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1.
ＴｈｅｈｙｐｏｔｈｅｓｉｓｏｆｔｒａｎｓｆｏｒｍａｔｉｏｎｏｆｂａｓａｌｔｔｏｅｃｌｏｇｉｔｅａｔｔｈｅｃｏｎｔｉｎｅｎｔａｌＭｏｈｏｄｉｓｃｏｎｔｉｎｕｉｔｙｉｎ 196 0ｓｅｖｅｒｂｒｏｕｇｈｔｂｒｏａｄｉｎｔｅｒｅｓｔｓｔｏｇｅｏｓｃｉｅｎｃｅｃｏｍｍｕｎｉｔｙ (ＲｉｎｇｗｏｏｄａｎｄＧｒｅｅｎ ,1996 ;ＧｒｅｅｎａｎｄＲｉｎｇｗｏｏｄ ,1972 ;ＩｔｏａｎｄＫｅｎｎｅｄｙ ,1971;ＫｕｓｈｉｒｏａｎｄＡｏｋｉ,196 8) .Ｔｈｉｒｔｙｙｅａｒｓｌａｔｅｒ ,ｗｉｔｈｔｈｅｄｉｓｃｏｖ ｅｒｉｅｓｏｆｃｏｅｓ… 相似文献
2.
Peter Wellman 《Australian Journal of Earth Sciences》2013,60(3-4):311-321
First order geodetic measurements show that strain rates in southeastern New South Wales are about 50 × 10‐8 y‐1. These strain rates are much greater than those suggested by seismicity. The direction of the principal axis of compression varies with position, but it is consistent with compression axis directions of the earthquake focal mechanisms in the Bowning area, and with the pattern of late Cainozoic vertical displacements suggested by geomorphology. In southwestern Western Australia strain identified from geodetic measurements is patchy in distribution, and is irregular in magnitude and direction. It is found close to areas of historic faulting, in areas of high measured stress, and across the Darling Fault line of weakness separating the Perth Basin from the Yilgarn Craton. 相似文献
3.
A suite of 27 oils from the Qinjiatun–Qikeshu oilfields in the Lishu Fault Depression of the Songliao Basin was analyzed using whole oil gas chromatography. In combination with the relative distribution of C27, C28, and C29 regular steranes, detailed geochemical analyses of light hydrocarbons in oil samples revealed crude oils characterized by the dual input of lower aquatic organisms and higher terrestrial plants. Several light hydrocarbon indicators suggest that the liquid hydrocarbons have maturities equivalent to vitrinite reflectances of around 0.78%–0.93%. This is consistent with the maturity determination of steranes C29 20S/(20S + 20R) and C29 ααβ/(ααα + αββ). Crude oils derived from the two distinct oilfields likely both have source rocks deposited in a lacustrine environment based on light hydrocarbon parameters and on higher molecular weight hydrocarbon parameters. The results show that light hydrocarbon data in crude oils can provide important information for understanding the geochemical characteristics of the Qinjiatun–Qikeshu oils during geologic evolution. 相似文献
4.
