经济全球化与国家能源安全

经济全球化进程的加快对国家经济安全提出了挑战。其中能源安全问题引起我国的关注。伴随着我国经济的快速增长和人民生活水平的提高，我国对能源的依赖程度不断提高。加强能源安全已成为21世纪中国经济社会可持续发展的重要问题之一。     

沃尔什变换在测井曲线分层中的应用研究

在岩性复杂的变质岩地区实施的大陆科学钻探，是通过采集井下不同深度岩石物理化学性质和物理场的各种数据，研究地壳特征及演化过程的各种科学问题。利用测井资料达到岩性剖面的重建是大陆科学钻探的重要目的之一。章利用沃尔什变换对钻孔岩性剖面进行分层，大重建的岩性剖面结果可以看出，该方法对于变质岩地区不同岩性的划分还是比较有效的。     

巴东长江公路大桥桥位边坡稳定可靠性研究

以巴东长江公路大桥桥位边坡为例，在前人稳定性评价的基础上，建立了基于剩余推力法和Sarma法的边坡稳定可靠性分析模型，分析表明边坡系统可靠性指标(β，Pf)能更准确地表达边坡稳定性、安全性和工程风险水平。     

新疆伊宁盆地活动断裂新活动特征研究

新疆伊宁盆地主要分布有巩留南、喀什河、雅马特等6条活动断裂，断裂走向近东西向与北酉一北北西向。其中巩留南断裂、喀什河断裂、雅马特断裂等在晚更新世一全新世时期有过多次显著的新活动，切错了晚更新世一全新世堆积物。在喀什河断裂上1812年发生了8级大展，形成长约100km的地震形变带。在巩留南断裂、雅马特断裂、伊宁断裂上也有受控于断裂近代新活动的中等地震发生。     

Investigation of spatially distributed braided river flows using a two‐dimensional hydraulic model

This paper reports the application of a two‐dimensional hydraulic model to a braided reach of the Avoca River, New Zealand. Field measurements of water surface elevation, depth and velocity obtained at low flow were used to validate the model and to optimize the parameterization of bed friction. The main systematic trends in the measured flow variables are reproduced by the model. However, field data are characterized by greater spatial variability than model output reflecting differences in the scale of processes measured in the field and represented by the model. Additional model runs were conducted to simulate flow patterns within the study reach at five higher discharges. The purpose of these simulations was to evaluate the potential for using two‐dimensional hydraulic models to quantify the reach‐scale hydraulic characteristics of braided rivers and their dependence on discharge. Changes in flow depth and velocity with increasing discharge exhibit trends that are consistent with the results of previous field investigations, although the tendency for the wetted area of the braidplain within particular depth and velocity categories to remain fixed as discharge rises, as has been noted for several braided rivers in New Zealand, was not observed. Modelled shear stress frequency distributions fit gamma functions that incorporate a distribution shape parameter, the value of which follows clear systematic trends with rising discharge. These results illustrate both the problems of, and potential for, using two‐dimensional hydraulic models in braided river applications. This leads to something of a paradox in that while such models provide a means of generating hydraulic information that would be difficult to obtain in the field at an equivalent spatial resolution, they are, due to the problems inherent to data collection, difficult to validate conclusively. Despite this limitation, the application of spatially distributed models to investigate relationships between discharge and reach‐scale form and process variables appears to have considerable potential. Copyright © 2003 John Wiley & Sons, Ltd.     

新产业区的形成机制及其与传统空间组织理论的关系

在新产业区概念和特征进行概括的基础上,归纳了产业区发展的一般过程,并重点对新产业区的形成机制及所具有的优势进行了探讨。地方化产业群及区域创新网络的形成是新产业区成熟的标志,知识外溢、经济外部性导致的收益递增,以及基于密切的内部联系引来交易成本的降低使新产业区获得了强大的经济竞争优势,新产业区的空间组织形式所具有的网络效应、创新效应和企业与地方文化的良好融合是经济竞争优势的根本。最后,对新产业区理论和传统的空间组织理论之间的关系进行了对比分析,总结了二者的之间的异同。     

Wrench tectonics flip at oblique subduction. A model from New Zealand

In eastern North Island New Zealand, oblique subduction of the Pacific Plate beneath the Australian Plate is associated with strain partitioning. Dextral along-strike component of displacement occurred first at Early Miocene major faults within the eastern fore-arc domain. These faults were active from Early Miocene to Pliocene times. Since Pliocene times, most of the movement occurs at western faults such as the Wellington Fault. The latter joins the back-arc domain to the north. The jump of wrench faulting is related to the oblique opening of the back-arc domain. Both phenomena are impeded southwards by the Hikurangi oceanic plateau entering the subduction zone. To cite this article: J. Delteil et al., C. R. Geoscience 335 (2003).     

