STRATIGRAPHY AND PAL?EONTOLOGY OF THE SINIAN ROCKS OF NANKOU

INTRODUCTION The Sinian rocks in China as far as we know are most well developedin Chihli and Shansi provinces. In Chihli, they are usually restricted to theupper part, as in Ta Yang, Pei Yu, Hsia Ma Ling, Ching Pei Kou and other     

THE VOLCANIC ROCKS IN PEI PIAO REGION

INTRODUCTION. The volcanic rocks in Pei Piao region have been already noticed by different authors. They were, however, only stratigraphically classified into two series known as the Upper Volcanic and the Lower Volcanic, while their petrographical characters and real rock types are yet in vague.     

Confirmation and Significance of Caledonian Metallogenic Epoch for Gold Deposits in South China

Caledonian gold deposits are widely distributed in South China.They are developed in both South China Caledonian fold belt and adjacent Proterozoic Jiangnan uplift.The host rocks are Proterozoic metamorphosed microclastic rocks in the Jiangnan uplift and Proterozoic and Cambrian strata,as well as Chengjiang and Caledonian igneous bodies in the South China flod belt.The distince differences between the Caledonian and the most developed Yenshanian glod deposits in South China are reflected in age and host-rock type,relations to Yenshanian magmatic activities,element association,mineral assemblage and glod deposit type.The studies have proven hat the Caledonian epoch is a principal metallogenic period of gold deposits in South China.This conclusion is of very important enlightening significance in exploration of Caledonian gold deposits in South China as well as in other Caledonian fold belts and adjacent uplifts in China.     

EXTRACTION OF THE STANDARD ENTHALPY OF FORMATION OF MINERALS FROM REVERSED EXPERIMENTAL DATA WITH INS

An improvement on the new method of Intervalhalving-Scanning (INS) proposed by the senior author for derivation of thermodynamic properties of minerals from reversed experiment (REP) data has been made in the present work. The treatment of the REP data of 6 reactions in the system MgO-SiO_2-H_2O and the derivation of △_(?)H(?) (298. 15K) for minerals Talc,Forsterite and Anthophyllite are chosen as an example for demonstration of the application of the method.INS is quite different from all the methods for the derivation in the literature and throughout based on thermodynamic principles and equations so that its thermodynamical validity is thoroughgoing.     

Hydrogeology in the Nordic Countries

Hydrogeology in the Nordic Countries is characterized by many types of aquifers and great differences in groundwater recharge. Fracture aquifers in crystalline, hard rocks are the most common type of aquifer with, in general, low fracture porosity and low well yields. The most productive crystalline rocks are the basalts in Iceland and the rapakivi granite in Finland. The fracture and fault zones have mostly high conductivity. Porous aquifers are found in various types of geology. The most porous ones are the lava-fields and the pyroclastic rocks in the active volcanic zone of Iceland, but glaciofluvial deposits such as eskers and deltas in Finland, Norway and Sweden, outwash plains in SW Denmark and sandurs in Iceland are also very porous and good aquifers, as are some sedimentary rocks in Denmark. The glacial till has, in general, low conductivity. Fractured porous aquifers in consolidated limestones and sandstones have high well yields in relatively young formations in Denmark and Scania in southern Sweden, but medium or low yields in older strata. Karst aquifers have limited extension, but there are some well developed ones in the Caledonian mountain range in Norway and Sweden. Geothermal water with a lot of springs and even geysers are common in Iceland and of great economic importance. The groundwater chemistry of the crystalline, hard rocks is notable for bacteria, brines and mixed water at great depths （more than 500 m） as well as high contents of arsenic, fluoride and radon in drilled wells in certain regions.     

