摘要
科洛杂岩出露于黑龙江省嫩江县大兴安岭北段,构造解析指示其为一大型伸展滑脱构造,整体反映杂岩体向南东伸展滑脱的特征。依据杂岩体显微构造特征,推测科洛地区伸展滑脱变形带变形温度约为300～450℃。滑脱带中变形花岗片麻岩样品中黑云母单矿物的^(40)Ar/^(39)Ar年龄为118.39～117.37 Ma,指示伸展滑脱带形成时代为早白垩世晚期。结合大兴安岭地区中生代岩浆活动特征和南北变质核杂岩对比研究,认为大兴安岭整体经历了早白垩世中晚期的快速隆升,形成一系列变质核杂岩,发育大规模伸展变形作用,与松辽盆地坳陷期具有良好的耦合关系。
Keluo complex at Nenjiang area in Heilongjiang Province is located in the northern part of the Da Hinggan Mountains. Based on the detailed field works and structural analysis we found that the Keluo complex have been suffered a large scale extensional sliding and formed a detachment structure with top to south-east. According to the feldspar-quartz micro-texture analysis ,we inferred that the deformation temperature of the extensional sliding is about 300℃ to 450℃. The 40Ar/39Ar measurement of biotite from the granitic gneiss samples yield plateau ages of 118.39 to 117.37 Ma,these ages indicate that the deformation time of the extensional sliding zone is in the late Early Cretaceous period. Combining the characteristics of the Mesozoic magmatism and comparative study of surrounding metamorphic core complexes in Da Hinggan Mountains,we suggested that the whole Da Hinggan Mountains underwent rapid uplift in middle-late Early Cretaceous and forming a series of metamorphic core complexes,the large- scale extensional deformation in this period had a good coupling relationship in time with the depressed period of Songliao Basin.
出处
《地质科学》
CAS
CSCD
北大核心
2012年第2期360-375,共16页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
国家油气专项"松辽盆地及外围上古生界油气资源战略选区"(编号:2009GYXQ12)
国家重点基金项目(编号:40739905)
博士点基金项目(编号:200801830041)资助
