Late Quaternary glacial and climate history of the Pamir Mountains derived from cosmogenic Be exposure ages

Moraines southwest of Lake Yashilkul, Pamir, Tajikistan, were dated using ¹⁰Be exposure ages of boulder surfaces. We found evidence for (1) an extensive glaciation ∼60,000 yr ago; (2) a less extensive glacial advance, which deposited a characteristic hummocky moraine lobe with exposure ages ranging from ∼11,000 to 47,000 yr, probably deposited at or before 47,000 yr ago; and (3) lateral moraines with exposure ages of ∼40,000 yr, 27,000 yr and 19,000 yr, respectively. Increasing aridity in the Pamir is most likely responsible for the progressively limited extent of the glaciers during the Late Pleistocene.     

东帕米尔北缘韧性剪切带中的多硅白云母及其地质意义

本文系统地研究了东帕米尔北缘韧性推覆剪切带内糜棱岩中的多硅白云母，电子探针分析和Ｘ射线衍射测试：从剪切带边缘→中心，多硅白云母硅平均含量为３．２０３４→３．３６０９；晶胞参数ｂ０值为９．０２４→９．０２７→９．０４１→９．０４５，其物相均为２Ｍ１型。发现糜棱岩中局部夹有硅线石，糜棱岩组合之上还发育数层红帘石石英岩。多硅白云母Ｋ－Ａｒ年龄平均值为３６．９５±１．２Ｍａ。故此确定该剪切带糜棱岩形成于低温（局部可达高温）、中至高压环境，形成时代为始新世末（３７Ｍａ）。     

东帕米尔"层控碳酸岩型"铁铜金矿浅释

东帕米尔“层控碳酸岩型”铁铜金矿,形成于中元古代裂谷构造环境,产于中深变质相与中浅变质相转换部位,塔昔达坂群底部.矿床属海底喷流(含火山喷流)沉积成因,为菱铁矿和细碎屑岩-碳酸盐岩夹少量火山岩的沉积建造.铁铜金矿显示出上铁锰下铜金的元素垂向分带,构成新疆一个有希望的成矿区域.     

帕米尔弧形构造带东北缘晚新生代构造活动的沉积与重矿物变化响应

帕米尔弧形构造带东北缘晚新生代沉积特征的研究对于理解帕米尔构造带弧形扩展机制具有重要意义。本文通过对帕米尔弧形构造带东北缘的晚新生代沉积地层的沉积特征对比研究和重矿物采样与组份分析,建立了帕米尔弧形构造带东北缘地区的晚新生代沉积联合柱状对比图和重矿物组份变化曲线。研究结果表明,晚新生代沉积与重矿物变化主要记录了帕米尔弧形构造带东北缘的两期构造活动。第一期构造活动发生在安居安组沉积时期,帕米尔弧形构造带东北缘的和什拉甫剖面、英科1井表现为粗碎屑沉积和对应的不稳定重矿物爆发,而南部的甫沙2井中则并未观察到,这一事件可能反映了喀什-叶城走滑系统在和什拉甫剖面附近的中新世构造启动。第二期构造活动发生在阿图什组沉积期间,帕米尔弧形构造带东北缘全区域出现了一套粗碎屑沉积和对应的不稳定重矿物爆发,反映了帕米尔弧形构造带东北缘在上新世以来大规模向北楔入塔里木盆地内部的构造过程。     

