bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical, Isotopic, and Fluid Inclusion Evidence for the Hydrothermal Alteration of the Footwall Rocks of the BIF‐Hosted Iron Ore Deposits in the Hamersley District, Western Australia
Authors: Haruna Makoto , Hanamuro Takahiro , Uyeda Kaoru , Fujimaki Hirokazu , Ohmoto Hiroshi
Published: November 2008

Abstract. The petrography, chemical, fluid inclusion and isotope analyses (O, Rb‐Sr) were conducted for the shale samples of the Mount McRae Shale collected from the Tom Price, Newman, and Paraburdoo mines in the Hamersley Basin, Western Australia. The Mount McRae Shale at these mines occurs as a footwall unit of the secondary, hematite‐rich iron ores derived from the Brockman Iron Formation, one of the largest banded iron formations (BIFs) in the world. Unusually low contents of Na, Ca, and Sr in the shales suggest that these elements were leached away from the shale after deposition. The δ18O (SMOW) values fall in the range of + 15.0 to +17.9 per mil and show the positive correlation with calculated quartz/sericite ratios of the shale samples. This suggests that the oxygen isotopic compositions of shale samples were homogenized and equilibrated by postdepositional event. The pyrite nodules hosted by shales are often rimmed by thin layers of silica of varying crystallinity. Fluid inclusions in quartz crystals rimming a pyrite nodule show homogenization temperatures ranging from 100 to 240d̀C for 47 inclusions and salinities ranging from 0.4 to 12.3 wt% NaCl equivalent for 18 inclusions. These fluid inclusion data give direct evidence for the hydrothermal activity and are comparable to those of the vein quartz collected from the BIF‐derived secondary iron ores (Taylor et al, 2001). The Rb‐Sr age for the Mount McRae Shale is 1,952 ± 289 Ma and at least 200 million years younger than the depositional age of the Brockman Iron Formation of ∼ 2.5 Ga in age. All the data obtained in this study are consistent with the suggestion that high temperature hydrothermal fluids were responsible for both the secondary iron ore formation and the alteration of the Mount McRae Shale.
Re‐Os Dating of Sulfides from the Volcanogenic Massive Sulfide Deposit at Gacun, Southwestern China
Authors: Hou Zengqian , Wang Shuxian , Du Andao , Qu Xiaoming , Sun Weidong
Published: November 2008

Abstract. The Re‐Os isotopic compositions of sulfide ores were analyzed for the Gacun, a volcanogenic massive sulfide deposit in southwestern China, to constrain the timing of mineralization. Sulfide ores from the deposit have a wide range of Re and Os concentrations, varying from 80.2 to 1543.2 ppb and from 0.307 to 8.83 ppb, respectively, and yielded a limited field of high 187Re/188Os and high 187Os/188Os ratios, ranging from 1452 to 3309 and from 5.77 to 13.24, respectively. All sulfide samples yielded an isochron with an age of 217±28 Ma and an initial 187Os/188Os ratio of around 0.52±0.73. The Re‐Os isochron age agrees with ages previously constrained by the other isotopic dating of the host rocks and fossil strata for the deposit. The rhythmic variation in 187Os/188Os and 187Re/188Os ratios within massive sulfide zone records a complicated process for ore‐forming fluids episodically vented into the brine pool on the Mesozoic seafloor.
Overview of the MITI Nankai Trough Wells: A Milestone in the Evaluation of Methane Hydrate Resources
Authors: Tsuji Yoshihiro , Ishida Hisashi , Nakamizu Masaru , Matsumoto Ryo , Shimizu Satoshi
Published: November 2008

Abstract. Bottom‐simulating reflectors suggestive of the presence of methane hydrates are widely distributed below the ocean floor around Japan. In late 1999, drilling of the MITI Nankai Trough wells was conducted to explore this potential methane hydrate resource and a Tertiary conventional structure. The wells are located in the Northwest Pacific Ocean off Central Japan at a water depth of 945 m. A total of six wells were drilled, including the main well, two pilot wells, and three post survey wells at intervals of 10–100 m. All wells except the first confirmed the occurrence of hydrates based on logging‐while‐drilling, wire‐line logging and/or coring using a pressure and temperature coring system in addition to conventional methods. Based on the various well profiles, four methane hydrate‐bearing sand‐rich intervals in turbidite fan deposits were recognized. Methane hydrates fill the pore spaces in these deposits, reaching saturation of up to 80 % in some layers. The methane hydrate‐bearing turbiditic sand layers are less than 1 m thick, with a total thickness of 12–14 m. The bottom depth of high hydrate concentration correlates well with the depth of the bottom‐simulating reflector. Based on these exploration results, the Japanese government inaugurated a 16‐year methane hydrate exploitation program in 2001.
The Geochemical Context of Gas Hydrate in the Eastern Nankai Trough
Authors: Waseda Amane , Uchida Takashi
Published: November 2008

Abstract. Geochemical studies for gas hydrate, gas and organic matter collected from gas hydrate research wells drilled at the landward side of the eastern Nankai Trough, offshore Tokai, Japan, are reported. Organic matter in the 2355 m marine sediments drilled to Eocene is mainly composed of Type III kerogen with both marine and terrigenous organic input. The gas hydrate‐bearing shallow sediments are immature for hydrocarbon generation, whereas the sediments below 2100 mbsf are thermally mature. The origins of gases change from microbial to thermogenic at around 1500 mbsf.

