东准噶尔卡拉麦里地区巴塔玛依内山组火山岩LA-ICP-MS锆石U-Pb年龄
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摘要
巴塔玛依内山组是一套以火山岩为主的陆相火山-沉积地层,在东准噶尔地区广泛分布,规模巨大,且形成时代久存争议。通过对卡拉麦里地区巴塔玛依内山组层型剖面的重新实测,以及对该组中下部层位玄武岩进行LA-ICP-MS测年,获得锆石U-Pb年龄为(338.7±7.7) Ma(MSWD=0.24)。所测锆石的CL图像上可见明显的震荡环带结构,且锆石Th/U比值为0.11～0.95,均大于0.10,13颗锆石的Th/U平均值为0.56,Th/U呈正相关,说明属岩浆锆石,指示其代表了巴塔玛依内山组的形成时代。结合前人的年代学数据及化石资料,将巴塔玛依内山组时代确定为早石炭世中期—晚石炭世初期,认为其中下部层位时代不晚于338.7 Ma。该成果进一步约束了区内陆相火山地层的时代,并为研究东准噶尔构造带的火山岩浆作用及其构造演化提供了新的年代学依据。
Batamayineishan Formation is a set of continental volcanic-sedimentary strata dominated by volcanic rocks.It is widely distributed in eastern Junggar,with a huge scale and a long-standing controversy about its age.The U-Pb zircon U-Pb age of Batamayineishan Formation in Kalamali area is(338.7±7.7) Ma(MSWD=0.24)by LA-ICP-MS dating of basalts in the middle and lower strata of the Formation.The CL images of the zircons show obvious oscillatory zonal structure,and the Th/U ratios of the zircons are between 0.11 and 0.95,all of which are greater than 0.10.The Th/U average of 13 zircons is 0.56.There is a positive correlation between the Th/U values,indicating that the zircons belong to magmatic zircons and represent the formation age of the Batamayineishan Formation.Based on previous chronological data and fossil data,the age of the Batamayineishan Formation is defined as the middle of the Early Carboniferous to the early stage of the Late Carboniferous.It is considered that the lower strata should be no later than 338.7 Ma.This result further constrains the age of continental volcanic strata and provides a new chronological basis for the study of volcanic magmatism and tectonic evolution in the eastern Junggar tectonic belt.
Batamayineishan Formation is a set of continental volcanic-sedimentary strata dominated by volcanic rocks.It is widely distributed in eastern Junggar,with a huge scale and a long-standing controversy about its age.The U-Pb zircon U-Pb age of Batamayineishan Formation in Kalamali area is(338.7±7.7) Ma(MSWD=0.24)by LA-ICP-MS dating of basalts in the middle and lower strata of the Formation.The CL images of the zircons show obvious oscillatory zonal structure,and the Th/U ratios of the zircons are between 0.11 and 0.95,all of which are greater than 0.10.The Th/U average of 13 zircons is 0.56.There is a positive correlation between the Th/U values,indicating that the zircons belong to magmatic zircons and represent the formation age of the Batamayineishan Formation.Based on previous chronological data and fossil data,the age of the Batamayineishan Formation is defined as the middle of the Early Carboniferous to the early stage of the Late Carboniferous.It is considered that the lower strata should be no later than 338.7 Ma.This result further constrains the age of continental volcanic strata and provides a new chronological basis for the study of volcanic magmatism and tectonic evolution in the eastern Junggar tectonic belt.
引文
[1]Sengor A M C.Paleotectonics of Asia:Fragments of a synthesis[J].Tectonic Evolution of Asia,1996.
[2]谭佳奕,吴润江,张元元,等.东准噶尔卡拉麦里地区巴塔玛依内山组火山岩特征和年代确定[J].岩石学报,2009,25(3):539-546.
[3]张元元,陈石,郭召杰,等.东准噶尔扎河坝地区古生代晚期火山岩的锆石SHRIMP U-Pb定年及其地质意义[J].岩石学报,2009,25(3):506-514.
[4]苏玉平,郑建平,GRIFFIN W L,等.东准噶尔盆地巴塔玛依内山组火山岩锆石U-Pb年代及Hf同位素研究[J].科学通报,2010,55(30):2931-2943.
[5]李玮,柳益群,董云鹏,等.新疆三塘湖地区石炭纪火山岩年代学、地球化学及其大地构造意义[J].中国科学:地球科学,2012,42(11):1716-1731.
[6]张峰,徐涛,范俊杰,等.东准噶尔石炭系巴塔玛依内山组火山岩全岩Sm-Nd等时线年龄及其构造意义[J].地球化学,2014(3):301-316.
[7]罗婷,陈帅,廖群安,等.东准噶尔晚石炭世双峰式火山岩年代学、地球化学及其构造意义[J].地球科学-中国地质大学学报,2016,41(11):1845-1862.
[8]朱志新,李少贞,李嵩龄.东准噶尔纸房地区晚石炭世巴塔玛依内山组陆相火山-沉积体系特征[J].新疆地质,2005,23(1):14-18.
