赣北地区地盆阶段特征及其形成环境探讨

本文从区域地球物理场、建造、构造型相、地球化学等特征方面首次论述了赣北地区地盆阶段特征，并对其构造环境进行了探讨。认为赣北及其邻区在地盆阶段处于活动的陆内裂谷构造环境，即绿岩带形成于陆内裂谷盆地中。     

西太平洋边缘海盆的形成与演化

从地球深部地幔流动引起的地质作用出发，结合裂谷的发展演化规律，认为地幔向东（或南东）的蠕散和流动促使亚洲大陆边缘地壳拉伸、变薄以致破裂，由大陆裂谷发展至弧后裂谷，形成西太平洋边缘海盆。最后提出边缘海盆发展演化的4个阶段，即：新生阶段（郯庐裂谷系）、幼年阶段（冲绳海槽）、青壮年阶段（日本海）和成熟阶段（南海）。     

Three-dimensional SeaMARC II,gravity, and magnetics study of large-offset rift propagation at the Pito Rift,Easter microplate

We present results from a SeaMARC II bathymetry, gravity, and magnetics survey of the northern end of the large-offset propagating East Rift of the Easter microplate. The East Rift is offset by more than 300 km from the East Pacific Rise and its northern end has rifted into approximately 3 Ma lithosphere of the Nazca Plate forming a broad (70–100 km) zone of high (up to 4 km) relief referred to as the Pito Rift. This region appears to have undergone distributed and asymmetric extension that has been primarily accommodated tectonically, by block faulting and tilting, and to a lesser degree by seafloor spreading on a more recently developed magmatic accretionary axis. The larger fault blocks have dimensions of 10–15 km and have up to several km of throw between adjacent blocks suggesting that isostatic adjustments occur on the scale of the individual blocks. Three-dimensional terrain corrected Bouguer anomalies, a three-dimensional magnetic inversion, and SeaMARC II backscatter data locate the recently developed magmatic axis in an asymmetric position in the western part of the rift. The zone of magmatic accretion is characterized by an axis of negative Bouguer gravity anomalies, a band of positive magnetizations, and a high amplitude magnetization zone locating its tip approximately 10 km south of the Pito Deep, the deepest point in the rift area. Positive Bouguer gravity anomalies and negative magnetizations characterize the faulted area to the east of the spreading axis supporting the interpretation that this area consists primarily of pre-existing Nazca plate that has been block faulted and stretched, and that no substantial new accretion has occurred there. The wide zone of deformation in the Pito Rift area and the changing trend of the fault blocks from nearly N-S in the east to NW-SE in the west may be a result of the rapidly changing kinematics of the Easter microplate and/or may result from ridge-transform like shear stresses developed at the termination of the East Rift against the Nazca plate. The broad zone of deformation developed at the Pito Rift and its apparent continuation some distance south along the East Rift has important implications for microplate mechanics and kinematic reconstructions since it suggests that initial microplate boundaries may consist in part of broad zones of deformation characterized by the formation of lithospheric scale fault blocks, and that what appear to be pseudofaults may actually be the outer boundaries of tectonized zones enclosing significant amounts of stretched pre-existing lithosphere.     

Oblique rifting in the Havre Trough and its propagation into the continental margin of New Zealand: Comparison with analogue experiments

The Havre Trough is opening by oblique back-arc rifting which is propagating into the continental margin of New Zealand at the Taupo Volcanic Zone. Variations of deformational style along the rift axis have been investigated by comparison with analogue experiments which incorporate brittle and ductile rheologies and are scaled for gravity. Based on the results of the analogue experiments, we present a tectonic model for oblique rifting in the Havre Trough, which involves the rheological contrast between oceanic and continental lithosphere and the oblique geometry of the continental margin of New Zealand with respect to the regional rift trend. The model shows that the continental margin, which is weaker than both oceanic and continental lithosphere, cannot support large shear stresses. The two lithospheres can be decoupled during extensional events along the marginal shear and, depending on the continental margin orientation, this shear can modify the regional stress field. A heterogeneous stress field will rotate normal stresses to be perpendicular or parallel to the margin. As the two lithospheres decouple during extension, the rift grabens and internal faults of the oblique rift system propagate normal to the marginal shear. This model explains the oblique trend of the Havre Trough's tectonic fabric and its relationships to the Vening Meinesz Fracture Zone which represents the oceanic/continental lithospheric boundary.As the Havre Trough rift propagates into the continental margin, rheological differences between oceanic and continental lithosphere result in variations in distribution of strain along the rift axis. Extension of oceanic sub-arc lithosphere is localized into a single rift graben. At the transition into continental rifting, the zone of extension widens into a number of rift grabens forming complex indentations into the margin. This change in deformation style is consistent with analogue experiments as well as other natural examples and results from the contrast in lithospheric rheology and its influence on the process of strain localization.     

