Petrology and Petrogenesis of the Eclogite in Mt.Dabie Area,Central China

The occurrence,mineralogy and geochemistry of eclogites in the Mt.Dabie area show that they were subjected to a high-pressure metamorphism together with the country rocks,but their petrochemistry and REE geochemistry show some difference from those of the country rocks.The geochemical characteristics of the eclogites are similar to those of bot continental tholeiitic basalt and oceanic tholeiitic basalt.The rocks probably subducted to the upper mantle with the Dabie metamorphic complex.When elevated to the surface,they were subjected to different staes of retrogressive metamorphism.     

Chemical study of limestone and clay for cement manufacturing in Darukhula,Nizampur District,Nowshera, North West Frontier Province （N.W.F.P.）, Pakistan

Limestone and clay samples were collected from Darukhula and adjoining areas of the Nizampur District Nowshera, N.W.EE, Pakistan, and analyzed for different parameters in order to search for new reserves of suitable material for the manufacture of different types of cements in N.W.F.P. It was found that the area under study contains three types of limestones, including high grade limestone, Darukhula limestone and siliceous limestone, which contain 53%, 49.03% and 45.19% CaO, respectively, and three types of clay, including maroon color, yellow to yel- lowish-green color and green color clay containing 57.76%, 65.47% and 61.24% SiO2, respectively. Chemical analysis of the limestone and clay samples collected from the deposits in the area under study showed that all the elements found in these samples are within the range of permissible limits for the production of high-strength Portland cement, sulphate resisting cement and white cement. This paper covers the detailed version of the potential raw material deposits at Darukhula and adjoining areas of the Nizampur District.     

Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 77, No. 1,2003

Distribution of Mid-Cretaceous Orbitolinids in Tibet and ItsPaleobiogeographic ImplicationsWAN Xiaoqiao, WU Yianhua and LI Guobiao (China Universityof Geosciences, Beijing 100083, China)Orbitolinids is a kind of large foraminifera. It occurredfrequently during the late Barremian to Cenomanian of theCretaceous and is distributed worldwide, especially in theshallow marine belts surrounding the Tethys Ocean. Itsdistribution in Tibet is limited to the Lhasa Block and some partsof the Qiangtang Basin. On both sides of this area, the     

Proceedings of the Special Meeting of the Geological Society on the 3rd November, 1931. With a Half-tone Block of the Pictures of the Grabau Medal.

In opening the meeting, the chairman made the following address: "It is my agreable duty to announce and make the award of the Grabau Medal to two members of our Society, Drs. J. S. Lee and Davidson Black. "The Grabau Medal was founded in 1925 by Mr. C. Y. Wang. the then President of the Geological Society. It was so named in honor of Dr. Grabau     

Hydrogeochemistry of the Winder River and adjoining tributaries, Balochistan, Pakistan

Quantitative estimation of ground and stream waters draining through sedimentary rocks of the Pab and Mor ranges (Jurassic-Cretaceous) and the Bela ophiolite has been made. The degree of correspondence among cations and anions has been estimated in order to evaluate their mutual relationships. The abundance of major ions is interpreted to be related to bedrocks and climatic conditions, which may contribute to the genetic affiliation. The log TDS and Na/Na Ca ratio reflected supremacy of weathering of rocks with some influence of evaporation. Ionic relationship is exhibited in the form of Stiff diagrams. Patterns of ionic composition revealed high NaCl, medium Ca(HCO3)2 and low MgSO4. Piper diagram has been used to classify the hydrofacies. The important hydrogeochemical parameters have been estimated for assessment of groundwater quality for domestic purposes in accordance to WHO. Irrigation water qualities have been evaluated in terms of EC, SAR, RSC, ESP and pH.     

