Biogeochemical Study of Tamarix Aphylla from Lasbela Area and Its Application in Prospecting of Ore Deposits

Biogeochemical investigation of Tamarix aphylla,a plant species, of the Las-bela area has been made.This area mainly consists of ophiolites associated with sed-imentary rocks of Jurassic and Cretaceous age .Quantitative estimations of important biogenic trace elements such as Fe,Mn,Pb,Zn,Cu,Cr,Ni, and Co have been carried out .Anomalous concentrations of these elements in plant species of certain regions can be used to locate possible occurrences of ore deposits in the area.The comparative strdy also reveals appreciable variations in the composition of trace elements in plants.The possible causes of variation in the constitrents of Tamarix aphylla from different localities have been discussed in the light of bed rock nature, mo-bility of element and average abundance in the plant.     

Prospects for deep and ultradeep oil and gas deposits in U.S.S.R.

In the U. S. S. R., so far, none of the hydrocarbon pools at depths exceeding 3500 m have been exploited. There are reasons to believe that large accumulations exist even below 5000 m depths, in areas shown on the map (fig. 1). Almost nine-tenths of proved economic reserves of oil and gas at shallow depths lie in terrigenous materials, the remainder in carbonates, in fissure-type-collectors. It is believed that the latter type of collectors will be found to be more abundant at greater depths. -- V. P. Sokoloff     

Geologic factors of distribution of mineral deposits in eastern U.S.S.R.

The Pacific Mobile belt is differentiated into an outer (continental) zone of predominantly Mesozoic folding (Verkhoyansk -Chukotka, Mongolo-Okhotsk, and Sikhote-Alin folded provinces) and an inner oceanic zone of Cenozoic folding, adjacent to mobile provinces of the "island arc" type (Sakhalin, the Kuriles, Kamchatka). These zones are separated by the East-Asian volcanic belt associated with a fault system which cuts off the older Mesozoic Verkhoyansk-Chukotka and Sikhote- Alin structures. Two important mineralization epochs are evident - Sino-Cambrian and late Mesozoic- Cenozoic. The Mesozoic-Cenozoic mineralization epoch exhibits a definite tendency for “rejuvenation” of the mineralization processes, going away from the continent and toward the Pacific trough, from late Jurassic in the eastern Trans-Baykal region and parts of the northeast to Neogene in the province of the Okhotsk geosynclines. An outstanding feature of endogeneous mineralization in this region is the linear arrangement of the ore zones determined by a system of major magma-controlling and other faults.—C. E. Sears     

Evaluation of biogeochemical prospecting methods in the search for sulfide deposits in the Appalachian piedmont, Virginia, U.S.A.

Soil and stream sediment sampling have been the primary geochemical exploration tools in the Appalachian piedmont to date. However, the great thicknesses of soil and saprolite found in the region coupled with the dense vegetation frequently encountered favor biogeochemistry as an alternative or supplemental method since deep-rooted plants sample closer to bedrock. To evaluate this method, an orientation survey was performed in which soils and vegetation at 17 sites north of Mineral, Virginia, were sampled and analyzed for Ag, Cd, Cu, Pb and Zn. The traverse included stations over the host rocks of massive sulfide mineralization, as well as over apparent “barren” country rock. Samples were analyzed by atomic absorption spectrophotometry using standard digestion and analytical techniques.Both A- and B-horizon soil metals generally appear to be reliable indicators of mineralization, with soils developed over sulfides showing up to three-fold enrichment in metal content relative to the average soils developed on the country rock. Correlation of metal concentrations in vegetation to soil metal concentrations reveal plant concentrations expressed on a dry-weight basis correlate stronger and more frequently to soil metals than do ash-weight concentrations. Copper shows some promise in selected organs and species, Ag appears fair but data are limited to one organ of one species, and plant Pb seems totally unresponsive to soil metal concentrations perhaps because foliar absorption is an important plant uptake mechanism here. However, Zn and Cd in organs of the oak group, especially mature leaves and twigs of the current year's growth show the greatest promise as prospecting tools. They correlate well with soil metals and when compared directly to the geology they reliably reflect mineralization. Although results using White oak were slightly less profound than those obtained from the Black-Red oak group, White oak may be preferred as it is a single, more widespread, easily-identifiable species. Copper and especially Zn although essential elements to plants, do not appear to be “difficult” elements for biogeochemical prospecting in the Appalachian piedmont.     

