检索结果-南通市图书馆

Sr Isotopes and REEs Geochemistry of Anhydrites from L Vent Black Smoker Chimney, East Pacific Rise 9oN–10oN

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2015年第6期26卷 920-928页

作者： Huiqiang Yao Huaiyang Zhou Xiaotong Peng Gaowen He guangzhou marine geological survey National Key Laboratory of marine Geology Tongji University guangzhou Institute of Geochemistry Chinese Academy of Sciences

High resolution sampling, for Sr isotope and REE analyses, was carried out along a transaction of L vent chimney collected from East Pacific Rise 9oN–10oN. Sr isotopes show these anhydrites are precipitated from a mixture between hydrothermal fluid and seawater. The calculated relative proportion of seawater and hydrothermal fluid shows that the mixing is heterogeneous on the transection of the L vent chimney. Anhydrites from the chimney show uniform chondrite-normalized REE pattern with enrichment of LREE and positive Eu anomaly. While normalized to the REE of end-member hydrothermal fluid, anhydrites also show uniform REE pattern but with negative Eu anomaly and enrichment of HREE. Combining previous studies on REEs of hydrothermal fluids from different hydrothermal systems and the hydrothermal fluid data from this region, we suggested that REE-anion complexing, rather than crystallography controlling, is the main factor that controls the REE partition behavior in the anhydrite during its precipitation from the mixture of hydrothermal fluid and seawater.

关键词： East Pacific Rise 9°N-10°N black smoker chimney anhydrite Sr isotope REE.

A Study on the Engineering geological Properties of Fine-grained marine Sediments

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 1993年第5期36卷 616-629页

作者：牛作民 Laboratory of guangzhou marine geological survey Ministry of Geology and Mineral Resources Guangzhou 510760 PRC

Through studies on the engineering geological properties of fine marine sediments, this article fully verified that the sedimentary environment is an important factor which determines the engineering geological properties of fine marine sediments. Meanwhile, these properties are controlled and affected by factors such as composition, physico-chemical nature, micro-textures, etc. of fine soils.

关键词： fine marine soil sedimentary environment engineering geology.

Stratal Carbonate Content Inversion Using Seismic Data and Its Applications to the Northern South China Sea

在线全文

学校读者我要写书评

暂无评论

Journal of China University of Geosciences 2006年第4期17卷 320-325,354页

作者：熊艳钟广法李前裕吴能友李学杰马在田 State Key Laboratory of marine Geology Tongji University Shanghai 200092 China Geophysical Exploration Company of Sichuan Petroleum Administration bureau Chengdu 610212 China guangzhou marine geological survey Guangzhou 510760 China

On the basis of the relationship between the carbonate content and the stratal velocity and density, an exercise has been attempted using an artificial neural network on high-resolution seismic data for inversion of carbonate content with limited well measarements as a control. The method was applied to the slope area of the northern South China Sea near ODP Sites 1146 and 1148, and the results are satisfaetory. Before inversion calculation, a stepwise regression method was applied to obtain six properties related most closely to the carbonate content variations among the various properties on the seismic profiles across or near the wells. These include the average frequency, the integrated absolute amplitude, the dominant frequency, the reflection time, the derivative instantaneous amplitude, and the instantaneous frequency. The results, with carbonate content errors of mostly ±5 % relative to those measured from sediment samples, show a relatively accurate picture of carbonate distribution along the slope profile. This method pioneers a new quantitative model to acquire carbonate content variations directly from high-resolution seismic data. It will provide a new approach toward obtaining substitutive high-resolution sediment data for earth system studies related to basin evolution, especially in discussing the coupling between regional sedimentation and climate change.

关键词： carbonate content inversion seismic data artificial neural network ODP Leg 184 northern South China Sea.

Glacial atmospheric CO_(2) decline in association with decrease of marine sedimentary phosphorus

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2006年第3期49卷 322-330页

作者： WENG Huanxin1, ZHANG Xingmao1, WU Nengyou2, WANG Ying1, CHEN Lihong1, ZHONG Hexian2 & QIN Yachao1 1. Institute of Environment & Biogeochemistry, Zhejiang University, Hangzhou 310027, China 2. guangzhou marine geological survey, CGS, MLR, guangzhou 510760, China Institute of Environment & Biogeochemistry Zhejiang University Hangzhou China guangzhou marine geological survey CGS MLR Guangzhou China

The environmental and biogeochemical information extracted from the sediments col- lected from the northern shelf of the South China Sea shows that terrigenous inputs of phosphorus into the sea remained relatively constant, and the variation of phosphorus contents at different depths was caused by climatic and environmental changes. The findings also suggest that the vertical varia- tion of phosphorus content was opposite to those of calcium carbonate and cadmium, and the func- tional correlation between CO2 and PO43? in seawater was given by calculating the chemical equilib- rium, indicating that the accumulation of marine sedimentary phosphorus may have something to do with the variation of atmospheric CO2. The decreased phosphorus accumulation as well as the cor- respondingly-increased calcium carbonate content might be one of key factors causing glacial at- mospheric CO2 decline.