Carbon isotope compositions of CH4 and CO2, and hydrocarbon compositions consistently suggest that the CH4 in the gas hydrate‐bearing sediments is generated by microbial reduction of CO2. The δ13C depth‐profiles of CH4 and CO2 suggest that the microbial methanogenesis is less active in the Nankai Trough sediments compared with other gas hydrate‐bearing sediments where solid gas hydrate samples of microbial origin were recovered. Since in situ generative‐potential of microbial methane in the Nankai Trough sediments is interpreted to be low due to the low total organic carbon content (0.5 % on the average) in the gas hydrate‐bearing shallow sediments, upward migration of microbial methane and selective accumulation into permeable sands should be necessary for the high concentration of gas hydrate in discrete sand layers.
Petrophysical Properties of Natural Gas Hydrates‐Bearing Sands and Their Sedimentology in the Nankai Trough
Authors: Uchida Takashi , Tsuji Takashi
Published: November 2008

Abstract. The Nankai Trough parallels the Japanese Island, where extensive BSRs have been interpreted from seismic reflection records. High resolution seismic surveys and drilling site‐survey wells conducted by the MTI in 1997, 2001 and 2002 have revealed subsurface gas hydrate at a depth of about 290 mbsf (1235 mbsl) in the easternmost part of Nankai Trough. The MITI Nankai Trough wells were drilled in late 1999 and early 2000 to provide physical evidence for the existence of gas hydrate. During field operations, continuous LWD and wire‐line well log data were obtained and numerous gas hydrate‐bearing cores were recovered. Subsequence sedimentologic and geochemical analyses performed on the cores revealed important geologic controls on the formation and preservation of natural gas hydrate. This knowledge is crucial to predicting the location of other hydrate deposits and their eventual energy resource. Pore‐space gas hydrates reside in sandy sediments from 205 to 268 mbsf mostly filling intergranular porosity. Pore waters chloride anomalies, core temperature depression and core observations on visible gas hydrates confirm the presence of pore‐space hydrates within moderate to thick sand layers. Gas hydrate‐bearing sandy strata typically were 10 cm to a meter thick. Gas hydrate saturations are typically between 60 and 90 % throughout most of the hydrate‐dominant sand layers, which are estimated by well log analyses as well as pore water chloride anomalies.

It is necessary for evaluating subfurface fluid dlow behavious to know both porosity and permeability of gas hydrate‐bearing sand to evaluate subsurface fluid flow behaviors. Sediment porosities and pore‐size distributions were obtained by mercury porosimetry, which indicate that porosities of gas hydrate‐bearing sandy strata are approximately 40 %. According to grain size distribution curves, gas hydrate is dominant in fine‐ to very fine‐grained sandy strata.
Detection of Methane Hydrate‐Bearing Zones from Seismic Data
Authors: Inamori Takao , Hato Masami
Published: November 2008

Abstract. The MITI Nankai Trough wells were drilled offshore Japan in the Tokai area in 1999 and 2000. The occurrence of methane hydrate was confirmed by various indicators in the borehole logs and from core data. These findings have a large impact on potential future Japanese energy resources and other related‐scientific interests.

We first tried to find the methane hydrate‐bearing zones using interval velocities derived from NMO velocity analysis. However, this analysis produced poor resolution. To achieve a more detailed delineation of the gas hydrate‐ and gas‐bearing zones, we executed a seismic impedance inversion calibrated by the logs from two of the MITI Nankai Trough wells. Although these two wells are only about 90 m apart, we were able to produce an impedance section with fine detail by adopting a simple initial model and incorporating physical properties of the methane hydrate‐bearing zones. The locations of the methane hydrate‐bearing zones are readily apparent in the final section.
Occurrence of Halogen‐rich Phlogopite in Late Cenozoic Volcanic Rocks in the Japanese Arcs
Authors: Imai Akira
Published: November 2008

Abstract. Halogen‐rich phlogopite occurs in the groundmass of andesite and dacite lavas from Late Tertiary to Quaternary volcanoes associated with native sulfur and limonite deposits (Shiretoko‐Iwozan, Hachimantai, Adatara, Omeshidake, Masaki) and hydrothermal ore deposits (Harukayama, Muineyama, Hishikari) in Japan. The F contents of the halogen‐rich phlogopite range from 3.6 to 5.7 wt%, corresponding to atomic F/(F+C1+OH) ratios ranging from 0.45 to 0.69. On the other hand, the Cl contents of the halogen‐rich phlogopite are around 0.2 wt%. The atomic Mg/(Mg+Fe) ratios range from 0.69 to 0.83.

The fluorine intercept value [IV(F)] defined by Munoz (1984) of the phlogopites ranges from 0.79 to 3.17, and the chlorine intercept value [IV(Cl)] ranges from ‐7.11 to ‐7.77. The observed IV(F) of the phlogopites broadly overlap the range of the IV(F) for biotites from porphyry copper deposits. On the other hand, the observed IV(Cl) are significantly lower than the IV(Cl) for biotites from porphyry copper deposits. Whereas the F contents of the phlogopite appear more prominent compared to the Cl contents, the calculation of halogen intercept values revealed that the phlogopites are enriched in Cl with respect to the element distribution effect of Mg‐Fe substitution. Since the degree of Cl enrichment of the phlogopite is more significant compared to that of biotite in porphyry copper deposits, the phlogopites are considered to have formed under the condition of significantly high activity of halogens. Hydrothermal ore deposits may be formed in magmatic hydrothermal system associated with volcanoes where halogen‐rich phlogopite is formed by hypersaline fluid.
Genesis of Kanggur Gold Deposit in Eastern Tianshan Orogenic Belt, NW China: Fluid Inclusion and Oxygen and Hydrogen Isotope Constraints
Authors: Wang Zhiliang , Jiang Neng , Wang Yitian , Mao Jingwen , Yang Jianmin
Published: November 2008

Abstract. Primary fluid inclusions in quartz and carbonates from the Kanggur gold deposit are dominated by aqueous inclusions, with subsidiary CO2‐H2O inclusions that have a constant range in CO2 content (10–20 vol %). Microthermometric results indicate that total homogenization temperatures have a wide but similar range for both aqueous inclusions (120d̀ to 310d̀C) and CO2‐H2O inclusions (140d̀ to 340d̀C). Estimates of fluid salinity for CO2‐H2O inclusions are quite restricted (5.9∼10.3 equiv. wt% NaCl), whereas aqueous inclusions show much wider salinity ranging from 2.2 to 15.6 equivalent wt %NaCl.

