广义索末菲积分的离散复镜像算法

本文对多分层媒质并矢格林函数中的索末菲积分,用Prony方法对其被积函数分式部分用指数函数逼近.利用索末菲恒等式,无穷积分就可化为闭合的级数形式.该闭合形式可看作一串离散镜像在观察点的解.所得结果与数值积分结果吻合很好.     

2.0 Ga orogenic graphite deposits and associated 13C-enriched meta-carbonate rocks from South China Craton: Implications for global Lomagundi event

The Lomagundi (-Jatuli) event, characterized by extremely high positive global inorganic carbon isotope excursion at about 2.2 billion years ago, is pivotal in investigating the causes and consequences of great oxygenation event, inventory and sequestration of carbon on the Earth’s surface, evolution of life, and more profoundly tectonic control on Earth’s environment. However, the reasons that caused the isotopic excursion are not resolved yet. Herein, we report the discovery of meta-carbonate rocks with distinct positive carbon isotopic excursion from the Paleoproterozoic continental collision zone of the Kongling Complex, South China Craton. The δ¹³C_V-PDB values for meta-carbonate rocks show positive values in the range from +5.5‰ to +11.6‰, whereas the δ¹³C_V-PDB values of associated graphite deposits range from ?25.8‰ to ?9.5‰. Zircon U-Pb-Hf isotopes from zircon-bearing meta-carbonate sample yielded weighted average ²⁰⁷Pb/²⁰⁶Pb age of 2001.3 ± 9.5 Ma, with corresponding ε_Hf(t) range from ?7.05 to ?3.16, comparable to the values of local 2.9–2.6 Ga basement rocks. Geochemical characteristics of meta-carbonate rocks, such as their rare earth element patterns and the trace element parameters of La, Ce, Eu, and Gd anomalies and Y/Ho ratio, suggest that the carbonate deposition took place in passive continental margin in association with large volumes of organic carbon. The extensive graphite deposits from Kongling Complex in South China Craton, their equivalents in the North China Craton and elsewhere across the globe prove that the burial of ¹²C-enriched organic carbon has eventually resulted in the global enrichment of ¹³C in the atmospheric CO₂, which is recorded in the marine carbonate rocks. Isotopic mass balance estimates indicate that more than half of the organic carbon was buried during the oceanic closure. Hence, the observed global shift could be directly related to the continent collision event in greater China, thus resolving the long-standing paradox of the Lomagundi global positive carbon isotope excursion. Moreover, the present results suggest that orogenesis play a significant role in sequestration of carbon into the continental crust.     

Deformation and possible origins of the Cooma Complex,southeastern Lachlan Fold Belt,New South Wales

The western half of the Cooma Complex, New South Wales, consists of three thrust‐bound blocks that contain the same structural fabrics, but with different orientations and intensities, owing largely to heterogeneous strain late in the deformation history. Correlation of these fabrics with those found regionally outside the complex shows that a well‐developed, gently dipping crenulation cleavage (S₄) apparently has no regional counterpart. This cleavage may have formed by vertical shortening that was restricted to the complex and its development may have been assisted by the higher temperatures there. The Cooma Complex is one of five metamorphic complexes in what is known as the Eastern Metamorphic Belt, which stretches several hundred kilometres through the southeastern Lachlan Fold Belt. The complexes may have formed as local hot spots, possibly related to underplating of mafic magma or intrusion of hot tonalites at or near the base of the Ordovician metasediments (or both). Whether or not these complexes are exhumed portions of an extensive layer in the mid‐crust of the fold belt can be tested by evaluating Late Ordovician/Early Silurian thermal gradients in the ubiquitous Ordovician metasediments.     

