科拉超深钻：期望与结果

科拉超深钻的钻进和探测首次提供了以前无法达到的深度的有关古老大陆地壳成分和构造的直接资料，岩石密度和它们弹性的各向异已成为当今地表地质正式描述形式和参考剖面的主要参数，所给出的完整模型的证据是基于科拉超深钻的探测及辅助的地表地质研究，模型认贝辰加矿区是一个幔源火山岩－侵入岩中心式成矿系统的水平部分，本文还对铜－镍硫化物矿床出条件给予了新的解释，并用助于理解贝辰加矿区在贝辰加一依曼德－瓦尔朱格缝合带     

苏联超深钻探在万米处发现热液型金属矿化

苏联在1962年决定实施一项国家性的超深钻探计划,孔深大于6000米.现计划约20个孔,其中第一个孔科拉SG-3位于穆尔曼斯克地区贝辰加镍矿区. 超深钻计划旨在解决三个互相关联而又极其复杂的课题:1.陆壳的构造和演化;2.探寻深处包括油气在内的矿床;3.在孔深10～15公里的高温高压条件下深孔钻探实践及其经济技术问题. 科拉钻孔深度已超过11500米(1982年8月孔深11515米),目标为15000米.至今世界上只有两个孔超过9000米(均位于美国的沉积     

科拉半岛超深钻深部地质和地球物理新资料

科拉超深钻已反驳了基于地表的地质和地球物理研究所建立起来的东巴尔干地质深部构造模式。无论原先什么样的推测,超深钻孔在6840m～12000m这段深度并没有碰到玄武岩或麻粒岩等基性岩石,而钻到的是太古宙科拉岩系中的花岗片麻岩。在这段上,变质火山成因的岩石与变质陆源岩互层产出,残余层状特征仍保留下来,这是与褶皱随深度增加而减弱的观点不符。以最大深度处,钻孔遇到一新的构造层,这被三维磁场测量和地球化学资料的结果所证实。 UD-3钻孔核部的构造岩石分析证实了元古宙内生作用对科拉岩系的强烈影响。在中元古宙(1.8～2.0Ga),Pechenga火山沉积杂岩和太古宙的花岗片麻岩均遭受从葡萄     

来自超深钻的重要信息

原苏联从60年代至现在,在外高加索、乌拉尔、滨里海,千岛群岛和卡累利阿等地打过许多深钻和超深钻,大部分深度在3—6km,其中最深的科拉井可达12261m。大量收集地球深部的各种信息,目的在揭露整个地壳剖面。迄今为止,这项世界上规模最大、钻探最深的超深钻取得了不少令人瞩目的成果,深部的含矿信息主要有以下几方面: 1.科拉井在1540—1800m处发现了含镍超基性岩带,铜镍矿化与变橄榄岩体有关;在6380m处的     

太古宙岩石剖面中的角闪岩

角闪岩在前寒武纪变质岩石中占有重要地位，本文以科拉超深钻资料为依据做一介绍。在ＣＴ－３科拉超深钻岩心剖面中，太古宙杂总厚度的３０％为角浆岩岩石。它们多数呈浅成整合和不整合层状产出于片麻岩和花岗岩围岩中。根据产状结构构造特征和矿物成分，整个剖面中的角闪岩可为二个成因类型１２个组。     

大陆超深钻与前寒武纪地质研究

大陆科学钻探是地球科学发展一定阶段的产物。原苏联的科拉超深钻和克里沃罗格超深钻的重要发现，检验了池代地学理论，使人们重新认识地壳结构等许多问题，因而促进了地球科学和大陆科学钻探的发展。     

1998年批准实施的国际地质对比计划(IGCP)项目介绍

国际地质对比计划（ＩＧＣＰ）是由国际地质科学联合会（ＩＵＧＳ）和联合国教科文组织（ＵＮＥＳＣＯ）联合资助的,目前ＩＧＣＰ在研项目共计４９个,１９９８年批准实施的项目有１０项。ＩＧＣＰ４０８项：深部与地表岩石和矿物研究———科拉超深钻孔（ＫＳＤＢ—３）...     

大陆超深钻与前寒武纪地质研究

大陆科学钻探基地球科学发展到一定阶段的产物．原苏联的科拉超深钻和克里沃罗格超深钻的重要发现，检验了当代地学理论，使人们重新认识地壳结构等许多问题，因而促进了地球科学和大陆科学钻探的发展．     

太古宙岩石剖面中的角闪岩

角闪岩在前寒武纪变质岩中占有重要地位，本文以科拉超越深钻资料为依据做一介绍。在CT－3科拉超深钻岩心剖面中，太古宙杂岩总厚度的30％为角闪岩岩石．它们多数呈浅成整合和不整合层状产出于片麻岩和花岗岩围岩中．根据产状结构构造特征和矿物成分，整个剖面中的角闪岩可分为二个成因类型和12个组。其中1－5组为副角闪岩总的具典型结晶片岩外貌；6－12组为正角闪岩，总的成因标志按年代系列为变辉长岩杂岩→变玢岩和变超镁铁岩，最后为年轻的喷出一杏仁状变焊绿岩。     

