辽南北瓦沟长英质岩石应变组构演化

岩石的应变组构型式与岩石成分、变形环境和应变过程有着密切关系。北瓦沟地区低角闪岩相条作下的长英质岩石,表现脆性、韧性和韧脆性过渡,因而在剪切作用过程中形成了相应的应变组构型式,即脆性应变组构、韧性应变组构和脆-韧性应变组构。而且随着应变过程的发展,应变组构也表现出一定的演化规律。     

建平地区三座庙序列侵入岩侵位机制讨论

通过野外对三座庙序列侵入岩的岩体平面与剖面形态、岩体的内部构造、岩石与围岩的构造型式、接触带的度形特征等宏观地质特征的研究,推测岩体侵入位机制为强力挤入方式定位,即气球膨张式。笔者运用岩石的有限应变测量原理和方法,结合岩组分析及流变学、现代变形理论,对三座庙序列的侵入岩岩石做了有限应变测量和岩组分析工作,所得定量资料为确定岩体的浸位机制提供了理论依据。三种岩石有限应变测量,即:算术平均法、长短轴法、Rf/φ曲线法的富林指数k值均在0相似文献   

锦屏电站坝厂区卸荷岩体力学参数研究

选择具有代表性的区块,根据结构面的性状和规模拟定模型层次和尺寸,建立岩体数值仿真模型,通过计算机数值仿真,采用卸荷非线性力学理论对锦屏电站坝厂区岩体进行卸荷岩体宏观力学特性及参数的数值分析;同时,用RMR法和BP神经网络法对岩体宏观力学特性及参数进行分析,综合确定岩体力学参数,为设计部门提供设计参考依据.     

REE Characteristics of the Kalatongke Cu-Ni Deposit, Xinjiang, China

On the basis of the study on the REE geochemistry of the ore minerals and host rocks of the Kalatongke Cu-Ni deposit, Xinjiang, it is indicated that the major ore minerals, sulfides, were sourced from the host mafic-ultramafic magma. Characterized by low REE content of sulfide, such a Cu-Ni sulfide deposit occurring in the orogen is obviously different from that on the margin of the craton. Because the mafic-ultramafic rocks from the Cu-Ni sulfide deposit occurring in the orogen is water-rich and the REEs of some sulfides show a particular "multiple-bending" pattern, which suggests coexistence of multiple liquid phases (fluid and melt), the sulfide melt possibly contains a great deal of hydrothermal fluids and increasingly developed gases and liquid-rich ore-forming fluids after the main metallogenic epoch (magmatic segregation stage).     

海拉尔盆地贝尔凹陷布达特群水力破裂的岩石学特征及其成因探讨

海拉尔盆地贝尔凹陷布达特群凝灰质泥岩中发育大量凝灰质泥岩角砾。岩芯及透射光显微镜观察发现,这是一种水力破裂体系中流体和岩石作用的产物一水压碎屑岩。水压碎屑岩的岩石学特征表现为：角砾之间具有可拼合性、岩芯横切面上发育大量“T”型垂直裂缝、微细纤维状铁白云石脉对壁生长。水力破裂作用的成因主要与布达特群岩性组合特征、构造-流体作用有关。     

Geochemistry of the ophiolite and oceanic island basalt in the Kangxian-Pipasi-Nanping tectonic mélange zone,South Qinling and their tectonic significance

Detailed studies indicate that Kangxian-Pipasi-Nanping tectonic zone is a complicated mélange zone which includes many tectonic slabs of different origins. Ophiolite (MORB-type basalt), oceanic island tholeiite and alkaline basalt have been identified. Moreover, this tectonic mélange zone is eastward connected with the Mianlüe suture zone. The deformation characteristics, consisting components and volcanic rock geochemical features for the Kangxian-Pipasi-Nanping tectonic mélange zone are much similar to those of the Mianlüe suture zone and Deerni ophiolite. Therefore, the Kangxian-Pipasi-Nanping tectonic mélange zone should be the westward extension part of the Mianlüe suture zone. It indicates that the Mianlüe suture zone had extended to the Nanping area.     

MULTIDISCIPLINARY INVESTIGATIONS ON THREE ROCK GLACIERS IN THE SWISS ALPS: LEGACIES AND FUTURE PERSPECTIVES

This paper recognizes the contribution of Professor Wilfried Haeberli for his inspiration and leadership in the field of permafrost science and his generous encouragement, both direct and indirect, to the ETH Researchers who have, through him, endeavoured to contribute to this fascinating research area. The multidisciplinary investigations described in this paper have focused on three rock glaciers, Muragl, Murtèl‐Corvatsch and Furggwanghorn, all of which have been subject to a varying degree of prior study, and which are continuing to attract new generations of researchers to understand and explain the processes and predict future behaviour. This paper marks a stage at which it is possible to summarize some advances in the state of the art and associated innovations that can be attributed to early motivation by Wilfried Haeberli and offers a tribute as well as gratitude for his ongoing feedback and advice. Some thoughts on the development of thermokarst due to water ponding and flow, and a conceptual model of geotechnical mechanisms that aim to explain some aspects of rock glacier kinematics, are also introduced.     

半干旱黄土丘陵区人工植被深层土壤干化效应

科学评估不同植被恢复模式的土壤干化效应是目前黄土高原生态恢复一个亟需解决的关键问题。本文以半干旱黄土丘陵区14种典型人工植被为例,通过构建土壤水分相对亏缺指数CSWDI和样地土壤水分相对亏缺指数PCSWDI,定量评估了不同植被深层土壤干化效应。研究发现:除农地和撂荒草地外,各植被深层土壤水分均随土层深度的增加而升高,深层土壤水分含量同土层深度之间呈一元线性关系。不同人工植被深层土壤相对干化程度存在差异,以油松林地最高,杨树侧柏混交林地最低。不同植被类型受其自身蒸腾耗水、根系特征和耕作等影响,土壤干化的程度在剖面上存在差异,但总体趋势为随深度增加而降低。针阔叶植被配置模式土壤水分状况要稍好于阔叶纯林的配置模式。     

1957—2007年雅鲁藏布江中游河谷降水变化的小波分析

通过对近51 a雅鲁藏布江中游河谷地区4个气象站逐日降水资料进行等权平均取值,采用气候倾向率和小波分析法,研究了不同时间尺度下近51 a降水变化趋势及周期特征。结果表明:研究区降水量以20世纪80年代为最少,2000年后年降水量与20世纪90年代和60年代基本持平。夏季和秋季降水量年代际变化与年降水量的变化基本一致。近51 a降水量增加趋势不显著。年降水量存在准3 a、8—11 a和30 a的周期,以准11 a周期最为突出。降水量变化以春季增长趋势最显著,可在干旱季补充土壤水分,减轻风沙化土地的发生发展。秋季和冬季增长趋势不明显,夏季降水量呈减小趋势。就季节降水变化的时间尺度和周期性而言,2007年后四季降水表现为,春季在20—30 a时间尺度上将处于偏高期,夏季在8—12 a时间尺度上将处于偏低期,秋季在8—12 a时间尺度上将处于偏低期,冬季在20—30 a时间尺度上将出现向降水偏高的过渡期。