Deep Structure,Volcanic and Seismic Activity Regime in Elbrus Region     

E. A. Rogozhin  M. Yu. Stepanova  Yu. V. Kharazova  A. V. Gorbatikov 《Geotectonics》2018,52(6):647-657

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The Structure and Formation Conditions of the Callovian–Oxfordian Deposits of Sudak Bay (Crimea)     

R. R. Gabdullin  N. V. Badulina  E. A. Bakai  E. V. Rubtsova  A. Yu. Yurchenko  E. V. Karpova  A. V. Ivanov  M. A. Varzanova  A. V. Sergienko  T. A. Konovalova  M. V. Parakhina 《Moscow University Geology Bulletin》2018,73(4):346-360

The composition and origin of the Callovian–Oxfordian deposits of the Sudak Bay were characterized on the basis of the generalization and analysis of our own results, as well as published and unpublished data. The botanical future was first implemented for the geological mapping of the Oxfordian deposits.  相似文献   

Patterns of Spatial Methane Distribution in the Upper Layers of the Permafrost in Central Yakutia     

M. Yu. Cherbunina  D. G. Shmelev  A. V. Brouchkov  V. S. Kazancev  R. N. Argunov 《Moscow University Geology Bulletin》2018,73(1):100-108

This article presents the results of long-term field studies on methane in the upper part of the permafrost for different geomorphological levels of Central Yakutia. Patterns of the spatial distribution of the methane content across different landscapes were found. The difference in the methane content in sediments of the Late Pleistocene ice complex on the left and right banks of the Lena River was found for the inter-alas areas. This was caused by different conditions of formation: the formation of a thin cover of deposits occurred under sub-aqua conditions favorable for methanogenesis on the left bank and in more dry aerobic conditions on the right bank. The highest concentrations of methane were found in alas deposits, where the major role belongs to the duration of freezing after draining the thermokarst lake in subaerial conditions. The methane content is highly variable both laterally and with depth in the studied deposits, but there is no redistribution after freezing; this allows one to use methane as a paleo indicator of the conditions of accumulation and freezing of sediments.  相似文献   

The Effect of Aggregation of Impurity Nitrogen on Diamond X-Ray Luminescence     

S.?V.?VyatkinEmail author  G.?Yu.?Kriulina  V.?K.?Garanin  D.?G.?Koshchug  E.?A.?Vasilyev 《Moscow University Geology Bulletin》2018,73(2):161-165

Two samplings of 65 diamond crystals divided by the intensity of a slow X-ray luminescence component are studied from the Arkhangel’skaya and Karpinskogo-1 pipes. IR and EPR spectroscopies revealed a relationship between the nitrogen A and P2 centers of the diamonds and the presence of a slow X-ray luminescence component. Its absence in most diamonds with high content of P1 (C) centers is explained by the low number of A and P2 centers.  相似文献   

Integrated Geophysical Works on the Kozlovka Anomaly (Kaluga Region)     

V.?A.?KulikovEmail author  N.?V.?Lubnina  A.?Yu.?Palenov  A.?V.?Solovieva 《Moscow University Geology Bulletin》2018,73(3):312-319

This work presents integrated geophysical studies that were carried out to identify the nature of the intense magnetic anomaly detected by the results of land surveying on the right bank of the Slushka River in the territory of the Yukhnovskii district of Kaluga Region. The comprehensive interpretation of the geophysical data and the laboratory measurements of the core made it possible to determine the nature and parameters of the anomaly-forming object that is located in the upper part of the section; it consists of loams that contain such magnetic minerals as greigite, pyrrhotite, and magnetite.  相似文献   

The Timescales of Magma Mixing in the Plumbing System of Bezymianny Volcano (Kamchatka): Insights from Diffusion Chronometry     

V. O. Davydova  V. D. Shcherbakov  P. Yu. Plechov 《Moscow University Geology Bulletin》2018,73(5):444-450

Intrusion of magma of contrasting composition into a magma chamber often triggers eruptions of arc volcanoes. Application of the diffusion chronometry method allowed us to determine the time when fresh magma was supplied to the shallow chamber of Bezymianny volcano in the case of six eruptions in 2006–2012 and to compare them to the recorded seismic activity of this volcano. Two types of eruptions of Bezymianny volcano were distinguished, with a contrasting orthopyroxene rim being formed in the respective magmas (a) up to 3 years and (b) up to 2 months before the beginning of an eruption. It was shown that these differences are caused by two different paths of magma supply to the shallow chamber of Bezymianny volcano.  相似文献   

The Structure of the Sedimentary Cover of the Kandalaksha Gulf,White Sea,from Seismoacoustic Data     

A.?V.?StarovoitovEmail author  M.?Yu.?Tokarev  Ya.?E.?Terekhina  N.?A.?Kozupitsa 《Moscow University Geology Bulletin》2018,73(3):295-305