P -T paths from anatectic pelites 总被引：2，自引：1，他引：1
Frank S. Spear Matthew J. Kohn John T. Cheney 《Contributions to Mineralogy and Petrology》1999,134(1):17-32
A relatively simple petrogenetic grid for partial melting of pelitic rocks in the NCKFMASH system is presented based on the
assumption that the only H2O available for melting is through dehydration reactions. The grid includes both discontinuous and continuous Fe-Mg reactions;
contours of Fe/(Fe+Mg) for continuous reactions define P-T vectors along which continuous melting will occur. For biotite-bearing assemblages (garnet+biotite + sillimanite + K-feldspar + liquid
and garnet + biotite + cordierite + K-feldspar + liquid), Fe/(Fe+Mg) contours have negative slopes and melting will occur
with increasing temperature or pressure. For biotite-absent assemblages (garnet + cordierite + sillimanite + K-feldspar + liquid
or garnet + cordierite + orthopyroxene + K-feldspar + liquid) Fe/(Fe + Mg) contours have flat slopes and melting will occur
only with increasing pressure. The grid predicts that abundant matrix K-feldspar should only be observed if rocks are heated
at P < 3.8 kbar, that abundant retrograde muscovite should only be observed if rocks are cooled at P > 3.8 kbar, and that generation of late biotite + sillimanite replacing garnet, cordierite, or as selvages around leu- cosomes
should be common in rocks in which melt is not removed. There is also a predicted field for dehydration melting of staurolite
between 5 and 12 kbar. Textures in migmatites from New Hampshire, USA, suggest that prograde dehydration melting reactions
are very nearly completely reversible during cooling and crystallization in rocks in which melt is not removed. Therefore,
many reaction textures in “low grade” migmatites may represent retrograde rather than prograde reactions.
Received: 5 March 1998 / Accepted: 7 August 1998 相似文献
5.
AbstractU-Pb. systematics of detrital zircons carry a mineral-specific information summarizing important geologic events during the preelastic slate of the minerals. Comparisons with U/Pb isotope rati of zircons from potential provenances reveal relationships between source areas of the zircons and their final location of deposition in a sedimentary basin. The Palaeozoic zircon detritus accumulated in sedimentary basins on the Rhenohercynian crustal segment is taken as an example to elucidate the plate-tectonical induced changes of the source areas by significant changes of the 206Pb/238 vs. 207Pb/235ratios in the zircons.The U-Pb systematic of detrital zircon- from the Cambrian sediments deposited in the Brabant Massif and in the Ardennes indicale two source areas. Part of the detritus derived from an area. where strong Cadomian-Panafrican events influenced the U-Pb systems of the zircons. The oilier part reflects a source, in which the U-Pb systems were able to preserve their Arehaean to Early Proterozoic age information. Zircons of the latter source record the most ancient ages so far observed in detrital zircons of the later Rhenohercynian crustal seg ment. The similarities with the U/Pb isotope ratios of zircons from the Armorican Massif, the Bohemian Massif. and certain regions of the Mps indicate a geotectonic position of the sedimentar) basin during Cambrian times in the periphery of the Condwana mega-continent.The detrital zircons accumulated in the Variscan Rhenish basin during the Lower Devonian show a completely different summarizing age information. The majority of the zircons reflect a Laurussian-type origin. which suggests a palaeogeographic position of the Variscan Rhenohercynian basin close to Laurussia. Euhedral zircons crystallized during Caledonian times document the erosion of Caledonian granitoids from structural highs in the Mid European Caledonides.Zircons of the Lower Carboniferous flysch sediments of todays Eastern Rhenish Massif originate from two source areas characterised by very different geologic histories. Euhedral zircons represent a rather young component of about 410 Ma in the detritus, whereas. in contrast. the well rounded crystals show a summarizing age-information identical to that of the zircons found in the Cambrian sandstones. The low ages resemble intrusion ages as recorded from the Mid-German-Crystalline-Rise, the high age reflect a Gondwana-type input into the Rhenohercynian sedimentary basin during Lower Carboniferous times. The detritus thus documents the Variscan collision and a renewed coherence of the Rhenohercynian crustal segment to Cnndwana.The zircon population from Upper Carboniferous molasse deposits is comprised of Condwana-tуpc material and of mate rial with similar U/Pb ratios as recorded in the Lower Devonian zircons. In parts the Variscan molasse must have been derived from sediments once deposited in a southern part of the Rhenohercynian basin and in the Saxothurìngian basin. U/Pb ratios of euhedral and round diamond-like lustrous zircons indicate a major geologic event at the Namurian/Westphalian boundary (310-315 Ma). These zircons thus reflect an influx of detritus into the molasse from other source rocks, probably synsedimentary volcanics. 相似文献
6.