秦岭造山带(陕西部分)中新生代陆内造山及与矿产关系

印支运动后的秦岭造山带受古亚洲构造域、环太平洋构造域和特题斯三大构造域联合作用,发生了强烈的陆内造山,奠定了该区条块相间构造岩片系统的基本构造格架,控制了本区斑岩型钼矿和众多热液型多金属矿产的最终成矿作用和矿带展布。     

新疆北山西段裂谷演化及金矿成矿规律

新疆北山裂谷构造带,呈北东东—北西西向展布,是在塔里木地块太古界、元古界的基础上开裂演化而成,总体呈两地块夹裂谷的构造格局,经历了-C、O—S、C—P3次大规模的裂开与闭合、由南向北迁移的演化模式。在该裂谷带晚古生代沉积盖层中分布着一系列不同类型的金矿(点),并划分了多个Au成矿亚带。笔者所论为新疆北山晚古生代金(铜)级成矿带金矿的成矿规律。根据赋矿岩系划分为6类,矿石建造划分为4类,分别为石英脉型、破碎蚀变岩型、破碎蚀变岩型 石英脉型、中酸性岩浆热液型,以石英脉 破碎蚀变岩型为主。控矿因素为沉积建造(火山岩-碎屑岩及碳质岩系)、韧-脆性断裂、岩浆岩等;成矿时代为华力西晚期、印支期、燕山期和喜马拉雅期,成矿作用与各期构造活动同步或准同步。     

Cenozoic deformation history of the Tancheng–Lujiang Fault Zone, north China, and dynamic implications

Abstract Based on a field analysis of slip vectors from Cretaceous and Tertiary rocks and coupled with rift basin analysis in north China, the Cenozoic deformation history of the Tancheng–Lujiang (Tan–Lu) Fault Zone can be divided into three main phases: early Tertiary normal faulting and northwest–southeast extension; Miocene normal faulting and northeast–southwest to north‐northeast–south‐southwest extension; and Quaternary dextral strike–slip faulting and east‐northeast transpression. The early Tertiary extension, which was responsible for rift basin formation in north China, originated from back‐roll mantle convection induced by westward subduction of the Pacific Plate beneath the Asia continent. The Miocene extension occurred possibly in association with the process of the Japan Sea opening. The Quaternary dextral slip was mainly localized along the middle part of the Tan–Lu Fault Zone and resulted from the far‐field effect of the late‐stage India–Eurasia convergence.     

黄骅裂谷盆地第三系深层水成因

在阐述盆地地质和含水系统、水文地质期、水压系统的定位基础上，通过建立数学模型，采用反演法、地静压力法，模拟计算了各研究层在各研究时期的砂、泥岩恢复厚度、压出水量、水交替强度。计算表明各研究层在各研究时期的压挤式水交替强度均小于1，累加值Es^2、Es^1、Ed层的大于1，Ng、Nm层的小于1；Ed层渗入水交替强度为0．44。各研究层在各研究时期渗流场的高水压带位置和流动态势具有相似性，并均以离心型流动为主要特征。水的初始与现代化学及其演化研究表明，6个研究层段均起始于不同浓度的同生沉积成因水，除Eκ^1层局部水的现代浓度比初始浓度显著降低，朝稀释淡化、反向变质的方向演化外，其他5个层段水的现代浓度比初始浓度均呈不同程度的增高，朝浓缩盐化、正向变质的地球化学方向发展，最终演化成为不同浓度的后生沉积成因水。     

中国西北地区陆内前陆盆地的鉴别标志

讨论了中国西北地区陆内前陆盆地的主要鉴别标志 :(1)不对称山前坳陷的构造几何形态 ;(2 )先缓后陡的两段式沉降曲线 ;(3)反沉积旋回上部磨拉石堆积、强烈构造运动和层内递进型构造角度不整合类型。认为在鉴别陆内前陆盆地中必须进行多项标志的综合分析     

Active tectonics of the Yizre'el valley, Israel, using high-resolution seismic reflection data

We present a series of high-resolution seismic reflection lines across the Yizre'el valley, which is the largest active depression in Israel, off the main trend of the Dead Sea rift. The new seismic reflection data is of excellent quality and shows that the valley is dissected into numerous small blocks, separated by active faults. The Yizre'el valley is found to consist of a series of half grabens, rather than a single half graben, or a symmetrical graben. The faults are generally vertical and appear to have a dominant strike-slip component, but some dip-slip is also evident. A marked zone of compression near Megido is associated with the intersection of the two largest faults in the valley, the Carmel fault and the Gideon fault. Variable trend of the faults reflects the complexity of the local geology along the boundary between the wide NW–SE trending Farah–Carmel fault zone and the E–W trending basins and ranges in the Lower Galilee. This tectonic complexity is likely to result from a highly variable stress pattern, modified by the structures inside it. Normal faulting in the valley occurred at an early stage of its development as a tectonic depression. However, strike-slip motion on the Carmel fault, and possibly also on some of the other faults, appears to have started together with the onset of normal faulting. Earthquake hazard in the area appears to be uniform as faults are distributed throughout the Yizre'el valley.