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81.
大兴安岭地区内生铜矿床的成因类型、成矿时代与成矿动力学背景 总被引:7,自引:4,他引:7
大兴安岭地区位于兴蒙造山带的东段,构造、岩浆活动强烈,蕴藏着丰富的内生有色金属、贵金属矿产资源。本文通过对该区内生铜矿床的地质特征、成因类型和年代学研究,初步将区内内生铜矿床划分为斑岩型、浅成热液高硫化型(铜银、铜锡)和接触交代型三种成因类型,除铜锡矿床外,它们的成矿作用均与高钾钙碱系列I型花岗质岩浆密切相关;其中斑岩型和浅成热液高硫化型(铜、银)的成矿分别发生在485Ma、180~170Ma和170~160Ma;而浅成热液高硫化型(铜锡)矿床与A型花岗质岩浆相关,成矿在150~135Ma之间;接触交代型与它们相伴生,主要发生在180~160Ma和150~135Ma。其成矿动力学背景分别与早古生代兴安地块与松嫩地块的拼合碰撞造山、中侏罗世的西伯利亚板块和华北板块的陆缘增生带碰撞缝合造山与早白垩世碰撞造山后的地壳伸展减薄作用过程相适应,矿床在不同阶段的造山挤压与伸展转换或造山期后的伸展阶段就位,这项研究为深入研究该区内生多金属成矿规律提供了科学依据。 相似文献
82.
松辽盆地大庆长垣隆起区砂岩型铀矿资源丰富,但成矿条件复杂。以大庆长垣南端四方台组砂岩型铀矿为研究对象,基于三维地震精细解译成果,对长垣隆起区铀矿的分布特征、富集主控因素及成矿模式开展研究。结果表明:①三维地震资料是刻画断层与砂体分布的有效手段;②砂岩型铀矿主要富集在四方台组一段的河道砂体中,与沟通深部油气储层的输导断层邻近;③河道砂体、油气输导断层及油气圈闭是控制砂岩型铀矿富集的3个主要因素;④长垣隆起区的砂岩型铀矿是含铀地下水与油气运聚协调配合局部富集的结果,建立了输导断层与油气圈闭联合控矿模式。研究成果为含油气盆地砂岩型铀矿勘探提供了新的思路。 相似文献
84.
烃气测量法在锡、金、铜、铅锌等金属矿床找矿中得到了广泛应用,而该技术在花岗岩型铀矿找矿中的应用鲜有报道。本文对桂北376铀矿床已知矿体开展了烃气测量试验,结果显示:相较于其他金属矿,该铀矿区花岗岩和土壤中总烃含量极低,而且花岗岩总烃含量(平均19.42μL/kg)高于上覆土壤(平均6.32μL/kg)。花岗岩中U与多数烃气组分呈负相关,与重烃呈正相关,重烃在U迁移过程中作用强于轻烃;花岗岩烃气标准化配分模式以C1、iC4和C2-正异常为特征;铀矿化程度与iC4/nC4、(C1+iC4+C2-)/(C2+C3+nC4)及C2-/C3-比值呈正相关,与C2+/∑C比值呈负相关等可为寻找铀矿提供依据。3... 相似文献
85.
86.
Ahmed Barakat Christian Marignac Marie-Christine Boiron Mohamed Bouabdelli 《Comptes Rendus Geoscience》2002,334(1):35-41
The gold showings at Bleida are hosted in Late Pan-African N50–80 °E quartz–hematite–chlorite 1 tension lenses that are related to the activity of major sinistral sub-east–west thrusts. Ores result from three superimposed stages of fluid migration. Gold occurs in microcracks offsetting the earlier minerals. Fluids evolved from COHN compositions with a saline component to boiling aqueous fluids. Pressure and temperature decreased from 50 MPa and 300 °C to less than 4 MPa and 150 °C. Thus, the gold showings at Bleida were formed in a typical geothermal (epithermal) setting, likely controlled by the Late Pan-African magmatism. To cite this article: A. Barakat et al., C. R. Geoscience 334 (2002) 35–41 相似文献
87.
