艾比湖流域抛物线形沙丘形态特征     

马倩  武胜利  曾雅娟  赵阳 《中国沙漠》2014,34(4):955-960

选择新疆艾比湖流域精河县东南部梭梭林沙地中的典型抛物线形沙丘为研究对象,以风沙地貌学、遥感、地理信息系统及测量学理论为基础,利用野外调查3S工作平台,运用RTK技术实地获取三维基础数据,通过ArcGIS10.0软件生成沙丘DEM,有效提取沙丘的地形因子和形态特征,量化分析了抛物线形沙丘的三维形态特征。结果表明：所研究抛物线形沙丘的平面形态为“U”形和“V”形,开口面向NW,即区域盛行风向,沙丘弧顶凸出指向SE,即下风方向,沙丘长轴走向与当地合成风向或输沙方向一致;迎风坡较缓,沙质较粗;背风坡较陡,沙质较细;横剖面不对称,北翼角长于南翼角;主要植被类型为梭梭,伴有芨芨草为主的若干草本,主要分布在风蚀洼地及沙丘脊上。运用RTK技术所获得的三维数据中,96%的高程值误差小于0.02 m,数据可靠。  相似文献   

东天山土屋—延东铜矿矿区晚志留世岩体的发现及构造意义   总被引：2，自引：0，他引：2  

肖兵  陈华勇  王云峰 《地学前缘》2015,22(6):251-266

东天山大南湖-头苏泉岛弧带位于吐哈盆地南缘,是中亚造山带的重要组成部分,也是我国新疆地区最重要的成矿带之一,其形成时间和构造属性一直存在争议。本次研究首次在该岛弧带中最大的斑岩矿床土屋延东铜矿区发现了晚志留世花岗闪长岩,并对其进行详细的岩石学、年代学、全岩元素地球化学和Sr - Nd - Hf同位素分析,探讨其岩浆来源和构造背景。LA - ICP - MS锆石U - Pb定年结果显示,该岩体成岩年龄为420 Ma左右,为晚志留世岩浆活动的产物。全岩元素地球化学研究结果表明,花岗闪长岩显示准铝质到弱过铝质,中等镁值和钙碱性系列的地球化学特征;微量元素方面则富集轻稀土(LREE)元素、大离子亲石元素(LILE：Rb,Ba,K)和地球化学性质活泼的不相容元素(U,Th,Pb),相对亏损高场强元素(HFSE：Nb,Ta,Ti)。这些主微量元素地球化学特征均显示出岛弧岩浆岩的地球化学属性,其εNd(t)值为4.05~4.07,87Sr/86Sr初始值为0.704 149~0.704 520,εHf(t)值为8.91~11.66。Sr - Nd - Hf同位素特征表明它们来源于新生地壳,没有受到明显的古老大陆地壳混染。晚志留世花岗闪长岩体的发现表明：大南湖-头苏泉岛弧带与其北部的哈尔里克岛弧带在早古生代可能属于同一大洋岛弧,并且与中部的卡拉塔格-小热泉子弧后(间)盆地构成统一的弧盆体系,该认识对解构东天山古生代弧盆体系演化具有较为重要的地质意义。  相似文献   

新疆呼图壁河“99·7’’洪水成因分析   总被引：1，自引：0，他引：1  

高玲  王晓峰 《沙漠与绿洲气象(新疆气象)》2008,2(4):31-33

依据有关气象与水文资料对新疆呼图壁河1999年7月20日12时发生的大洪水进行了分析,从而揭示呼图壁河“99．7”洪水发生、发展的成因。  相似文献   

0.5 m GeoEye卫星遥感影像立体测图试验研究     

许捷  王克峰 《测绘与空间地理信息》2012,35(4):160-161

利用0.5 m GeoEye卫星遥感影像立体像对和外业施测一定数量的控制点和检查点,进行1∶10000比例尺地形图立体测图试验研究,探索了所能达到的精度情况.  相似文献   

新疆彩霞山铅锌矿床稀土元素地球化学研究     

王虹  ;桑少杰  ;彭明兴  ;梁婷  ;高景刚  ;王崇礼 《西安地质学院学报》2009,(2):142-147

通过对新疆彩霞山铅锌矿床不同类型岩石和矿石的稀土元素地球化学特征的研究,探讨了岩石和矿石中稀土元素地球化学行为。结果显示,矿床中稀土元素的分布是不均匀的。在稀土元素配分模式上,活化的白云石大理岩与矿石是相近的,具有显著的δEu正异常和弱的δCe负异常,表明成矿与白云石大理岩的关系密切。同时,根据稀土元素特征的变化,提出了矿床的形成可能与岩浆活动有关的研究思路。  相似文献   

U–Pb and Re–Os geochronology and geochemistry of the Donggebi Mo deposit,Eastern Tianshan,NW China: Insights into mineralization and tectonic setting     

