安徽省巢湖地区二叠纪栖霞组、孤峰组硅质岩地球化学特征对比及大地构造背景分析
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摘要
为探讨下扬子地区二叠系硅质岩的硅质来源和形成背景,以巢湖地区二叠纪栖霞组和孤峰组硅质岩为研究对象,收集了前人大量有关栖霞组和孤峰组的研究成果和数据,并对采自栖霞组和孤峰组硅质岩样品进行了主量元素、微量元素、稀土元素测试。栖霞组、孤峰组硅质岩样品测试结果显示,硅质岩的稀土元素经北美页岩标准化后的配分曲线近似平坦型向左倾斜,有弱Ce负异常,且HREE弱富集,反映了热水沉积硅质岩的特征。研究区硅质岩样品的Al-FeMn三角图中,样品投点分布较广,即Al比值变化范围较大,认为是岩浆在喷发过程中受硅-铝质陆壳混染作用的结果。结合沉积环境判别指标分析认为:栖霞组硅质岩沉积时期其沉积环境主要为大陆边缘环境;孤峰组硅质岩沉积时期其沉积环境为大陆边缘-海盆过渡环境。从栖霞组到孤峰组沉积时期,海侵规模不断变大,水体变深,海盆面积扩大,研究区在不同时期沉积环境存在差异。研究区栖霞组、孤峰组硅质岩的沉积与大陆边缘裂陷活动紧密相关。
Aiming to discuss the origin and sedimentary background of Permian chert in Yangtze region,we took the siliceous rocks as samples from Qixia Formation and Gufeng Formation in Chaohu area,which located in the northern margin of the Yangtze block. In this study,we collected previous research data of these two formations and systematically analyzed major,trace and rare elements data of siliceous rocks collected from the two formations. Test results of samples which we got in this study show that rare earth elements( REEs) pattern curves lean slightly to the left,with slight Ce negative anomaly and HREE relative enrichment,reflects the characteristics of the hydrothermal chert. The points pitched on the Al-Fe-Mn diagram of Qixia Formation and Gufeng Formation siliceous rocks indicate that most of the samples are high in Al. In this paper,we proposed that magma suffered the contamination of the Si-Al rich continental crust during the eruption,with high Al ratio. Combined with diagrams of sedimentary environments we came to a conclusion that cherts in Qixia Formation and Gufeng Formation were deposited at continental margin,continental margin-ocean basin,respectively. From Qixia Period to Gufeng Period,transgression scale became large,the depth of seawater became large,the area of oceanbasin expanded,which made sedimentary environment different. The siliceous rocks sedimentation in both Qixia Formation and Gufeng Formation was closely related to continental margin chasmic activities.
Aiming to discuss the origin and sedimentary background of Permian chert in Yangtze region,we took the siliceous rocks as samples from Qixia Formation and Gufeng Formation in Chaohu area,which located in the northern margin of the Yangtze block. In this study,we collected previous research data of these two formations and systematically analyzed major,trace and rare elements data of siliceous rocks collected from the two formations. Test results of samples which we got in this study show that rare earth elements( REEs) pattern curves lean slightly to the left,with slight Ce negative anomaly and HREE relative enrichment,reflects the characteristics of the hydrothermal chert. The points pitched on the Al-Fe-Mn diagram of Qixia Formation and Gufeng Formation siliceous rocks indicate that most of the samples are high in Al. In this paper,we proposed that magma suffered the contamination of the Si-Al rich continental crust during the eruption,with high Al ratio. Combined with diagrams of sedimentary environments we came to a conclusion that cherts in Qixia Formation and Gufeng Formation were deposited at continental margin,continental margin-ocean basin,respectively. From Qixia Period to Gufeng Period,transgression scale became large,the depth of seawater became large,the area of oceanbasin expanded,which made sedimentary environment different. The siliceous rocks sedimentation in both Qixia Formation and Gufeng Formation was closely related to continental margin chasmic activities.
引文
[1]朱同兴.安徽南部下二叠统结核状硅质岩和层状硅质岩的沉积学特征及成因探讨[J].岩相古地理,1989(5):1-8.
