新疆叶城“7·6”滑坡泥石流灾害调查与形成机理研究

2016年7月6日晨0时40分左右,新疆喀什地区叶城县柯克亚乡六村发生特大滑坡泥石流灾害,造成重大人员伤亡和财产损失。本研究采用地面调查、访问和遥感解译方法,从滑坡、泥石流形成的地形地貌、地层岩性和水文气象条件着手,分析了滑坡特征与成因,泥石流形成条件、灾害链过程与致灾机理,并对未来本区滑坡泥石流的发展趋势进行了预测。现场调查表明:（1）位于西昆仑山北坡中高山区的六村与七村毗邻区域,在6日凌晨发生的大暴雨,触发了38处群发性浅层黄土滑坡,属蠕滑-拉裂机制,且部分大滑坡表现为远程滑坡-泥流特征;（2）这些滑坡体堆积在“V”形沟谷中形成堰塞坝,其中六村上游发育15处滑坡和2个滑坡堰塞坝,在持续降水和小型沟谷泥石流的作用下,滑坡坝发生串联式溃决而形成堵溃型泥石流,冲毁六村居民区和道路;（3）同时,该毗邻区域两侧存在超过227处的黄土滑坡变形体,未来在区域气候由暖干转向暖湿条件下,强降雨的极端气候事件会增多,若遭遇强降雨,研究区仍然会爆发滑坡-堰塞坝-溃决泥石流模式的灾害,其规模可能比“7·6”事件还大。建议深化本区浅层黄土滑坡变形机理、临界雨量及泥流运动机理等方面的深入研究,同时加强滑坡泥石流的监测和预测研究。     

西昆仑山区湖泊初探

本文论述了西昆仑山区湖泊的分布、成因、水化学特征以及其演化历史与高原隆升、古气候变化、高山冰川进退之间的关系。研究结果表明,该区湖泊主要靠暖季高山带的冰雪融水补给,故矿化度的变化与其距补给源的远近密切相关;它们在第四纪期间的演化是高原构造隆升和全球气候变化二者作用的结果;根据现有资料,该区湖泊的演化历史可大致分为3个阶段,即距今4.6万年以前的大湖期,晚更新世晚期的湖面波动期和全新世的湖泊退缩期。     

中仑昆山北坡黄土特征及其环境

根据野外调查和实验分析资料,阐述和分析中昆仑山北坡黄土的形成时代、物质成分和结构及沉积条件,认为黄土属晚第四纪风积物质,现代黄土堆积持续进行,物质主要来源于塔克拉玛沙漠。在干旱气候背景上,7000—5000a.B.P.为明显相对湿润时期。     

Fission Track Geochronology of Xiaonanchuan Pluton and the Morphotectonic Evolution of Eastern Kunlun since Late Miocene

Apatite fission track （AFT） thermochronology of seven samples from the Xiaonanchuan （小南川） pluton in the Kunlun （昆仑） pass area was carried out, for the purpose of determining the timing of cooling and the relation between the exhumation and the morphotectonic processes. The AFT ages yield low denudation rates of 0. 020--0. 035 mm/a during the late Miocene, which correspond to a stable geomorphic and weak tectonic uplifting environment. The low denudation rates can be considered as the approximate tectonic uplifting rates. The AFT geochronology shows puroxysmully rapid cooling since the Pliocene and an apparent material unroofing of more than 3 km in the Xiaonanchuan area. This was not the result of simple denudation. The rapid cooling was coupled with the intensive orogeny since the Pliocene, which was driven by tectonic uplifting. The accelerated relief building was accompanied by a series of faulting, which caused the basin and the valley formation and sinking. The space pattern of the AFT ages also shows differential uplifting, which decreases northwardly. This trend is supported by the regional AFT data, which indicate that the exhumation decreases northwardly in eastern Kunlun. This trend also exists in cast-west orientation from the western Kunlun range to the eastern. The uplif- ting trend is also supported by gcomorphic characteristics including the elevation and the relief differences well as the distribution of the Late Cenozoic volcanism.     

新疆西昆仑地区干旱荒漠景观区域化探方法技术初步研究

西昆仑地区地处中国风成沙的沉降区，与其它区相比较，风成沙粒级偏细。风成沙中主要颗粒成分为石英长石，但偏粗粒级混有一定比例近源岩屑；细粒级云母和暗色矿物颗粒增多，导致风成沙各粒级元素含量人布从粗粒至细粒级呈两头偏高，中间偏低的趋势。该区水系中普遍见风成沙掺入，水系沉积物从粗至细粒级石英长石颗粒逐渐增多，岩屑颗粒逐渐减少，石英长石主要来自风成沙。水系沉积物中，元素含量以80目级为界出现明显差异，－80目粒级元素含量明显受到风成沙干扰。因此，在该区开展区域化探采样粒级应为－10－＋80目粒级。奥依且克地区－10－＋80目和－80目两种粒级试点测量结果，表明－10－＋80目粒级的正确性。     

The Early Paleozoic Tectonic Evolution of the West Kunlun Mountains：New Constraint from the North Kueda Pluton

Systematic geochemical studies have been conducted on the North Küda Pluton, West Kunlun, in order to reveal its petrogenesis and tectonic implications. The North Küda Pluton is a potassium-rich (K₂O>5.4wt% ) I-type granitic pluton and does not contain any alkaline ferromagnesian mineral. Its relatively high REE, LILE (e.g. Rb, Cs, U and Th) and HFSE (e. g. Nb, Zr) contents make it very akin to the A-type granites. Its heterogeneous Sr (⁸⁷Sr/⁸⁶Sr_i = 0.7049∼0.7098) and Nd (εNd_T= −1.05∼−4.04) isotope compositions preclude the possibility of a pure sedimentary or igneous source. Instead, its geochemical compositions suggest that it may be derived from partial melting of a complex source, which consists of igneous and sedimentary rocks. Its intraplate characteristics, together with coeval mafic dykes, indicate an extensional environment at the end of Caledonian. The recognition of the extensional event does not support a continuous subduction-accretion model for the Paleozoic tectonic evolution of the West Kunlun Mountains. On the contrary, it provides new evidence for the twostage island-arc model.     

西昆仑加里东期造山作用初探

在西昆仑前山一带存在一个发育完全的加里东期碰撞造山带，该造山带代表了古秦－－祁－－昆大洋的消亡和两侧大陆的剧烈碰撞，古昆仑洋可能开始裂解于震旦纪，寒武纪达最大程度，奥陶纪开始向南俯冲消减，志留纪两侧陆块发生碰撞。其曼于特－－库地蛇绿岩为其洋壳残片，北侧的塔里木板块南缘具被动边缘性质，南侧的西昆仑地块为活动边缘性质，同时有大量俯冲型，碰撞型和造山期后伸展型花岗岩侵入，晚泥盆世紫红色磨拉石建造代表了这一过程的结束。     

昆仑山中的一座古城

民丰县境吐浪哈吉河上游东南向的“帕西木”(又称大麻扎),有众多的古迹显示,推断这里应是《汉书·西域传》中所记载的戌卢古国。沿吐浪哈吉河主流向西南继行,是昆仑山与藏北高原相连的古通道之一。这些道路的研究,是揭示昆仑古城存在的有力佐证。     

古今帕米尔

帕米尔高原位于亚洲中部，地处中国新疆维吾尔自治区的西南，并向西延伸至塔吉克斯坦和阿富汗。帕米尔高原是天山、昆仑山、喀喇昆仑山和兴都库什山等交汇而成的，是中国自古以来习惯称之为“葱岭”的一部分。