Use of gas-liquid inclusions in prospecting and exploration for postmagmatic ore deposits and blind ore bodies

Hydrothermal ore deposits are commonly surrounded by an inner halo of hydrothermal alteration, a wider halo of unaltered rocks enriched in mobile trace elements, and a "streaming-through" halo formed by the nearly spent solutions. The streaming-through halo is characterized by an abundance of submicroscopic - secondary liquid-gas inclusions, but has no other, distinctive chemical or petrographic properties. A "decreptoacoustic" method, with which samples of gangue or wall rock minerals are heated to 700°C while the number of decrepitations are counted, has-been developed to study rock samples or the light fraction of sediments derived-from a mineralized area. This method, when used in conjunction with geochemical and other standard methods, shows promise of becoming a powerful prospecting tool. -- E. Ingerson.     

找寻特大型隐伏矿床的衍生矿床导向和成矿轨迹追踪研究

本文通过对挡墙背滑动土楔体力矩平衡的分析，提出了一种求解压力合力作用的力矩平衡新方法。并给出了三种类型挡墙的土压力合力作用位置的计算公式；以供参考。     

Biogeochemical prospecting for uranium in Nova Scotia

Ashed twigs of Picea rubens (red spruce) collected over an area of uranium mineralization in central Nova Scotia were analyzed for uranium in the course of biogeochemical prospecting for this element. Uranium levels in background samples were significantly lower than in those collected from areas with mineralization either at depth or on the surface. Scintillometric data were useful only to differentiate background and surface mineralization. Uranium levels in soils showed no correlation whatsoever with mineralization or with radiometry. There was a very high degree of correlation between the scintillometric data and uranium concentrations in ashed twigs and it is considered that twigs of Picea rubens might be successfully used for biogeochemical prospecting for uranium in this area.     

Thermal waters in the U.S.S.R.

A very interesting and informative paper on widespread occurrence of a thermal hydrosphere. Geothermal power uses are discussed. Distribution of heated waters, some up to 150° C is discussed in considerable detail, especially with reference to possible power utilization of the geothermal energy. Seven hydrothermal regions of the U.S.S.R. are discussed and delineated. Chemical quality of waters is referred to. There is a summary listing of locations in the U.S.S.R. where thermal waters could be utilized for generation of electric power. — B. N. Cooper.     

Socio-economic geography in the U.S.S.R.

A major field of research since the 1920s has been methods and theories of economic regionalization. The territorial-production complex is now recognized as a key developmental tool within the framework of economic-planning regions. Recently, there has been a more marked growth of study into problems of natural-resource development, social progress and change in the U.S.S.R. as well as into the spatial structure of other nations, particularly other socialist countries and non-socialist developing countries.     

地球化学测量在乌兰乌珠尔多金属找矿中的作用

乌兰乌珠尔位于柴达木盆地西缘东昆仑西段,柴西缘1∶20万地球化学扫面在该区圈定综合异常一处,通过对该异常作1∶5万水系沉积物测量加密分解,进一步浓缩找矿靶区,对分解后的子异常采用岩石测量控制异常浓集中心层位,然后对异常地段作工程验证,发现了多金属矿床一处。说明地球化学测量在柴西缘地区寻找多金属矿是有效的,可为该区找矿提供参考。     