PETROGRAPHIC SUBDIVISION AND SEDIMENTARY ENVIRONMENTS OF THE CAMBRIAN CARBONATE ROCKS IN THE XIADONG AREA

1. Introduction The most developed area of Cambrian carbonate rocks in China is the Xiadong area in the west of Hubei Province, including Yichang, Zigui, Changyang and Yidu . In this area Cambrian carbonate rocks are well exposed and have various types of carbonate rock containing abundant fossils. One of the standard sections of Chinese Cambrian is also in this area. As early as in the early 20th century, a few foreign scholars, such as Pumpeuy, Richtuofeu, Willes, have made geologica…     

Study of Residual Basin and Tectonolayering Based on Airborne Gravity and Magnetic Data

This paper takes the South Yellow Sea as an example to show a new method for comprehensive geological-geophysical research such as residual basin and tectonolayering using airborne gravity and magnetic data in China. Based on airborne gravity and magnetic data, by measuring and analyzing stratigraphic density and susceptibility, the depths to the pre-Sinian magnetic basement top, the pre-Jurassic top and the Cenozoic bottom, are obtained by forward and inverse methods constrained by seismic and drilling data; and furthermore, the residual thicknesses of the Sinian–Triassic, the Jurassic–Cretaceous and the Cenozoic are calculated. Based on airborne gravity and magnetic anomalies, the faults in the pre-Sinian magnetic basement, the Jurassic-Cretaceous and the Cenozoic are respectively interpreted by the qualitative and quantitative methods. On the basis of the above study, and combining regional important tectonic events, four tectonolayers are divided in the vertical succession in South Yellow Sea, namely the pre-Sinian magnetic basement, the Sinian-Triassic, the Jurassic-Cretaceous and the Cenozoic. The result shows that there are thick Cenozoic and Jurassic-Cretaceous strata and thin residual Sinian-Triassic strata in the Suzhong-Huangnan depression area, but there are thin or only sporadic Mesozoic-Cenozoic terrestrial strata and thick Sinian-Triassic marine strata reserved in Subei-Huangzhong uplift area and Sunan-Wunansha uplift area. The four tectonolayers are very different in structures as well as distributions in plane.     

THRUST NAPPE STRUTRUE IN THE JINGGANG MOUNTAIN：CHARACTERISTICS AND SIGNIFICANCE FOR PROSPECTION OF ORE DEPOSITS

Nappe structure, as was first discovered by the authors during the regional geological survey at the scale of 1:50,000 in The Jinggang Mountain, is mainly comprised of a series of NNE-NE-striking thrust fault zones and thrust sheets among them. Sinian, Cambrian, Ordovician, Devonian, Carboniferous, Triassic, Jurassic and Cretaceous strata are involved in the thrust nappe system. The nappe structure is of the type of duplex structures formed as a result of the earlier stage migration from SE to NW and late stage migration from E to W of sedimentary cover or basement strata. Formation of the nappe structure in the studied area involves two main epochs: Early Yanshanian and Late Yanshanian to Early Himalayan. The mineral deposits and the buried coalfields in the area, especially the latter, are extensively controlled by the nappe structure.     

Exhalites Associated with Pb-Zn Mineralization in Devonian System and Their Prospecting Implications,Qinling,China

The exhalation origin of the ankerite-siliceous rocks associated with Pb-Zn mineralizations in the Devonian system of Qinling is discussed in the light of geologic setting,sedimentary-tectonic environment,lithological and chemical characteristics.On this basis,criteria for distinguishing them and their potential role as an indicator in prospecting are described.Ankerite-siliceous rocks are developed in the strata-bound Pb-Zn polymetallic belt in the Devonian system of Qinling.They are microcrystalline,dark grey and compact in appearance and are commonly carbonaceous,As a persistent ore-bearing horizon in the region,their genetic relation to the Pb-Zn deposits in generally accepted.However,a consensus has yet to be reached among geologists concerning their origein as a product of hydrothermal metasomtism at the late stage of sedimentation or as exhalite resulting from submarine exhalation.Accumulating evidence from direct observations on modern submarine hydrothermal systems strongly indicates that seafloor exhalation is a much more common geologic process than previously thought nd its metallogenic implications have long been overlooked.Characteristics of the ankerite-siliceous rocks as a product of exhalation and their significance as a guide in prospecting are described on the basis or geological setting,lithology,lithochemistry,REE,and isotopic and trace element features.     

