天山山脉中新生代差异隆升及其机制探讨     

孙岳  陈正乐  王永  韩凤彬  吴玉  孟令通  张昊 《大地构造与成矿学》2016,(2):335-343

为了揭示长约2500 km的天山山脉中新生代隆升特征,本文系统梳理分析了已发表的磷灰石裂变径迹数据和本次野外采样测得磷灰石裂变径迹数据约460个,岩性以花岗岩和砂岩为主。结果显示整个天山山脉隆升具有明显的时空差异性。白垩纪以前记录的径迹数据约占14%,白垩纪以来的数据约占86%,晚古生代末天山已有径迹年龄记录,到晚侏罗世天山部分地区发生隆升,整体隆升不明显,早白垩世以来整个天山普遍隆升,且存在多期隆升事件,但隆升剥蚀速率存在明显差异。南北方向上,自南向北径迹年龄有减小的趋势,揭示山脉隆升自南天山向北天山扩展;东西方向上,西天山隆升时限较东天山隆升早,但白垩纪以来东、西天山均有隆升记录。天山山脉差异性隆升是不同陆块对亚洲板块南缘碰撞增生作用的共同结果,其内部块体的结构特征和力学性质是差异隆升的基础和前提。  相似文献   

黔北务川丰乐铝土矿床地质特征及沉积环境探讨     

罗俊峰  王林  谢樨 《矿产与地质》2016,(3):421-425

丰乐铝土矿床位于黔北务正道铝土矿成矿带的南东端,是近年在铝土矿勘查的空白区新探明的中型矿床。勘查发现矿床中含矿岩系顶部拥有不含或偶含炭质岩系的地质特征,与务正道地区其它铝土矿床存在差异性。微量元素Cr/Ni判别显示了含矿岩系的多物源性,V/Zr及Sr/B揭示该区具有海相―陆相或过渡相―海相的沉积特征。结合前人研究成果综合分析认为,该区沉积环境为受海侵影响的近滨海湖泊―沼泽相环境。  相似文献   

Active Characteristics and Paleoearthquakes in the West Kalpin Nappe Since the Holocene,SW Tianshan Mountain     

Li An  Ran Yongkang  Liu Huaguo  Xu Liangxin 《地球科学进展》2016,31(4):377-390

the Kalpin nappe is an important multiple thrust system. It is important to study the Cenozoic tectonic of the Tianshan Mountain. Holocene active characteristics and paleoearthquake of the Kalpin nappe can be used to evaluate the neotectonic of this area. In this paper, we accurately measured the fault scarp in the front of three thrust-fold faults and analyzed paleoearthquake events in the trenches of the Kalpin nappe. Using the ¹⁰Be exposure age, we obtained those geomorphic surface ages and paleoearthquake times. The result showed that the slip rates of the west Kalpintag fault, aozitag fault and the tuoketag fault were 1.45(+1.68/-0.44) mm/a, 0.81(+0.35/-0.19) mm/a and (0.3±0.05) mm/a, respectively since the Holocene. The slip rate indicated that the increased activity transferred from back-row fault to front-row fault and accorded with the piggy-back propagation model in the Tianshan Mountain. Displacements and recurrence intervals of paleoearthquakes was similar to the slip rate characteristics. It also showed paleoearthquakes in the front row fault were stronger than paleoearthquakes of the back row fault. The strong paleoearthquake which caused the highest surface rupture happened in the Kalpintag fault. The interval of paleoearthquakes was about 4 ka and the displacement of every paleoearthquake was about 3 m in the west Kalpintag fault; the interval of paleoearthquakes was about 2 ka and the displacement of every paleoearthquake was about 1m in the aozitag fault; the tuoketag fault ruptured only one paleoearthquake since 7 ka. The Piqiang tear fault was the tectonic result of different shortening rate between the west Kalpin system and the east Kalpin system. The shortening rate of west Kalpin system was obviously stronger than the east Kalpin system. The huge separation distance was near 20 km between the east and the west back-row fault. Because the slip rate of system transferred to the front-row fault in the piggy-back propagation model, the separation distance (~4 km) between the east and the west front-row fault was increasing.  相似文献   

