Management of karst water resources in mining area: dewatering in mines and demand for water supply in the Dongshan Mine of Taiyuan, Shanxi Province, North China

Coalfields in North China contain six to seven coal seams in the Permo-Carboniferous strata. The coal seams are underlain by the Ordovician limestone. Large-scale dewatering or depressurizing of the karst aquifer was considered essential to avoid water inrushes and keep the mines safely operational. This practice, however, has caused water supply shortage in the mining areas. The most effective solution to this conflict is to use the uncontaminated karst water from the mines for water supply. This paper explores a management model to maximize the utilization of the karst water while maintaining the safe operation of the mines. The model can provide essential information on water resource distribution for decision makers. The model was applied to the Dongshan Coal Mine in Taiyuan City, China.     

蒲阳河流域地下水水化学及同位素特征

保定西部山前地区位于太行山及华北平原交界带,为缓解极端气候灾害对生产生活的影响,维持地下水资源的可持续开发利用,开展相关的地下水水化学及同位素特征研究。研究区地下水化学类型以HCO3—Ca·Mg、HCO3·SO4—Ca·Mg及SO4·HCO3—Ca·Mg为主,区内地下水主要来源于大气降水,流域内地表水补给地下水;地下水中化学成分为Ca2＋、Mg2＋、HCO-3、SO2-4,主要来源于岩石风化作用,同时受到人类活动的影响,地下水中硝酸盐含量明显升高;由于受到褶皱构造的控制,流域的上游及平原区均出现年龄大于60年的地下水,多数岩溶水年龄较复杂,从现代水到大于60年的水均有分布。研究成果为流域内水资源的合理开发利用提供建议,区内岩溶地下水的开发将在一定程度上缓解极端天气的影响。     

冷水坑矿田层状富铅锌矿赋矿围岩——铁锰碳酸岩角砾岩物质来源及成因分析

冷水坑矿田具有浅部斑岩型矿体与深部层状矿体的复杂组合,深部层状矿体赋存于上侏罗统打鼓顶组晶屑凝灰岩所夹的(铁锰)碳酸岩角砾岩层中。从(铁锰)碳酸岩角砾岩的基本地质特征入手,论述和分析了(铁锰)碳酸岩角砾岩的主要物质成分组成、分布、产状及与矿体关系等特点,结合矿物X-射线粉晶分析、碳-氧同位素和氢-氧同位素佐证,认为(铁锰)碳酸岩角砾岩为深水湖泊相火山-沉积成因,与层状矿体形成密切相关,后期斑岩岩浆就位及其流体活动对早期火山沉积碳酸岩层叠加改造,从而形成了与斑岩具有成因联系的层状富铅锌银矿床。     

江西北部及邻区地震活动特征

利用不同时间尺度、不同震级下限的资料,分析了江西北部及邻区的地震活动时空分布特点。结果显示：本区地震活动成组现象明显．中强地震前中短期阶段的地震学异常特征主要表现为地震空区、地震条带或中等地震集中增强区。未来数年内本区还有可能发生中强地震,目前应当高度重视区域的震情发展趋势。     

郑庄油区长6储层特征及其综合评价

据野外踏勘、钻井取心、录井和测井等资料,对研究区储层特征进行了综合研究。结果显示,该区长 6储层主要为成分成熟度较低的长石砂岩,其物源可能主要来自花岗岩区,部分来自沉积岩和变质岩区;沸石粒间溶孔和长石粒内溶孔是研究区储层的主要孔隙类型;储层物性影响因素主要包括其物质组成、沉积微相和成岩作用。该区储层可划分为4类,其中优质(Ⅰ类)和较好(Ⅱ类)储层主要分布在分流河道、河口坝微相或溶蚀孔隙发育的地区。研究成果为进一步制定合理的开发方案及剩余油挖潜等提供了基础依据。      

辽东连山关地区重熔混合岩岩石地球化学特征

连山关地区重熔混合岩位于太古宙钾长花岗岩和浪子山组一段石英岩之间,受韧性剪切带控制,局部地段缺失,为动态部分熔融作用形成。其主量元素以富Si、略富Al、富Na、富K和低Mg、低ca为特点;微量元素表现出富集Be、Mo、Pb、Y、Ba、La、Cu和亏损Co、Ni、Zn、Cr、Ti、V,且与铀关系密切的共生元素有Pb、Mo、V、Be等特点;稀土元素具有明显的轻稀土富集和重稀土相对亏损等特征,具有较显著的Eu负异常。重熔混合岩的成因为韧性剪切作用中围岩的易熔组分不完全、不均匀重熔作用后冷凝再同化形成,重熔混合岩与铀矿化关系密切。     