Silver and Sulfosalt Minerals in Tungsten Deposits,South China

Silver occurs in South China wolframited-quartz veins in three forms:(1)as micro inclusions of Ag2S and AgBiS2,(2) as argentite and matildite as a result of exsolution and(3)as Ag-bearing sulfosalts and independent silver minerals.According to mineral assemblaged the Ag-bearing tungsten deposits are classified as two types:(1)Ag-bearing W-Bi deposits in eastern Nanling,where gustavite has been found and（2）Ag-bearing W-Sn(Sb)deposits which are mainly distributed in western Nanling.The authors consider that the enrichment of silver and sulfosalt minerals in the lower parts of pneumato-hypothermal tungsten deposits is the result of reversed vertical zoning caused by high concentrations of F and S in the ore-forming fluids.     

FORMATION OF LARGE-SCALE TECTONIC ELEMENTS FROM THE POSITION OF CENTRIFUGAL-INERTIAL FORCE ACTION

We describe the earlier unknown, when applied to global tectonics, centrifugal inertial mechanism of lithosphere plate moving under the effect of forces appearing as a result of Earth‘s planetary rotation. The mechanism stated gives an insight into global tectonics of plates with the indirect participation of emanation streams which, in their turn, are the derivatives of centrifugal and inertial forces of planetary motion. The application of this mechanism provides a logical explanation for the regularities of global tectogenesis including the formation of mountain ridges mainly of submeridional and sublatitudinal strike, and also the drift of continental plates from the east to the west and from the south to the north. The mechanism clarifies the significance of the Arctic and the Antarctic Circles as geodynamic barriers.     

Conditions of Petroleum Geology of the Qiangtang Basin of the Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau located in the Tethyan tectonic domain is the best developed region of Mesozoic and Cenozoic marine sediments in China. The Qiangtang basin is the biggest and relatively stable area of the plateau. Triassic and Jurassic hydrocarbon source rocks are extensively distributed in the basin. There exist good dolomite and organic reef reservoirs and mudstone and evaporite cap rocks, as well as well-developed structural traps in the basin; in addition destroyed petroleum traps have been discovered. Therefore, the conditions of petroleum geology in the Qiangtang basin are excellent     

Mantle plumes and their record in Earth history

In recent years, the study of mantle plumeshas become a “hot spot” in earth sciences;enormous papers and data have been published, and many mantle plume-related questions have arisen: Did mantle plumes in the Precambrian behave the same way as they do today? What are the roles of plumes in the evolution of the earth? What are the effects of mantle plumes on global changes and metallogenesis? These issues are frequently encountered and hotly debated in a wide range of earth science fields such as tectonics geochemistry, geophysics, metallogenesis,     

DEEP WELLS IN THE PEKING AREA

The underground water-supply of the plain of North Chihli is of sufficient importance to geologists and civil engineers to warrant the placing in readily available form of some data till now not easily accessible.     

Organic Material and Trace Elements of Bituminous Rocks in the Ozankiiy Field, Ankara, Turkey

Bituminous rocks in the Ozankoey （Ankara） field are different from those of the Paleocene- Eocene Mengen and Giineytepe （Bolu） regions in metal enrichment levels. Organic carbon （Corg） content of organic material-rich rocks in the Ozankoey （Ankara） field is 3.66-40.72% wt averaging 14.34%. The dominant organic materials are algae/amorphous accompanied by minor amount of herbaceous material （The dominant kerogen type is Type-I with a limited amount of Type-Ⅱ kerogen.）. The bituminous rocks in the Ozankoey field are enriched in heavy metals such as Ni, Mn, As and Cr. In comparison with the average enrichment values of dements, Ni, Mn, As and Cr in bituminous shales of the Ozankoey field are as about 4.38, 14.93, 10.90 and 5.58 times as average values. The average concentrations of these heavy metals are also as high as 215× 10^-6, 828 × 10^-6, 58.54 × 10^-6, and 148 × 10^-6 respectively. In addition, sorption properties of day and organic materials are also important for metal enrichments in the bituminous shales.     

