高校地质学报
高校地質學報
고교지질학보
GEOLOGICAL JOURNAL OF CHINA UNIVERSITIES
2014年
3期
81-92
,共12页
刘红旭%颜丹平%何建国%陈峰%高洪雷%所世鑫%王勋%张晓%曹清艳%王永文%赵建
劉紅旭%顏丹平%何建國%陳峰%高洪雷%所世鑫%王勛%張曉%曹清豔%王永文%趙建
류홍욱%안단평%하건국%진봉%고홍뢰%소세흠%왕훈%장효%조청염%왕영문%조건
构造活动性%核废处置场%阿齐山-雅满苏地区%裂变径迹%隆升剥露
構造活動性%覈廢處置場%阿齊山-雅滿囌地區%裂變徑跡%隆升剝露
구조활동성%핵폐처치장%아제산-아만소지구%렬변경적%륭승박로
tectonic activity%geological disposal of radioactive waste%Aqishan-Yamansu%apatite fission track%uplift and exhumation
构造活动性是核废处置场评价的一项基本判别要素。文中通过对东天山阿齐山-雅满苏地区磷灰石裂变径迹测年及构造隆升剥蚀过程的模拟来评价核废处置场的构造活动性。结果表明阿齐山-雅满苏地区样品磷灰石裂变径迹年龄集中分布在81.7~51.4 Ma之间，反映出东天山地区晚白垩世-始新世存在一次明显的构造冷却事件，这与天山地区晚白垩世的抬升剥露事件相一致。磷灰石裂变径迹长度介于13.60±0.11~14.36±0.10μm之间，其长度标准差为0.98~1.22μm，显示该区磷灰石径迹形成后没有发生过明显的退火作用。根据地温梯度计算得到晚白垩世-始新世东天山阿齐山-雅满苏地区隆升剥蚀速率为270~580 m/Ma。现有地质资料及热史模拟结果表明，东天山阿齐山-雅满苏地区在晚白垩世-始新世（84~49 Ma）期间经历了强烈的构造隆升-剥露事件，自始新世以后50 Ma以来，地壳处于稳定状态，新生代构造活动不明显，其活动强度明显有别于天山其他地段。东天山阿齐山-雅满苏地区现在的构造地貌基本继承了晚白垩世的特征，处于构造活动平稳期，符合核废处置场选址的构造要求。
構造活動性是覈廢處置場評價的一項基本判彆要素。文中通過對東天山阿齊山-雅滿囌地區燐灰石裂變徑跡測年及構造隆升剝蝕過程的模擬來評價覈廢處置場的構造活動性。結果錶明阿齊山-雅滿囌地區樣品燐灰石裂變徑跡年齡集中分佈在81.7~51.4 Ma之間，反映齣東天山地區晚白堊世-始新世存在一次明顯的構造冷卻事件，這與天山地區晚白堊世的抬升剝露事件相一緻。燐灰石裂變徑跡長度介于13.60±0.11~14.36±0.10μm之間，其長度標準差為0.98~1.22μm，顯示該區燐灰石徑跡形成後沒有髮生過明顯的退火作用。根據地溫梯度計算得到晚白堊世-始新世東天山阿齊山-雅滿囌地區隆升剝蝕速率為270~580 m/Ma。現有地質資料及熱史模擬結果錶明，東天山阿齊山-雅滿囌地區在晚白堊世-始新世（84~49 Ma）期間經歷瞭彊烈的構造隆升-剝露事件，自始新世以後50 Ma以來，地殼處于穩定狀態，新生代構造活動不明顯，其活動彊度明顯有彆于天山其他地段。東天山阿齊山-雅滿囌地區現在的構造地貌基本繼承瞭晚白堊世的特徵，處于構造活動平穩期，符閤覈廢處置場選阯的構造要求。
구조활동성시핵폐처치장평개적일항기본판별요소。문중통과대동천산아제산-아만소지구린회석렬변경적측년급구조륭승박식과정적모의래평개핵폐처치장적구조활동성。결과표명아제산-아만소지구양품린회석렬변경적년령집중분포재81.7~51.4 Ma지간，반영출동천산지구만백성세-시신세존재일차명현적구조냉각사건，저여천산지구만백성세적태승박로사건상일치。린회석렬변경적장도개우13.60±0.11~14.36±0.10μm지간，기장도표준차위0.98~1.22μm，현시해구린회석경적형성후몰유발생과명현적퇴화작용。근거지온제도계산득도만백성세-시신세동천산아제산-아만소지구륭승박식속솔위270~580 m/Ma。현유지질자료급열사모의결과표명，동천산아제산-아만소지구재만백성세-시신세（84~49 Ma）기간경력료강렬적구조륭승-박로사건，자시신세이후50 Ma이래，지각처우은정상태，신생대구조활동불명현，기활동강도명현유별우천산기타지단。동천산아제산-아만소지구현재적구조지모기본계승료만백성세적특정，처우구조활동평은기，부합핵폐처치장선지적구조요구。
Tectonic activity is a fundamental discriminant factor in site assessment for radioactive waste. The tectonic activity of geological repository of radioactive waste which is located at Aqishan-Yamasu in the East Tianshan was evaluated through model studying the uplift and exhumation history by the apatite fission track dating. The result shows that apatite fission track pool-age data range from 81.7 to 51.4 Ma which recorded a cooling event of the East Tianshan during the Late Cretaceous to Eocene, which is consistent with a tectonic uplift and denudation event in the Late Cretaceous in the Tianshan. The mean track lengths range from 13.60±0.11 to 14.36±0.10 μm with the standard deviations of 0.98 ~1.22 μm, which suggests that most tracks didn’ t experience thermal annealing process after they were formed. Based on evaluated geothermal gradient, the mean exhumation rate in the East Tianshan during the Late Cretaceous to Eocene was calculated to reach 270~580 m/Ma. The geological data and further temperature-time modeling of apatite was conducted, indicating that an exhumation event existed from the Late Cretaceous to Eocene (84~49 Ma); after 50 Ma, the crust of the east Tianshan has been in a steady state, and the Cenozoic tectonic activity in Aqishan-Yamansu area has become significantly weaker than other area of Tianshan. The study shows that the geomorphologic features of present Tianshan inherit that from the Late Cretaceous, and weak tectonic activity conforms to the tectonic requirements of geological disposal of radioactive waste.