《《幕》》2008,31(3):344-345
In the March 2007 edition of Episodes, an article described the origins of OneGeology and progress during its first 12 months. Since March 2007, the project has moved forward dramatically and in August 2008, at the 33rd International Geological Congress in Oslo, it was launched to the world. 相似文献
7.
Muhammad MURTAZA Abdul Hadi Abd RAHMAN Joerg MUTTERLOSE Najiatun NAJLA Mazshurraiezal Bin NASIR 《《地质学报》英文版》2021,95(2):333-341
Discovery of the remains of belemnites referred to the Hibolithes sp. from the Jurassic–Cretaceous Pedawan Formation in Sarawak, on the island of Borneo(Malaysia) comprises four fragments of belemnite rostra. The specimens are characterized by multiple fractures and vein filling. Two fragments measuring about 130 mm are relatively intact, with only part of the alveolar region missing; a third piece represents the middle part of a rostrum, and the fourth specimen is too fragmentary to be assigned to any specific part of the rostrum. Based on specimen characteristics, a Tithonian–Hauterivian age is plausible. The sedimentary succession that yielded the belemnite material comprises thick shale that reflects the Te division of Bouma sequence. The occurrence of a Hibolithes taxon in the uppermost Jurassic to lowermost Cretaceous Pedawan Formation sediments in Borneo reflects a near to global palaeobiogeographic distribution of this genus. 相似文献
8.
Abstract For the first time, we apply different geospeedometric models to garnet zoning patterns that were obtained in this study from detailed EMP analyses for garnets from eclogites and granulite in the Dabie‐Sulu orogen. Various zonings of cation diffusion were preserved in the garnets, enabling the acquirement of average cooling rates for the high‐to ultrahigh‐pressure rocks without using geochronological approaches. The coesite‐bearing hot eclogites yield fast cooling rates of about 20 to 30°C/Ma subsequent to peak metamorphic temperatures, whereas the cold eclogite gives a relatively slow cooling rate of 8°C/Ma at its initial exhumation. A very slow cooling rate of <0.3°C/Ma is obtained for the granulite at Huangtuling, suggesting that the granulite may not be involved in the continental deep subduction. 相似文献
9.
Why do people not learn from flood disasters? Evidence from Vietnam’s northwestern mountains 总被引：4，自引：2，他引：2
Iven Schad Petra Schmitter Camille Saint-Macary Andreas Neef Marc Lamers La Nguyen Thomas Hilger Volker Hoffmann 《Natural Hazards》2012,62(2):221-241
This article explores how the causes and impacts of a flood event as perceived by local people shape immediate responses and future mitigation efforts in mountainous northwest Vietnam. Local flood perception is contrasted with scientific perspectives to determine whether a singular flood event will trigger adjustments in mitigation strategies in an otherwise rarely flood-affected area. We present findings from interdisciplinary research drawing on both socioeconomic and biophysical data. Evidence suggests that individual farmers?? willingness to engage in flood mitigation is curbed by the common perception that flooding is caused by the interplay of a bundle of external factors, with climatic factors and water management failures being the most prominent ones. Most farmers did not link the severity of flooding to existing land use systems, thus underlining the lack of a sense of personal responsibility among farmers for flood mitigation measures. We conclude that local governments cannot depend on there being a sufficient degree of intrinsic motivation among farmers to make them implement soil conservation techniques to mitigate future flooding. Policy makers will need to design measures to raise farmers?? awareness of the complex interplay between land use and hydrology and to enhance collective action in soil conservation by providing appropriate incentives and implementing coherent long-term strategies. 相似文献
10.
