Surface movements in Bologna (Po Plain — Italy) detected by multitemporal DInSAR

We studied the surface deformations affecting the southeastern sector of the Po Plain sedimentary basin, in particular the area of Bologna. To this aim an advanced DInSAR technique, referred to as DInSAR-SBAS (Small BAseline Subset), has been applied. This technique allows monitoring the temporal evolution of a deformation phenomenon, via the generation of mean deformation velocity maps and displacement time series from a data set of acquired SAR images. In particular, we have processed a set of SAR data acquired by the European Remote Sensing Satellite (ERS) sensors and compared the achieved results with optical levelling measurements, assumed as reference. The surface displacements detected by DInSAR SBAS from 1992 to 2000 are between 10 mm/year in the historical part of Bologna town, and up to 59 mm/year in the NE industrial and agricultural areas. Former measurements from optical levelling referred to 1897 show 2-3 mm/year vertical movements. This trend of displacement increased in the second half of the 20th century and the subsidence rate reached 60 mm/year. We compared the more recent levelling campaigns (in 1992 and late 1999) and DInSAR results from 1992 to 1999. The standard deviation of the difference between levelling data, projected onto the satellite Line Of Sight, and DInSAR results is 2 mm/year. This highlights a good agreement between the measurements provided by two different techniques. The explanation of soil movements based on interferometric results, ground data and geological observations, allowed confirming the anthropogenic cause (surface effect due to the overexploitation of the aquifers) and highlights a natural, tectonic, subsidence.     

Geological factors associated with unsuccessful exploration wells in the northern margin of the Qaidam basin

We investigated the geological factors associated with unsuccessful exploration wells in the northern margin of the Qaidam basin to better understand their cause. The structural situation, the hydrocarbon accumulation mechanism and unsuccessful well data collected from 1996 to 2005 were studied. The results show that the main geological factors associated with unsuccessful exploration wells are a lack of effective source rocks and a lack of effective traps, as well as the migration-accumulation conditions that exist in this area. The basin was reformed by Meso-Cenozoic tectonic evolution. Multi-stage tectonic activities have both positive and negative effects on hydrocarbon accumulation. Source rocks distribution, effective migration channels, effective traps and the tectonic evolution effects on hydrocarbons should be the key objects for further studies.     

Plate tectonic reconstructions with continuously closing plates

We present a new algorithm for modeling a self-consistent set of global plate polygons. Each plate polygon is composed of a finite list of plate margins, all with different Euler poles. We introduce a "continuously closed plate" (CCP), such that, as each margin moves independently, the plate polygon remains closed geometrically as a function of time. This method solves emerging needs in computational geodynamics to combine kinematic with dynamic models. Because they have polygons that are too widely spaced in time and have inconsistent motions between margins and plates, traditional global plate tectonic reconstructions have become inadequate for geodynamics. The CCP algorithm has been incorporated into the GPlates open-source paleogeographic system. The algorithm is a set of procedures and data structures that operate on collections of reconstructed geometric data to form closed plate polygons; the main data structures used for each plate polygon are based on a nested hierarchy of topological elements. Reconstructions with CCPs can be created, edited, visualized, and exported with GPlates. The native storage of the dynamic reconstructions is the GPlates Markup Language, GPML, which uses an XML-based file format called GML. We demonstrate the utility of the CCP method by creating a global reconstruction with continuously closing plates from 140 Ma to the present using data from existing, traditional reconstructions.     

核废物处置库厂址的地震地质评价

讨论了核废物处置库地震地质评价的基本目的和任务，提出了与能动构造和设计基准地震动相关的５项评价内容，给出了它们之间的逻辑关系和评价程序．     

三维地震在绿色开采中的作用和发展

三维地震是煤矿采区首选的地球物理勘探方法，它为“绿色开采”中的“地质环境”提供科学依据，随着煤炭资源开发向纵、深发展，要求提供更多、更细的工程地质、灾害地质信息，这促使三维地震应由构造勘探向岩性勘探、由浅部向深部、由单波向多波发展；资料处理和解释由叠后偏移向叠前偏移及全三维可视化、网络计算系统发展。     

潞安矿区构造格局及构造演化

山西省潞安矿区盖层构造格局具有东西分带、南北分段的基本特点，构造变形强度由东向西递增，由单斜过渡为轴向近南北的宽缓褶曲，由正断层过渡为逆断层，断层走向由北东和北西向过渡为近南北向。基底构造和区域构造应力是控制盖层构造格局的两个基本因素；煤田构造的形成和发展经历了３个主要阶段。     

从"构建"到"建构":优秀建筑作品的必由之路——由几个实例看建构学在当代的应用和发展

“建构”为建筑的基本属性,是体现建筑品质的重要因素.建筑如何从起初的“构建”达到“建构”的目的,是值得关注的问题.文章以实例为基础,结合“建构”体系的评价标准进行分析,展示当代建筑的“建构”.     