Continental subduction and exhumation of UHP rocks. Structural and geochronological insights from the Dabieshan (East China)

In the Dabieshan, the available models for exhumation of ultrahigh-pressure (UHP) rocks are poorly constrained by structural data. A comprehensive structural and kinematic map and a general cross-section of the Dabieshan including its foreland fold belt and the Northern Dabieshan Domain (Foziling and Luzenguang groups) are presented here. South Dabieshan consists from bottom to top of stacked allochtons: (1) an amphibolite facies gneissic unit, devoid of UHP rocks, interpreted here as the relative autochton; (2) an UHP allochton; (3) a HP rock unit (Susong group) mostly retrogressed into greenschist facies micaschists; (4) a weakly metamorphosed Proterozoic slate and sandstone unit; and (5) an unmetamorphosed Cambrian to Early Triassic sedimentary sequence unconformably covered by Jurassic sandstone. All these units exhibit a polyphase ductile deformation characterized by (i) a NW–SE lineation with a top-to-the-NW shearing, and (ii) a southward refolding of early ductile fabrics.

The Central Dabieshan is a 100-km scale migmatitic dome. Newly discovered eclogite xenoliths in a Cretaceous granitoid dated at 102 Ma by the U–Pb method on titanite demonstrate that migmatization post-dates HP–UHP metamorphism. Ductile faults formed in the subsolidus state coeval to migmatization allow us to characterize the structural pattern of doming. Along the dome margins, migmatite is gneissified under post-solidus conditions and mylonitic–ultramylonitic fabrics commonly develop. The north and west boundaries of the Central Dabieshan metamorphics, i.e. the Xiaotian–Mozitan and Macheng faults, are ductile normal faults formed before Late Jurassic–Early Cretaceous. A Cretaceous reworking is recorded by synkinematic plutons.

North of the Xiaotian–Mozitan fault, the North Dabieshan Domain consists of metasediments and orthogneiss (Foziling and Luzenguang groups) metamorphosed under greenschist to amphibolite facies which never experienced UHP metamorphism. A rare N–S-trending lineation with top-to-the-south shearing is dated at 260 Ma by the ⁴⁰Ar/³⁹Ar method on muscovite. This early structure related to compressional tectonics is reworked by top-to-the-north extensional shear bands.

The main deformation of the Dabieshan consists of a NW–SE-stretching lineation which wraps around the migmatitic dome but exhibits a consistently top-to-the-NW sense of shear. The Central Dabieshan is interpreted as an extensional migmatitic dome bounded by an arched, top-to-the-NW, detachment fault. This structure may account for a part of the UHP rock exhumation. However, the abundance of amphibolite restites in the Central Dabieshan migmatites and the scarcity of eclogites (found only in a few places) argue for an early stage of exhumation and retrogression of UHP rocks before migmatization. This event is coeval to the N–S extensional structures described in the North Dabieshan Domain. Recent radiometric dates suggest that early exhumation and subsequent migmatization occurred in Triassic–Liassic times. The main foliation is deformed by north-verging recumbent folds coeval to the south-verging folds of the South Dabieshan Domain. An intense Cretaceous magmatism accounts for thermal resetting of most of the ⁴⁰Ar/³⁹Ar dates.

A lithosphere-scale exhumation model, involving continental subduction, synconvergence extension with inversion of southward thrusts into NW-ward normal faults and crustal melting is presented.     