新疆西天山铁木里克铁矿床火山岩锆石U-Pb年代学、岩石地球化学特征及地质意义   总被引：1，自引：0，他引：1  

王大川  段士刚  陈杰  蒋宗胜  张作衡  贾金典 《岩石学报》2016,32(5):1391-1408

铁木里克铁矿位于西天山阿吾拉勒铁铜成矿带中段,矿床围岩为一套以粗面安山岩、安山岩和流纹岩为主的连续变化的中酸性火山岩。本文通过对铁木里克铁矿床火山岩进行LA-ICP-MS锆石U-Pb定年,并且结合Hf同位素和岩石地球化学研究,对火山岩的形成时代以及大地构造背景进行探讨。锆石LA-ICP-MS测年结果显示,粗面安山岩、安山岩以及流纹岩的测年结果分别是318.8±2.3Ma、320.8±2.5Ma和319.1±3.5Ma。地球化学分析表明该套火山岩属于高钾钙碱性-钾玄岩系列,富集轻稀土元素(LREE)和大离子亲石元素(LILE;如Rb、Th、K),重稀土元素(HREE)配分平坦,同时具有Nb、Ta的强烈亏损,具有明显的岛弧火山岩地球化学特征。在火山岩的大地构造判别图解上,样品点都落在了大陆弧部分。锆石的Hf同位素显示εHf(t)具有一致的变化范围(+6.2~+12.0),指示火山岩具有相同的岩浆来源,都是来源于早古生代新生陆壳的重熔,形成于相同的构造岩浆背景下。结合区域地质资料,本文认为铁木里克铁矿床出露的这套高钾钙碱性-钾玄岩系列火山岩可能是南天山洋闭合末期到陆陆碰撞早期大陆弧岩浆作用的产物。  相似文献   

吉尔吉斯斯坦中天山地质特征及研究进展   总被引：2，自引：1，他引：1       下载免费PDF全文

陈博  马中平  孟广路  王斌  曹积飞  李文渊 《中国地质》2016,(2):458-469

文章通过对近年来有关吉尔吉斯中天山研究进展的梳理,结合在吉尔吉斯斯坦的实地考察,系统论述了中天山基础地质情况,并简述与岩浆活动有关的成矿作用。吉尔吉斯斯坦境内的天山由"尼古拉耶夫线"和阿特巴什—伊内尔切克断裂划分为北、中、南3部分。中天山两侧的缝合带限定了早古生代古吉尔吉斯洋和晚古生代南天山洋的发展和消亡过程。组成中天山的不同块体大多具有古元古界的基底,古生代总体处于大陆坡-边缘海沉积环境。晚古生代产出与俯冲相关的岩浆作用和后碰撞岩浆作用,前者与斑岩型铜矿、接触交代型铜-金矿相关,后者与造山型金矿相关。  相似文献   

New tectonic map of Northern-Central-Eastern Asia:Position and evolution of Mesozoic sedimentary basins     

《世界地质(英文版)》2016,(4):261-276

The beginning of the XXI century was marked a new rising of the international tectonic cartography as a result of analysis and synthesis of a huge volume of geological information obtained for the territory of Asia especially during the last 30 years. The previous tectonic maps for Asia were created in the 1960 s--1970 s of the last century. Since that time,the national geological surveys have compiled tectonic maps exclusively in the limits of their own state boundaries. The international cooperation of five countries since 2002( Russia,China,Mongolia,Kazakhstan and Republic of Korea) gave a unique possibility to join the data into a united cartographic form as Atlas of Geological Maps( since 2002-Atlas of Geological Maps of Central Asia and since 2007-Atlas of Geological Maps of Northern-Central-Eastern Asia). Both atlases include four maps: geological,tectonic,metallogenic,and energy resources. Tectonic Map of Northern-Central-Eastern Asia and Adjacent Areas at scale 1 ∶ 2 500 000 was the key map for further compilation of the metallogenic and energy resources( coal,oil and gas) maps. By this reason,special attention was given to showing the structure and composition of the Mesozoic sedimentary basins in Northern-Central- Eastern Asia as the most perspective structures for oil-and-gas and coal prospect.  相似文献   