The 6D values of fluid inclusions in carbonates vary from ‐45 to ‐61 %, in well accord with the published δD values of fluid inclusions in quartz (‐46 to ‐66 %). Most of the δ18O and δD values of the ore‐forming fluids can be achieved by exchanged meteoric water after isotopic equilibration with wall rock by fluid/rock interaction at a low water/rock ratio. However, the exchanged meteoric water alone cannot explain the full range of δ18O and δD values, magmatic and/or meta‐morphic water should also be involved. The wide salinity in aqueous inclusions may also result from mixing of meteoric water and magmatic and/or metamorphic water.
Timing of the Mineralization and Volcanism at Cibaliung Gold Deposit, Western Java, Indonesia
Authors: Harijoko Agung , Sanematsu Kenzo , Duncan Robert A. , Prihatmoko Sukmandaru , Watanabe Koichiro
Published: November 2008

Abstract. The Cibaliung deposit is a low‐sulfidation type epithermal gold deposit situated about 70 km west of the Bayah dome complex. The gold‐bearing quartz veins are hosted by basaltic andesite of the Honje Formation, which is comparable to the host rock of gold deposits at the Bayah dome complex.

In order to clarify the timing of the mineralization and the volcanism at the Cibaliung area, two radiometric dating methods were applied. First, 40Ar/39Ar dating was conducted on six adularia samples to elucidate the age of mineralization. Second, K‐Ar method was applied to two samples of the host rock, andesite and the Cibaliung tuff, in order to reveal the timing of volcanism.

The 40Ar/39Ar dating determined mineralization ages in the range from 11.18 to 10.65 Ma while the K‐Ar dating indicated the age of the andesite and the Cibaliung tuff to be 11.4±0.8 Ma and 4.9±0.6 Ma, respectively. These results imply that the epithermal gold mineralization in the Cibaliung area is related to the volcanic activity that produced the Honje Formation, while the Cibaliung tuff played an important role in the preservation of the Cibaliung deposit. The Cibaliung deposit is the oldest epithermal gold deposit yet discovered in western Java.
Gold Mineralization at the Kyaukpahto Mine Area, Northern Myanmar
Authors: MyintSwe Ye , Lee Insung , Htay Than , Aung Min
Published: November 2008

Abstract. Gold mineralization at Kyaukpahto occurs as a stockworks/dissemination style with localized breccia zones in silicified sandstones of the Male Formation (Eocene). The mineralization appears to be closely associated with NNE‐SSW trending extensional faults probably related directly to the dextral movement of the Sagaing Fault system. Intense silicifica‐tion associated with sericitization, argillic alteration and decalcification is recognized in the Kyaukpahto gold deposit. The important ore minerals associated with the gold mineralization are pyrite, arsenopyrite and chalcopyrite with minor amounts of other sulfides. Gold occurs as free particles or locked with pyrite, arsenopyrite, chalcopyrite and tetrahedrite. Silver, copper, arsenic and antimony particularly appear to be good pathfinders and the best geochemical indicators of gold mineralization at Kyaukpahto. Electron microprobe analysis indicates that the fineness for the native gold ranges from 844 to 866. Present geological, mineralogical and geochemical investigations demonstrate that the Kyaukpahto gold deposit has been formed as a result of hydrothermal processes in a shallow level epithermal environment.
Volatile Phase Separation in Silicic Magmas at Bajo de la Alumbrera Porphyry Cu‐Au Deposit, NW Argentina
Authors: Harris Anthony C. , Kamenetsky Vadim S. , White Noel C. , Steele David A.
Published: November 2008

Abstract. At the Bajo de la Alumbrera porphyry Cu‐Au deposit, NW Argentina, several key textural elements preserve evidence for volatile separation. Interconnected miarolitic cavities, while being studied extensively in granites, have now been recognized in intrusions related to porphyry Cu mineralization. Pods of saccharoidal quartz are connected by narrow, anastomosing zones of graphic quartz‐alkali feldspar intergrowths and ragged biotite (with lesser apatite and magnetite). Their connectivity can be as much as 15 cm; however, more commonly, the interconnected miarolitic cavities are approximately 1 to 2 mm across and 5 cm or less, long. Features such comb‐quartz layered textures and magmatic‐hydrothermal veins (P veins), combined with aqueous fluid phase equilibria from fluid inclusions, better constrain physical models of exsolution. We interpret these textures in the context of vapour phase formation, coalescence and accumulation in an evolving silicic magma. Recognition of textures, such as the interconnected miarolitic cavities reported here, may provide a simple exploration tool for porphyry Cu deposits, helping explorers to recognize evidence for a potentially fertile intrusions.
Exploration Indices and Mineral Potential Map of the Kuroko Deposits in Northeast Japan
Authors: Kubota Hiroshi , Urabe Tetsuro , Yamada Ryoichi , Tanimura Shojiro
Published: November 2008

Abstract. Recent discoveries of seafloor hydrothermal mineralization in submarine volcanic centers of felsic magma in western Pacific island arcs are regarded as modern analogues of Kuroko type deposits. Studies of these deposits and their surrounding geology raised question whether the exploration activity for the Kuroko deposits on land which peaked in the 1960's was adequate or not. However, such an evaluation is not easy because the exploration data are about to be lost as a result of the closure of all the Kuroko mines in the area since 1994.

