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871.
鲁中南泰莱盆地岩溶地下水赋存特征和找水规律   总被引:1,自引:0,他引:1  
结合泰安市岱岳区水文地质调查资料和实施27口钻井发现:在鲁中南泰莱盆地西部山区,碳酸盐岩裸露,崎岖不平的峰丛谷地、峰丛洼地地貌导致水力坡度大,地下水沿构造断裂呈线状快速径流,地下水非饱和,无统一水力联系,岩溶地下水分布极不均匀成为钻井取水的难点,寻找有利蓄水构造成为钻井找水关键;在盆地东部和南部靠近河谷的缓丘平原覆盖型岩溶分布区,水文地质单元上处于地下水径流排泄区,岩溶地下水丰富且呈层状、面状分布,水力联系密切,滞流形成饱水带,利于钻井开采地下水资源,但应着重关注火山侵入岩等隔水岩层的展布情况,综合分析岩溶含水层厚度、地下水水位和汇水条件。  相似文献   
872.
根据盐城市2017年MOD11A2地表温度数据,结合FROM-GLC10地表覆盖类型数据以及MOD15A2叶面积指数LA I数据对其热岛效应的特性进行具体分析.结果表明:(1)白天城市用地的平均地表温度高于其他地表覆盖类型,并且无季节性差异,其中夏季为33.2℃,而河流区域平均地表温度最低,其中冬季为9.1℃.(2)不...  相似文献   
873.
Four outcrops of Lower Cretaceous (Barremian) karst bauxites located in Teruel (NE Spain) were analysed. The deposits show a heterogeneous-chaotic lithostructure consisting of pisolitic bauxite blocks embedded in lateritic red clays filling karst cavities. The research has focused on the geochemical study of major, minor, and trace elements (including some critical to industry) of both the bauxites and clays. The objective was to investigate the bauxite precursor material and to characterize the system’s geochemical evolution. Geochemical analyses were carried out by inductively-coupled plasma optical emission and mass spectroscopy. An absolute weathering index has been calculated to estimate element mobility, assuming Ti as an immobile element and the Upper Continental Crust (UCC) as parent material. Further, selected samples were observed by field emission scanning electron microscopy. The data indicate that both the bauxites and red clays originated by intense chemical weathering from more mafic argillaceous sediments than the UCC. Ongoing weathering caused the bauxitization of the upper parts of the original profile, preventing the lower parts from being bauxitized, thus producing the ferrallitized clays underlying the pisolitic bauxites. Subsequent karst reactivation gave rise to the current lithostructure. Ferrallitization is related to Fe, Sc, and V enrichment. On the other hand, although bauxites are relatively enriched in some elements compared to clays, the more intense chemical weathering associated with bauxitization led to chemical homogenization and widespread element depletion. During the bauxitization, Al, Ti, Zr, Cr, and probably Hf and the critical element Nb behaved as more immobile elements in the system. Bauxitization also enhanced homogenization and depletion of the REE, which is more pronounced for the LREE. HREE trends seem to be partly related to the concentration of Ti oxides in the bauxites, whereas P-bearing phases, more frequent in the clays, control the LREE. Subsequent to bauxitization, partial kaolinization of the bauxite took place related to the circulation of acid solutions that also caused the karst reactivation. These late processes caused some Al depletion in the bauxites and enhanced Fe loss together with V and, to a lesser extent, Ge.  相似文献   
874.