[2]夏邦栋,钟立荣,方中,等.下扬子区早二叠世孤峰组层状硅质岩成因[J].地质学报,1995,69(2):125-137.
[3]杨水源,姚静.安徽巢湖平顶山中二叠统孤峰组硅质岩的地球化学特征及成因[J].高校地质学报,2008,14(1):39-48.
[4]韩宗珠,肖楠,李安龙,等.安徽巢湖下二叠统孤峰组硅质岩沉积地球化学特征与沉积环境[J].中国海洋大学学报,2014,44(4):78-85.
[5]程成,李双应,赵大千,等.扬子地台北缘中上二叠统层状硅质岩的地球化学特征及其对古地理、古海洋演化的响应[J].矿物岩石地球化学通报,2015,34(1):155-166.
[6]KAMETAKA M,TAKEBE M,NAGAI H,et al.Sedimentary environments of the Middle Permian phosphorite-chert complex from the northeastern Yangtze platform,China;the Gufeng Formation:a continental shelf radiolarian chert[J].Sedimentary Geology,2005,174(3/4):197-222.
[7]吕炳全,瞿建忠.下扬子地区早二叠世海进和上升流形成的缺氧环境的沉积[J].科学通报,1989,34(22):1721-1724.
[8]王汝建,沈高平,KATSUO Sashida.苏皖地区孤峰组放射虫动物群及其古环境意义[J].地质论评,1997,25(5):559-564.
[9]邱振,王清晨.广西来宾中上二叠统硅质岩海底热液成因的地球化学证据[J].中国科学:地球科学,2011,41(5):725-737.
[10]柴华,胡望水,唐友军,等.安徽宿松地区中二叠统栖霞组上升流相烃源岩地球化学特征[J].石油天然气学报,2012,34(3):1-6.
[11]杨锐,李红,柳益群,等.安徽巢湖地区中二叠统栖霞组灰岩中燧石成因[J].现代地质,2014,28(3):501-511.
[12]MURCHEY B L,JONES D L.A mid-Permian chert event:Widespread deposition of biogenic siliceous sediments in coastal,island arc and oceanic basins[J].Palaeogeography,Palaeoclimatology,Palaeoecology,1992,96:161-174.
[13]罗志立,金以钟,朱夔玉,等.试论上扬子地台的峨眉地裂运动[J].地质论评,1988,34(1):11-24.
[14]YAO X,ZHOU Y,HINNOV L A.Astronomical forcing of a Middle Permian chert sequence in Chaohu,South China[J].Earth and Planetary Science Letters,2015,422:206-221.
[15]WANG Yue,JIN Yugan.Permian palaeogeographic evolution of the Jiangnan Basin,South China[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2000,160(1):35-44.
[16]何雨旸,赵广涛,赵利,等.巢北地区二叠系栖霞组碳酸盐岩地球化学特征及其古环境意义[J].中国海洋大学学报,2014,44(5):79-88.
[17]杨瑞东.贵州晚二叠世硅质岩类型及沉积地球化学特征[J].贵州地质,1992,23(2):171-176.
[18]CHEN D,QING H,YAN X,et al.Hydrothermal venting and basin evolution(Devonian,South China):Constraints from rare earth element geochemistry of chert[J].Sedimentary Geology,2006,183(3):203-216.
[19]FLEET A J.Hydrothermal and Heterogeneous Ferromanganese Deposits[M].New York:Plenum Press,1983:1-20.
[20]刘家军,郑明华.硅岩的新成因——热水沉积作用[J].四川地质学报,1991,11(4):251-255.
[21]刘家军,郑明华,刘建明,等.西秦岭寒武系金矿床中硅岩的地质地球化学特征及其沉积环境意义[J].岩石学报,1999,15(1):145-154.
[22]周永章,何俊国,杨志军,等.华南热水沉积硅岩建造及其成矿效应[J].地学前缘,2004,11(2):373-377.
[23]MURRAY R W,TEN BRINK M R B,JONES D L,et al.Rare earth elements as indicators of different marine depositional environments in chert and shale[J].Geology,1990,18(3):268-271.
[24]MURRAY R W.Chemical criteria to identify the depositional environment of chert:general principles and applications[J].Sedimentary Geology,1994,90(3):213-232.