The Metal Mining Agency of Japan (MMAJ), therefore, decided to compile existing data on about 180 Kuroko deposits and related mineral occurrences in northeast Japan as a new Kuroko database.

This study extends a concept called “exploration indices” which was developed based on a case study of the thoroughly surveyed Hokuroku district to draw a potential map of the Kuroko occurrences for the entire northeast Japan quantitatively with a Geographical Information System (GIS). Effective exploration indices include: 1) distribution of dacitic‐rhy‐olitic submarine volcanic rocks of the Nishikurosawa and Onnagawa stages, 2) distribution of intrusive rocks of pre‐ and post‐Kuroko horizon, 3) low aeromagnetic anomaly caused by hydrothermal alteration of magnetite, 4) low gravity anomaly which suggests depressions in the basement rocks such as a tectonic basin and/or caldera, and 5) nearby existence of vein type deposits. It is concluded that about 33 % of known Kuroko deposits fall within the high potential zone (score=4 and 5) that occupies only 4 % of the entire northeast Japan arc. The Kuroko potential map is, therefore, useful for limiting the target area for Kuroko type deposits in an island arc setting.
Germanium‐bearing Colusite in Siliceous Black Ore from the Ezuri Kuroko Deposit, Hokuroku District, Japan
Authors: Komuro Kosei , Kajiwara Yoshimichi
Published: November 2008

Abstract. Germanium‐bearing colusite occurs with sphalerite, galena, tetrahedrite‐tennantite, chalcopyrite and pyrite in microdruses and veinlets in the siliceous black ore from the Ezuri Kuroko deposit in the Hokuroku district of Japan. X‐ray microdiffractometry of this mineral gives strongest lines at 1.60, 1.32 and 1.09 Å, which are consistent with the known powder diffraction data of colusite. On the basis of 32 S atoms per formula unit, electron microprobe analyses yield empirical chemical formulae of (Cu24 0Fe0.3Zn1.0)σ25.3V1.9(As4.8Sb0.2)σ5.0Ge 1.3S32 for Ge‐bearing colusite in close association with sphalerite, and (Cu24.6Fe0.9)σ25.4V1.8(As4.1 Sb0.2)σ4.3Ge1.7S32 for that coexisting with chalcopyrite, consistent with the ideal formula of Cu24+xV2(As, Sb)6‐x(Sn, Ge)xS32 (x = 0 to 2) proposed by Spry et al. (1994) for this mineral species. The Ge‐bearing colusite mineralization is suggested to have occurred concurrently with consolidation of the siliceous black ore, possibly during hydrothermal modification in association with the igneous activity of the Ohtaki quartz diorite of the later Onnagawa stage. It is likely that biogenic siliceous ooze, a possible precursor of the siliceous black ore, may have served as an in situ source of Ge as well as other essential rare elements, leading to the formation of Ge‐bearing colusite during transformation or recrystallization of biogenic opal into a‐quartz.
SHRIMP U‐Pb Zircon Age of the Inishi Migmatite around the Kamioka Mining Area, Hida Metamorphic Complex, Central Japan
Authors: Sakoda Masatoshi , Kano Takashi , Fanning C. Mark , Sakaguchi Takaaki
Published: November 2008

Abstract. SHRIMP U‐Pb ages were determined on single zircons separated from the Inishi migmatite in the Kamioka mining area, Hida metamorphic complex, central Japan. Twenty one determinations were distributed within the age of 234.2±1.8 Ma, excluding one inner core of a grain. As the analyzed crystals were mostly euhedral igneous zircons, the age indicates the crystallization of zircons from granitic melt during the formation of Inishi migmatite. The age of ca. 234 Ma corresponded to the later stage of the major regional metamorphic event in the Hida complex, while the age of ca. 265 Ma determined in a grain suggested the inherited age of the earlier phase of the metamorphism.
A Possible Role of Boiling in Ore Deposition: A Numerical Approach
Authors: Hoshino Kenichi , Itami Tom , Shiokawa Ryouta , Watanabe Makoto
Published: November 2008

Abstract. A possible role of boiling of the H2O‐NaCl‐CO2(‐H2S) fluid in ore deposition has been examined numerically by using the equations of state (EOS) of Duan et al. (1995, 1996), a modified EOS of Bowers and Helgeson (1983) and the water‐rock interaction simulator MIX99 (Hoshino et al., 2000).

The following three models are examined to evaluate an efficiency of boiling on mineral precipitation: (1) hypothetical non‐boiling process, (2) hypothetical boiling process with sulfur partitioned only in liquid phases and (3) boiling process in which partition ratios of H2S between liquid and vapor phases are assumed to be the same as those of CO2. The processes are simulated from 450d̀C and 900 bar to 310d̀C and 620 bar with an analytical step of 10d̀C / 20 bar. Boiling occurs below 400d̀C in the latter two processes when the initial composition (in mole fraction) of the fluid is: XH2o = 0.84, XNaC1 = 0.10 and XCo2 = 0.06.