关键词： sedimentary phosphorus, calcium carbonate, atmospheric CO2, northern shelf of the South China Sea, biogeochemistry.

geological Evidence for the Presence of the Emperor Event in China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1993年第2期67卷 235-244页

作者： Ge Tongming, Fan Limin and Liu Jian guangzhou marine geological survey, Ministry of Geology and Mineral Resources of China, guangzhou guangzhou marine geological survey Ministry of Geology and Mineral Resources of China Guangzhou

The presence of the reversals of the geomagnetic field within the Brunhes is indicated by paleomagnetic stuides on Cenozoic volcanic rocks in the Leizhou Peninsula, loess strata and Quaternary marine sediments in the Pearl River Mouth basin in China. These regional reversals occured at 0.58±0.13 Ma, 0.45 Ma and 0.47—0.48 Ma respectively according to the results of K-Ar isotopic dating and climatostratigraphic and biostratigraphic analyses. The reversals equivalent to the Emperor Event is suggested.The reversals revealed in different regions with various lithologic characters in China prove that the Emperor Event is a global reversal event rather than a geomagnetic excursion, and its confirmation will permit a precise definition of the Middle/Late Pleistocene boundary.

关键词： Brunhes polarity reversal Emperor Event

Weathered and Volcanic Provenance-Sedimentary System and Its Influence on Reservoir Quality in the East of the Eastern Depression, the North Yellow Sea Basin

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2018年第2期29卷 353-368页

作者： Dan Gao Rihui Cheng Yanjie Shen Liaoliang Wang Xiaoqiang Hu College of Earth Sciences Jilin University Changchun 130061 China guangzhou marine geological survey Guangzhou 510075 China

Seismic stratigraphy, core logging and the data from cores are used to identify the development and evolution of the east provenance-sedimentary system and to analyze its influence on the quality of reservoirs in the eastern depression of the North Yellow Sea Basin. The eastern provenance-sedimentary system is a fan delta （delta） and subaqueous fan sedimentary system with volcanic provenance. Its evolution is closely related to internal uplift and coeval volcanic activity. During faulting and volcanic activity, an internal uplift gradually formed and the eastern provenance-sedimentary system began to develop. Clastic materials from the weathered uplift and volcanic activity were the main sources of sediment and were deposited in the Middle Jurassic to the Early Cretaceous. A subaqueous fan sedimentary system developed in the Middle Jurassic, a deltaic to subaqueous fan sedimentary system developed in the Late Jurassic, and a fan delta to subaqueous fan sedimentary system developed in the Early Cretaceous. The volcaniclastic detritus was mainly composed of acidic materials with a small amount of intermediate materials. The reservoir in the eastern sedimentary system is a type of tight sandstone with ultra-low porosity and very low permeability due to the influence of volcanism and diagenesis. The reservoir quality is worse than those of the northern and the western sedimentary systems. However, the high volume of volcanic materials and deep-marine sedimentary conditions resulted in good-quality hydrocarbon source rocks that ensures the exploration potential in the eastern sedimentary system reservoir.

关键词： the eastern depression of the North Yellow Sea Basin provenance-sedimentary system volcanism reservoir.

Deep origin of Cenozoic volcanoes in Northeast China revealed by 3-D electrical structure

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2020年第4期63卷 533-547页

作者： Shiwen LI Aihua WENG Jianping LI Xuanlong SHAN Jiangtao HAN Yu TANG Yanhui ZHANG Xueqiu WANG College of Geo-exploration Sciences&Technology Jilin UniversityChangchun 130026China guangzhou marine geological survey China Geological SurveyGuangzhou 510760China College of Earth Sciences Jilin UniversityChangchun 130026China