[25]HASKIN L A,HASKIN M A,FREY F A,et al.Relative and absolute terrestrial abundances of the rare earths[J].Origin and Distribution of the Elements,1968,1:889-911.
[26]CRERAR D A,NAMSON J,CHYI M S,et al.Manganiferous cherts of the Franciscan assemblage;I,General geology,ancient and modern analogues,and implications for hydrothermal convection at oceanic spreading centers[J].Economic Geology,1982,77(3):519-540.
[27]KIMURA H,WATANABE Y.Oceanic anoxia at the Precambrian—Cambrian boundary[J].Geology,2001,29(11):55-80.
[28]杨恩林,陈恨水,陈焕,等.黔东留茶坡组硅质岩元素地球化学特征与形成环境[J].矿物学报,2011,31(3):406-411.
[29]RONA P A.Criteria for recognition of hydrothermal mineral deposits in oceanic crust[J].Economic Geology,1978,73(2):135-160.
[30]ADACHI M,YAMAMOTO K,SUGISAKI R.Hydrothermal chert and associated siliceous rocks from the Northern Pacific their geological significance as indication of ocean ridge activity[J].Sedimentary Geology,1986,47(1):125-148.
[31]朱嗣昭,HIROMI Nagai,MASAO Kametaka,等.一种特殊类型硅质岩——浮石状燧石[J].高校地质学报,1999,5(3):345-350.
[32]曹秋香,郭福生,刘向铜,等.浙江江山丁家山组层状硅质岩阴极发光特征及成因探讨[J].沉积学报,2008,26(5):797-803.
[33]姚旭,周瑶琪,李素,等.硅质岩与二叠纪硅质沉积事件研究现状及进展[J].地球科学进展,2013,28(11):1189-1200.
[34]冯少南.东吴运动的新认识[J].现代地质,1991,5(4):378-384.
[35]颜佳新,赵坤.二叠-三叠纪东特提斯地区古地理、古气候和古海洋演化与地球表层多圈层事件耦合[J].中国科学:D辑,2002,32(9):751-759.
[2]夏邦栋,钟立荣,方中,等.下扬子区早二叠世孤峰组层状硅质岩成因[J].地质学报,1995,69(2):125-137.
[3]杨水源,姚静.安徽巢湖平顶山中二叠统孤峰组硅质岩的地球化学特征及成因[J].高校地质学报,2008,14(1):39-48.
[4]韩宗珠,肖楠,李安龙,等.安徽巢湖下二叠统孤峰组硅质岩沉积地球化学特征与沉积环境[J].中国海洋大学学报,2014,44(4):78-85.
[5]程成,李双应,赵大千,等.扬子地台北缘中上二叠统层状硅质岩的地球化学特征及其对古地理、古海洋演化的响应[J].矿物岩石地球化学通报,2015,34(1):155-166.
[6]KAMETAKA M,TAKEBE M,NAGAI H,et al.Sedimentary environments of the Middle Permian phosphorite-chert complex from the northeastern Yangtze platform,China;the Gufeng Formation:a continental shelf radiolarian chert[J].Sedimentary Geology,2005,174(3/4):197-222.
[7]吕炳全,瞿建忠.下扬子地区早二叠世海进和上升流形成的缺氧环境的沉积[J].科学通报,1989,34(22):1721-1724.
[8]王汝建,沈高平,KATSUO Sashida.苏皖地区孤峰组放射虫动物群及其古环境意义[J].地质论评,1997,25(5):559-564.
[9]邱振,王清晨.广西来宾中上二叠统硅质岩海底热液成因的地球化学证据[J].中国科学:地球科学,2011,41(5):725-737.
[10]柴华,胡望水,唐友军,等.安徽宿松地区中二叠统栖霞组上升流相烃源岩地球化学特征[J].石油天然气学报,2012,34(3):1-6.
[11]杨锐,李红,柳益群,等.安徽巢湖地区中二叠统栖霞组灰岩中燧石成因[J].现代地质,2014,28(3):501-511.
[12]MURCHEY B L,JONES D L.A mid-Permian chert event:Widespread deposition of biogenic siliceous sediments in coastal,island arc and oceanic basins[J].Palaeogeography,Palaeoclimatology,Palaeoecology,1992,96:161-174.