Ore deposition occurs abruptly at a boiling point when the partition ratios of total sulfur (Xsvap/Xsliq) are as high as those of total carbon during boiling. A decrease of concentration of sulfur in the liquid phase during boiling leads to an increase of pH of the solution, resulting in propelling mineral precipitation. It has been made clear that a possible role of boiling in ore formation mainly depends on the partition ratios of sulfur between the liquid and vapor phases, although they cannot be estimated accurately by the currently available EOS.
Mode of Occurrence and Characteristics of Mn‐ore Bodies in Iron Ore Group of Rocks, North Orissa, India and Its Significance in Resource Evaluation
Authors: Mishra Patitapaban , Mvohapatra Birendra K. , Singh Prem P.
Published: November 2008

Abstract.Several meso‐scale manganese ore bodies, scattered within Jone's horse‐shoe shaped synclinorium, in Bonai‐Keonjhar region of north Orissa are well known in the mineral map of India. Different grades of manganese ores are being exploited from this region by various agencies over a few decades. However, deceptive nature of ore bodies and complexity in control of mineralisation greatly confuse the exploration geologists for evaluation of these resources.

In a recent study, the authors have classified Mn‐ore bodies of this region into three broad categories such as stratiform, stratabound (‐replacement) and lateritoid types based on mode of occurrence and their other chemical characteristics. Mn‐ore bands occur in close association with BIF and iron ores. Volcaniclastic shale in large geographic extension encloses these ore bodies.

In the stratiform category of ore bodies (BMnF, analogous of BIF), manganese and shale bands, in variables thickness, alternate with each other and extend to a great depth. Such ore bodies generally constitute marginal to low‐grade ores, are characterised by low Mn/Fe ratio (∼2) and have relatively lower abundance of trace (1500 to 2500 ppm) and relatively higher REE constituents. The stratabound‐replacement types of ore bodies are of intra‐stratal nature, occurring within tuffaceous shale. These are mostly shear‐controlled ore bodies extending along a zone of certain width. Increase in average Mn/Fe ratio (∼6) and trace content (5000 to 8500 ppm) by 5 to 2.5 order of magnitude respectively or more above stratiform category are characteristic of these deposits. The lateritoid ore bodies have limited depth persistency. Such deposits are usually very low in Mn/Fe ratio (<1), trace (<2000 ppm) and REE contents.

Different methods of exploration techniques are suggested for various categories of Mn‐ore bodies. In this context, the above findings would be the database for the exploration geologists to evaluate the potential of newer/existing Mn‐ore resources in this part of north Orissa.
Geology and Mineralogy of the Baolun Hydrothermal Gold Deposit in the Hainan Island, South China
Authors: Wang Ping'an , Kaneda Hiroaki , Ding Shijiang , Zhang Xiaowen , Liao Xiangjun , Dong Faxian , Li Zhongjian , Liu Xiaochun , Lai Yong
Published: November 2008

Abstract. The Baolun quartz vein type Au deposit, is located at the southwestern Hainan Island. It occurs next to a Triassic ilmenite‐series/S‐type syenogranite complex. A 40Ar/39Ar plateau age for muscovite from the master orebody is dated to be 219.4±0.6 Ma, suggesting that the gold deposit genetically related to the granite pluton. In the Baolun mining area, orebodies of auriferous quartz vein and wall rock alteration occur in NNW‐striking fracture zones hosted by weakly metamorphosed turbidite of the Lower Silurian age. Eight fracture zones, 400∼1300 m long and 10∼30 m wide, have been identified. The five fracture zones of them form orebodies. The ores are mainly of quartz vein type. More than 20 orebodies in shapes of vein and lens of 195∼751 m in length and 0.20∼7.49 m in thickness are known, and 14 of them occur in the No. 1 vein belt. Silicification, sericitization and pyritization are closely related to the Au mineralization. The ores exhibit commonly 1.54∼29.48 g/t in Au grade, partially >98 g/t. The master orebody is 720 m long and 2.62 m thick in average, with 9.53∼29.27 g/t Au. Gold reserves of more than 70 t have been proven by geological exploration. More than 20 metallic minerals including native gold and sulfides such as pyrite, pyrrhotite, chalcopyrite, and others are identified to be formed in four ore‐forming stages: (1) Au‐coarse grain quartz stage, (2) Au‐fine grained quartz stage, (3) Au‐bismuthide‐bismuth sulfosalt‐sulfide‐quartz stage, and (4) calcite‐sulfide‐quartz stage. The Au mineralization in this deposit occurred mainly in the first three stages. A variety of Bi‐ and Te‐bearing minerals is closely associated with native gold suggesting that the mineralization may take place in a relatively high temperature.
Ethnographic Approaches to Race, Genetics and Genealogy
Authors: Tyler Katharine
Published: November 2008

In recent years, there has been a technological advance and commercial boom in genetic technologies and projects, including a renewed scientific interest in the biological status and genetic constitution of race. This article provides an overview of sociological approaches to the study of race and genetics, and argues that these analyses should pay detailed critical attention to laypeople's engagements with the new genetic technologies. Drawing upon growing bodies of ethnographic literature within anthropology, geography and sociology, this paper unravels the complex and ambivalent ways in which laypeople think about the biological and genetic constitution of racial identities. Two specific bodies of literature are examined. First, the new kinship studies within anthropology that explores laypeople's engagements with the new reproductive technologies, such asin vitrofertilization. Second, laypeople's uses of genealogical technologies that claim to trace family ancestries, including racial descent and ethnic origins.
A New Paradigm of Organized Crime in the United States: Criminal Syndicates, Cyber‐gangs, and the Worldwide Web
Authors: Britz Marjie T.
Published: November 2008

