三峡库区泥灰质岩石斜坡带构造对岩溶地质灾害的控制机理   总被引：1，自引：0，他引：1  

张加桂 《水文地质工程地质》2004,31(6):43-47

三峡库区三叠系巴东组(T26)泥灰质岩石岩溶是移民迁建中发现的重大工程地质问题。泥灰质岩石中的构造非常复杂，包括老构造、新构造和表生构造，它们共同控制了岩溶作用。老构造中，褶皱和断裂带等局部构造控制着岩溶的重要部位和重要层位，节理和层理等小构造使岩溶普遍存在。新构造时期地表隆升和河流切割使岩体卸荷松动，岩溶通道扩宽。表生岩溶构造加密了岩溶通道，使岩溶作用增强。三峡库区泥灰质岩石斜坡带地质灾害形成的机理遵循着构造控制下岩溶发育的规律性，致使岩溶地质灾害具有范围广、规模大和结构复杂的特点。岩溶地质灾害的形式包括地面不均匀沉降、地裂缝、滑坡、崩塌、泥石流和地面塌陷。  相似文献   

正交法在注浆材料优化设计中的应用          下载免费PDF全文

杨秀竹王星华  雷金山 《探矿工程》2004,31(3):7-9

应用正交试验设计法，对粘土固化浆液的配比进行了优化，得到了最佳配比，并将其应用于洛湛铁路益娄段岩溶路基的注浆加固，收到了很好的整治效果。  相似文献   

高坪-吉心段公路喀斯特工程地质综合勘察   总被引：1，自引：0，他引：1  

姜友生  刘玉山  王国斌 《山地学报》2004,22(3):343-346

以沪蓉国道主干线湖北省高坪-吉心段的喀斯特地质勘察工作为例，探讨喀斯特地区公路工程地质综合勘察的基本方法。在喀斯特地区运用遥感和地理信息技术技术、地质测绘、综合物探以及地质钻探等勘察手段，通过综合分析各种勘探成果，能够较准确地查明可溶岩的分布、喀斯特形态类型、分布规律、控制因素以及喀斯特水的赋存、分布和运移规律等，并根据不同的喀斯特地貌提出了有针对性的处理对策。通过不断的实践和经验总结。针对喀斯特工程地质问题合理运用综合工程勘察方法，能做出科学的分析评价，可以适应喀斯特区公路建设的需要，并且供今后在喀斯特地区修建公路时参考和借鉴。  相似文献   

The influence of land use change on karst water quality of Shuicheng Basin in Guizhou Province     

JIA Yanan  YUAN Daoxian 《地理学报》2004,14(2):143-150

The influence of land use and land cover on ecological environment is a focus of global change research. The paper chooses an industrial city-Shuicheng in Guizhou Province-as a study area because the karst water quality around the city is deteriorating with land use and land cover change. The natural susceptibility of karst water system is an important factor leading to karst water pollution. But land use and land cover change is also a main factor according to the chemical analysis of karst water quality and land use change. So it is a good way to protect karst water through rational planning and managing of land use and land cover.  相似文献   

Origin of the salt valleys in the Canyonlands section of the Colorado Plateau: Evaporite-dissolution collapse versus tectonic subsidence     

F. Gutirrez 《Geomorphology》2004,57(3-4):423-435

The salt valleys over the axis of the salt-cored anticlines in the Paradox fold and fault belt (Canyonlands, Utah and Colorado) are created by subsidence of the anticline crests. Traditionally, the collapse of the anticlinal crests was attributed to dissolution of the salt walls (diapirs) forming the anticline cores. Recent studies based on scaled physical models and field observations propose that the salt valleys are a result of regional extension and that salt dissolution had only a minor influence in the development of the axial depressions. This paper presents several arguments and lines of evidence that refute the tectonic model and support the salt dissolution subsidence interpretation.The development of contractional structures in salt dissolution experiments led the advocates of the tectonic interpretation to reject the dissolution-induced subsidence explanation. However, these salt dissolution models do not reproduce the karstification of salt walls in a realistic way, since their analog involves removal of salt from the base of the diapirs during the experiments. Additionally, numerous field examples and laboratory models conducted by other authors indicate that brittle subsidence in karst settings is commonly controlled by subvertical gravity faults.Field evidence against the regional extension model includes (1) a thick cap rock at the top of the salt walls, (2) the concentration of subsidence deformation structures along the crest of the anticlines (salt walls), (3) deformational structures not consistent with the proposed NNE extension, like crestal synforms and NE–SW grabens, (4) dissolution-induced subsidence structures controlled by ring faulting, revealing deep-seated dissolution, (5) large blocks foundered several hundred meters into the salt wall, (6) evidence of recent and active dissolution subsidence, and (7) the aseismic nature of the recently active collapse faults. Although underground salt dissolution seems to be the main cause for the generation of the salt valleys, this phenomenon may have been favored by regional extension tectonics that enhance the circulation of groundwater and salt dissolution.  相似文献   