[13]罗志立,金以钟,朱夔玉,等.试论上扬子地台的峨眉地裂运动[J].地质论评,1988,34(1):11-24.
[14]YAO X,ZHOU Y,HINNOV L A.Astronomical forcing of a Middle Permian chert sequence in Chaohu,South China[J].Earth and Planetary Science Letters,2015,422:206-221.
[15]WANG Yue,JIN Yugan.Permian palaeogeographic evolution of the Jiangnan Basin,South China[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2000,160(1):35-44.
[16]何雨旸,赵广涛,赵利,等.巢北地区二叠系栖霞组碳酸盐岩地球化学特征及其古环境意义[J].中国海洋大学学报,2014,44(5):79-88.
[17]杨瑞东.贵州晚二叠世硅质岩类型及沉积地球化学特征[J].贵州地质,1992,23(2):171-176.
[18]CHEN D,QING H,YAN X,et al.Hydrothermal venting and basin evolution(Devonian,South China):Constraints from rare earth element geochemistry of chert[J].Sedimentary Geology,2006,183(3):203-216.
[19]FLEET A J.Hydrothermal and Heterogeneous Ferromanganese Deposits[M].New York:Plenum Press,1983:1-20.
[20]刘家军,郑明华.硅岩的新成因——热水沉积作用[J].四川地质学报,1991,11(4):251-255.
[21]刘家军,郑明华,刘建明,等.西秦岭寒武系金矿床中硅岩的地质地球化学特征及其沉积环境意义[J].岩石学报,1999,15(1):145-154.
[22]周永章,何俊国,杨志军,等.华南热水沉积硅岩建造及其成矿效应[J].地学前缘,2004,11(2):373-377.
[23]MURRAY R W,TEN BRINK M R B,JONES D L,et al.Rare earth elements as indicators of different marine depositional environments in chert and shale[J].Geology,1990,18(3):268-271.
[24]MURRAY R W.Chemical criteria to identify the depositional environment of chert:general principles and applications[J].Sedimentary Geology,1994,90(3):213-232.
[25]HASKIN L A,HASKIN M A,FREY F A,et al.Relative and absolute terrestrial abundances of the rare earths[J].Origin and Distribution of the Elements,1968,1:889-911.
[26]CRERAR D A,NAMSON J,CHYI M S,et al.Manganiferous cherts of the Franciscan assemblage;I,General geology,ancient and modern analogues,and implications for hydrothermal convection at oceanic spreading centers[J].Economic Geology,1982,77(3):519-540.
[27]KIMURA H,WATANABE Y.Oceanic anoxia at the Precambrian—Cambrian boundary[J].Geology,2001,29(11):55-80.
[28]杨恩林,陈恨水,陈焕,等.黔东留茶坡组硅质岩元素地球化学特征与形成环境[J].矿物学报,2011,31(3):406-411.
[29]RONA P A.Criteria for recognition of hydrothermal mineral deposits in oceanic crust[J].Economic Geology,1978,73(2):135-160.
[30]ADACHI M,YAMAMOTO K,SUGISAKI R.Hydrothermal chert and associated siliceous rocks from the Northern Pacific their geological significance as indication of ocean ridge activity[J].Sedimentary Geology,1986,47(1):125-148.
[31]朱嗣昭,HIROMI Nagai,MASAO Kametaka,等.一种特殊类型硅质岩——浮石状燧石[J].高校地质学报,1999,5(3):345-350.
[32]曹秋香,郭福生,刘向铜,等.浙江江山丁家山组层状硅质岩阴极发光特征及成因探讨[J].沉积学报,2008,26(5):797-803.
[33]姚旭,周瑶琪,李素,等.硅质岩与二叠纪硅质沉积事件研究现状及进展[J].地球科学进展,2013,28(11):1189-1200.
[34]冯少南.东吴运动的新认识[J].现代地质,1991,5(4):378-384.
[35]颜佳新,赵坤.二叠-三叠纪东特提斯地区古地理、古气候和古海洋演化与地球表层多圈层事件耦合[J].中国科学:D辑,2002,32(9):751-759.