This paper explores the creation and evolution of organized crime as a concept within the United States. The paper argues that traditional definitions are both incomplete and inaccurate due primarily to their reliance on La Cosa Nostra (i.e. Italian mafia) models and inflexibility. The author proposes the introduction of a new definition, and distinguishes between computer crime committed by organized crime groups and organized criminal activity in a technological environment. In addition, a distinction is made between organized crime and cyber‐gangs. Finally, the author discusses specific examples of computer crime committed by criminal syndicates.
Rentenreform in China
Authors: Salditt Felix , Whiteford Peter , Adema Willem
Published: November 2008

Auszug  Der vorliegende Artikel analysiert Chinas Fortschritte bei der Errichtung eines nationalen Altersversicherungssystems, beschreibt das System eingehend und beurteilt, inwieweit es sein Hauptziel, mehr Menschen soziale Sicherheit zu gewähren, erreicht hat. Seit 1997 wurden viele Reformen eingeleitet, aber trotz Fortschritten ist der Geltungsbereich des Systems begrenzt, und der Deckungsgrad unter städtischen Arbeitnehmern liegt unter 50 Prozent. Die Landbevölkerung bleibt weitgehend außerhalb des Systems, und wahrscheinlich wird der Großteil der Bevölkerung noch viele Jahre von der Unterstützung durch Angehörige abhängen. Es besteht ein „demografisches Fenster“ bis etwa 2015, um diese Unzulänglichkeiten anzugehen. Die Ausweitung der Deckung durch eine bessere Einhaltung der Beitragspflicht durch Arbeitnehmer und Betriebe sowie das anhaltende finanzielle Engagement gegenüber der Nationalen Kasse für soziale Sicherheit sind entscheidend für die Errichtung der landesweiten finanziellen und institutionellen Basis, die die Folgen einer in den kommenden Jahren wesentlich älteren Bevölkerung abfedern kann.
Chancen eines Grundeinkommens in Deutschland
Authors: Opielka Michael
Published: November 2008

Auszug  Der Beitrag diskutiert die Frage, ob die Chancen für die Einführung eines von der Teilnahme am Arbeitsmarkt unabhängigen Grundeinkommens in der deutschen Sozialpolitik in den letzten Jahren gestiegen sind. Nach einem Abriss der Systemprinzipien des deutschen Sozialstaats wird die neuere Entwicklung der Grundeinkommenssicherung durch die Zusammenlegung von Arbeitslosenhilfe und Sozialhilfe seit 2003 kritisch analysiert. Die damit verbundenen Abstiegsängste bis in die deutsche Mittelschicht belebten die bereits in den 1980er‐Jahren geführte Debatte um ein Grundeinkommen neu. Am Beispiel von zwei Modellen („Grundeinkommensversicherung“, „Solidarisches Bürgergeld“) werden konkrete Probleme der Systemgestaltung und Realisierungschancen erörtert.
Impending collapse of bluefin tuna in the northeast Atlantic and Mediterranean
Authors: MacKenzie Brian R. , Mosegaard Henrik , Rosenberg Andrew A.
Published: November 2008

The abundance of bluefin tuna, Thunnus thynnus, in the east Atlantic and Mediterranean has declined in recent decades. The International Commission for the Conservation of Atlantic Tunas (ICCAT), the regional bluefin tuna management authority, has developed a plan to promote recovery by 2022, while still permitting fishing to continue during the period 2008–2010. Here we predict that the adult population in 2011 will likely be 75% lower relative to 2005 and that quotas in some intervening years will allow the fishery to capture legally all of the adult fish. Population demographics (proportion of older fish and repeat spawners in population) indicate that buffering capacity against years of poor reproduction has been reduced. This population is at risk of collapse (90% decline in adult biomass within three generations, the criterion used by the IUCN for defining populations as Critically Endangered), even under the currently agreed recovery plan, unless new conservation measures are implemented in the next few years.
Pulmonary metastasis of a gastrointestinal stromal tumor of the rectum identified at 10‐year follow‐up
Authors: Seok Sang Hee , Sung Woo Jung , Kim Mi Jin
Published: November 2008

Gastrointestinal stromal tumors (GISTs) present as a spectrum, from clinically benign to malignant. Metastases usually become clinically apparent within 18–24 months of diagnosis, though they can develop as many as 30 years after primary tumor removal. The most common metastatic sites are the peritoneal surface and the liver. Pulmonary metastases are less common (approximately 7% of all metastises). Here, we report a case of pulmonary metastasis of a GIST of the rectum. A 50 year‐old‐woman, having received a Miles' operation for GIST of the rectum 10 years previous, was found to have a tumor in the right lung during a follow‐up examination. A 2.5 cm sized well‐demarcated mass presented in her lung parenchyma. The tumor was composed of spindle and epithelioid cells showing diffuse and strong cytoplasmic positivity for CD 117. These histologic and immunohistochemical findings proved that the tumor may have been the result of metastasis from the GIST of the rectum. This case suggests that GIST can metastasize after a long disease‐free interval and that such cases should be carefully and regularly followed up indefinitely.
Unsolved allegation of sexual intercourse and Viagra for possible causes of sudden unexpected death at the forensic autopsy
Authors: Park Moon‐Il , Jeon Seok‐Hoon , Kim Hyoung‐Joong , Choi Byung‐Ha , Park Hye‐Jin , Yang Kyung‐Moo , Kim Yu‐Hoon , Lee Bong‐Woo , Choi Young‐Shik , Kim Youn‐Shin , Chung Nak‐Eun , Lee Han‐Young , Lee Won‐Tae
Published: November 2008