金矿自然重砂矿物组合规律及其找矿指示意义

对云南、海南、江西、湖北、河南、新疆、浙江、山东、辽宁等27个省185个典型金矿床的自然重砂矿物进行统计分析,发现自然重砂矿物对金矿具有良好的响应,自然金、黄铁矿、方铅矿、黄铜矿、白铅矿、辰砂等对寻找金矿具有指示意义。不同成因类型的金矿床反映出的自然重砂矿物组合不同,斑岩型金矿床的标型指示矿物组合为自然金+黄铁矿+方铅矿+重晶石+闪锌矿+白铅矿+金红石,卡林型—类卡林型金矿床的标型指示矿物组合为自然金+黄铁矿+方铅矿+辉锑矿+毒砂+雄(雌)黄,而造山型+矽卡岩型+热液型+构造蚀变岩型金矿床的标型指示矿物组合为自然金+黄铁矿+方铅矿+辰砂。不同区域的金矿床反映出的自然重砂矿物组合也各有差异,闪锌矿为南方各省金矿床的特征矿物,辰砂和白钨矿为北方地区金矿床的特征矿物,重晶石和白铅矿为西部地区金矿的特征矿物。综合研究认为,自然重砂具有直接找矿和指导找矿的作用,按照特定成因类型和区域金矿床所建立的自然重砂矿物组合对建立矿床找矿模型具有重要的意义。     

Deinocephalians of the U.S.S.R.

The deinocephalian pelvic girdle, of general pelycosaurian structure, is useful in systematic diagnosis. In primitive Russian deinocephalians, two contrasting pelvic patterns are recognized, one light, thin-walled, narrow, and of V-shaped cross-section, and the other massive, thick-walled, wide, and of U-shaped cross-section. The former is characteristic of two families of lightly- built, mobile land carnivores, the Eotitanosuchidae and the Brithopodidae. The Eotitanosuchidae are more primitive and pelycosaur-like, while the Brithopodidae show more variation, and specializations of large size, shallower acetabulum (related to mobility?), and re-enforcement of a weak pubic symphysis by additional processes. The massive type of pelvis characterizes large, heavily built herbivorous animals of the family Estemmenosuchidae. In general pelvic structure, the Estemmenosuchidae resemble the South African anteosaurs and tapinocephalians and the Russian tapinocephalians. In detail, however, they show a more primitive stage of evolution, overlaid by characteristic specializations which relate them more closely to the advanced Russian forms than to those of South Africa. Three new genera are erected, Biarmosaurus, fam. Eotitanosuchidae; Chthomaloporus, fam. Brithopodidae; and Molybdopygus, fam. Estemmenosuchidae. One specimen formerly referred to Deuterosaurus Yefremov 1954, and five formerly included in the type of Brithopus Yefremov 1954 are referred to Molybdopygus. The more primitive deinocephalians are from Yezhovo in the Ocher District, Perm Province, while more advanced forms are from Isheyevo, in Tataria, where-therocephalians and other South African elements are also found. It is therefore concluded that the Ochersk beds are older than those of Isheyevo and must be dated to zone I of Yefremov's system. — N. Hotton III.     

新疆天山黑色岩系型矿床的地质特征及找矿方向

概要介绍了中国天山黑色岩系分布和黑色岩系型矿床的地质特征。中国天山黑色岩系发育，主要集中在古生代，其次为中生代，目前发现与黑色岩系有关的矿种有金、钒、铀、磷、锑。中亚天山黑色岩系中发现了穆龙套和库姆托尔世界级金矿床，中国天山是其东延部分，发现了萨瓦亚尔顿、大山口、萨恨托亥等金矿床，呈现出良好的找矿前景。穆龙套金矿和萨瓦亚尔顿金矿是黑色岩系型金矿的典型代表，中国黑色岩系型金矿与中亚黑色岩系型金矿有许多相似之处。分析认为，吉根-塔尔特库里、乌兰赛尔-大山口、乌什北山、阿克牙孜河等地是最具前景的找金矿靶区，今后应加大萨瓦亚尔顿金矿的勘查和研究力度，同时注意寻找黑色岩系中的铂、钯、铜等矿种。     

Eozoic complexes of the U.S.S.R.