Soil layers at the Tunguska event site may have accumulated infalling extraterrestrial matter derived from the Tunguska Cosmic
Body (TCB). Using mineralogical, textural, and chemical criteria, a set of metal and silicate spherules of probably cosmic
origin was identified in the collection of spherules and rounded particles recovered from sites with high concentrations of
magnetic spherules on a terrace above the floodplain of the Chunya River. The metal spherules consist of Ni(Cr)-bearing wüstite
and magnetite with Ni-rich metal inclusions. The silicate spherules are glassy, cryptocrystalline, barred, and porphyritic
melted micrometeorites, some of which contain metal droplets. The number of spherules counted in our samples is higher than
the background level, indicating the possible presence of the TCB material. 相似文献
11.
Failure of borehole sources in weathered and fractured crystalline basement aquifers in Malawi in southern Africa has been linked with poor borehole design, mechanical failure and badly sited boreholes. However, recent work in Malawi indicates that demand may now exceed long-term resource potential in some places and that this is also a cause of water point failure. An 11-year climate cycle (including a wet and dry period) necessitates overdraft from groundwater storage during the dry-cycle years before episodic rainfall events in the wetter part of the cycle again recharge the aquifers. Data, particularly groundwater hydrograph data, are sparse, but sufficient to evaluate the long-term renewable groundwater potential for both fractured and weathered basement-aquifer types in each of the 15 management areas in Malawi. The groundwater potential or long-term renewable resource (recharge) is given by the sum of Darcian throughflow and dry-season depletion of storage. Estimated rural demand exceeds the renewable resource in the fractured-rock aquifer in two management units and in the weathered-rock aquifer in two other units. Although there is inherent uncertainty in the water-balance estimates, the likelihood that rural demand is exceeding long-term average recharge in some areas is cause for concern. 相似文献
12.
This paper reviews research on coprolites from India, providing the first evidence of microcoprolites from the early Miocene (Aquitanian) Khari Nadi Formation sedimentary succession, exposed about 1.5 km northeast of the village of Kotada, Kachchh (Kutch) District, Gujarat State, western India. Morphometric and size comparisons (in a statistical framework) with known coprolites from the Mesozoic-Cenozoic successions of India (including those recorded herein) and globally suggest that fishes were the likely producers of the Kotada coprolites. Scanning electron microscopy confirms the presence of fish dental remains within the coprolites, while both Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) reveal the phosphatic nature of the microscopic coprolite specimens (recorded herein) hinting that the producer(s) were predominantly carnivorous (ichthyophagous) in their diet. Furthermore, X-Ray Fluorescence (XRF) analysis of the host and associated lithologies allows us to deduce that the Kotada coprolites were deposited in a shallow marine environment, with possible aerial exposure of the host lithology occurring at some point after deposition. To the best of our knowledge, the present report is the first record of microscopic fish coprolites from India, as well as being the first from the Aquitanian of India and the oldest Neogene record from India. 相似文献
13.
Liying XU Nanqi REN Xingzu WANG Yongfeng JIA 《中国地球化学学报》2006,25(B08):153-153
Water pollution of river basin has increased with increasing discharge of sewage and the water quality has deteriorated due to the discharge of organic wastewater. Pretreatment of organic wastewater before discharging is of significance for the protection of water resources. The anaerobic digestion of organic substrates has been a well-developed biological treatment method for wastewater and wastes. Especially, the biohydrogen production using organic wastewater can produce an energy product and simultaneously reduce the pollution intensity of the wastes. Microorganisms with high hydrogen-producing capacity perform an important function in biohydrogen production. In this paper, we investigated the zymolytic characteristics of a novel strain of bacteria B49 isolated from anaerobic activated sludge using waste liquid from a sugarhouse as substrate. The effect of yeast extract on microbial conversion of waste liquid from the sugarhouse was investigated. Different carbohydrates （such as glucose, sucrose, trisaccharide, molasses, etc.） in the waste liquid serve as major energy sources for B49＇s cell growth. The hydrogen yield of 2410 mL-H2/L-culture was obtained using glucose as substrate. When the waste liquid from the sugarhouse （molasses） was used as substrate, maximum hydrogen yield of 2460 mL-H2/L-culture was obtained at 2% of molasses. 相似文献
14.