新疆塔什库尔干温泉地区花岗岩体侵入与新生代构造变形:对东北帕米尔中新世构造演化的启示

帕米尔高原是受到印度-亚洲大陆碰撞、持续汇聚影响最显著的地区之一,以强烈地壳增厚和缩短、大量断裂和片麻岩穹窿的形成以及广泛的陆内岩浆活动为特征。以往有关帕米尔陆内岩浆岩的讨论多集中于对其地球化学成分及其所指示的构造背景的研究方面,而对岩浆形成与大型新生代构造之间的联系研究较少。本文通过对东北帕米尔塔什库尔干温泉地区新生代花岗岩及其围岩中锆石U-Pb和Ar-Ar年代学研究,结合该地区新生代构造变形分析,揭示岩浆侵入与区域构造变形之间的关系。U-Pb及Ar-Ar测年结果显示温泉地区花岗岩脉形成时代为中新世（11.8±0.2Ma）,其及其围岩在10.8±0.1Ma冷却到300℃左右;中新世花岗岩脉中继承锆石及围岩片岩中碎屑锆石U-Pb的年龄分布特征迥异,它们分别具有类似松潘-甘孜地体以及中帕米尔地体的物质来源。花岗岩内部几乎无变形,围岩片岩变形主要体现为近E-W向的伸展构造,反映其形成于拉张为主的构造应力环境。结合区域构造背景,推测温泉中新世花岗岩脉为公格尔山、慕士塔格峰构造单元岩石部分熔融产物,是在东北帕米尔地壳从挤压增厚向局部伸展转换的过程中形成的,此时,公格尔伸展断裂系可能已经开始发育;此后,直到6~4Ma,公格尔伸展断裂系开始快速运动,与之相伴公格尔-慕士塔格片麻岩穹窿快速折返。     

KINEMATICS OF QUATERNARY EXTENSION IN THE PAMIR

KINEMATICS OF QUATERNARY EXTENSION IN THE PAMIR1　BurtmanVS ,MolnarP .GeologicalandgeophysicalevidencefordeepsubductionofcontinentalcrustbeneaththePamir[J].SpecPapGeolSocAm ,1993,2 81:76 . 2　StreckerMR ,FrischW ,HamburgerMW ,etal.QuaternarydeformationintheEasternPamirs ,TadzhikistanandKyrgyzs tan[J].Tectonics,1995 ,14(5 ) :10 6 1～ 10 79.…     

THE NORTHWARD PROPAGATION OF THE ARC TECTONICS OF THE NORTHEAST PAMIR AND NORTHWEST TARIM BASIN

THE NORTHWARD PROPAGATION OF THE ARC TECTONICS OF THE NORTHEAST PAMIR AND NORTHWEST TARIM BASINThisworkispartoftheresearchproject“themechanismofJiashistrongearthquakeswarmandprediction ofearthquakeriskinthenortheastPamir     

Mesozoic–Cenozoic multistage tectonic evolution of the Pamir: Detrital fission-track constraints from the Tajik Basin

Knowledge of the tectonic history of the Pamir contributes to our understanding of both the evolution of collisional orogenic belts as well as factors controlling Central Asian aridification. It is, however, not easy to decipher the Mesozoic–Cenozoic tectonics of the Pamir due to extensive Neogene deformation in an orogen that remains largely understudied. This study reports detrital apatite and zircon fission-track (FT) ages from both the eastern Tajik Basin sedimentary rocks and Pamir modern river sands. These FT data, supported by vitrinite reflectance and zircon and apatite U–Pb double dating, suggest that the majority of the FT ages are unreset and record exhumation stages of the Pamir, which has served as the source terrane of the Tajik Basin since the Cretaceous. Furthermore, we combine the new data with a compilation of published detrital apatite and zircon FT data from both the Tajik Basin sedimentary rocks and Pamir modern river sands, to explore the Mesozoic–Cenozoic tectonic history of Pamir. Deconvolved FT Peak Ages document two major Mesozoic exhumation events associated with the Late Triassic–Early Jurassic Cimmerian orogeny that reflects accretion of the Pamir terranes, as well as the Early–early Late Cretaceous deformation associated with the northward subduction of the Neo-Tethys Ocean beneath Pamir. The compiled data also show significant Late Eocene–Neogene exhumation associated with the ongoing formation of the Pamir, which peaks at ca. 36, 25, 14 and 7 Ma.     

帕米尔北缘木什背斜第四纪滑脱褶皱作用与北翼逆断裂的生长

发育在帕米尔弧形推覆构造带最前缘的木什活动背斜是一南缓北陡的第四纪滑脱褶皱,背斜的最小地壳缩短量为0.7km,构造隆升幅度可达1.5km.木什背斜北翼逆断层由一系列坡向北的反向断层陡坎组成,不同断坎间垂直位移分布呈现此消彼长的特征,不论是整个北翼逆断层西段还是单条断坎,其垂直位移均呈东高西低的不对称分布,位移梯度东高西...