潞安矿区奥陶系岩溶演化主控因素分析

通过野外调查、室内实验与钻探资料对比分析对潞安矿区奥陶系岩溶演化主控因子特征进行研究.结果表明:1) 加里东-海西期老岩溶形成在奥陶系顶部的峰峰组内;新构造运动期新岩溶只发育在裸露区-浅埋区和新断裂带上,形成多层水平岩溶洞穴.2) 中奥陶统存在3个韵律结构使浅部新岩溶发育产生强弱相间的层控现象;石膏层的膏溶作用产生了膏溶角砾岩带、压碎岩带和裂隙带,是泥灰岩段成为裂隙岩溶含水段的主因.3) 浅部走向强径流带与贯穿深浅部的逆倾向弱径流带的共同作用,使CaCO3 ,MgCO3溶蚀区域很局限,新岩溶只在浅部与老岩溶叠加;中深部老岩溶和陷落柱处于沉淀充填状态.4) 新构造断裂带是矿区西部岩溶地下水获得浅层地下水越流补给的通道,也是弱富水区中强富水带.     

桂中坳陷上古生界页岩气保存条件

桂中坳陷上古生界中、下泥盆统以及下石炭统页岩具有良好的生烃及储集条件,但受多期构造运动改造,页岩气保存条件复杂。从宏观和微观分析入手,对该区上古生界页岩气保存条件进行综合评价,预测其勘探潜力及有利勘探区。在野外地质调查的基础上,结合钻井资料、镜质体反射率、粘土矿物X-射线衍射、泥页岩物性分析数据以及构造演化史和埋藏史-热史恢复,从盖层封闭性、断裂和抬升剥蚀作用影响等方面评价了桂中坳陷上古生界页岩气保存条件。结果表明：桂中坳陷中泥盆统泥页岩沉积厚度大（暗色泥页岩厚250~650 m）、分布连续且韧性和微观封闭性较好,可作为页岩气直接和区域盖层;下石炭统虽然分布局限,但韧性和封闭性好,可作为局部盖层;燕山期为研究区主要变形期,大量叠瓦状逆冲断裂和高角度逆冲断层在此时发育,对现今残存的页岩气藏分布格局起着决定性影响,坳陷中、西部遭受的构造改造相对较弱;强烈的剥蚀作用破坏了页岩气的保存,但坳陷中、西部地区剥蚀程度较小。总之,桂中坳陷中、西部的柳江低凸起内天山背斜及西部、马山断凸中部和红渡浅凹中部一带页岩盖层分布稳定且韧性和封闭性较好、遭受的构造破坏较弱、剥蚀厚度较小,为页岩气有利勘探区。     

塔里木盆地寒武纪层序岩相古地理

通过钻井取心及露头沉积相观察、地震层序解释及地震相分析,结合蛇绿混杂岩带分布及板块构造演化等区域地质资料,对三级层序地层格架下的塔里木盆地寒武纪岩相古地理特征进行了研究。结果表明,塔里木板块内部存在3个孤立碳酸盐台地（塔西台地、罗西台地及库鲁克塔格台地）及其间深水沉积区的古地理格局,塔西南地区存在寒武系深水盆地相沉积分布区,并且该深水盆地相沉积分布区可能是以和田河气田为代表的塔西南地区海相油气藏的主力烃源区。发生于早震旦世和早寒武世的塔里木板块北缘大陆裂谷运动,以及震旦纪-寒武纪的张裂构造环境控制了塔里木板块内部多个孤立碳酸盐台地及其间深水沉积区的形成。从早寒武世到晚寒武世,虽然塔里木板块内的古地理格局总体没有发生大的变化,但以塔西台地为主的孤立碳酸盐台地均发生了进积-加积作用而变得更大,并且不同时空台地边缘类型及其叠置型式也发生了变化,主要表现为早寒武世以发育缓坡-（斜坡坡度较小的）弱镶边台地边缘为主,中-晚寒武世以发育弱镶边-（斜坡坡度较大的）镶边台地边缘为主。