Soviet geologists consider the Precambrian to be divided into two groups — Archaean and Proterozoic; but such a division is unsatisfactory. A major unconformity separates Proterozoic volcanic and sedimentary formations from an underlying sequence that contains two supergroups of supercrustal formations. The oldest of these is unanimously considered to be Archaean. Rocks of that supergroup play an essential part in the composition of the Baltic, Ukrainian, Aldan and Anabar Shields and of the ancient fold belts of the East-European and Siberian platforms.Distinctive features in the composition, tectonic structure, metamorphism and metallogeny of Archaean complexes lead to the conclusion that they were formed in specifically mobile areas, different from geosynclinal areas.The other supergroup of high-grade metamorphic rocks has no clear place in the accepted two-fold stratigraphic scheme of the Precambrian, and it is considered sometimes to be Archaean and sometimes to be Early Proterozoic. We propose restoring the forgotten name “Eozoic” for that supergroup. Eozoic complexes are characterized by peculiarities of composition and inner structure, which signify changes in the tectonic regime of the earth at the lower and upper boundaries of the Eozoic Supergroup. These peculiarities give grounds for distinguishing the Eozoic Supergroup as an independent stratigraphic division.The Stanovoy Complex of the southern part of the Aldan Shield is a stratotype for the Eozoic Supergroup. Many well-known stratigraphic subdivisions of the Siberian Platform (e.g., the Eniseiskaya, the Birusinskaya series and others), the Taratash Complex of the Urals, the Goranskaya and Shahdarinskaya series of the South-West Pamir, the Tikitch complex and Aulskaya series of the Ukrainian Shield, and in part the Belomorsky Complex of the Baltic Shield, as well as some others, are also Eozoic.The Eozoic complexes are characterized by the following specific features: only some supercrustal formations are typical for them; the small number of rock types which have a total thickness about 5–6 km; relatively monotonous mineral composition of the rocks; variable quantitative ratios of rocks; absence of contrasting marker beds; regional metamorphism and ultrametamorphism in the amphibolite facies; wide development of ultrametamorphic granitoids and migmatites; distinct tectonic differentiations of the basin of sedimentation.Dates determined by isotopic analyses, which mostly reflect the metamorphism of the deposits, fall predominantly in the range 2600–3100 Ma.     

通化二密地区中生代火山成矿作用及找矿方向

通过对二密地区中生代火山活动规律，岩浆演化序列、火山喷发期次与成矿作用的研究，对控制火山活动的基底断裂构造的调查，以及松顶山石英闪长岩（次火山岩）岩石单位的划分，认为：该地区成矿与中生代侏罗纪火山活动密切相关；成矿时间长、期次多、矿体类型复杂；区内尚存在很好的找矿远景，按照新的找矿方向，在火山活动中心成矿条件有利于段采用有效的找矿手段，有望找到新的矿产基地或隐伏的工业矿体。     

中国银矿床地质控矿规律及若干找矿方向

本文在前人研究的基础上,概述了地层、构造和岩浆岩对我国银矿产出和分布的控制特点和规律:银矿赋矿地层以泥盆系最多,其次是中元古界、石炭系等,按赋矿岩性则以碳酸盐岩最多,变质岩次之;古老地块边缘裂陷槽和增生带、区域性深大断裂及多组构造汇聚部位及陆相断陷盆地是我国银矿产出和分布的重要控制因素;海相火山岩、陆相火山岩、侵入岩控制着我国不同地区和类型的银矿产出。分析了我国大型、超大型银矿的找矿前景和方向,提出川西义敦岛弧带、川滇黔接壤地区和大兴安岭成矿带是大型、超大型银矿的重要找矿区,继续加强我国陆相火山岩型大型、超大型银矿的寻找和研究;重视在萤石矿床分布区、黑色岩系分布区找银矿及火山岩地区找银锰型矿床;充分利用银矿找钨、锡等其他矿种。     

遥感在新疆淖毛湖戈壁找矿中的应用

根据不同地质体在不同波段上的光谱特征，选择不同波段的TM数据进行假彩色合成，主成分分析，匹配滤波及多种处理方法，对淖毛湖戈壁琼河坝地区的线环构造特征，赋矿岩层，矿化蚀变等示矿要素进行增强处理和特征提取，取得较好效果，为在戈壁地区快速追踪找矿信息，指导成矿预测提供了重要的基本资料。     

Some patterns of abyssal structure in the U.S.S.R.

Analysis of blocks and linear sutures in the base of the Russian Platform shows significant variations in their tectonic activities in different stages of the platformal evolution. --AGI Staff.