Eoarchean–Paleoproterozoic zircon inheritance in Japanese Permo-Triassic granites (Unazuki area,Hida Metamorphic Complex): Unearthing more old crust and identifying source terrranes

U–Pb zircon geochronology of two Permo-Triassic granites (samples OT-52 and OT-272 with ages of 229 ± 8 Ma and 256 ± 2 Ma, respectively) in the Unazuki area, Hida Metamorphic Belt, southwest Japan, revealed the presence of Eoarchean to Paleoproterozoic inheritance. Inheritance is consistent with both samples showing low zircon saturation temperatures for their bulk compositions. In OT-52, dark in CL, low Th/U zircon domains have a mean ²⁰⁷Pb/²⁰⁶Pb age of 1940 ± 17 Ma, which is consistent with an age of 1937 ± 6 Ma for anatexis in the Precambrian Busan gneiss complex in Korea. Eoarchaean inherited zircons with ²⁰⁷Pb/²⁰⁶Pb ages from ca. 3750 to 3550 Ma are common in OT-272 but are few in OT-52, suggesting a source from rocks with affinities to those in the Anshan area in the northeast China part of the North China Craton. On the other hand, a Hida Metamorphic Belt metasedimentary gneiss into which the granites were intruded contains ca. 1840, 1130, 580, 360, 285 and 250 Ma zircons (Sano et al., 2000). These ages suggest that the Unazuki Mesozoic granites did not originate from proximal Hida Metamorphic Complex rocks, but instead from unrelated rocks obscured at depth. The predominance of Eoarchean to Paleoproterozoic age components, and the marked lack of 900–700 Ma components suggest that the source was the (extended?) fringe of the North China Craton, rather than from Yangtze Craton crust. The Mesozoic evolution of Japan and its linkages to northeast Asia are discussed in the context of these results.     

PRINCIPAL COMPONENT ANALYSIS APPLIED TO THE STUDY OF SUCCESSIVE COMPLEX FORMATION DATA IN CU(II)-ETHANOLAMINE SYSTEMS

Application of principal component analysis to Cu(II)-ethanolamine complex formation data is shown.Determination of the number of complex species is obtained from the rank of the matrix of spectral datausing either Gauss elimination or factorial analysis.Relevant information concerning species distributionversus pH is obtained from the plot of the signficant factors upsurging from the evolution of spectraltitration data.     

地表冻融过程被动微波遥感机理研究进展

地表冻融过程及参数特征是陆表过程、气候模式、全球变化等研究的重要方面。被动微波遥感由于具有对土壤水分敏感、高时间分辨率等特点,非常适合用于地表冻融过程的监测和相关参数的反演。在分析地表冻融过程被动微波遥感机理研究发展现状的基础上,面向全球范围内大尺度陆表冻融过程微波遥感算法发展的需求,针对由土壤、积雪和植被组合的复杂地...     

Fluid-induced high-temperature metasomatism at Rundv?gshetta in the Lützow-Holm Complex,East Antarctica: Implications for the role of brine during granulite formation

We report new petrological, phase equilibria modeling, and fluid inclusion data for pelitic and mafic granulites from Rundv?gshetta in the highest-grade region of the Neoproterozoic Lützow-Holm Complex(LHC),East Antarctica, and provide unequivocal evidence for fluid-rock interaction and high-temperature metasomatism in the presence of brine fluid. The studied locality is composed dominantly of well-foliated pelitic granulite(K-feldspar+quartz+sillimanite+garnet+ilmenite) with foliation-parallel bands and/or layers of mafic granulite(plagioclase+orthopyroxene+garnet+ilmenite+quartz+biotite). The boundary between the two lithologies is defined by thin(about 1 -20 cm in thick) garnet-rich layers with a common mineral assemblage of garnet+plagioclase+quartz+ilmenite+biotite ? orthopyroxene. Systematic increase of grossular and decrease of pyrope contents in garnet as well as decreasing Mg/(Fe+Mg) ratio of biotite from the pelitic granulite to garnet-rich rock and mafic granulite suggest that the garnet-rich layer was formed by metasomatic interaction between the two granulite lithologies. Phase equilibria modeling in the system NCKFMASHTO demonstrates that the metasomatism took place at 850 -860℃, which is slightly lower than the peak metamorphism of this region, and the modal abundance of garnet is the highest along the metapeliteemetabasite boundary(up to 40%), which is consistent with the field and thin section observations. The occurrence of brine(7.0 -10.9 wt.% Na Cleqfor ice melting or 25.1 -25.5 wt.% NaC leqfor hydrohalite melting) fluid inclusions as a primary phase trapped within plagioclase in the garnet-rich layer and the occurrence of Cl-rich biotite(Cl = 0.22 -0.60 wt.%) in the metasomatic rock compared to that in pelitic(0.15 -0.24 wt.%) and mafic(0.06-0.13 wt.%) granulites suggest infiltration of brine fluid could have given rise to the high-temperature metasomatism. The fluid might have been derived from external sources possibly related to the formation of major suture zones formed during the Gondwana amalgamation.     