There is a controversy on the causal relationship of sexual intercourse as a cause of sudden death. Since sildenafil (Viagra™) has been introduced in 1998, there are more concerns on the safety issue of sildenafil and sexual activity as a forensic determination of the cause of death in those cases. We have collected 68 cases of sudden death occurred within 24 hours after sexual intercourse among 13,824 cases for five years from 2001 at the head office of the National Institute of Scientific Investigation in Seoul, Korea. There were 59 men and 9 women (M:F = 6.6:1). The most common cause of death was ischemic heart disease (20 in 68, 29.4%) in both men and women. Sildenafil (Viagra™) was detected in blood in 8 men and only in gastric content in 2 men (10/59, 17.0%). The level in the 8 men was in range of 0.04 to 0.48 with average 0.15 μg/ml. We could not conclude at this study on whether sexual activities and/or sildenafil are considered to have significant contribution to their death, but we would like to warn patients with cardiovascular diseases for the possible risk for sudden unexpected death particularly when their environments are in an unusual situation.
Current information on the infectious risks of allogeneic blood transfusion
Authors: KITCHEN ALAN D. , BARBARA JOHN A. J.
Published: November 2008

The safety of allogeneic blood and blood products in relation to infection risk is paramount, even though absolute safety is an ideal that clearly cannot be attained. In countries with developed healthcare systems and with effective and well‐managed national transfusion services, any residual infection risk is generally much lower than the risk of non‐infectious adverse events. The number of infectious agents known to be transmitted by transfusion is not insignificant, but at the same time only a proportion of these present a significant universal threat. It is therefore important to understand and attempt to quantify the residual infectious risks associated with transfusion. These risks generally fall into two categories: the risk of infection because of the failure to identify infection in a donation from a recently infected donor and the risk of infection from a ‘new’ infectious agent or from one that donations are not routinely screened for. Both of these scenarios are ‘real’ in the sense that these are the threats faced every day by transfusion services. The mitigation of such threats is by ensuring that there are effective donor screening and deferral procedures in place, that the screening performed is carried out to the highest possible standards in terms of sensitivity and reliability, and finally that the transfusion service actively monitors ‘new’ or emerging infectious threats so that action can be taken if the safety of the blood supply is likely to be compromised, as well as maintaining hemovigilance of adverse events in recipients of transfusions.
Immunological complications of blood transfusion
Authors: TAYLOR CLARE , NAVARRETE CRISTINA , CONTRERAS MARCELA
Published: November 2008

In the developed world, most of the reported complications of transfusion have an immunological basis. Although the media and the public are worried about the infectious risks of transfusion, hemovigilance reports show that antigen–antibody reactions are responsible for the vast majority of acute and delayed transfusion reactions. Among the immediate complications of transfusion, the most common and serious are intravascular hemolytic transfusion reactions because of ABO incompatibility caused by giving the wrong blood to a patient (e.g. group A blood to a group O recipient). Fortunately, the vast majority of ABO‐incompatible transfusions do not lead to major morbidity or mortality. Another important cause of severe immediate transfusion reactions is transfusion‐related acute lung injury (TRALI), caused by white cell antibodies in donor plasma. The most common, although not severe, acute tansfusion reactions are urticaria and febrile, nonhemolytic, mostly preventable by leukodepletion and leukoreduction. Delayed transfusion reactions are: (i) hemolytic, caused by anamestic responses to red cell antigens, causing hemolysis days after the transfusion; (ii) post‐transfusion purpura, caused by an anmnestic response to platelet antigens; (iii) graft‐versus‐host disease, caused by engrafted donor lymphocyte reacting against the recipient; and (iv) immunological refractoriness to platelet transfusions, caused mostly by human leukocyte antigen antibodies destroying transfused platelets. The diagnosis of most of these complications can now be made by immunohematologists, with the aid of specialist reference laboratories, thus enabling prompt therapy as required.
Infrared features of classic choroidal neovascularisation in exudative age-related macular degeneration
Authors: Semoun O , Guigui B , Tick S , Coscas G , Soubrane G , Souied E H
Published: November 2008

Aim:

Wet age-related macular degeneration (AMD) represents a heterogeneous group of phenotypes, all defined by fluorescein angiography features (FA). Imaging of wet AMD is extensively described in literature, including colour pictures, FA, indocyanine green angiography (ICG) and optical coherence tomography (OCT). The purpose of this study was to describe features of infrared (IR) pictures of a homogeneous subgroup of classic choroidal neovascularisation (CNV) associated with wet AMD,

Methods:

We analysed 22 eyes of 22 consecutive patients with classic CNV. All patients underwent a complete ophthalmological examination including colour fundus photography, infrared picture, fluorescein angiography, indocyanine green angiography and an optical coherence tomography.

Results:

Infrared pictures revealed a whitish ring surrounding the neovascular lesion in all eyes (22/22). The whitish ring corresponded in all cases to the borders of the CNV defined on the early phase of FA and ICG pictures. The ring had an “O-shape” in 15/22 cases (68%) and a “U-shape” in 7/22 cases (32%).

