内蒙古东乌旗达赛脱铅锌矿的控矿构造     

田继勋 《地质找矿论丛》2005,20(Z1):102-105

通过对东乌旗区域构造及达赛脱铅锌矿区构造带的分析,阐明了NEE向构造为达赛脱铅锌矿区的主要控矿构造.  相似文献   

我国内蒙古发现的砷铁钙石   总被引：1，自引：0，他引：1  

张岐大  宋大康 《矿物学报》1990,10(1):80-84

砷铁钙石发现于内蒙古白云石大理岩中的金砷铅矿体内，共生的主要矿物有砷铁矾、砷铅石、臭葱石、自然金等。砷铁钙石为金黄色放射状，半金属光泽或丝绢光泽，比重3．56，摩氏硬度4．5，折光率值大于1．800，二轴晶（一）。针铁钙石的化学成分（％）为：CaO 12.96,Fe2O3 28.00,As2O5 40.49,MgO 0.30,H2O 10.35 Pb-O 0.19,总计92．29。结晶化学式为：Ca3Fe^ (AsO4)4(OH)6·3H2O。X射线为晶衍射强度有：8．948（100，200），2．961（44，600），2．777（6，204），2．222（19）。主要红外吸收谱带在3366，1634，946，787，507cm^-1处。  相似文献   

钇易解石的高分辨电子显微学研究     

西门露露  贾春林  丁孝石 《矿物学报》1990,(2)

本文利用EM-430分析透射电子显微镜研究了内蒙古斑岩型稀有金属矿床中的天然量质钇易解石。电子衍射分析表明该矿物系斜方晶系,其晶胞常数为:a=5.22,b=10.92,c=7.44。同时摄取了Z轴方向及X轴方向投影的高分辨结构象。结构象与由X射线结构分析导出的人工晶质易解石结构模型中重原子排列吻合得很好。  相似文献   

内蒙古二连盆地早三叠世地层及孢粉组合的发现   总被引：3，自引：2，他引：1  

胡桂琴  徐晓峰 《地层学杂志》1999,23(4):263-269,T002

二连盆地曾被认为是缺失三叠纪沉积的地区。通过阿拉坦合力凹陷坦参１井的孢粉化石分析,首次证实了在二连盆地存在早三叠世地层。坦参１井的下三叠统的视厚度１ ３３９ｍ （井深５５８～１ ８９７ｍ ）,以紫红色、棕红色的泥岩为主,夹灰绿色泥岩,向下岩性变粗,含砾泥岩、砂砾岩增加,与上覆侏罗系及下伏上二叠统皆呈不整合接触。井深７００～１ ８９６ｍ 产以Ｌｉｍ ａｔｕｌａｓｐｏｒｉｔｅｓ大量出现、Ｔａｅｎｉａｅｓｐｏｒｉｔｅｓ具一定含量、出现Ｌｕｎｄｂｌａｄｉｓｐｏｒａ、Ａｒａｔｒｉｓｐｏｒｉｔｅｓ和Ｌｕｅｃｋｉｓｐｏｒｉｔｅｓ为主要特征的早三叠世孢粉化石组合。这一发现对重新认识二连盆地的地质发育历史颇有意义  相似文献   

内蒙古喀喇沁堆晶岩捕虏体和寄主闪长岩的同位素年龄   总被引：14，自引：0，他引：14  

邵济安  张任祜  韩庆军  张履桥  乔广生  桑海清 《地球化学》2000,29(4):331-336

喀喇沁地区们于大兴安岭中生代构造岩浆岩带与华北克拉通交汇部位。研究区的闪长岩侵入到太古宙基底中。闪长岩中含有二辉岩、辉长岩、苏长岩、角闪岩、斜长岩等不同组分的镁铁质－超镁铁堆晶岩捕虏体和基性麻粒岩捕虏体,它们是幔源玄武质岩浆底侵作用的产物。分别用Ｒｂ－Ｓｒ法、Ｋ－Ａｒ法和Ａｒ－Ａｒ法,对堆晶岩捕虏体及其寄主岩全岩或单矿物进行了详细的同位素地质年代学研究,共获得各种年龄数据８件,橄榄辉石岩的全岩Ｒｂ  相似文献   

Age and petrogenesis of late Mesozoic intrusions in the Huoluotai porphyry Cu-(Mo) deposit,northeast China: Implications for regional tectonic evolution     

《地学前缘(英文版)》2022,13(2):101344

Multi-stage igneous rocks developed in the recently discovered Huoluotai Cu-(Mo) deposit provide new insights into the controversial late Mesozoic geodynamic evolution of the northern segment of the Great Xing’an Range (NSGXR). Zircon U-Pb dating suggests that the monzogranite, ore-bearing granodiorite porphyry, diorite porphyry, and granite porphyry in the deposit were emplaced at 179.5 ± 1.6, 148.9 ± 0.9, 146.1 ± 1.3, and 142.2 ± 1.5 Ma, respectively. The Re-Os dating of molybdenite yielded an isochron age of 146.9 ± 2.3 Ma (MSWD = 0.27). The Jurassic adakitic monzogranite and granodiorite porphyry are characterized by high SiO₂ and Na₂O contents, low K₂O/Na₂O ratios, low MgO, Cr, and Ni contents, low zircon ε_Hf(t) values relative to depleted mantle, and relatively high Th contents. They were produced by partial melting of a subducted oceanic slab, with involvement of marine sediments in the magma source and limited interaction with mantle peridotites during magma ascent. The Late Jurassic diorite porphyry is characterized by moderate SiO₂ contents, high MgO, Cr, and Ni contents, and positive dominated ε_Hf(t) values, indicating it was produced by partial melting of a subduction-modified lithospheric mantle wedge and underwent limited crustal contamination during magma ascent. The early Early Cretaceous adakitic granite porphyry shows high SiO₂ and K₂O contents and K₂O/Na₂O ratios, low MgO, Cr, and Ni contents, enriched Sr–Nd isotopic compositions, and slightly positive zircon ε_Hf(t) values, suggesting it was produced by partial melting of thickened mafic lower crust. The NSGXR experienced a tectonic history that involved flat-slab subduction (200–160 Ma), and tearing and collapse (150–145 Ma) of the Mongol–Okhotsk oceanic lithosphere. The period of magmatic quiescence from ca. 160 to 150 Ma was a response to flat-slab subduction of the Mongol–Okhotsk oceanic lithosphere. Crustal thickening in the NSGXR (145–133 Ma) was due to the collision between the Amuria Block and the Siberian Craton.  相似文献   

