摘要
采用Sm Nd同位素定年方法 ,测得江苏北部新沂地区踢球山三个榴辉岩岩体时代为 :2 2 1.6± 8.4Ma ,2 13.6± 9.2Ma和 2 16 .6± 8.1Ma;εNd(t)分别为 - 2 .9,- 2 .9和 - 3.0。采用Rb Sr定年方法得到其中一个榴辉岩的年龄为 2 0 1± 2 1Ma ;87Sr/ 86Sr =0 .70 5 35± 37。Sm Md年龄被看作为踢球山超高压变质之后板块折返过程中的高压榴辉岩相重结晶阶段年龄。Rb Sr年龄反映了踢球山榴辉岩体的板块折返过程中的角闪岩相退变质阶段开始年龄。
Sm Nd isotope ages of 221.6±8.4 Ma, 213.6±9.2 Ma and 216.6±8.1 Ma, respectively, have been obtained for three eclogite bodies in the Tiqiushan region, northern Jiangsu Province. One of the Tiqiushan eclogite bodies is dated by a Rb Sr isochron at 201±21 Ma. The Sm Nd age could be interpreted to record recrystallization of the Tiqiushan eclogite body at high pressure eclogite facies during exhumation of the subducted plate, whereas the Rb Sr age may correspond to initial amphibolite facies retrograde metamorphism of the same eclogite body. Collision between the Sino Korean and Yangtze plates occurred around the late Triassic time.
出处
《高校地质学报》
CAS
CSCD
2003年第2期237-243,共7页
Geological Journal of China Universities
基金
地质矿产部九五攻关项目 (No .950 1 1 0 2 0 4 0 1 )
国家自然科学基金 (No.469731 97)
南京大学成矿作用国家重点实验室基金
南京大学分析测试基金资助项目
