Remote and in situ plume measurements of acid gas release from La Soufrière volcano, Guadeloupe     

Marie-Lise Bernard  Jack Molini  Rose-Helen Petit  Franois Beauducel  Gilbert Hammouya  Guy Marion 《Journal of Volcanology and Geothermal Research》2006,150(4):395-409

This paper presents the first remote measurements of La Soufrière gas emissions since the fumarolic and seismic reactivation in 1992. The chemical composition of the plumes has been measured from May 2003 to September 2004 using an Open Path Fourier Transform InfraRed (OP-FTIR) spectrometer, up to 15 m downwind the South Crater. HCl is clearly detected (concentration between 2.4 and 12 ppmv) whereas SO₂ and H₂S generally remain below the detection limit of the OP-FTIR. Direct measurements of SO₂ and H₂S near the South Crater with a Lancom III analyzer show a fast decrease of their concentrations with the distance. Calculated Cl / S mass ratios are high: from 9.4 ± 1.7 at 15 m from the vent to 2.8 ± 0.6 at 140 m. The enrichment in HCl of the gas emitted at La Soufrière, observed since 1998, corresponds to the degassing of a magma enriched in Cl and depleted in S. This result agrees with isotopic measurements which suggest a magmatic origin of the gases. Readjustments inside the volcanic system may have taken place during the seismic activity beginning in 1992 and enhance the transfer of magmatic gases to the summit.  相似文献   

杉松岗钴(铜镍)矿床地质特征及找矿远景     

刘文香  王坤 《吉林地质》2006,25(3):24-28

杉松岗钴(铜镍)矿床产于古元古代裂谷海槽褶皱地带,是国内新近发现的新类型矿床.它赋存于老岭群富硼、碳粘土岩夹硅质岩建造之中.通过对矿床的地质、地球化学特征研究,初步认为该矿床受后期变质热波的强烈叠加作用,形成沉积变质热液叠加改造型矿床.同时阐述了该矿床地质特征及找矿远景.  相似文献   

INFLUENCE OF TIBETAN PLATEAU ON AIR-SEA INTERACTION OVER TROPICAL PACIFIC IN OCEAN-ATMOSPHERIC COUPLED SYSTEM^*          下载免费PDF全文

Wu Aiming  Ni Yunqi 《Acta Meteorologica Sinica》1998,12(3):257-274

A hybrid coupled ocean-atmosphere model is designed,which consists of a global atmospheric general circulation model(L9R15 AGCM)and a simple ocean model(ZC ocean model over tropical Pacific).Using the model,experimental predictions are performed for the 1986/87 El Nino event and the 1988/89 La Nina event with and without the Tibetan Plateau respectively(called TP FORC and NTP FORC hereinafter).It is found as follows:(1)The coupled system can successfully predict the El Nino or La Nina event even if the Tibetan Plateau orography is not included in the model.The patterns of SSTA and wind anomalies in the model without the Tibetan Plateau are similar to those with the Tibetan Plateau,which further verifies the fact that ENSO process is mainly caused by the air-sea interaction in tropical Pacific.(2)However.the existence of the Tibetan Plateau exerts its influences on the intensity and duration of El Nino(or La Nina).It is unfavorable to the development and maintenance of westerly anomalies,so to some extent,restrains the development of El Nino,but favors the development of La Nina.(3)Effects of the Tibetan Plateau orography on the wind anomalies in the coupled system are different from those inuncoupled AGCM simulation.  相似文献   

电镀镍锰胎体金刚石钻头的应用   总被引：6，自引：1，他引：5       下载免费PDF全文

李超群 《探矿工程》1998,(2):36-38

对电镀镍锰胎体金刚石钻头和镍钴胎体钻头的使用情况进行了对比。实践证明,镍锰胎体钻头特别适用于钻进坚硬破碎、强研磨性地层和软硬交替的地层。  相似文献   

金川铜、镍(含PGE)岩浆硫化物矿床母岩浆成分的估计   总被引：2，自引：1，他引：1  

徐章华  汤中立 《现代地质》1998,12(4):506-514

利用金川侵入体的岩石化学和铂族元素资料,根据Ｒｏｅｄｅｒ和Ｅｍｓｌｉｅ的橄榄石液相平衡原理,估计金川超镁铁质岩的母岩浆为大约含１０８％ＭｇＯ的高镁玄武岩浆;将其与不同构造背景下形成的玄武岩岩石化学成分进行对比,认为金川侵入体的母岩浆的化学成分与巴西北部Ｍａｒａｎｈａｏ低Ｔｉ玄武岩浆的化学成分相似,代表了一种大陆裂谷背景下火山活动的产物。  相似文献   