Hydrogeochemistry of karst underground waters at shallow depth in Guiyang City, Guizhou Province     

董志芬  朱立军吴攀沈峥  封志勇 《中国地球化学学报》2005,24(2):194-200

The aim of this study is to shed light on the hydrogeochemical characteristics of karst underground waters at shallow depth in Guiyang City, Guizhou Province with an emphasis on the geochemistry of major elements. Guiyang City bears abundant underground waters and it is also an important representative of the karst areas throughout the world. Ca^2 and Mg^2 are the dominant cations, accounting for 81% -99.7% of the total, and HCO3^- and SO4^2- are the dominant anions. Weathering of limestones and dolostones is the most important factor controlling the hydrogeochemistry of underground waters, and weathering of sulfate and evaporite rocks is less important. Moreover, the precipitation and human activities also have a definite influence on the hydrogeoehemistry of underground waters in the region studied.  相似文献   

采空区二维超声波物理模型实验研究     

赵家福  田钢  石战结  王者江 《吉林大学学报(地球科学版)》2005,(Z1)

由于对资源矿产的过度开采使得矿山地区(尤其是煤矿)出现了采空区,从而引起地表塌陷等地质灾害。为了深入了解地震方法在采空区调查中的应用效果,从超声波物理模型实验研究出发,论述了物理模型的原理和制作,研究了采空区的地震波场特征,并利用W inse is软件对所采集的二维超声波实验数据进行了处理。由叠偏剖面推断的采空区的位置与实际模型相符,从而验证了超声波采空区物理模型试验是有效的、可信的;同时可以为实际探测采空区提供进一步的理论依据。  相似文献   

Erratic judgements: re-evaluating solutional erosion rates of limestones using erratic-pedestal sites, including Norber, Yorkshire     

H S Goldie 《Area》2005,37(4):433-442

The re-interpretation of surface karst landforms in Northern England has led to a re-examination of well-known erratic-pedestal sites that were the origin for karst denudation rates applied extensively, on the supposition that erratics protect underlying limestone from rainwater solution. Height of the pedestal has been used to calculate long-term solutional-lowering, as much as 50 cm in 15 ka (33.3 mm/ka) from UK sites. The sites include Norber and Scar Close, Yorkshire, UK. This paper shows that the sites have been misinterpreted, in particular at Norber where the erratics lie on a pre-existing structurally stepped surface. Norber and several other sites also experience much mechanical weathering, in relatively weak, well-fractured limestones, a process which must be distinguished from solution. Sites in strong, less-fractured limestones demonstrate lower rates, which are sounder indications of land surface lowering. Some pedestals have been confirmed as partly resulting from solutional weathering in surrounding soil and vegetation. Re-evaluation reduces solution rates to 3–13 cm in 15 ka. Applying such rates has profound implications for understanding limestone landscapes, challenging orthodox views.  相似文献   

桂林地区古人类演化及环境变迁研分     

王华  杨琰  张会领 《地球学报》2005,26(Z1):205-208

桂林地区曾是古人类活动活跃的地区，据可以断代的古人类洞穴遗址统计，发现桂北地区大部分的洞穴遗址其年代的下限都在距今约7000a 左右，此后古人类离开了洞穴，史前文化也随之发生了重要改变。影响古人类演化的因素鹅很多，究竟是什么原因驱使古人类离开洞穴，改变生活习性，这一问题一直都是困扰考古学界的难题。本文通赤研究桂北地区洞穴遗址的堆积特点，结合洞穴沉积－堆积物的特征及其孢粉记录的古气候信息，探讨了季风气候变化对桂林地区古气候变化的影响作用和气候演变历史，揭示了桂林地区全新世以来的季风气候变化时间序列和突变事件以及对古人类生存环境的影响。距今7000a 左右为中全新世气候适宜期，东亚夏季风强盛，气温升高，桂林地区的降雨增多，一方面由于地下河水位升高，淹没了穴居洞穴，其次是由于降雨增多，导致洞穴湿度增大，从而迫使古人类搬出洞穴。  相似文献   

桂林地区岩溶水87Sr/86Sr特征   总被引：2，自引：0，他引：2  

王涛  王增银 《地球学报》2005,26(Z1):299-302

锶是岩石圈上部含量最大的微量元素，其元素及其同位素化学性质都比较稳定。不同水岩作用条件下，锶元素含量及其同位素值都不一样。本文通过对桂林地区的两个典型岩溶地下河系统不同类型地下水样87Sr/86Sr值和Sr含量的分析，得出；流经不同岩层的地下水其87Sr/86Sr值和Sr含量不同，同一地下河系统中不同类型地下水的87Sr/86Sr值Sr含量不同，其值的差异由岩性和水岩作用决定。说明87Sr/86Sr值能反映地下水的形成、径流和混合作用，是较理想的示踪剂，在岩溶水研究中具有很广阔的应用前景。  相似文献