Papua New Guinea Highlands: palaeomagnetic constraints on terrane tectonics

Oblique convergence since the Early Cenozoic between the northward-moving Australian plate, westward-moving Pacific plate and almost stationary Eurasian plate has created a world-ranking tectonic zone in the eastern Indonesia–New Guinea–Southwest Pacific region (Tonga–Sulawesi megashear) that is notorious for its complex mix of tectonic styles and terrane juxtapositions. Unlike an ancient analog—the Mesozoic–Cenozoic Cordillera of North America—palaeomagnetic constraints on terrane motions in the zone are few. To improve the framework of quantitative control on such motions and therefore our understanding of the development of the zone, results of a palaeomagnetic study in the Highlands region of Papua New Guinea (PNG), in the southern part of the New Guinea Orogen, are reported. The study yields new insights into terrane tectonics along the Australian craton's active northern margin and confirms the complexity of block rotations to be expected at the local scale in tectonically intricate zones. The study is based on more than 500 samples (21 localities) collected from an interior and an exterior zone of New Guinea's central cordillera. The two zones are separated by the Tahin and Stolle–Lagaip–Kaugel Fault zones and collectively represent the para-autochthonous northern margin of the Australian craton. Samples from the interior zone, which in the study area comprises a cratonic spur of uncertain—probably displaced—origin, come from Triassic to Miocene sediments and subordinate volcanics of the Kubor Anticline, Jimi Terrane, and Yaveufa Syncline (16 localities) in the central and eastern Highlands. Samples from the exterior zone, which represent a basement-involved, Pliocene foreland fold-and-thrust belt, come from Middle Eocene to Middle Miocene carbonates and clastics (five localities) in the southern Highlands of the Papuan Fold Belt. Results permit us to constrain the tectonic evolution of the two zones palaeomagnetically. Using mainly thermal demagnetization techniques, three main magnetic components have been identified in the collection: (1) a recent field overprint of both normal and reverse polarity; (2) a pervasive overprint of mainly normal polarity that originated during extensive Middle to Late Miocene intrusive activity in the central cordillera; and (3) a primary component which has been identified in only 7 of the 21 localities (5 of 11 stratigraphic units represented in the collection). All components show patterns of rotation that are consistent within the zones, but differ between them. In the interior zone (central and eastern Highlands), large-scale counterclockwise rotations of between 30°+ and 100°+ have been established throughout the Kubor Anticline and Jimi Terrane, with some clockwise rotation present in the southern part of the Yaveufa Syncline. In contrast, in the Mendi area of the exterior zone (southern Highlands), clockwise rotations of between 30°+ and 50°+ can be recognized. These contrasting rotation patterns across the Tahin and Stolle–Lagaip–Kaugel Fault zones indicate decoupling of the two tectonic zones, probably along basement-involved faults. The clockwise rotations in the southern Highlands of the Papuan Fold Belt are to be expected from its structural grain, and are probably governed by regional basement faults and transverse lineaments. In contrast, the pattern of counterclockwise rotations in the Kubor Anticline–Jimi Terrane cratonic spur of the central and eastern Highlands was unexpected. The pattern is interpreted to result from non-rigid rotation of continental terranes as they were transported westward across the northeastern margin of the Australian craton. This margin became reorganised after the Middle Miocene, when the steadily northward-advancing Australian craton impinged into the westward-moving Pacific plate/buffer-plate system. Transpressional reorganisation under the influence of the sinistral Tonga–Sulawesi megashear became enhanced with Mio-Pliocene docking, and subsequent southward overthrusting, of the Finisterre Terrane onto the northeastern margin of the Australian craton.     

Cenozoic Plate interaction of the Australia and Philippine Sea Plates: “hit-and-run” tectonics

Recent studies in northwest New Guinea have shown the presence of at least two marginal basins of different age, both of which formed in back-arc settings. The older basin opened between the Middle Jurassic and Early Cretaceous, a remnant of which is now preserved as the New Guinea Ophiolite. Its obduction started at 40 Ma and it was finally emplaced on the Australian margin at 30 Ma. The younger basin was active during the Oligocene to Middle Miocene and was obducted in the Early Pliocene. Studies of the western edge of the Philippine Sea also reveal an important deformation of the Philippine arc in the Oligocene, which hitherto has remained unexplained. Using information from these systems, paleomagnetic results, kinematic reconstructions and geochemistry of the supra-subduction ophiolite, we present a plate model to explain the region's Eo–Oligocene development. We suggest that an extensive portion of oceanic crust extended the Australian Plate a considerable distance north of the Australian Craton. As Australia began its steady 7–8 cm/year northward drift in the Early Eocene, this lithosphere was subducted. Thus, the portion of the Philippine Sea Plate carrying the Taiwan–Philippine Arc to its present site may have actually been in contact with the ophiolite now in New Guinea and obduction led to deformation of the Philippine Sea Plate itself. Neogene Plate kinematics transported the deformed belt in contact with the Sunda block in the Late Miocene and Pliocene. This interpretation has implications for the origin for the Philippine Sea Plate and the potential incorporation of continental fragments against its boundaries.