新疆额尔宾山花岗岩侵位年龄和成因及其对南天山洋闭合时代的限定     

杨莉  陈文  张斌  尹继元  孙敬博  李洁  喻顺  杨静  袁霞 《地质通报》2016,35(1):152-166

额尔宾山花岗岩岩体位于南天山晚古生代侵入岩带,对该花岗岩进行锆石U-Pb定年获得296.1±1.8Ma的年龄,为早二叠世。岩石主量元素分析结果表明,该花岗岩的Si O2含量为66.96%~67.3%,富碱(Na2O+K2O=7.53%~7.97%),K2O/Na2O1(1.15~1.27),属高钾钙碱性系列岩石;Al2O3为15.56%~15.62%,Al2O3K2O+Na2O+Ca O,属于过铝型。岩石稀土元素配分模式呈现轻稀土元素(LREE)富集((La/Yb)N=27.03~30.62)、重稀土元素(HREE)亏损((LREE/HREE)=18.2~20.1)、具有中等程度的负Eu异常(δEu=0.64~0.68)。微量元素判别结果显示,其具有I-A型花岗岩过渡的特征。结合区域地质背景综合分析,初步认定该岩体可能形成于南天山同碰撞向后碰撞构造体制转换时期,据此可以推测南天山洋盆闭合时限至少应该在早二叠世以前。  相似文献   

区域地球化学评价中变异系数校正参数的意义     

刘明义  张晶  孟广路  胡立 《现代地质》2018,32(5):1074

通过对我国新疆西天山各地球化学区数据的归纳和研究,计算西天山12种常见成矿元素在各地球化学区的富集系数,提出校正系数公式,并将变异系数进行合理的校正与排序。与实际矿床和矿点结合,验证校正系数的正确性和适用性,预测元素成矿有利顺序和规律,总结出西天山富集系数与变异系数在成矿中的制约关系。该方法实现了不同成矿元素之间成矿条件的对比,拓宽了地球化学参数的适用性,提高了在勘探程度较低的地区地球化学评价方法的准确性,为地球化学评价提供科学依据。  相似文献   

Ore-forming Fluid and Mineral Source of the Hongshi Copper Deposit in the Kalatage Area, East Tianshan, Xinjiang, NW China   总被引：1，自引：0，他引：1  

YU Mingjie  WANG Jingbin  MAO Qigui  FANG Tonghui  ZHANG Rui 《《地质学报》英文版》2018,92(5):1769-1783

The Hongshi copper deposit is located in the middle of the Kalatage ore district in the northern segment of the Dananhu-Tousuquan island-arc belt in East Tianshan, Xinjiang, NW China. This study analyses the fluid inclusions and H, O, and S stable isotopic compositions of the deposit. The fluid-inclusion data indicate that aqueous fluid inclusions were trapped in chalcopyrite-bearing quartz veins in the gangue minerals. The homogenization temperatures range from 108°C to 299°C, and the salinities range from 0.5% to 11.8%, indicating medium to low temperatures and salinities. The trapping pressures range from 34.5 MPa to 56.8 MPa. The δ18OH2O values and δD values of the fluid range from ?6.94‰ to ?5.33‰ and from ?95.31‰ to ?48.20‰, respectively. The H and O isotopic data indicate that the ore-forming fluid derived from a mix of magmatic water and meteoric water and that meteoric water played a significant role. The S isotopic composition of pyrite ranges from 1.9‰ to 5.2‰, with an average value of 3.1‰, and the S isotopic composition of chalcopyrite ranges from ?0.9‰ to 4‰, with an average value of 1.36‰, implying that the S in the ore-forming materials was derived from the mantle. The introduction of meteoric water decreased the temperature, volatile content, and pressure, resulting in immiscibility. These factors may have been the major causes of the mineralization of the Hongshi copper deposit. Based on all the geologic and fluid characteristics, we conclude that the Hongshi copper deposit is an epithermal deposit.  相似文献   

中国—吉尔吉斯斯坦天山构造格架与演化          下载免费PDF全文

孟广路  罗彦军  王斌 《中国地质调查》2018,5(1):28-36

中国—吉尔吉斯斯坦天山地处中亚天山造山带中段,地质构造复杂,矿产资源丰富。在前人资料基础上,基于区域构造-岩石组合的分布发育及时空属性特征,统一将研究区划分为哈萨克斯坦和塔里木两大板块,二者由南天山晚古生代缝合带所焊接。其中,进一步划分为5个二级单元,18个三级单元。研究认为,研究区内北、中、南天山构造格架连续,在800 Ma(相当于南华纪下限)前后都完成了大陆块体的拼合,成为全球新元古代罗迪尼亚超大陆的组成部分。此后经历了大致相同的构造演化史,从中二叠世开始全区转化成陆内盆山构造格局,新生代印度大陆同欧亚大陆碰撞使这一陆内盆山构造格局不断臻于完善。  相似文献