Organic Material and Trace Elements of Bituminous Rocks in the Ozank(o)y Field, Ankara, Turkey

Bituminous rocks in the Ozank(o)y (Ankara) field are different from those of the Paleocenecontent of organic material-rich rocks in the Ozank(o)y (Ankara) field is 3.66-40.72 % wt averaging 14.34%. The dominant organic materials are algae/amorphous accompanied by minor amount of herbaceous material (The dominant kerogen type is Type-Ⅰ with a limited amount of Type-Ⅱ kerogen.).The bituminous rocks in the Ozank(o)y field are enriched in heavy metals such as Ni, Mn, As and Cr. In comparison with the average enrichment values of elements, Ni, Mn, As and Cr in bituminous shales of the Ozank(o)y field are as about 4.38, 14.93, 10.90 and 5.58 times as average values. The average concentrations of these heavy metals are also as high as 215 × 10-6, 828 × 10-6, 58.54 × 10-6, and 148× 10-6 respectively. In addition, sorption properties of clay and organic materials are also important for metal enrichments in the bituminous shales.     

Characteristics of geothermal reservoirs and utilization of geothermal resources in the southeastern coastal areas of China

Based on regional geological setting, stratigraphic distribution and other geological conditions, this paper summarized three types of geothermal reservoirs in the southeast coastal areas of China: Cenozoic sandstone or sandy conglomerate reservoir, Mesozoic granite fissure reservoir and Paleozoic karst reservoir. Cenozoic sandstone or sandy conglomerate reservoirs are mainly located in Cenozoic basins, such as Zhangzhou, Fuzhou, Sanshui and Leiqiong basins. The Tertiary sedimentary basins such as Leiqiong Basin and Sanshui Basin, are controlled by NE-trending faults, while the Quaternary sedimentary such as Zhangzhou and Fuzhou basins are controlled by NW-trending faults. Mesozoic granite fissure reservoirs are mainly distributed in the southeast coastal areas, such as Zhangzhou, Fuzhou, Fengshun, Yangjiang and southern part of Hainan Province. The distribution of good Mesozoic granite fissure reservoir in these areas is mainly controlled by NE-trending faults. Paleozoic carbonate reservoirs are widely distributed in these areas. Most carbonate rocks are from the upper Paleozoic strata, such as those in the area of Huizhou in Guangdong Province. The major types of geothermal systems in the southeast coastal areas of China belong to medium and low-temperature convection. The geothermal resources developed from the ground to-3 000 m underground could be utilized directly for space heating, greenhouse heating, aquaculture pond heating and industrial uses, as well as other purposes. The geothermal resources with a depth of 3 000～6 000 m underground is mainly featured by Hot Dry Rock(HDR) with a temperature ranges from 150 ℃ to 200 ℃, which is conductive to the development of Enhanced Geothermal System(EGS) and can be utilized for power generation.     

GEOCHEMISTRY OF EARLY CRETACEOUS TRACHYTES OF DONGLINGTAI FORMATION FROM THE XISHAN AREA, BEIJING： CONSTRAINTS ON MELTING OF LOWER MAFIC CRUST

Felsic igneous rocks are of widespread magma types in continental orogenic belt, the petrologic genesis of which provides very important indication for understanding crustal evolution and melting geodynamic process within orogenic belt. Because of the differences of meltingdynamic condition, e.g. (1) composition of source rock; (2) physical chemistry conditions such as temperature, pressure etc.; (3) composition of residual phases and so on, felsic igneous rocks exhibit distinctly diverse petro…     

The Pan-African Ophiolites and Related Mineralization in Egypt

<正>Precambrian ophiolites are abundant in the ArabianNubian Shield of NE Africa and Arabia and range in age from 690 to 890 Ma.In Egypt,they are widely distributed in the central and southern Eastern Desert and occur as nape complexes along sature zone or dismembered masses in metavolcano-sedimenatry assemblages.The ophiolite     

Processes on the Thermodynamic?Properties?of?Lithium?Borates

正1 Introduction Lithium and its compounds as national strategic resources are extensively used in national defense,industrial and agricultural production.As we know,the salt lakes in the western of China are famous for its high