[9]杨高学,李永军,佟丽莉,等.新疆东准噶尔卡拉麦里钾质玄武岩的地球化学特征、成因及其构造意义[J].岩石学报,2010,26(8):2345-2356.
[10]窦亚伟,孙喆华.新疆北部晚古生代植物概况[J].地质学报,1985(1):3-13.
[11]宋彪,张玉海,刘敦一.微量原位分析仪器SHRIMP的产生与锆石同位素地质年代学[J].质谱学报,2002,23(1):58-62.
[12]李艳广,汪双双,刘民武,等.斜锆石LA-ICP-MS U-Pb定年方法及应用[J].地质学报,2015,89(12):2400-2418.
[13]吴元保,郑永飞.锆石成因矿物学研究及其对U-Pb年龄解释的制约[J].科学通报,2004,49(16):1589.
[14]闫存凤,袁剑英,吉利民,等.新疆准噶尔盆地东缘下石炭统滴水泉组孢粉组合[J].地层学杂志,1995,19(2):104-109.
[15]杨品荣,杨文强,蒙有言,等.新疆克拉麦里造山带下石炭统地层系统及其沉积构造背景[J].地质科技情报,2007,26(5):6-10.
[16]新疆维吾尔自治区地质矿产局,全国地层多重划分对比研究(65):新疆维吾尔自治区岩石地层[M].武汉:中国地质大学出版社,1999,1-430.
[17]韩宝福,季建清,宋彪,等.新疆准噶尔晚古生代陆壳垂向生长(Ⅰ)--后碰撞深成岩浆活动的时限[J].岩石学报,2006,22(5):1077-1086.
(1)新疆地矿局第一地质大队.新疆库普幅1∶20万(L-46-25)区域地质矿产报告,1966
[2]谭佳奕,吴润江,张元元,等.东准噶尔卡拉麦里地区巴塔玛依内山组火山岩特征和年代确定[J].岩石学报,2009,25(3):539-546.
[3]张元元,陈石,郭召杰,等.东准噶尔扎河坝地区古生代晚期火山岩的锆石SHRIMP U-Pb定年及其地质意义[J].岩石学报,2009,25(3):506-514.
[4]苏玉平,郑建平,GRIFFIN W L,等.东准噶尔盆地巴塔玛依内山组火山岩锆石U-Pb年代及Hf同位素研究[J].科学通报,2010,55(30):2931-2943.
[5]李玮,柳益群,董云鹏,等.新疆三塘湖地区石炭纪火山岩年代学、地球化学及其大地构造意义[J].中国科学:地球科学,2012,42(11):1716-1731.
[6]张峰,徐涛,范俊杰,等.东准噶尔石炭系巴塔玛依内山组火山岩全岩Sm-Nd等时线年龄及其构造意义[J].地球化学,2014(3):301-316.
[7]罗婷,陈帅,廖群安,等.东准噶尔晚石炭世双峰式火山岩年代学、地球化学及其构造意义[J].地球科学-中国地质大学学报,2016,41(11):1845-1862.
[8]朱志新,李少贞,李嵩龄.东准噶尔纸房地区晚石炭世巴塔玛依内山组陆相火山-沉积体系特征[J].新疆地质,2005,23(1):14-18.
[9]杨高学,李永军,佟丽莉,等.新疆东准噶尔卡拉麦里钾质玄武岩的地球化学特征、成因及其构造意义[J].岩石学报,2010,26(8):2345-2356.
[10]窦亚伟,孙喆华.新疆北部晚古生代植物概况[J].地质学报,1985(1):3-13.
[11]宋彪,张玉海,刘敦一.微量原位分析仪器SHRIMP的产生与锆石同位素地质年代学[J].质谱学报,2002,23(1):58-62.
[12]李艳广,汪双双,刘民武,等.斜锆石LA-ICP-MS U-Pb定年方法及应用[J].地质学报,2015,89(12):2400-2418.
[13]吴元保,郑永飞.锆石成因矿物学研究及其对U-Pb年龄解释的制约[J].科学通报,2004,49(16):1589.
[14]闫存凤,袁剑英,吉利民,等.新疆准噶尔盆地东缘下石炭统滴水泉组孢粉组合[J].地层学杂志,1995,19(2):104-109.
[15]杨品荣,杨文强,蒙有言,等.新疆克拉麦里造山带下石炭统地层系统及其沉积构造背景[J].地质科技情报,2007,26(5):6-10.
[16]新疆维吾尔自治区地质矿产局,全国地层多重划分对比研究(65):新疆维吾尔自治区岩石地层[M].武汉:中国地质大学出版社,1999,1-430.
[17]韩宝福,季建清,宋彪,等.新疆准噶尔晚古生代陆壳垂向生长(Ⅰ)--后碰撞深成岩浆活动的时限[J].岩石学报,2006,22(5):1077-1086.
(1)新疆地矿局第一地质大队.新疆库普幅1∶20万(L-46-25)区域地质矿产报告,1966