An outline of the petrology, structure and age of the Pompangeo Schist Complex of central Sulawesi, Indonesia

Variably dismembered and metamorphosed accretionary complexes constitute the basement of much of the Indonesian island of Sulawesi. The most extensive of these is the Pompangeo Schist Complex, which crops out over ∼ 5000 km² in central Sulawesi, and is predominantly composed of interbanded phyllitic marble, calcareous phyllite, graphitic schist and quartzite; rocks of terrigenous to shallow marine origin. Along the eastern margin of the complex, schists are interthrust with unmetamorphosed Jurassic sandstone, which may represent parental material of the complex. The schists are unconformably overlain by pelagic sediments with an Albian–Cenomanian biostratigraphy. Synmetamorphic progressive deformation of the Pompangeo Schist Complex has resulted in repeated isoclinal folding and a strong transposition foliation striking north-northwest/south-southeast and dipping west, subparallel to the compositional banding of the complex; microstructural fabrics indicate a top-to-east sense of shear. On a regional scale the Pompangeo Schist Complex is lithostratigraphically coherent and an east-to-west metamorphic field gradient is recognizable, which, if continuous, represents a relatively low thermal gradient of ∼ 15 °C/km. K–Ar dating yielded ages of ca 111 Ma. Correlative metamorphic rocks appear to underlie the entire Neogene magmatic province, since they occur sporadically throughout western Sulawesi, including the Bantimala region of the South Arm. The Pompangeo schist metamorphism cannot be correlated with arc magmatism in western Sulawesi, which is of Neogene age. The Pompangeo and Bantimala schists, as well as other accretionary complexes in western Sulawesi, were probably generated in the same subduction system that was responsible for the extensive Mesozoic continental arc in central Kalimantan, at the eastern margin of Sundaland.     

基于WebGIS Geocoding搜索与Lambert变换的研究与实现

针对项目平台系统开发中遇到的批量POI（PointofInterest）数据与平台地图进行匹配的问题进行分析与研究．通过地理编码对经纬度进行搜索,并建立经纬度与Lambert投影变换的数据模型。运用C#语言进行实现验证,并完成批处理经纬度搜索与投影变换的功能。最终将覆盖全国范围内所有POI坐标数据与平台地图成功匹配,满足了项目的需求,也使平台开发的功能得以进一步加强,为平台支持多分辨率、多尺度、多投影的全球空间数据提供了技术积累。     

桐柏秦岭岩群的两类变质作用

本文重点对河南桐柏地区的秦岭岩群进行了观察与研究,根据野外地质、岩相关系及同位素测年资料,提出该区秦岭岩群具有明显不同的两类变质作用,一是较早期的高温麻粒岩相变质作用,以包体或长透镜群、甚至巨型条块状局限于中部郭庄组的花岗质片麻岩之中。根据伟晶岩、片麻岩及麻粒岩锆石年龄的综合限定,该变质作用的时间可能为~498Ma,多数人主张的445~430Ma的麻粒岩相变质年龄实际上是早期锆石被后期岩浆或变质事件引起的同位素体系重启年龄。另一种是相对晚期的角闪岩相变质作用,变质程度以角闪岩相为主,局部达高角闪岩相,没有任何早期高温或高压变质的残留迹象,形成秦岭岩群中主导类型的变质作用。同样,采用伟晶岩及有关片麻岩和麻粒岩中锆石测年限定,角闪岩相变质时间可能为~472Ma。高温麻粒岩的产出具有其特殊机制,大量的花岗质岩浆侵位过程中把地壳深部的高温麻粒岩裹挟上升至浅部层次,随后一起遭受区域上的角闪岩相变质作用。