MO Jinyou ZHAO Zhongru WANG Wei XU Xing 《《地质学报》英文版》2007,81(4):550-554
A new hadrosaurid dinosaur,Nanningosaurus dashiensis gen.et sp.nov.,is described based on an incomplete skeleton from the Late Cretaceous red beds of the Nalong Basin,Guangxi,southern China.Diagnostic features for the new taxon include the presence of a tall and sharply peaked dorsal process of the maxilla with reduced process of the jugai and a distinct lacrimal facet,gracile humerus with low,rounded deltopectoral crest,mandibular condyle of the quadrate transversly broad with reduced paraquadrate notch,dentary tooth with sinuous median carina and subsidiary ridge,relatively few tooth positions,ischial shaft straight along most of its distance,but to curve dorsally and expand at the distal end before the ischial foot begins.Phylogenetic analysis suggests that Nanningosaurus dashiensis is a basal member of Lambeosanrinae. 相似文献
15.
Diffuse pollution from livestock production in China 总被引：2，自引：0，他引：2
王晓燕 《中国地球化学学报》2005,24(2):189-193
With economic development and living standard improvement, livestock and poultry production has grown up rapidly, also has become the leading source of pollution in vast rural areas in China.The estimated annual loss amount of COD, BOD, NH3-N from manure in 2001 is 7.28 million ton, 4.99 million ton and 1.32 million ton, respectively. The COD loss amount from manure is close to the sum of COD from industrial and domestic wastewater. Because animal waste and wastewater can enter water bodies from spills or breaks of waste storage structures ( due to accidents or excessive rain) , and non-agricultural application of manure to cropland, this contamination has resulted in quality degradation of surface and underground drinking water supplies. Areas with concentrated livestock operations are showing elevated nutrients and organic pollutant contents in surface waters. This widespread contamination of water has prompted governments at various levels to adopt regulations and measures to control the spreading of livestock pollution. 相似文献
16.
Studies of the mantle-derived iherzolites from Nushan show that in addition to CO2,there were present H2O and small amounts of CO, CH4, SO2,Cl and F in the initial mantlc fluids derived fron the asthenospheric mantlc plumc .The imitial fluids accumulated in some regions of the mantle, resulting in lowering of the mantle solidus (and liquidus) and partial melting of the upper mantle. Melts formed from low-degree of fluid-involved partial melting of the upper mantle would be highly enriched in incompatible elements.Fluies and melts are allthe metasomatic agents for mantle metasomatism, and the interaction between them and the depleted mantle could result in the substan-tial local enrichment of LREE and incompatible elements in the latter.In case that the concentration of H2O in the fluids (and melts) is lower ,only cryptic metasomatism would occur, in case that the concentration of H2O is higher,the degree of partial melting would be higher and hydrous metasomatic phases(e.g. amphiboles )would nucleate. Under such circumstances, there would occur model metasomatism. 相似文献
17.
BAO Houyin LI Zhenglin LIU Xijun SUO Mengyin ZHAO Yinqiang ZHAO Yunbiao QI Junda 《《地质学报》英文版》2019,93(Z2):7-8
Orientale size craters are not recognized on Earth nor expected for Phanerozoic and Proterozoic eons from conventional crater size frequency distributions (Ivanov et al., 2002). Here suggested are three such Phanerozoic craters, modified by plate tectonics, and tentatively correlated with extinction and “ophiolite obduction” events. Hypothesis testing is proposed and plate tectonics implications are discussed. Such basins might manifest:
- circular to elliptical rims (or rim segments), with exposed lithospheric mantle, as strain markers for plate boundary motion;
- thick ejecta near rim expressed as “ophiolitic melange”;
- power law decay of ejecta thickness with radial distance from rim (McGetchin et al., 1973) and/or systematic azimuthal variation of ejecta thickness for low angle impacts (Schultz, 1999);
- weathering resistant shocked mantle minerals (Bohor et al., 1990) in ejecta;? global spherule layer with PGE anomalies (Alvarez et al., 1980);
- rim structures consistent with cratering mechanics (Melosh, 1989; Kenkmann, 2014);
- impact melt basement (Grieve et al., 1992; Pierazzo et al. 2000) recording uniform cooling age and Earth's magnetic polarity of the time. Tentatively suggested Phanerozoic impact basins:
- Yucatan Basin: Greater Antilles ophiolite rim – KPg Boundary? Maastrichtian ophiolite obduction in southeast Cuba (Iturralde‐Vinent et al., 2006).