《Ore Geology Reviews》2017

The Donggebi Mo deposit located in NW China is a newly discovered, large, stockwork-type Mo deposit with ore reserves of 441 Mt @ 0.115% Mo. Ore bodies occur along faults and fractures at the external contact zone of a concealed porphyritic granite and volcaniclastic rocks of Gandun Formation, spatially associated with a fine-grained granite. Mo-bearing veins are mainly assemblages of volatile-rich K-feldspar-quartz-oxide, K-feldspar-quartz, polymetallic sulfides and calcite-quartz. Zircon LA-ICP-MS U–Pb dating yielded concordant ages of 234.6 ± 2.7 Ma and 231.8 ± 2.4 Ma for the porphyritic granite and the fine-grained granite, respectively; molybdenite Re–Os dating gave an isochron age of 234.0 ± 2.0 Ma. These ages further confirm an important and extensive magmatic-metallogenic event in Eastern Tianshan during the Triassic Indosinian orogeny. Whole-rock major and trace element analyses indicate that the granitic rocks associated with Mo mineralization are high in Si, K, Rb, Th, Nb, Ta, Ga and LREE, but low in P, Ti, Sr and Ba, belonging to high-K calc-alkaline granites with A-type features. Magma was likely derived from the re-melting of thickened lower crust in a post-collision compression environment in the Late Permian, experienced strong crystal fractionation and formed the large Donggebi Mo deposit under an intra-plate extension setting in the Early to Middle Triassic.  相似文献   

Magmatic evolution of the Tuwu–Yandong porphyry Cu belt,NW China: Constraints from geochronology,geochemistry and Sr–Nd–Hf isotopes     

《Gondwana Research》2017

The Tuwu–Yandong porphyry Cu belt is located in the Eastern Tianshan mountains in the eastern Central Asian Orogenic Belt. Petrochemical and geochronological data for intrusive and volcanic rocks from the Tuwu and Yandong deposits are combined with previous studies to provide constraints on their petrogenesis and tectonic affinity. New LA–ICP–MS zircon U–Pb ages of 348.3 ± 6.0 Ma, 339.3 ± 2.2 Ma, 323.6 ± 2.5 Ma and 324.1 ± 2.3 Ma have been attained from intrusive units associated with the deposits, including diorite, plagiogranite porphyry, quartz albite porphyry and quartz porphyry, respectively. The basalt and andesite, which host part of the Cu mineralization, are tholeiitic with high Al₂O₃, Cr, Ni and low TiO₂ contents, enriched LREEs and negative HFSE (Nb, Ta, Zr, Ti) anomalies consistent with arc magmas. Diorites are characterized by low SiO₂ content but high MgO, Cr and Ni contents, similar to those of high-Mg andesites. The parental magma of the basalt, andesite and diorite is interpreted to have been derived from partial melting of mantle-wedge peridotite that was previously metasomatized by slab melts. The ore-bearing plagiogranite porphyry is characterized by high Na₂O, Sr, Cr and Ni contents, low Y and Yb contents, low Na₂O/K₂O ratios and high Sr/Y ratios and high Mg#, suggesting an adakitic affinity. The high ε_Nd(t) (5.02–9.16), low I_Sr (0.703219–0.704281) and high ε_Hf(t) (8.55–12.99) of the plagiogranite porphyry suggest they were derived by a partial melting of the subducted oceanic crust followed by adakitic melt-mantle peridotite interaction. The quartz albite porphyry and quartz porphyry are characterized by similar Sr–Nd–Hf isotope but lower Mg# and whole-rock (La/Yb)_N ratios to the plagiogranite porphyry, suggesting they were derived from juvenile lower crust, and negative Eu anomalies suggest fractionation of plagioclase. We propose that a flat subduction that started ca. 340 Ma and resulted in formation of the adakitic plagiogranite porphyry after a period of “steady” subduction, and experienced slab rollback at around 323 Ma.  相似文献   

新疆库米什断陷盆地内盐湖及钾硝石矿的形成   总被引：1，自引：0，他引：1  

黄铁栋 《水文地质工程地质》2005,32(6):20-24

库米什盆地是新生代断陷盆地,处于干燥大陆气候控制区,湖水一直处在蒸发浓缩状态,在上更新统后期(约35kaBP)开始有石盐矿生成,全新统后期(4.5ka BP)地壳稳定,气候持续干旱,形成厚大的石盐主矿体,并且逐步进入干盐湖阶段,晶间卤水进一步浓缩,形成液相KNO3矿,在其上形成了富钾石盐壳。  相似文献   

新疆鄯善彩霞山铅锌矿床地质特征及找矿模型建立   总被引：1，自引：0，他引：1  

彭明兴  王君良  虞文英  张征  张阗  王文娟 《新疆地质》2006,24(4):405-411

彩霞山铅锌矿床位于塔里木板块北缘活动带卡瓦布拉克-星星峡中间地块,容矿地层为长城系星星峡群,含矿岩性为黄铁矿化白云石大理岩、少量为含碳质粉砂岩.矿体受阿其克库都克大断裂之次级断裂形成的破碎带控制,矿体形态多为脉状、透镜状、似层状.近矿围岩蚀变强烈,主要有硅化、黄铁矿化、透闪石化、碳酸盐化等.其成因类型为沉积变质-中低温热液改造型.  相似文献   

艾比湖流域K3孔地区古地理演化分析与探讨     

张磊  乃尉华  张金起 《地下水》2006,28(4):80-81

准噶尔盆地艾比湖流域K3钻孔是研究准噶尔盆地艾比湖流域地下水资源及其环境问题、合理建立水文地质概念模型提供地质基础,为生态地质环境评价提供依据.本文根据K3钻孔岩芯采集样品和测试结果,对艾比湖流域K3孔地区古地理演化进行了分析和探讨.  相似文献