analyses of sedimentary sequence,mineral composition,sedimentary texture and structure,chemical components,as well as carbon and oxygen isotopes of the carbonates.The results indicate that the Yinkeng Formation contains four sedimentary facies,including the shallow open platform,upper slope,lower slope,and deep basin from bottom up,with the water depth and sea level deepening and rising,respectively.Nodular limestones,which are composed of nodules and matrix,are common in this formation.The nodule is gray or gray white micritic calcite while the matrix occurs predominantly of yellow,brown-yellow,and yellowgray calcareous mudstones.Three types of nodular limestones,namely the banded nodular limestone,discontinuous nodular limestone,and random nodular limestone,are regularly distributed in the section,which may reflect original sedimentary environment from upper slope,lower slope to deep basin,respectively,with dissolution gradually increasing,and following diagenetic intensity.In addition,theδ13C values of the carbonate in the Yinkeng Formation range from-5.97‰ to-1.17‰,displaying an obvious positive excursion with the magnitude up to 4.80‰,which may result from the biotic recovery,burial of organic matters,sea-level rising,and environmental changing.
In this paper,we discussed the sedimentary and diagenetic environments of the Early Triassic Yinkeng Formation at the west Pingdingshan section,Chaohu,Anhui Province,based on the detailed analyses of sedimentary sequence,mineral composition,sedimentary texture and structure,chemical components,as well as carbon and oxygen isotopes of the carbonates.The results indicate that the Yinkeng Formation contains four sedimentary facies,including the shallow open platform,upper slope,lower slope,and deep basin from bottom up,with the water depth and sea level deepening and rising,respectively.Nodular limestones,which are composed of nodules and matrix,are common in this formation.The nodule is gray or gray white micritic calcite while the matrix occurs predominantly of yellow,brown-yellow,and yellowgray calcareous mudstones.Three types of nodular limestones,namely the banded nodular limestone,discontinuous nodular limestone,and random nodular limestone,are regularly distributed in the section,which may reflect original sedimentary environment from upper slope,lower slope to deep basin,respectively,with dissolution gradually increasing,and following diagenetic intensity.In addition,theδ13C values of the carbonate in the Yinkeng Formation range from-5.97‰ to-1.17‰,displaying an obvious positive excursion with the magnitude up to 4.80‰,which may result from the biotic recovery,burial of organic matters,sea-level rising,and environmental changing.
引文
陈强,张慧元,李文厚,郝松立,刘卓.2012.鄂尔多斯奥陶系碳酸盐岩碳氧同位素特征及其意义.古地理学报,14(1):117~124.
冯增昭,吴胜和.1987.下扬子地区中一下三叠统青龙群岩相古地理研究及编图.沉积学报,5(3):40~58.
高剑峰,陆建军,赖鸣远,林雨萍,濮巍.2003.岩石样品中微量元素的高分辨率等离子质谱分析.南京大学学报(自然科学版),39(6):844~850.
郭福生,彭花明,潘家永,杜杨松,刘林清,罗能辉,饶明辉,王正其.2003.浙江江山寒武系碳酸盐岩碳氧同位素特征及其古环境意义探讨.地层学杂志,27(4):289~297.
郭刚,童金南,张世红,张杰,白凌燕.2007.安徽巢湖早三叠世印度期旋回地层研究.中国科学(D辑:地球科学),37(12):1571~1578.
靳学斌,李壮福,陆鹿,冯乐.2014.下扬子巢湖地区下三叠统瘤状灰岩成因再探讨.高校地质学报,20(3):445~453.
李心清,万国江.1999.碳酸盐岩氧、碳稳定同位素地球化学研究目前面临的几个问题.地球科学进展,14(3):262~268.
李玉成.1998.华南晚二叠世碳酸盐岩的碳同位素旋回对海平面变化的响应.沉积学报,16(3):52~57.
林春明,黄志城,刘家润,凌洪飞,张顺,赵彦彦.2002a.安徽巢湖凤凰山石炭系微相和层序地层特征.岩石学报,18(3):424~433.
林春明,张顺,王淑君,刘家润,凌洪飞.2002b.苏皖地区石炭系露头层序地层研究.沉积学报,18(4):537~544.
林春明,凌洪飞,王淑君,张顺.2002c.苏皖地区石炭纪海相碳酸盐岩碳、氧同位素演化规律.地球化学,31(5):415~423.
林春明,杨湘宁,卓弘春,漆滨汶.2005.贵州宗地剖面晚石炭世-二叠纪早期层序地层特征.地质论评,51(6):698~707.
罗顺社,汪凯明.2010.河北宽城地区中元古代高于庄组碳酸盐岩碳氧同位素特征.地质学报,84(4):492~499.
钱迈平,郭佩霞.1996.下扬子区三叠纪古生物和古地理变迁及其主要原因.江苏地质,20(3):156~165.
童金南,殷鸿福.1999.浙江长兴煤山剖面Griesbachian期旋回地层研究.地层学杂志,23:130~135.