广西德保纤维状须藤石的发现与研究

广西德保二叠系合山组的含煤地层中,发现了罕见的白色纤维状二八-三八面体含镁铝的绿泥石——须藤石。电镜下为薄的板条状。结构式:K_(0.01)(Li_(0.02) Mg_(1.73)—Al_(3.13)Fe_(0.02))_(4.90)(Si_(3.10) Al_(0.90))4 O_(10)(OH)_8。单斜晶系,Ⅱ_b多型,修正后的晶胞参数:α=0.5226±0.0002nm,b=0.9061±0.0003nm,c=1.4285±0.0005nm,β=97°11′±2′,V=0.671±0.0004nm~3。实测d_((001))=1.417±0.001nm,d_((060))=0.15098±0.00009nm。底面反射以I_((003))为最强。提供了该矿物的热谱及红外光谱,并研究了它的加热相变。须藤石的围岩为碳质的绢母云钠母云累托石粘土岩。须藤石的纤维集合体呈脉状,多分布在平行岩层间和层内裂隙中,或围绕在黄铁矿的周围。其成因为热液充填和交代。     

南海西缘新生代沉积盆地形成动力学探讨

通过对南海西缘新生代沉积盆地伸展作用、沉降、构造变形等特征分析,检查印支地块多条近北西向走滑断裂时间、幅度等特征以及与盆地之间联系,结果表明印度-欧亚碰撞引起的逃逸作用与南海西缘新生代盆地没有直接的成因联系;两个与俯冲有关的不同扩张机制与南海西缘新生代盆地有成因联系,即(1)太平洋板块在古新世到始新世的滚动后退,太平洋-欧亚板块汇聚速率的降低驱使这些盆地产生初始伸展作用;(2)渐新世到中中新世古南海南倾俯冲板块的拖曳力,进一步驱使这些盆地的伸展及接着的南海扩张.     

基于不同积雪日定义的积雪资料比较分析

利用天气现象定义与积雪深度定义两种方法对全国884个台站的积雪日资料进行统计处理, 分别整理出每一台站各个积雪年的积雪日数、积雪深度、 初终雪间隔日数3个要素的两套数据, 并进行对比分析. 结果表明: 在全国东部大部分地区及新疆地区, 两种数据差别不大, 但在东北及青藏高原两套数据的差别较大. 在积雪日数的比较中, 两种数据在东北及青藏高原的差别基本都在10 d以上, 积雪深度的差别在0.4 cm以上, 初终雪间隔日数的差别以青藏高原最明显, 大部分地区的差别在15 d以上, 甚至有达到30 d以上的区域. 对青藏高原东北边坡代表站的积雪平均值进行M-K突变检验发现, 积雪深度定义的积雪日数与间隔日数减少趋势略大于天气现象定义统计的数值;而在积雪深度的比较中则相反. 两种定义的积雪间隔日数均在1987年出现突变.     

Sedimentary characteristics of the Jurassic Zhiluo Formation and uranium deposits in Zhiluo-Diantou area,southern Ordos Basin

Diantou uranium deposits and multiple uranium mineralization sites have been discovered in the sandstones in the lower member of the Jurassic Zhiluo Formation in the southern Ordos Basin. However, the study on the sedimentary facies of the Zhiluo Formation, which restricts the prospecting work of sandstone-type uranium deposits. Based on the outcrop measurements and drilling core cataloging, and combined with the geological drilling data of petroleum, coal, and nuclear industry, we have elaborated the sedimentary characteristics of the Zhiluo Formation in the Fuxian area. We have also combined uranium source, structure, post-alteration and other factors to explore the relationship between sedimentary faces and uranium metallogenic conditions in the study area. The study found that in the lower member of the Jurassic Zhiluo Formation, the thickness of the sand body is 30-65 m and sand ratio is 0.6-0.75. It is gravel and sandy braided river deposit. In the upper member of the Jurassic Zhiluo Formation, the thickness of the sand body is 10-38 m, and the sand ratio is 0.15-0.45 and is a meandering river deposit. The study area is located at the center of the lake basin and sedimentary facies is coastal shallow lacustrine in the upper member of the Jurassic Zhiluo Formation. Sedimentary environment, sedimentary facies, the intersection of braided river channels, sand body thickness, sediment particle size and mudstone interlayer play an important role in controlling uranium mineralization. The exploration of uranium deposits in the northern part of the deposit should focus on the intersection or bifurcation of the braided river channel in the lower part of the Zhiluo Formation. The charcoal- and pyrite-bearing sandstone of channel bar can be used as a prospecting indicator for uranium mineralization.