大陆深部地壳研究中的地质──地球化学方法概述

迄今为止，地球物理方法一直是研究深部地壳结构的重要方法，这种方法主要是利用岩石的物理性质来推测深部地壳的物质组成，地壳的分层及分层界面性质。随着近年来研究发现许多依据地球物理资料和地表地质确定的深度超过1500m即定目标都未得到深钻或超深钻的证实（肖庆辉，1993），这种结果在地学界引起很大反响。从另一个意义上，由地球物理方法确定的地壳仅反映其终态，而对复杂的地壳演化方面尚显不足。深钻和超深钻方法近年来已成为探测深部地完结构的一种重要方法，它可以直观的研究深部地壳的岩浆作用、构造作用、成矿作用，也是研究…     

Composition and structure of minerals from Paleoproterozoic sedimentary rocks in the section of the Kola Superdeep Borehole and their homologs in outcrops

Geochemical and structural features of microcline, quartz, and carbonates from the sedimentary Luchlompolo Formation (III SF) of the Pechenga volcano sedimentary complex were compared in outcrops at a depth of 20–400 m in the section of satellite Borehole IX and of 4.8 km in the Kola Superdeep Borehole (SD-3). The rocks occupying an identical position in the section of this formation are homologous and characterized by similar composition and spectroscopic properties of rock-forming minerals. A certain variance in defect structure is revealed in minerals from shallow and deep levels. The crystal structure of microcline and dolomite from deep levels of the Kola Superdeep is distinguished by a larger amount of defects. The isomorphic replacement of Ca with Mn ions in dolomite increases with depth, probably owing to more intense metamorphism and further long-term standing at elevated pressure and temperature. The concentration of Al admixture in quartz decreases with depth, and isomorphic substitution of Al for Si shifts toward compensation with the alkali element in response to the same factors. The decrease in the number of natural paramagnetic Al centers in quartz and decrease in oxygen vacancies with depth is regarded as an effect of the current PT conditions.     

俄罗斯贝辰加镍-铜硫化物矿床研究进展

贝辰加镍-铜硫化物矿床位于俄罗斯北极圈内科拉半岛西北部,是一个世界级镍-铜矿集区。矿集区目前共发现25个含工业矿体的侵入体,分东、西2个矿带,已探明镍资源量470×104t,品位1.2%,铜储量350×104t,品位0.9%,与俄罗斯诺里尔斯克、加拿大萨德伯里、中国金川等矿床并列为世界级大型铜镍硫化物矿床。贝辰加杂岩体由4套古元古代火山-沉积旋回构成,含矿的为第四套火山-沉积旋回皮尔咖加维建造。矿集区内的火山-沉积作用发生在1940~2500Ma之间,成矿作用发生在1950~1990Ma之间,矿化作用发生在古元古代该地区岩浆演化的晚期阶段。贝辰加镍-铜矿赋矿岩石为富铁苦橄岩,具有高铁、低Al2O3,高Ti O2、Zr和其他不相容元素的特点,强烈富集LREE,地球化学特征类似于板内玄武岩或碱性玄武岩。矿床成矿模式为地幔柱分支分异成的贝辰加岩体侵入裂陷槽,其西部矿体侵入至沉积地层之上,东部矿体侵入到沉积地层内部。硫通过岩浆侵位过程中的同化作用进入岩浆,形成硫化物熔融体,并在后期经历了构造变形、热液叠加等作用后形成了浸染状、角砾状等多种类型的矿化。     

Petrochemical systematics of amphibolites from the Archean section of the Kola Superdeep Borehole

This paper addresses the problem of the systematization of amphibolites from the Archean part of the section of the SG-3 Kola Superdeep Borehole. It was shown that a combined petrochemical and geochemical approach allows one to classify these rocks with high confidence and to distinguish supposedly Archean and Proterozoic varieties among them. It was found that Proterozoic rocks account for about 50–70% of basic rocks in the Archean section. Homologues of the basic metavolcanics of the Matert Formation were detected among the Proterozoic metaigneous rocks of the Archean section of the SG-3, which casts doubt on the conclusion of some authors on the allochthonous origin of the upper levels of the northern Pechenga section, including its productive horizons. This result has very important metallogenic implications. Original Russian Text N.E. Kozlov, E.V. Martynov, N.E. Kozlova, T.V. Kaulina, Yu.P. Smirnov, 2007, published in Geokhimiya, 2007, No. 2, pp. 150–158.     