童金南,赵来时,左景勋,Hansen H J,Zakharov Y D.2005.安徽巢湖地区下三叠统综合层序.地球科学一中国地质大学学报,30(1):40~46.
童金南,左景勋,赵来时,段冶,张建军,Zakharov Y D,Hansen HJ.2004.安徽巢湖下三叠统剖面研究.北京:地质出版社,地层古生物论文集,第28辑:147~163.
童金南,殷鸿福.2015.三叠纪年代地层与中国建阶.地球科学一中国地质大学学报,40(2):189~197.
童金南.1997.下扬子区海相三叠系层序地层研究.中国科学(D辑:地球科学),27(5):407~409.
王大锐,冯晓杰.2002.渤海湾地区下古生界碳、氧同位素地球化学研究.地质学报,76(3):400~408.
张霞,林春明,凌洪飞,蒋少涌,李艳丽,高丽坤,姚玉来,刘晓.2009.浙西地区奥陶系砚瓦山组瘤状灰岩及其成因探讨.古地理学报,11(5):481~490.
赵来时,童金南,Orchard,左景勋.2005.安徽巢湖地区下三叠统牙形石生物地层分带及其全球对比.地球科学-中国地质大学学报,30(5):623~634.
左景勋,童金南,邱海鸥,赵来时.2003.巢湖地区早三叠世碳氧同位素地层对比及其古生态环境意义.地质地球化学,31(3):26~33.
左景勋,童金南,邱海鸥,赵来时.2004.巢湖平顶山北坡剖面早三叠世碳、氧同位素地层学研究.地层学杂志,28(1):35~40,47.
左景勋,童金南,邱海鸥,赵来时.2006.下扬子地区早三叠世碳酸盐岩碳同位素组成的演化特征.中国科学(D辑:地球科学),36(2):109~122.
左景勋,童金南,赵来时,常德峰,赵荣军.2013.早三叠世下扬子古海洋地球化学环境的修复过程.地球科学-中国地质大学学报,38(3):441~453.
Derry L A,Kaufman A J,Jacobsen S B.1992.Sedimentary cycling and environmental change in the Late Proterozoic:Evidence from stable and radiogenic isotopes.Geochimica et Cosmochimica Acta,56:1317~1329.
Grotsch J,Billing I and Vahrenkamp V.1998.Carbon-isotope stratigraphy in shallow-water carbonates:implications for Cretaceous black-shale deposition.Sedimentology,45:623~634.
Kaufman A J,Knoll A H.1995.Neoproterozoic variations in the C-isotopic composition of seawater:stratigraphic and biogeochemical implications.Precambrian Research,73:27~49.
Mii H S,Grossman E L,Yancey T E.1999.Carboniferous isotope stratigraphies of North America:implication for Carboniferous paleocenography and Mississippian glaciation.Geological Society of America Bulletin,111(7):960~973.
QingHairuo,Veizer J.1994.Oxygen and carbon isotopic composition of Ordovician brachiopods:implications for coeval seawater.Geochimica et Cosmochimica Acta,58(20):4429~4442.
Tong J N,Qiu H O,Zhao L S,Zuo J X.2002.Lower Triassic Carbon Isotope Excursion in Chaohu,Anhui Province,China.Journal of China University of Geosciences.13(2):98~106.
Veizer J,Bruckschen P,Pawellek F,Diener A,Podlaha O G,Carden G A F,Jasper T,Korte C,Strauss H,Azmy K,Ala D.1997.Oxygen isotope evolution of Phanerozoic seawater.Palaeogeography,Palaeoclimatology,Palaeoecology,132:159~172.
Veizer J,Demovic R.1974.Strontium as a tool in facies analysis.Journal of Sedimentary Research,44(1):93~115.
冯增昭,吴胜和.1987.下扬子地区中一下三叠统青龙群岩相古地理研究及编图.沉积学报,5(3):40~58.
高剑峰,陆建军,赖鸣远,林雨萍,濮巍.2003.岩石样品中微量元素的高分辨率等离子质谱分析.南京大学学报(自然科学版),39(6):844~850.
郭福生,彭花明,潘家永,杜杨松,刘林清,罗能辉,饶明辉,王正其.2003.浙江江山寒武系碳酸盐岩碳氧同位素特征及其古环境意义探讨.地层学杂志,27(4):289~297.
郭刚,童金南,张世红,张杰,白凌燕.2007.安徽巢湖早三叠世印度期旋回地层研究.中国科学(D辑:地球科学),37(12):1571~1578.
靳学斌,李壮福,陆鹿,冯乐.2014.下扬子巢湖地区下三叠统瘤状灰岩成因再探讨.高校地质学报,20(3):445~453.
李心清,万国江.1999.碳酸盐岩氧、碳稳定同位素地球化学研究目前面临的几个问题.地球科学进展,14(3):262~268.
李玉成.1998.华南晚二叠世碳酸盐岩的碳同位素旋回对海平面变化的响应.沉积学报,16(3):52~57.