Abstracts of Acta Geologica Sinica (Chinese Edition)Vol. 76, No. 1,2002

Lithology and Protoliths of HP-UHP Eclogite Facies Metamorphic Rocks and Relevant Rocks of the Changpu-Bixiling Area, Dabie Mountains CHENG Yuqi~1, ZHANG Yuxun~2, GAO Tianshan~3 and JIAN Ping~1(1. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037; 2. China Geological Survey, Beijing 100029; 3. Geological Survey of Anhui Province, Hefei 230001) Two NNW-trending HP belts are found in the Changpu-Bixiling area, Yuexi County, Anhui Province. The western belt from Tuqiaochong to the Changpu Hydropower Station consists mainly of banded jadeite quartzite and marble with minor quartz-beating dark eclogite and light-coloured eclogite, and the     

Assessment of heavy metals contamination in soils of Dexing region, Jiangxi Province, China

Heavy metal contamination has attracted huge concern due to its toxicity, abundance and persistence in the environment, and subsequent accumulation in soil, sediment and water. Mining is one of the most important sources of heavy metals in the environment. Mining-milling operations and disposal of tailings （the finely ground remains of milled ores） in addition to smelting and metal refining provide significant sources of pollution. Mining and mineral processing in the Dexing region of China have been carried out for over forty years and have contaminated the soils with heavy metals, Many studies were conducted to assess and establish the extent of heavy metal contamination in the soils due to mining. The aim of this work was to assess the environmental impact of mining on soils in the Dexing region and to identify the main factors involved in heavy metals dispersion. A 4800 km^2 study area was assessed with respect to its heavy metals on the basis of the current guideline values. In order to assess the extent of heavy metals contamination resulting from past mining activities in the Dexing region, 919 soil samples were collected and analyzed for As, Hg, Cd, Cr, Zn, Cu and Pb, Heavy metals levels were determined using inductively couple plasma-atomic emission spectrometry and X-ray fluorescence spectrometry. Results of soil samples reported concentrations between 1.790-899 mg/kg for As, 0.034-4.980 mg/kg for Hg, 0.043-8.330 mg/kg for Cd, 10-666 mg/kg for Cr, 25-18500 mg/kg for Zn, 6-1825 mg/kg for Cu, and 16-1312 mg/kg for Pb, respectively. The maximum values of As, Hg, Cd, Cr, Zn, Cu and Pb concentration in soils were up to 60, 33, 41, 7, 185, 52 and 37 times higher than the tolerable level, respectively. Meanwhile, the single-factor pollution index and Nemerow pollution index were used to assess the environment quality of heavy metals contamination.     

Geological features of Larderello－Travale and Mt.Amiata geothermal areas （southern Tuscany, Italy）

This paper summarises the geological features of the Larderello-Travale and Monte Amiata areas, where the world‘s most ancient exploited geothermal fields are located. In both geothermal areas, three regional tectonostratigraphic elements are distinguished, from the top: (a) Late Miocene-Pliocene and Quaternary,continental to marine sediments; (b) the Ligurian and Sub-Ligurian complexes, which include remnants of the Jurassic oceanic realm and of the transitional area to the Adriatic margin, respectively; (c) the Tuscan Unit(Tuscan Nappe), composed of sedimentary rocks rang-ing in age from Late Triassic to Early Miocene. The sub-stratum of the Larderello and Monte Amiata areas isreferred to as the Tuscan Metamorphic Complex. This ismainly known through drilling of geothermal wells. This complex is composed of two metamorohic units: the upper Monticiano-Roccastrada Unit and the lower Gneiss Complex. The Monticiano-Roccastrada Unit consists of(from top to bottom): the Verrucano Group,the Phyllite-Quartzite Group and the Micaschist Group.The Gneiss Complex consists only of pre-Alpine poly-metamorphic gneiss. The Tuscan Metamorphic Complexis affected by contact metamorphism by Plio-Quater-nary granitoids and their dy ke swarms. Hydrothermal phenomena still occur in both geothermal fields. The Larderello-Travale and Mt. Amiata geothermal fields are located in the inner Northern Apennines, in an area that has been subject to extension since the ?Early-Mid-dle Miocene. Two main extensional events are well expressed in the structures of the geothermal areas. The first extensional event (?Early-Middle Miocene) deter-mined the tectonic delamination of the Ligurian Units and Tuscan Nappe. The second extensional event (LateMiocene-Present) is characterized by high-angle nor-mal faults bounding the Neogene tectonic depressions of southern Tuscany.     