- Sulu Sea Basin: Palawan, Sabah etc. ophiolite rim – Middle Miocene Disruption? MM ophiolitic mélange emplacement in Sabah (Clennell, 1991).
- Loyalty Basin: New Caledonia ophiolite and d'Entrecasteaux ridge rim – EO Boundary? EO ophiolite obduction in New Caledonia (Cluzel et al., 2012).
18.
《International Geology Review》2012,54(9):1067-1077
Two occurrences of Viséan ammonoids in the Ural Mountains form the basis for this paper. In the Kzyl-Shin Gorge on the Kiya river, Aktiubinsk province, a bed of gray fragmental limestone, 1 m thick, has yielded the following genera: *Prolecanites, *Pronorites, Beyrichoceras, *Nomismoceras, *Girtyoceras, Trizonoceras, Arcanoceras, and *Goniatites. Also, east of the village of Novosamarskaya on the Sakmara river, Orenburg province, a black limestone block contains the genera marked with an asterisk (*) in the list above, together with Kazalchoceras. The Kzyl-Shin assemblage is of particular interest because it includes Beyrichoceras, generally not found with Goniatites this high in the Carboniferous section. Based on the Goniatites, assignable to the group of G. crenistria Phillips, and other components, the assemblage is dated as very late Visean. It probably is equivalent to the bottom part of the Caney Shale of Oklahoma that contains Girtyoceras meslerianum (Girty) and Goniatitesmultiliratus Gordon. The overlying part of the Caney Shale and the higher beds near the Kzyl-Shin Gorge contain Neoglyphioceras and are considered to be Namurian in age. New species described in this paper are Prolecanites kiaensis, Pronorites ultimus, Beyrichoceras tardum, Girtyoceras kazakhorum, and Arcanoceras praecox. --M. Gordon, Jr. 相似文献
19.
ZHANG Zihui HOU Lianhai HASEGAWA Yoshikasu Jingmai O＇CONNOR Larry D. MARTIN Luis M. CHIAPPE 《《地质学报》英文版》2006,80(5):631-635
1 Introduction Enantiornithines were the dominant birds nearly worldwide throughout the entire span of the Cretaceous (Chiappe, 1995; Feduccia, 1996). The adaptive radiation of opposite birds is little known besides the disparity of rostral morphology in Boluochia (Zhou, 1995), Longipteryx (Zhang et al., 2001), Longirostravis ( Hou et al., 2004), and the presence of stomach contents that reflect a diversity of diets. Like the structure of rostrum, differentiation of the locomotor apparatu… 相似文献
20.
A comparative study of rice paddies and the uncovered water field in Taoyuan(Hunan) showed that methane emission from rice-vegetated paddy fields in 1993 was different from that in 1992(I,e,lower in rates and irregular in pattern).Climate has obvious influence on methane emission .And ebullition made a considerable contribution to the total flux of methane emission from rice paddies (45%).This implies that the intensification of paddy cultivation of rice might not be,as was proposed,the main con-tributor to the observed gradual increasing of atmospheric methane.24-hour automatic measurements of atmospheric temperature,air temperature and methane concentration in the static sampling boxes revealed that temperature,in addition to fertilization and irrigation style,is one of the most important factors that control the emission of methane from rice paddies. 相似文献