Conclusion:

Analysis of infrared pictures in classic CNV constantly revealed a whitish ring that is correlated to the limits of the lesion. IR picture is a non invasive imaging of the macula, but the specificity of the features needs to be investigated in further studies.
Response of tapered piles to axial harmonic loading
Authors: Ghazavi Mahmoud
Published: November 2008

This paper presents a new mathematical approach for the analysis of a harmonically vibrating, linear, elastic, tapered pile. The soil consists of a number of horizontal elastic strata that are homogeneous, isotropic, and linearly viscoelastic. The governing differential equation for an arbitrary pile segment is obtained and solved. The solution starts from the pile toe and ends up with the pile head. It will be shown that when the taper angle is increased, the resonant amplitudes of piles decrease. It will also be demonstrated that the resonance amplitudes and resonant frequencies of the floating tapered pile and a uniform pile of the same volume and length vary slightly. However, the resonant amplitude of an end-bearing tapered pile is significantly less than that of the equivalent uniform pile. It will generally be concluded that the use of tapered piles subjected to axial harmonic vibrations is superior to the use of cylindrical piles of the same length and volume. This is very attractive for dynamically loaded piles, encouraging the practical use of tapered piles.
An analytical solution for jointed tunnel linings in elastic soil or rock
Authors: El Naggar Hany , Hinchberger Sean D.
Published: November 2008

This paper presents a closed-form solution for tunnel linings that can be idealized as an inner jointed segmental lining and an outer thick-walled cylinder embedded in a homogeneous infinite elastic soil or rock. Solutions for moment and thrust have been derived for cases involving slip and no slip at the lining–ground and lining–lining interfaces. In addition, the closed-form solution is verified by comparing it with finite element results where it is shown to agree well with this more sophisticated method of analysis.
Effect of depositional method on the microstructure of silty sand
Authors: Yamamuro Jerry A. , Wood Fletcher M. , Lade Poul V.
Published: November 2008

The results from a laboratory experimental study on silty sand are presented. A scanning electron microscope (SEM) was used to investigate the effect of depositional method and silt content on the grain contact structure of silty sand. Triaxial specimens containing Nevada sand with various quantities of nonplastic silt were isotropically consolidated to 25 kPa and then preserved through epoxy impregnation. Specimens were formed using both dry funnel deposition and water sedimentation. A procedure was developed that allowed the microstructure to be quantified in terms of potentially stable and unstable grain contacts. As silt content increased, the percentage of stable grain contacts decreased. Specimens formed by dry funnel deposition contained a higher percentage of potentially unstable grain contacts than those reconstituted by water sedimentation, possibly reflecting a more compressible particle structure. This effect became more pronounced as silt content increased. A description of the specimen preservation technique as well as the methodology used to both prepare and analyze SEM specimens for grain contact analysis are presented.
A FRAMEWORK OF SCHEDULING MODELS IN MACHINING WORKSHOP FOR GREEN MANUFACTURING
Authors: HE YAN , LIU FEI , SHI JINLIANG
Published: November 2008

Reducing environmental impacts and resource consumption in manufacturing processes is one of the important issues in green manufacturing. However, this attention has focused primarily on the activities of the design and the process planning, and the production scheduling activity has been overlooked especially for discrete manufacturing systems such as machining workshop. This paper presents a framework of the scheduling models in machining workshop that integrated resource and environmental considerations into production scheduling activities. The scheduling framework builds upon the schematic model and the analysis of resource and environmental dimensions of machining processes, and is used to guide the scheduling model construction which seeks to reduce resource consumption and environmental impacts at the operational scheduling level. The example is presented to demonstrate the application of the framework.
CC-DHCR PLANNING AND SCHEDULING METHOD BASED ON SLAB CLUSTER
Authors: LIANG HELAN , LI SUJIAN
Published: November 2008

Focusing on the limitations of the traditional Continuous Casting-Direct Hot Charge Rolling (CC-DHCR) planning and scheduling methods that rarely consider dynamic scheduling problems, a new method is put forward. The key idea is to make out clusters and integrated plans in the planning layer, and then to adjust the rolling sequences according to the slab cluster-based strategy in the dynamic scheduling layer. Results of the test with data from practical production process show that the method can effectively solve the CC-DHCR planning and scheduling problem and increase the DHCR ratio.
RESEARCH ON IMPROVING PERFORMANCE OF THE MOTORCYCLE ENGINE AT LOW AND MEDIUM SPEED
Authors: HUANG QI , GUO GANG
Published: November 2008

It is important to improve engine performance at low and medium speed according to Chinese motorcycle market. Firstly, it is found that inlet channel with a smaller caliber and a longer passage will make a better characteristic curve. Secondly, increasing compression ratio can improve performance by changing piston shape and reducing the height of cylinder. Thirdly, modifying air filter can improve performance also.
RESEARCH ON PATTERN SYSTEM DESIGN IN PRODUCT DEVELOPMENT
Authors: WANG JUQUN , LIU GENG
Published: November 2008

The concept of pattern system design was presented. The pattern design methods with system characteristic were classified as the process pattern system design and the object pattern system design, both of which were studied in detail. Through integrating process pattern system design and object pattern system design, a P-OI (Process-Object Integration) pattern system design method was proposed. In addition to some common advantages in pattern system design methods such as sharing and reusing system resource, the P-OI pattern system design method is also consistent with integral criterion, well process and object integration, and prominent system open connectivity, all of which are of vital importance for high effectiveness and quality but of low cost during the development of products.
DETERMINE THE DISTRIBUTION AND HISTORY OF WORKPIECE TEMPERATURE FOR DRY MILLING
Authors: DENG WEN JUN , XIA WEI
Published: November 2008

A 2D finite element model of dry milling process is developed to determine the temperature distribution and temperature history of workpiece. The flow stress of workpiece is taken as a function of strain, strain rate and temperature in order to reflect realistic behavior in machining process. Temperature-dependent material properties are also employed in the analysis. From the simulation, a lot of information on dry milling process can be obtained; cutting force, cutting temperature, chip shape, temperature distribution, etc. The temperature history of the machined layer can be reported by conducting a point tracking. The predicted temperature profile at conventional cutting speeds and high speed machining are obtained. The finite element model appears to be perfectly representative of dry milling process and can be used to predict instantaneous temperature profile and temperature history into the depth of the workpiece.