贵州地区岩溶普遍发育,岩溶区矿产资源丰富。由于含矿层及上下部地层含水性强至极强,矿产开采过程中水害问题突出。大型地下堰塞水体是形成矿井突水的主要水体之一,因其隐蔽性高,防范难度极大。阐明大型地下堰塞水体成因及其形成矿井突水的特点,对矿山生产防水治水有重要意义。以赫章县珠市铁矿山2015年“11·22”突水事故为例,在对突水矿井开展技术调查的基础上,结合矿山水文地质条件,通过对断层构造部位的岩溶发育特点、地下水径流、赋存状态以及形成矿井突水的水源类型、各类水体形成突水特征等分析,揭示了岩溶区大型地下堰塞水体的形成机制; 阐明了该类水体形成矿井突水的一般特征及突水征兆; 明确了造成赫章县珠市铁矿山矿井突水的水源为大型地下堰塞水体,事故系矿井爆破掘进过程中揭穿大型地下堰塞水体下部岩溶管道所致。大型地下堰塞水体形成矿井突水有其独特性,针对性地开展矿井防治水工作,及时采取合理、有效的防治水措施意义重大。  相似文献   
875.
The Kuqa foreland basin, adjacent to the South Tianshan Mountains, is a major hydrocarbon accumulation basin in Western China. The Kelasu structural belt is the focus for hydrocarbon exploration in the basin due to the presence of ramp-related anticline traps and a thick salt seal. The model of the Kelasu sub-salt structure is still contentious because of the structural complexity and poor seismic imaging below the salt layer. The area–depth–strain (ADS) method is applied to the southern part of the Kelasu Fault, a regional fault that cuts basement rocks. The ADS results are consistent with the seismic data, which indicate that both thin-skinned thrusting and basement-involved deformation occur within the Kelasu structure, with the Kelasu Fault acting as the boundary between the two regions of contrasting deformation. The ADS results also suggest that the depth of the lower detachment of the thin-skinned thrust belt is 9.5–10 km, which may correspond to the base of the Triassic. The Kelasu structure has undergone approximately 8.15–10.76 km of horizontal shortening in the east and 16.34 km in the west of the structure.  相似文献   
876.
杜怡星  时志强 《沉积学报》2017,35(3):460-469
在川西北地区绵竹汉旺、安县雎水剖面上三叠统卡尼阶海绵礁(丘)灰岩顶部发现古喀斯特;野外露头可见明显的花斑状构造以及蜂窝状溶孔,显微镜下可见泥晶化颗粒,喀斯特角砾以及喀斯特溶孔充填物,其中包括泥-亮晶方解石,生物碎屑以及陆源石英颗粒;根据露头岩性和显微薄片特征判断其属于早成岩期喀斯特;喀斯特成单层发育,之上覆盖化石丰富的黄色或黑色页岩,其中的菊石化石鉴定表明其为上卡尼阶底部沉积。该喀斯特是重要的等时界面,且可作为该地区上下卡尼阶的界线。喀斯特之上的岩性在汉旺和雎水有差异:在绵竹汉旺青岩沟剖面,喀斯特灰岩之上覆盖有黑色粉砂质页岩与生屑灰岩(如层状海绵灰岩、海百合灰岩),在汉旺观音崖剖面,喀斯特面之上发育海绵丘灰岩及页岩,在安县雎水剖面,古喀斯特发育在滚落的海绵巨砾之上。综合研究表明,喀斯特的形成与早期龙门山的隆升以及卡尼期湿润气候事件在发生时间上非常相近,推测其成因与龙门山的隆升以及卡尼期湿润气候事件有关。  相似文献   
877.