内蒙古月牙山蛇绿岩特征及形成的构造背景:地球化学和Sr-Nd同位素制约   总被引：9，自引：0，他引：9  

周国庆  赵建新  李献华 《地球化学》2000,29(2)

内蒙古白云山－月牙山－洗肠井蛇绿岩（简称月牙山蛇绿岩）发育较完整,推覆构造也很发育。其变质橄榄 岩、方辉橄榄岩强烈亏损ＴｉＯ_２,辉绿岩ＴｉＯ_２也较低,而稀土元素分布模式为平缓型。斜长花岗岩类亏损高场强元素 （ＨＦＳＥ）和重稀土元素,富集大离子亲石元素（ＬＩＬＥ）,一个石英问长岩样品（Ｙ１０）具有高Ｓｉ、高Ｍｇ、低Ｔｉ的玻镁安山 岩特征。Ｎｄ同位素特征表明,辉绿岩和石英闪长岩具有高而均一的正ε_（Ｎｄ）（ ｔ）值（＋ ６． ４～＋ ７． ９）,说明辉绿岩和石英 问长岩来自同一亏损地幔所产生的岩浆,没有遭受明显的陆壳混染,但受过由俯冲洋壳释放出的流体的交代,花岗 质岩石是其衍生物。参考等时线年龄（４７０ Ｍａ）与地层古生物证据相符。蛇绿岩的（~（８７）Ｓｒ／~（８６）Ｓｒ）;值变化较大,具海水蚀变特征。岩石、地层、地球化学和Ｓｒ－Ｎｄ同位素综合制约表明,该蛇绿岩形成于塔里木北缘多岛弧弧间盆地的初期扩张阶段,属Ｐｅａｒｃｅ提出的ＳＳＺ型蛇绿岩。  相似文献   

2012年12月20-23日巴州寒潮降雪天气的特征分析     

周雪英  彭军  段均泽 《沙漠与绿洲气象(新疆气象)》2014,8(3):48-55

利用常规观测资料、自动站、T639客观分析资料,结合天气学原理和天气动力学诊断分析方法,对2012年12月20-23日巴音郭楞蒙古自治州（以下简称巴州）的寒潮天气过程的成因和降雪天气特征进行分析,并给出巴州降雪天气概念模型。结果表明：这次寒潮降雪过程是北欧阻塞高压向东南衰退,导致脊前横槽转成竖槽东南移,高空冷空气南压至40°N附近,造成巴州强降温、强降雪等寒潮天气,降雪阶段关键影响系统是700 hPa上的冷暖切变和风场辐合,水汽主要源自中低层西北方的经向和低层东南方的纬向输送;后续的冷凝降雪和阴雪阶段天气局地特征明显,水汽源自850 hPa至近地层局地的垂直输送。  相似文献   

Early Mesozoic tectono-magmatic activity and mineralization in Northeast China: evidence from Re–Os to U–Pb studies of the Taipingchuan porphyry Cu–Mo deposit in the Derbugan metallogenic belt     

《International Geology Review》2012,54(15):1837-1851

The Taipingchuan Cu–Mo deposit is a recently discovered large porphyry deposit located in the north of the Derbugan metallogenic belt of northeastern China. The geochronological data of the deposit yielded a Late Triassic zircon U–Pb age of 202 ± 6 Ma from a granodiorite porphyry that hosts the Cu–Mo mineralization. Measured Re–Os isotopes of seven disseminated molybdenite samples yielded an isochron age of 200 ± 5 Ma with mean square of weighted deviates of 2.7, while those of seven veinlet molybdenite samples also produced an isochron age of 200.1 ± 2.5 Ma and mean square of weighted deviates of 3.3. These isochron ages show that a Cu–Mo mineralization event occurred at ca. 200 Ma. Based on regional tectonic evolution, we propose that the Late Triassic Cu–Mo mineralization of the host porphyry in the Derbugan metallogenic belt was mainly associated with the subduction of the Mongol–Okhotsk Ocean slab under the Ergun block, contrary to previous suggestion that it was related to the subduction of the Mesozoic Palaeo-Pacific plate.  相似文献   

内蒙古金矿床的成因类型划分          下载免费PDF全文

黄少奇 《地质找矿论丛》2005,20(Z1):43-48

将内蒙古已知金矿划分为5大类型20个矿床亚类:即重熔岩浆热液金矿、变质热液金矿、沉积变质热液金矿、火山-次火山热液金矿、砂金矿.对各类型金矿床的地质成因特征进行了初步探讨.  相似文献