Phytoremediation of Nephrolepis auriculata （L.） for arsenic, mercury, lead and cadmium in the multiple contaminated softs

In recent years, the concentrations of heavy metals in Chinese herb of Ligusticum chuanxong Hort are overranging the standard of national port of green herbs in GAP bases of Dujiangyan City, Sichuan Province. The aim of the research is to disclose the remediation behavior ofNephrolepis auriculata （L.）, a novel pteridophyta found in our research with abundant arsenic, mercury, lead and cadmium from soils. The concentrations of arsenic, mercury, lead and cadmium in the series samples corresponding to roots, stems, leaves ofNephrolepis auriculata （L.） which had been trained in lab with a series of potted incubation experiments through the orthogonal test, were analyzed. Based on the results, methods of the range analysis and variance analysis were used, and it is demonstrated that （1） Nephrolepis auriculata （L.） has a function to beneficiate heavy metals of arsenic and lead, and can well concentrate cadmium and mercury from soils. The distributive behaviors of arsenic, mercury, lead and cadmium in N. sauriculata （L.） follow the order： roots〉leaves〉corms〉stems, stems〉leaves〉roots〉corms, roots〉stems 〉corms〉leaves, stems〉leaves〉roots〉corms; the correlations of the concentrations for arsenic, lead, cadmium and mercury in different tisses of Nephrolepis auriculata （L.） and soils were carried out. Then, the effects of pH value, contents of EDTA and humic acid in soils to arsenic and mercury accumulated by Nephrolepis auriculata （L.） were further studied.     

Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 79, No. 1,2005

An Ichnofossil, U-shaped Burrow, in Continental Depositfrom the Lower Devonian Danlin Formation in DushanCounty, Guizhou Province, ChinaWANG Yue1,2(1. Faculty of Earth Sciences and Mineral Resources, ChinaUniversity of Geosciences, Beijing 100083; 2. Faculty ofResource and Environment, Guizhou University, Guiyang,Guizhou 550003)Diplocraterion Torell 1870, U-shaped with spreite, wasconsidered to be one of the main ichnofossils of Skolithosichnofacies of Seilacher (1964, 1967) and…     

The mechanisms of paragenesis and separation of silver, lead and zinc in hydrothermal solutions

On the basis of an experimental study and thermodynamic calculation, the mechanisms of paragenesis and separation of silver, lead and zinc in the hydrothermal system have been studied. At acidic to nearly neutral pH, their chloride complexes are stable, and among them the chloride complexes of zinc are most stable. And the sulfide complexes are the dominant species at nearly neutral to alkaline pH,while the sulfide complexes of silver are most stable. With decreasing temperature, [ Cl^-] ,fO2, and increasing pH, the solubilities of silver, lead and zinc will decrease, leading to their deposition and separation. For sulfide complexes, the concentrations of reduced sulfur and pH are two important factors affecting their stabilities. Complexes of different forms and stabilities respond to the variation of conditions to different extents, which gave rise to the paragenesis and separation of silver, lead and zinc in the whole ore-forming process of dissolution, transport and deposition.     

The Geology and Tectonic Settings of China＇s Mineral Deposits by Franco Pirajno. Springer Verlag, Berlin, 2013, 679 pp. ISBN： 978-94-007-4443-1

China is the third largest country in the world,with a land area of about 9.6 million km2.It is endowed with abundant mineral resources,and the metal mining activity can be traced back to ca.8000 years ago.However,due to language barrier,little has been known about the geology and tectonics to the outside world until 1980s.In the last three decades,a great deal of knowledge has been gained,enhanced by a vigorous cooperation between Chinese and Western geologists.Research papers about geological,geochemical,and geochronological features of mineral deposits of China are widely published and cited in international journals.A comprehensive and comprehensible English literature that summarises the features of mineral deposits in China,however,is still lacking.     