The Kola Superdeep Drillhole and the nature of seismic boundaries

The Kola Superdeep Drillhole was drilled through 7 km of Proterozoic rocks of the Pechenga structure and 5 km of the Archean basement in the Baltic Shield to 12 km depth. The results of drilling revealed a significant heterogeneity of physical properties of the crystalline rocks and a surprisingly high porosity and water content throughout the section. Seismic wide-angle reflection data, obtained in the region of the hole, were used to delineate the volcanic-sedimentary layers of the Pechenga structure and the intersecting faults. These studies revealed also a subhorizontal boundary at a depth of 7 km of uncertain origin. Core sampling implies that this boundary is associated with a change in core pressure, with higher porosity and with velocity anisotropy. A change in rock fissuring and in the fluid regime correlates with a velocity inversion zone reached by the hole at a depth of 4.5 km.     

The Mineral Composition of Paleoproterozoic Metamorphosed Massive Sulfide Ores in the Kola Region (A Case Study of the Bragino Ore Occurrence,Southern Pechenga)

Geology of Ore Deposits - Many massive sulfide ore occurrences and deposits in the Kola region are located within the Paleoproterozoic Pechenga–Imandra–Varzuga rift belt (2.5–1.7...     

Physical and mechanical properties of selected amphibolite core samples from the Kola Superdeep Borehole KSDB-3

Laboratory tests of physical and mechanical properties were performed on amphibolites representing two units from the Kola Superdeep Borehole KSDB‐3 (Russia) ? the Proterozoic Karelian Complex (depths of 3043 m, 3530 m and 4389 m) and the Archean Kola–Belomorian Complex (depths of 7951 m, 8942 m and 9904 m). Obtained grain density and bulk density values are nearly identical for all tested samples, but porosities increased slowly with depth. Marked differences in strength properties were found between amphibolite samples from the Karelian Complex and amphibolite samples from the Kola–Belomorian Complex. The uniaxial compressive strength of the samples from the lower part of the borehole is significantly smaller than in samples from the upper part; a similar trend was found for triaxial tests. The values of the deformation modulus, Young's modulus and Poisson's ratio obtained from samples of the Karelian Complex are considerably higher than those from the Kola–Belomorian Complex. Observed mechanical properties are explained by the variable grain‐size distribution and by the spatial arrangement of main rock‐forming minerals. These properties are also influenced by recovery of rocks from great depths.     

Seismites in Late Pleistocene and Holocene deposits of the northwestern Kola region (northern Baltic Shield)

New data on soft-sediment deformation in Late Pleistocene and Holocene deposits of the northwestern Kola Peninsula (Pechenga River valley) are reported and analyzed in terms of paleoseismicity implications. Soft-sediment deformation is assigned to paleoseismic triggers on the basis of special criteria. One sedimentary section in the Pechenga valley bears signature of several seismic events at the Late Pleistocene–Holocene boundary, constrained by radiocarbon dates. According to the morphology, sizes, and types of seismites, the earthquakes had an MSK-64 intensity at least VI–VII. The observed earthquake-induced deformation may be associated with tectonic subsidence of the Pechenga valley block.     

Sources of Terrigenous Clastic Material of the Pechenga Ore-Bearing Structure from Data of Detrital Zircon Isotopic Analysis (SIMS SHRIMP-II,LA-ICPMS)

Doklady Earth Sciences - The research results were received from studying the Pechenga ore-bearing Paleoproterozoic structure, which is located on the northwestern part of the Kola region. The...     

A 3D-stress model in the area of the Kola super-deep well (SD-3)

A 3D-computer model of the stress field in the area of the Pechenga Syncline (Baltic Shield) is suggested. The model is based on tectonophysical modeling using optically active materials. The reliability of the results is supported by comparison of the modeling results with data on elastic-anisotropic characteristics of rocks in the section of the Kola super-deep well down to a depth of 12 km. The model can be applied for detecting areas of high tangential stresses values, with which hazardous geological processes are associated.     

Andesite–Basaltic Dike Magmatism in the Paleoproterozoic Rift System of the Kola Craton,Baltic Shield

New structural and petrogeochemical data are obtained on poorly known dikes composed of quartz dolerites of andesite–basaltic composition and located at the northwestern termination of the Murmansk block (Kola Craton). These data allowed us to compare the studied dikes with more well-known units from the dike swarm in the area of the settlement of Liinakhamari and the volcanics of the Pechenga structure, and to discuss their joint geodynamic position. Dolerite dikes are 2.3 Ga in age and intrude granites and plagiogranites of 2.4 and 2.8 Ga in age, respectively. The specificity of the composition of the rocks of andesite–basaltic composition from the dike series, as well as that of the volcanics from the first (Akhmalakhti) formation of the Pechenga structure, is determined by their structural position in the marginal part of the “fading” Sumian plume and in the zone of dynamic influence of regional strike–slip fault zones.