小南山铜镍矿区及外围地质地球物理特征及其找矿方法试验研究   总被引：3，自引：0，他引：3  

陈旺 《矿产与地质》1997,11(5):347-352

小南山铜镍矿区的地面磁法（△Ｔ）、可控源音频大地电磁法（ＣＳＡＭＴ）、瞬变电磁法（ＴＥＭ）、激发极化法（ＩＰ）和原生晕方法的试验研究，表明航磁及地面磁法对基性、超基性岩体的中弱磁性有较好的反映，能圈定其形态、产状；ＣＳＡＭＴ法对基性、超基性岩体的低阻和矿化体及矿体的特低阻能进行电性分层，同时也能反映断裂构造带、蚀变矿化带的异常特征；ＴＥＭ法对硫化物铜镍矿化体有敏感的导电反映；ＩＰ法能有效地圈定矿化蚀变带或矿化体形态；Ｃｕ、Ｎｉ、Ｃｏ、Ａｓ、Ａｇ元素原生晕异常有直接指示找矿的良好效果。该区应用这些方法相互配合，综合找矿是行之有效的找矿手段。  相似文献   

厄尔尼诺现象对北半球大气环流和中国降水的影响   总被引：48，自引：7，他引：48  

赵振国 《大气科学》1996,20(4):422-428

本文主要讨论了厄尔尼诺现象对北半球大气环流和中国季风降水的影响。研究表明，在厄尔尼诺开始年的春夏季，对流层上部位势高度和副热带高压都处在由弱到强的转变状态，我国东部地区大范围少雨；秋季发生明显的趋势转折，秋季到次年夏季，对流层上部位势高度升高，副高增强西伸，除次年2、3月份全国大范围少雨外，其余月份大都为南多北少的分布型，这种分布形态在开始年秋季最典型。厄尔尼诺开始年、次年，长江中下游入梅期偏晚。  相似文献   

A STUDY OF CLIMATOLOGICAL ASPECTS OF FLOW FIELD AND HEAT EXCHANGE ON TROPICAL PACIFIC SURFACE IN THE EL NINO AND LA NINA EVENTS          下载免费PDF全文

Ma Kaiyu  Pan Yinong  Jiang Dayong 《Acta Meteorologica Sinica》1996,10(1):31-40

In this paper, based on the 2°× 2° grid data COADS from 1950—1987 the flow field and heatexchange anomalies on the tropical (11°S—11°N, 120°E—80°W) Pacific surface (TPS) are studiedin El Nino and La Nina events. During E1 Nino, the zonal pressure gradient and the trade windsdecrease on the TPS, the tropical convergence strengthens on the TPS, especially on the centralTPS, the sensible and latent heat exchanges increase, the net longwave radiation and incident solarradiation decrease and the net gain (loss) of heat reduces (increases) on the central and easternTPS. During La Nina the results turn out the contrary. Finally, two feedback mechanisms whichinclude the dynamic, thermal and hydrological processes during E1 Nino and La Nina are summa-rized and a conceptive model for El Nino-La Nina cycle is given.  相似文献   

大气环流模式对ENSO时间尺度风应力距平的模拟     

吴秋霞  倪允琪 《热带气象学报》1997,13(3):227-236

通过与观测作比较。评估低分辨率的大气环流模式模拟的风场，模式风场是使用观测海温场外强迫，从１９７９年到１９８８年共积分十年得到的，模式输出为月平均值。结果表明，模式能够相当真实地模拟出风距平场的演变，用风应力距平强迫简单模式，积分十年（１９７９－１９８８），得到的海温距平场（月平均值）和观测海温距平场作比较，模式结果较真实地模拟了１９８２－１９８３年及１９８６／１９８７年暖事件的赤道地区海温距平场  相似文献   

Porphyrin geochemistry of Atlantic Jurassic-Cretaceous black shales     

Earl W. Baker  J. William Louda   《Organic Geochemistry》1986,10(4-6)

Late Jurassic-early Cretaceous black shales and an overlying sequence of Albian-Campanian zeolitic claystones from the Falkland Plateau (DSDP/IPOD Leg 71, Site 511) were analyzed for tetrapyrrole pigment type and abundance. The “black shale” sequence was found to be rich in DPEP-series dominated free-base, nickel (Ni) and, to a lesser extent, vanadyl (V = 0) porphyrins. A low level of organic maturity (i.e. precatagenesis) is indicated for these strata as nickel chelation by free-base porphyrins is only 50–75% complete, proceeding down-hole to 627 meters sub-bottom. Electronic and mass spectral data reveal that the proposed benzo-DPEP (BD) and tetrahydrobenzo-DPEP (THBD) series are present in the free-base and Ni species, as well as the more usual occurrence in V = 0 porphyrin arrays. Highly reducing conditions are suggested by an abundance of the PAH perylene, substantial amounts of the THBD/BD series and a redox equilibrium between free-base DPEP and 7,8-dihydro-DPEP series, which exist in a 7:1 molar ratio. The Albian-Campanian claystone strata were found to be tetrapyrrolepoor, and those pigments present were typed as Cu/Ni highly dealkylated (C₂₆ max.) etioporphyrins, thought to be derived via redeposition and oxidation of terrestrial organic matter (OM). Results from the present study are correlated to our past analyses of Jurassic-Cretaceous sediments from Atlantic margins in an effort to relate tetrapyrrole quality and quantity to basin evolution and OM sources in the proto-Atlantic.  相似文献