The Characteristics of Migration of Ore Solutions in No.6 East Tin Deposit of the Songshujiao Orefield, Gejiu

No. 6 East tin deposit in the Songshujiao orefield, Gejiu, is characterized by one-stage hydrothermal activity and monotonous country rocks. The authors selected this deposit and used the multivariate statistical analysis to study the types of association of main ore-forming elements at different temperatures and pressures and their distribution in the deposit. On that basis combined with the structural analysis of the deposit, the recto-geochemical features of No.6 East tin deposit have been revealed and the direction and channel of migration of the ore solutions in faults and the deposit have been deduced. This research can appropriately elucidate the control of faults on the migration of ore solutions and the sites where ore solutions are dispersed and accumulated, thus providing the theoretical basis for the prediction of hydrothermal deposits in question.     

Reservoir geochemistry of the Tazhong Oilfield in the Tarim Basin, China, Part II. Migration, accumulation and mixing of crude oils

Measurements of the absolute and relative concentrations of nitrogen-containing compounds in crude oils from different reservoir strata (Ordovician, Silurian and Carboniferous) in the Tazhong region of the Tarim Basin, Xinjiang, China, showed that even though there are quite a number of factors affecting the distributional and compositional characteristics of neutral nitrogen-containing compounds in crude oils, the distributional and compositional characteristics of crude oils whose source conditions are approximate to one another are influenced mainly by the migration and fractionation effects in the process of formation of oil reservoirs. In addition, crude oils in the Tazhong region show obvious migration-fractionation effects in the vertical direction. Carboniferous crude oils are characterized by high migration parameters and low compound concentrations, just in contrast to Ordovician crude oils. This indicates that crude oils from shallow-level oil reservoirs were derived from those of deep-level oil reservoirs via faults, unconformable contact or carrier beds. Crude oils from the Tazhong region show some migration-fractionation effects in the lateral direction, but mixing of crude oils derived from different hydrocarbon source rocks in the process of formation of oil reservoirs made it more complicated the migration and accumulation of crude oils, as well as the formation of oil reservoirs.     

Characteristics of Non—Point Source Pollution in the Watershed of Miyun Reservoir,Beijing,China

Nitrogen and phosphorus are the major nutrients to cause eutrophication to degrade water quality of the Miyun Reservoir,a very important drinking water source of Bijing,China,and they are mainly from non-point sources.The watershed in Miyun County was selected as the study region with a totoal area of 1400km^2.Four typical monitoring catchments and two experimental units were used to monitor the precipitation,runoff,sediment yield and pollutant loading related to various land uses in the meantime.The results show that the total nutrient loss amounts of TN and TP are 898.07t/a,and 40.70t/a,respectively,in which nutrients N and P carried by runoff are 91.3% and 77.3%,respectively.There is relatively heavier soil eroson in the northern mountain area whereas the main nutrient loss occurs near the northeast edge of the reservoir.Different land uses would influence the loss amounts of non-point source pollutants.The amount of nutrient loss from the agricultural land per unit is highest,that from forestry comes next that from grassland is lowest.However,due to the variability of land use areas,agricultural land contributes a lot to TP and forestry lands to TN.     

Evolution of Sedimentation and Tectonics of the Youjiang Composite Basin, South China

Located at the southern margin of the South China plate, the Youjiang basin is a closely related to the NW- and NE-trending syndepositional faults in respect to the configuration and structure of the basin. The evolution of the Youjiang basin progressed through two stages. In the Hercynian period, the opening of the Ailaoshan-Honghe ocean basin gave rise to a number of NW-trending rift belts in the Youjiang area. During this period, deep-water sediments were dominant and the basin was possesed of the characteristics of the rift system of passive continental margins. In the early Indosinian after the Dongwu movement, the circum - Pacific tectonism led to a major change in the configuration and structure of the basin. In the meantime, the Ailaoshan ocean basin began to be subducted towards the northeast, thus causing the basin to be split and expand again, and then the basin developed into the stage of the back -arc basin. At the end of the Indosinian period, the basin gradually closed from east to west,     

Chemical Composition of Ancient Celadon Material （1127-1279 A.D.） from Zhejiang, China and Its Implication