The three-dimensional(3-D)electrical structure of the upper-mantle was used to examine the deep origins of and relationship among the Cenozoic volcanoes located in Northeast China(NEC).High-quality,long-period magnetotelluric(LMT)full-impedance tensor data were collected in NEC and subjected to 3-D Gauss-Newton inversion in order to construct a resistivity *** resulting model reveals the presence of multiple localized low-resistivity anomalies(LRAs)within the high resistivity lithosphere beneath *** LRAs partially coincide with Cenozoic volcanoes on the *** LRAs that form a larger,annular LRA were observed in the deep upper mantle beneath the Songliao Basin,whereas vein-like LRAs were found in the asthenosphere that connect the lithosphere and deep upper *** analyses suggest that the LRAs may have been caused by fluid-induced *** on our electrical model,we propose that,following dehydration of the subducted Western Pacific slab into the mantle transition zone(MTZ)beneath NEC,the released water migrated upward and caused partial melting at the top of the MTZ beneath the Songliao *** the effect of buoyancy,the melted mantle formed a thermal upwelling that caused melting of asthenosphere before diapiring at the base of the dry *** magma then penetrated structural boundaries(such as thinner,weaker,or activated suture zones)and finally reached the Earth's *** melting and upwelling of hot mantle materials may have resulted in large-scale volcanism in the region throughout the Cenozoic,including the eruption of Changbai Mountain and Halaha *** results suggest that the Cenozoic NEC volcanoes may all share a similar mode of genesis,and probably originated from the annular LRA in the deep upper mantle.

关键词： Northeast China Cenozoic volcanoes Three-dimensional magnetotelluric inversion Partial melting Upper mantle

Geochemical Characteristics and Gas-to-Gas Correlation of Two Leakage-type Gas Hydrate Accumulations in the Western Qiongdongnan Basin, South China Sea

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2022年第2期96卷 680-690页

作者： LAI Hongfei QIU Haijun LIANG Jinqiang KUANG Zenggui FANG Yunxin REN Jinfeng LU Jing’an Southern marine Science and Engineering Guangdong Laboratory(guangzhou) Guangzhou 511458China MNR Key Laboratory of marine Mineral Resources Guangzhou Marine Geological SurveyMinistry of Natural ResourcesGuangzhou 510075China

In recent years,a series of highly saturated leakage-type gas hydrates have been discovered in the western Qiongdongnan Basin(QDNB),South China *** on the molecular compositional and isotopic characteristics of the gas samples relevant to the gas hydrates collected from the two leakage-type gas hydrate accumulations in the GMGS5 and GMGS6 drilling zones,a detailed geochemical gas-to-gas correlation was conducted in this study,in order to further understand the geochemical characteristics and possible hydrocarbon sources of these gas *** natural gas relevant to the gas hydrates in the GMGS5 block is characterized by wet gas(67.96%0.9)and lack molecular and carbon isotope *** 40%‒60%of the methane within the gas hydrate is of microbial origin,while the C^(2+)gas components are typical coal-type gas that are derived from thermogenic source rocks or deeply-buried natural gas *** addition,typical in situ primary microbial methane(−80.6‰<δ^(13)C-C_(1)<−67.7‰)was discovered in well W b,which was applied to estimate the contribution of the microbial gas to the gas *** gas-to-gas correlation results show that the hydrate gases within the two leakage-type gas hydrate accumulations in the GMGS5 and GMGS6 blocks are geochemically different,suggesting that they may have been derived from different source *** results further indicate that the deeply-buried thermogenic gas significantly contributed to the shallowly-buried gas hydrates in the western QDNB and multiple effective thermogenic source kitchens provided the hydrocarbon gas in the gas hydrate accumulations.

关键词： gas hydrate gas genetic type hydrocarbon gas source geochemical characteristics

Sedimentary Features and Sea-Level Changes Reflected in Drill Holes in the Zhuhai Area

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1999年第2期73卷 216-224页

作者： CHEN Junren WAN Ling guangzhou marine geological survey MGMR P. O. Box 950 Guangzhou 510075

Abstract Experimental examinations and analyses have been made of the sediments from drill holes in the Zhuhai area, Guangdong Province. The studies show that there occurred four transgressions in this area over the historical times. The first transgression occurred at 7500 a B.P., with the maxium sea level up to about 1 m above the present level. The second transgression occurred at 5750 a B.P., with the sea level possibly 4 m higher than the present. The third and fourth transgressions took place at 4650 a B.P. and 2600 a B.P. respectively, which lasted for a long time with multiple fluctuations. The fifth transgression is in process. It could be predicted that the sea level at Zhuhai would rise by 15–20 cm in the coming 50 years.

关键词： sedimentary features sea-level changes Zhuhai