Evaluating the impact of allogenic water and sulfuric acid on karst carbon sink not only helps to improve the accurate calculation of soil CO2 uptake by rock weathering, but also obtains a complete understanding of the global carbon cycle. Groundwater samples were collected from four karst subterranean rivers watershed within different lithology strata in Wushui Basin, upstream of Beijiang Basin, Hunan Province, for revealing the important impact of silicate weathering on hydrochemistry of groundwater. To estimate the contribution of soil CO2 uptake by silicate weathering to CO2 uptake by rock weathering, the Galy model was employed in this article. The important impact of sulfuric acid on CO2 uptake by carbonate weathering resulting from the substitution of carbonic acid by protons from sulfuric acid was investigated. Our results showed that the concentration of Na+, K+ and SiO2 in L01,L02 subterranean river with silicate strata in watershed were higher than that in L03,L04 subterranean river without silicate strata in watershed, which implied that the contribution of silicate weathering to Na+,K+ and SiO2 was very important in watershed within silicate strata . The changeable equivalent ratio between (Ca2++Mg2+) and HCO3- was 1.05 to 1.15, and the value of [Ca2++Mg2+]/[HCO3-+SO42-] was 0.99 to 1.08. The concentrations of Ca2+ and Mg2+ exceeded the equivalent concentrations of HC3-, and the excess of Ca2+ and Mg2+cations were compensated by SO42-, which suggested that sulfuric acid has an important influence on carbonate dissolution. The contribution of soil CO2uptake by silicate weathering to CO2 consumption in L01 and L02 subterranean river were 3.36% and 2.22%, respectively, whereas the contribution in L03, L04 subterranean river were less than 0.50%, indicating that the contribution of soil CO2 uptake by silicate weathering was important in the subterranean river basin within silicate strata. Due to the contributions made by sulfuric acid, the CO2 consumption in four subterranean rivers decreased by 4.84%, 4.52%, 6.20%, 9.36%, respectively.  相似文献   
878.
可持续回灌是地热资源循环采用的基本。本文通过热储敏感性、堵塞原因、成井结构以及地面装置分析了回灌衰减的原因。认为物理堵塞是回灌堵塞的主要原因,成井结构是维持可持续回灌的关键,标准的地面设备可避免由于物理和化学原因引起的堵塞。本文采用成功的成井结构和标准的地面装置开展馆陶组热储回灌地热资源循环采用的示范工程建设,回灌率达到100~123 m3/h,实现了天津滨海新区馆陶组热储回灌突破,保证了滨海新区馆陶组地热资源循环利用。  相似文献   
879.
Evaporite karst has intensively developed recently along the Dead Sea (DS) coastal area in Israel and Jordan. It takes place in very saline groundwater dissolving buried salt layers, causing collapse of the surface. In this paper, groundwater salinity throughout the DS coastal area is investigated using the Transient Electromagnetic (TEM) method. Twenty-eight TEM soundings along the DS coastal area were carried out close to observation boreholes to calibrate resistivity–salinity relationships. Groundwater electrical conductivity was measured in these boreholes, and its salinity was analyzed at the laboratory by the Geological Survey of Israel (GSI). Quantitative relationships between bulk resistivity (ρx), water resistivity (ρw) and chloride concentration (Ccl) were derived in the resistivity range less than 1.0 Ω·m that enabled to evaluate the salinity of the aquifer in in situ conditions. Average values of the effective porosity of sandy sediments, φe = 0.32, and of silty ones, φe = 0.44, were used to generate the corresponding Archie equations. The study has shown that a DS aquifer with bulk resistivity in the range of 0.55–1.0 Ω·m contains in pores brine with 50–110 gchloride/l of (22–50% of that in saturated conditions, respectively), i.e. it keeps the potential to dissolve up to 114–174 g/l of salt.  相似文献   
880.
通过对太行山南段平顺铁矿矿区构造特征及岩浆岩的动力学分析研究,认为第一岩浆岩带属于被动侵位机制,岩体内部成矿潜力较大;第二岩浆岩带为主动侵位机制,背斜核部及岩体与围岩的接触部位为有利成矿区。同时根据岩石、矿石的稀土元素、微量元素、Pb同位素特征及矿体与岩体的关系,认为晚期闪长岩是主要的成矿母岩,但早期基性—超基性岩间接为铁矿的形成提供了一定的物质来源;矿体的形态明显受到接触面及周边构造形态的控制,呈不规则板状、透镜状、分枝状、羽状分布。最后运用矿体成矿规律、磁异常、电法异常等找矿预测方法,在研究区内圈出了龙降沟岩体南缘、双井、东郊3个找矿预测区。  相似文献   
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