The microprobe EDXRF equipment was used for analysis of the major and trace elements in glaze layer-transitive layer-body layer of the celadon from the Altar Yao （Kiln） and Laohudong Yao in the Southern Song Dynasty （1127-1279 A.D.）, Zhejiang, China. The K values of the discriminant factor for the celadon wares are larger than 8, which means the celadon of the Altar Yao and Laohudong Yao are different from that of the Longquan Yao. The former two belong to the Guan Yao system （the Chinese imperial kilns）, but the latter to the Min Yao system （the Chinese popular kilns）. The principle component analysis shows their relationship between the Altar and Laohudong wares with provenance postulation. The thickness of the transitive layer in the Altar and Laohudong wares is obviously different, which reveals the microstructure characteristics of the celadon even though both kinds of wares belong to the imperial kiln system.     

Forms of Iron in the Phosphorites of Abu—Tartur Area,Egypt

The Campanian-Maastrichtian phosphatic deposits in Egypt,called the Duwi Forma-tion,comprise a part of the extensive Middle East to North African phosphogenic province of Late Cretaceous to Paleogene age.The province holds the greatest accumulation of phosphorites in the geological history,possibly in excess of 70 billion metric tons.The phosphate resources in Egypt alone exceed 3 billion metric tons.Two-third of these three billions occur only in the Abu-Tartur area.Among the phosphorite deposits in Egypt,the phosphorites of the Abu-Tartur area are characterized by high contents of iron ranging from 3% to 7% with an average of 5%.The detailed mineralogical and geochemical studies on the Abu-Tartur phosphorites revealed that iron is found in the form of pyrite,ankerite,clay minerals,microinclusions,and iron oxide.Pyrite,which is the major fraction,occurs as filling cement and partial to complete teplacement of phosphatic grains and confined to the fresh phosphorites while iron oxide occurs as cryp-tocrystalline aggregates of red to brown particles and is confined to the weathered outcrops.Ex-clusive relations between pyrite in the fresh phosphorite samples inside the Abu-Tartur mine and iron oxide in the equivalent horizon of the weathered exposure indicated that iron oxide was formed by the oxidation of pyrite as a result of weathering.All of these forms harm the quality of ore,manufacturing processes,and the produced phosphoric acid and fertilizers.     

Biogeochemical evaluation of Nannorrhops ritchiana： A Mg-flora from Khuzdar, Balochistan, Pakistan

Nannorrhops ritchiana （ Mazari Palm） is a distinctive flora growing in the Saharo-Sindian region. It is well distributed on the ultramafic soil, derived from the Bela Ophiolite in the Khuzdar District, Balochistan, Pakistan. Quantitative estimation of Ca, Mg, Fe and Ni in soil and plant ash has been carried out. The constituents of plant ash have been discussed in relation to soil chemistry, pH, climate, mobility, average abundance in plant ash and exclusion mechanism of the flora. Relationship among Ca, Mg, Fe and Ni has been established using scattergrams to evaluate the biogeochemistry of the plant. High contents of Mg and high coefficient of biological absorption allow it to be classed as Mg-flora. Both Ca and Fe appeared to be antagonistic to Mg. The metal assemblage of N. ritchiana nicely reflected the nature of the bed rock as being serpentinized ultramafic, and its corresponding soils. Good exclusion mechanism of N. ritchiana did not allow it to absorb high Ni from the soil. Relatively high concentrations of Ni in N. ritchiana from the Baran Lak area can be used to localize Ni-mineralization in the study area. Statistical analyses, such as minimum, maximum, mean, mode, median, standard deviations, and coefficient of correlation, were also made to improve raw geochemical data and interpretations.     

Dehydration—Melting Experiments on the Khondalite Series,North Segment of Helan Mountain—I.Determination of Critical Melt Fraction

Dehydration-melting experiments were conducted on granulite and Al-gneiss,the two most representative rock-types of the khondalite series in the northern segment of the Helan Mountain.The critical melting fraction was determined to be 30% in volume,which is of great significance with respect to the P-T-t path of metamorphism and granite generation in the region.