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The response of the Sao Paulo Continental Shelf (SPCS) to synoptic wind forcing has been analyzed. Two different methods are
used for this purpose, one based on hydrographic data, bottom topography, and geographical characteristics, and a second on
analyzing currentmeter data directly and using empirical orthogonal functions. Both methods show similar results for an essentially
barotropic shelf. The SPCS response in the subinertial frequency band appears to be trapped on the continental shelf. Numerical
experiments have also been carried out showing results that qualitatively agree with the observations, including the velocity
component parallel to the coastline.
Supported by CAPES. 相似文献
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Ibitiara岩体出露在南美巴西中东部巴伊亚州Sao Francisco克拉通内,岩性为花岗闪长岩,属于壳幔岩浆混合作用形成的准铝质-弱过铝质钙碱性Ⅰ型花岗岩。地球化学研究表明该花岗闪长岩富集Ba等大离子亲石元素(LILE)和不相容元素U、Th等,强烈亏损高场强元素(HFSE) Nb、P、Ti等,为富硅、高钾钙碱性岩系列,稀土元素显示轻微负Eu异常,轻重稀土分馏相对明显,富集轻稀土,配分曲线呈明显右倾稀土配分模式。锆石SHRIMP U-Pb测试Ibitiara岩体形成年代为2 103±8 Ma,为古元古代层侵纪晚期-造山纪早期岩浆活动的产物。该岩体形成年龄与亚马逊构造旋回(2.1 Ga±)岩浆活动区域构造背景相呼应,可能为哥伦比亚超大陆聚合增生大西洋陆块群岩浆活动的产物。 相似文献
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《International Geology Review》2012,54(15):1864-1875
ABSTRACTIn the mines of the Nacional de Grafite Company around Itapecerica (Minas Gerais), located in the southern Sao Francisco Craton, occurs a supracrustal succession of high-grade metamorphic rocks including quartzite, garnet-biotite gneiss, and graphite schist formed in the Palaeoproterozoic (2.0 Ga). During metamorphic processes, organic matter was progressively transformed into graphite. From four graphite samples of three different mines (two samples from high-grade metamorphic graphite schist and two generated by hydrothermal recrystallization of the graphite schist), the origin and formation temperature of this mineral was obtained by C isotopes, X-ray diffraction (XRD), and Raman spectroscopy. The values of δ13C range between ?21.23 and ?27.89 ‰, indicating that the source of the graphite was a primitive biogenic carbon material. High-grade metamorphic graphites show average temperatures around 729°C, while hydrothermal recrystallizated graphites (vein-graphites) show temperatures around 611°C by XRD, which correspond to granulite- to amphibolite facies conditions. The hydrothermal process with percolation of C-O-H fluids leads to a decrease in the crystal size along stacking direction (Lc(002)) when compared with the previously formed high-grade metamorphism graphites. An update of the current tectonic model about the collisional process during Rhyacian-Orosirian orogeny in the Sao Francisco Craton is proposed to insert the formation of the Itapecerica graphite-rich metasedimentary sequence. 相似文献
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圣保罗案文的基本要点 总被引：1，自引：0，他引：1
陈迎 《气候变化研究进展》2007,3(3):177-182
2006年8月,BASIC项目的巴西课题组推出了一个后京都国际气候制度的全面设计方案,简称圣保罗案文。概括介绍了该案文的设计思路和基本要点,包括全球中长期目标、附件I和非附件I国家的不同义务、市场机制、适应问题、技术研发和转让,以及议定书的审评和遵约机制等。在此基础上,简要比较了圣保罗案文与巴西案文的不同特点,客观评价了圣保罗案文在政治阻力和技术难度上存在的内在缺陷。 相似文献
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