林春明,黄志城,刘家润,凌洪飞,张顺,赵彦彦.2002a.安徽巢湖凤凰山石炭系微相和层序地层特征.岩石学报,18(3):424~433.
林春明,张顺,王淑君,刘家润,凌洪飞.2002b.苏皖地区石炭系露头层序地层研究.沉积学报,18(4):537~544.
林春明,凌洪飞,王淑君,张顺.2002c.苏皖地区石炭纪海相碳酸盐岩碳、氧同位素演化规律.地球化学,31(5):415~423.
林春明,杨湘宁,卓弘春,漆滨汶.2005.贵州宗地剖面晚石炭世-二叠纪早期层序地层特征.地质论评,51(6):698~707.
罗顺社,汪凯明.2010.河北宽城地区中元古代高于庄组碳酸盐岩碳氧同位素特征.地质学报,84(4):492~499.
钱迈平,郭佩霞.1996.下扬子区三叠纪古生物和古地理变迁及其主要原因.江苏地质,20(3):156~165.
童金南,殷鸿福.1999.浙江长兴煤山剖面Griesbachian期旋回地层研究.地层学杂志,23:130~135.
童金南,赵来时,左景勋,Hansen H J,Zakharov Y D.2005.安徽巢湖地区下三叠统综合层序.地球科学一中国地质大学学报,30(1):40~46.
童金南,左景勋,赵来时,段冶,张建军,Zakharov Y D,Hansen HJ.2004.安徽巢湖下三叠统剖面研究.北京:地质出版社,地层古生物论文集,第28辑:147~163.
童金南,殷鸿福.2015.三叠纪年代地层与中国建阶.地球科学一中国地质大学学报,40(2):189~197.
童金南.1997.下扬子区海相三叠系层序地层研究.中国科学(D辑:地球科学),27(5):407~409.
王大锐,冯晓杰.2002.渤海湾地区下古生界碳、氧同位素地球化学研究.地质学报,76(3):400~408.
张霞,林春明,凌洪飞,蒋少涌,李艳丽,高丽坤,姚玉来,刘晓.2009.浙西地区奥陶系砚瓦山组瘤状灰岩及其成因探讨.古地理学报,11(5):481~490.
赵来时,童金南,Orchard,左景勋.2005.安徽巢湖地区下三叠统牙形石生物地层分带及其全球对比.地球科学-中国地质大学学报,30(5):623~634.
左景勋,童金南,邱海鸥,赵来时.2003.巢湖地区早三叠世碳氧同位素地层对比及其古生态环境意义.地质地球化学,31(3):26~33.
左景勋,童金南,邱海鸥,赵来时.2004.巢湖平顶山北坡剖面早三叠世碳、氧同位素地层学研究.地层学杂志,28(1):35~40,47.
左景勋,童金南,邱海鸥,赵来时.2006.下扬子地区早三叠世碳酸盐岩碳同位素组成的演化特征.中国科学(D辑:地球科学),36(2):109~122.
左景勋,童金南,赵来时,常德峰,赵荣军.2013.早三叠世下扬子古海洋地球化学环境的修复过程.地球科学-中国地质大学学报,38(3):441~453.
Derry L A,Kaufman A J,Jacobsen S B.1992.Sedimentary cycling and environmental change in the Late Proterozoic:Evidence from stable and radiogenic isotopes.Geochimica et Cosmochimica Acta,56:1317~1329.
Grotsch J,Billing I and Vahrenkamp V.1998.Carbon-isotope stratigraphy in shallow-water carbonates:implications for Cretaceous black-shale deposition.Sedimentology,45:623~634.
Kaufman A J,Knoll A H.1995.Neoproterozoic variations in the C-isotopic composition of seawater:stratigraphic and biogeochemical implications.Precambrian Research,73:27~49.
Mii H S,Grossman E L,Yancey T E.1999.Carboniferous isotope stratigraphies of North America:implication for Carboniferous paleocenography and Mississippian glaciation.Geological Society of America Bulletin,111(7):960~973.
QingHairuo,Veizer J.1994.Oxygen and carbon isotopic composition of Ordovician brachiopods:implications for coeval seawater.Geochimica et Cosmochimica Acta,58(20):4429~4442.
Tong J N,Qiu H O,Zhao L S,Zuo J X.2002.Lower Triassic Carbon Isotope Excursion in Chaohu,Anhui Province,China.Journal of China University of Geosciences.13(2):98~106.
Veizer J,Bruckschen P,Pawellek F,Diener A,Podlaha O G,Carden G A F,Jasper T,Korte C,Strauss H,Azmy K,Ala D.1997.Oxygen isotope evolution of Phanerozoic seawater.Palaeogeography,Palaeoclimatology,Palaeoecology,132:159~172.
Veizer J,Demovic R.1974.Strontium as a tool in facies analysis.Journal of Sedimentary Research,44(1):93~115.
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