Francisco González-Sánchez Antoni Camprubí Eduardo González-Partida Rafael Puente-Solís Carles Canet Elena Centeno-García Viorel Atudorei 《Mineralium Deposita》2009,44(3):343-361
Northeastern Mexico hosts numerous epigenetic stratabound carbonate-hosted low-temperature hydrothermal deposits of celestine,
fluorite, barite and zinc-lead, which formed by replacement of Mesozoic evaporites or carbonate rocks. Such deposits can be
permissively catalogued as Mississippi Valley-type (MVT) deposits. The deposits studied in the state of Coahuila are associated
with granitic and metasedimentary basement highs (horsts) marginal or central to the Mesozoic Sabinas Basin. These horsts
controlled the stratigraphy of the Mesozoic basins and subsequently influenced the Laramide structural pattern. The Sabinas
Basin consists of ~6,000-m-thick Jurassic to Cretaceous siliciclastic, carbonate and evaporitic series. The MVT deposits are
mostly in Barremian and in Aptian-Albian to Cenomanian formations and likely formed from basinal brines that were mobilized
during the Laramide orogeny, although earlier diagenetic replacement of evaporite layers (barite and celestine deposits) and
lining of paleokarstic cavities in reef carbonates (Zn–Pb deposits) is observed. Fluid inclusion microthermometry and isotopic
studies suggest ore formation due to mixing of basinal brines and meteoric water. Homogenization temperatures of fluid inclusions
range from 45°C to 210°C; salinities range from 0 to 26 wt.% NaCl equiv., and some inclusions contain hydrocarbons or bitumen.
Sulfur isotope data suggest that most of the sulfur in barite and celestine is derived from Barremian to Cenomanian evaporites.
Regional geology and a compilation of metallogenic features define the new MVT province of northeastern Mexico, which comprises
most of the state of Coahuila and portions of the neighboring states of Nuevo León, Durango and, perhaps extends into Zacatecas
and southern Texas. This province exhibits a regional metal zonation, with celestine deposits to the south, fluorite deposits
to the north and barite and Zn–Pb deposits mostly in the central part. 相似文献
88.
89.
额尔齐斯河流域及某稀有多金属矿废水铀、钍含量分布及其环境影响 总被引:5,自引:0,他引:5
运用简易、快捷、灵敏的ICP-MS法直接测定稀有多金属矿以及河水样品中的铀钍含量,并推算其与比放射性活度之间的定量关系,客观评价了某稀有多金属矿废水中的放射性水平以及额尔齐斯河流域的放射性污染现状。研究表明,某稀有多金属选矿废水铀含量可达78.311μg/L,钍含量达0.627μg/L。额尔齐斯河流域各支流河水铀、钍平均含量分别为0.584μg/L、0.025μg/L,其干流河水钍平均含量为0.019μg/L,而铀平均含量达2.234μg/L,远高于世界河水铀平均含量0.309μg/L。 相似文献
90.
The Rockhole area, Northern Territory, Australia, hosts a number of Proterozoic unconformity-related uranium deposits. The geology of the area features within Paleoproterozoic rocks of the Pine Creek Orogen, near the unconformity with overlying platform cover sandstone of the Paleo- to Mesoproterozoic McArthur Basin. Landsat Enhanced Thematic Mapper plus (ETM+) data was used in the Rockhole area to assist in mapping geological structures and lithology, and to identify anomalous concentrations of ferrous minerals, the product of alteration, which can be indicators of buried uranium mineralization. Several image-processing procedures were applied to the ETM+ data to identify, isolate and enhance mineralogical information as simple and complex false color composites. ETM+ 754 shown as red green and blue respectively was the best simple image. Overall, complex images based on Principal Component Analysis proved to be the most useful products. Sandstone, shale and siltstone, the target lithologies, Koolpin Formation, the target stratigraphic unit, and bleaching pattern due to the removal of iron(II) compounds, the target alteration pattern, were confidently mapped to provide information required by the mineral emplacement model, which ultimately identified areas of likely uranium mineralization. Thus the contrasting behavior of the two principle oxidation states of uranium and iron can be utilized to map/delineate bleached alteration zones associated with economic concentrations of uranium using multispectral sensors like Landsat or better hyperspectral sensors. 相似文献