现代地质
現代地質
현대지질
Geoscience
2015年
4期
873-883
,共11页
红层盆地%火山岩%LA-ICP-MS%锆石U-Pb年龄%浙江丽水
紅層盆地%火山巖%LA-ICP-MS%鋯石U-Pb年齡%浙江麗水
홍층분지%화산암%LA-ICP-MS%고석U-Pb년령%절강려수
red-bed basin%volcanic rock%LA-ICP-MS%zircon U-Pb age%Lishui,Zhejiang Province
为查明丽水地区火山活动与盆地形成、演化之间的关系,在碧湖盆地、章村盆地、丽水盆地等红层盆地区域地质调查基础上,对盆地内中性-酸性火山岩夹层进行了精确测年和岩石化学分析,火山岩岩石地球化学表明,碧湖盆地、丽水盆地、章村盆地岩石化学成分基本一致。火山岩LA-ICP-MS 锆石U-Pb测年表明:碧湖盆地朝川组火山岩年龄为(123±2)Ma,章村盆地馆头组火山岩年龄为(111±3)Ma,丽水盆地塘上组火山岩年龄为(95±1)Ma。该地区盆地间火山岩夹层存在28 Ma时差,反映了丽水—余姚断裂带的活动延续性。
為查明麗水地區火山活動與盆地形成、縯化之間的關繫,在碧湖盆地、章村盆地、麗水盆地等紅層盆地區域地質調查基礎上,對盆地內中性-痠性火山巖夾層進行瞭精確測年和巖石化學分析,火山巖巖石地毬化學錶明,碧湖盆地、麗水盆地、章村盆地巖石化學成分基本一緻。火山巖LA-ICP-MS 鋯石U-Pb測年錶明:碧湖盆地朝川組火山巖年齡為(123±2)Ma,章村盆地館頭組火山巖年齡為(111±3)Ma,麗水盆地塘上組火山巖年齡為(95±1)Ma。該地區盆地間火山巖夾層存在28 Ma時差,反映瞭麗水—餘姚斷裂帶的活動延續性。
위사명려수지구화산활동여분지형성、연화지간적관계,재벽호분지、장촌분지、려수분지등홍층분지구역지질조사기출상,대분지내중성-산성화산암협층진행료정학측년화암석화학분석,화산암암석지구화학표명,벽호분지、려수분지、장촌분지암석화학성분기본일치。화산암LA-ICP-MS 고석U-Pb측년표명:벽호분지조천조화산암년령위(123±2)Ma,장촌분지관두조화산암년령위(111±3)Ma,려수분지당상조화산암년령위(95±1)Ma。해지구분지간화산암협층존재28 Ma시차,반영료려수—여요단렬대적활동연속성。
The geochemistry characteristics of volcanic rocks in three basins indicate that the basins of Bihu, Lishui,Zhangcun have the same composition of the petrochemistry,and that the three basins mentioned above were formed in volcanic island arc.From LA-ICP-MS zircon U-Pb data of volcanic rocks in three basins,we found that the volcanic age of Chaochuan Formation in Bihu basin was (123 ±2)Ma,Guantou Formation in Zhangcun basin was (1 1 1 ±3 )Ma,Tangshang Formation in Lishui basin was (95 ±1 )Ma.The age data for those volcanic rocks in three basins show that the time of volcanic activity continued 28 Ma or so,and those data also reflect the activity continuation of Lishui-Yuyao fault.