The geological structure of water areas adjacent to the White Sea biological research station of Moscow State University (Rugozero Bay and Great Salma Strait; both are parts of the Kandalaksha Gulf, White Sea) was studied for the first time based on the seismoacoustic data. The morphology of the top of the Achaean basement, the structure of the Quaternary sedimentary cover, and the bottom topography were investigated. The sequence of glacial deposits dated back to the last glaciation and the compound sequence consisting of glaciolacustrine, glacial-marine, and marine sediments are distinguished. The spatial locations and changes of their thicknesses are considered. It is shown that the recent bottom topography is controlled by predominantly NW- and NE-striking faults that run through the entire sedimentary sequence, including the Holocene sediments.  相似文献   

A Thermodynamic Model of the Water–Rock Interaction under Hydrothermal Exposure of the Bazhenov Formation     

E.?S.?SidkinaEmail author  I.?A.?Bugaev  A.?Yu.?Bychkov  A.?G.?Kalmykov 《Moscow University Geology Bulletin》2018,73(4):375-379

Thermodynamic modeling of the hydrothermal exposure of the rocks of the Bazhenov Formation resulted in revealing the equilibrium mineral associations at 50–350°C and the pressure of saturated water vapor. The calculation results show that mineral parageneses varied slightly with the increase of temperature. Thus, zeolites were characterized by the stilbite–laumontite–wairakite series; kaolinite, pyrite, dolomite, and brannerite were replaced by montmorillonite and/or albite, pyrrhotite, calcite, and uraninite, respectively. The modeling results were confirmed in experiments.  相似文献   

安徽省凤阳江山金矿床赋矿地层和相关岩浆岩锆石年代学研究及其意义     

陈杨  范裕  刘青  李朝维  黄岩  陈曦  王彪  刘一男 《矿床地质》2018,37(6):1217-1236

安徽省北部蚌埠隆起区被认为是山东胶东招远金成矿带以西的延伸部分,但蚌埠隆起区内之前一直未发现成规模的金矿床。江山金矿床是最近新发现的中型金矿床,区内成矿作用的时代、赋矿地层的归属仍缺乏系统的年代学证据。文章对蚌埠隆起区内江山金矿床的赋矿地层和相关岩浆岩开展系统的年代学研究,明确了赋矿地层时代归属,并限定了成矿时代的上限和下限。矿床赋矿围岩浅粒岩的结晶年龄为(2496±19)Ma,变质年龄为(2452±47)Ma;斜长角闪岩的变质年龄为(1824±11)Ma,对比区域地层岩性和时代,确定矿床的赋矿围岩为新太古代五河群西堌堆组,而非过去认为的庄子里组。矿床中穿切矿体的脉岩花岗闪长斑岩的结晶年龄为(121.2±1.4)Ma,代表成矿时代的下限;赋矿岩体巨斑花岗斑岩的结晶年龄为(128.3±1.7)Ma,代表了成矿时代的上限。通过与胶东金成矿带的对比,认为蚌埠隆起区与胶东地区的前寒武纪变质基底演化历史相似,江山金矿床的成矿作用类型属于胶东焦家式金矿,在此基础上,推测蚌埠隆起区西芦山岩体和淮光岩体有较大的成矿潜力。  相似文献   

西南印度洋脊龙旂热液区富铝蚀变黏土矿物类型和地球化学特征研究     

曹凯君  吴仲玮  孙晓明  王琰  林晓 《岩矿测试》2018,37(6):607-617

产出于不同地质背景下的热液成因黏土矿物组成、晶体结构及化学成分等信息,可指示与海底热液作用有关的水-岩反应过程和流体的物理化学条件变化。但目前对于以西南印度洋脊为代表的超慢速扩张脊热液区的黏土矿物研究程度较低,尚未了解其经历的热液蚀变作用及形成过程。本文综合应用SEM-EDS、XRD、FT-IR、EPMA和LA-ICP-MS等多种分析测试手段对采自龙旂热液区矿化蚀变角砾的形貌结构、矿物组成及其化学成分进行系统表征。研究表明:该蚀变角砾中的共生矿物相主要由具二八面体结构、富Al端元的蒙皂石族矿物贝得石与蛋白石组成,角砾中可见呈细粒浸染状的TiO_2。蚀变黏土矿物的化学成分较为单一,具有富Al、贫Mg和贫Fe的特征;其稀土元素总量普遍不高(2. 43～43. 45μg/g),配分模式呈负Eu异常(0. 31～0. 53)而未显示Ce异常(1. 09～1. 16)。推断产出于硫化物堆积丘体边部的矿化角砾长期受酸性、相对还原的、低温热液流体持续叠加和淋滤改造,除Al和Ti以外大部分元素被活化迁移,形成矿物组成简单的富铝黏土矿物相。本研究查明了龙旂热液区新的蚀变黏土矿物类型及其元素地球化学特征,反映该区广泛发育低温热液蚀变作用,为进一步探讨西南印度洋超慢速扩张脊热液成矿系统的水-岩反应过程提供了一定依据。  相似文献