Book review: Canada’s Groundwater Resources,edited by Alfonso Rivera (Fitzhenry & Whiteside,Canada, 2014)     

Yongxin Xu 《Hydrogeology Journal》2014,22(7):1725-1726

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晋冀低山丘陵区人工扰动植被花粉组合特征          下载免费PDF全文

李洁  许清海  曹现勇  田芳  丁伟  梁剑 《古地理学报》2014,16(2):227-238

54个晋冀低山丘陵区人工和人工扰动植被表土花粉样品分析表明:花粉组合以草本植物花粉(74.5％)为主,乔木花粉含量低于20％。人类活动较强的农田以谷物禾本科、蒿属和藜科花粉为主,人类活动较弱的荒地以蒿属、藜科和杂草禾本科花粉为主。人类活动强度不同,指示种不同,孢粉浓度亦不同;农田指示种为谷物禾本科、葡萄科和胡桃科,孢粉浓度约4380粒/g;而蒿属、蓼科和蔷薇科则为荒地指示种,孢粉浓度约10983粒/g。农作物种植方式不同,谷物禾本科花粉含量不同,单一禾本科作物种植区谷物禾本科花粉含量(40.2％)高于多种作物混作区(18.8％)和荒地(3.8％)的含量。谷物禾本科含量的变化可以为利用化石花粉提取和检测人类活动信息提供依据,也可为利用地层中谷物禾本科花粉判断古代农业活动提供依据。  相似文献   

中国西部地区方沸石胶结相与碎屑岩次生优质储集层形成机制   总被引：2，自引：0，他引：2       下载免费PDF全文

孙玉善  刘新年  张艳秋  董尉凯  徐彦龙  师桂霞  林艳波  李安琼 《古地理学报》2014,16(4):517-526

含油气盆地碎屑岩次生优质储集层的发育,除了与广泛发育的方解石胶结相有关外,在中国西部还有一类与沸石族自生矿物胶结的成岩相有关,其中以溶蚀方沸石胶结相形成的次生优质储集层与油气聚集成藏又有十分密切的关联。经实例分析:与自生方沸石胶结有关的成岩相主要受控于扇(辫状河)三角洲前缘相带、火山岩物源和成岩早期的碱性环境;次生优质储集层的形成在时间上主要处于成岩中期A阶段,在空间上受控于邻近的烃源岩、圈闭和输导体的沟通。方沸石矿物在物理性质上具有抗压易溶(有机酸)作用,较其他常见的自生矿物(胶结物)相对优越,就方沸石易于溶蚀的特点而言是较为理想的自生矿物(胶结物)。其溶蚀对孔隙度的贡献率在50％～75％之间,发育几率占绝对优势。所以,在方沸石发育的相带中寻找以粒间溶蚀孔为主的优质储集层,具有可靠的操作性和现实性。  相似文献   

Re–Os isotope and platinum-group element geochemistry of the Pobei Ni–Cu sulfide-bearing mafic–ultramafic complex in the northeastern part of the Tarim Craton     

Sheng-Hong Yang  Mei-Fu Zhou  Peter C. Lightfoot  Ji-Feng Xu  Christina Yan Wang  Chang-Yi Jiang  Wen-Jun Qu 《Mineralium Deposita》2014,49(3):381-397

A number of mafic–ultramafic intrusions that host Ni–Cu sulfide mineralization occur in the northeastern Tarim Craton and the eastern Tianshan Orogenic Belt (NW China). The sulfide-mineralized Pobei mafic–ultramafic complex is located in the northeastern part of the Tarim Craton. The complex is composed of gabbro and olivine gabbro, cut by dunite, wehrlite, and melatroctolite of the Poyi and Poshi intrusions. Disseminated Ni–Cu sulfide mineralization is present towards the base of the ultramafic bodies. The sulfide mineralization is typically low grade (<0.5 wt.% Ni and <2 wt.% S) with low platinum-group element (PGE) concentrations (<24.5 ppb Pt and <69 ppb Pd); the abundance of Cu in 100 % sulfide is 1–8 wt.%, and Ni abundance in 100 % sulfide is typically >4 wt.%. Samples from the Pobei complex have εNd (at 280 Ma) values up to +8.1, consistent with the derivation of the magma from an asthenospheric mantle source. Fo 89.5 mol.% olivine from the ultramafic bodies is consistent with a primitive parental magma. Sulfide-bearing dunite and wehrlite have high Cu/Pd ratios ranging from 24,000 to 218,000, indicating a magma that evolved under conditions of sulfide saturation. The grades of Ni, Cu, and PGE in 100 % sulfide show a strong positive correlation. A model for these variations is proposed where the mantle source of the Pobei magma retained ~0.033 wt.% sulfide during the production of a PGE-depleted parental magma. The parental magma migrated from the mantle to the crust and underwent further S saturation to generate the observed mineralization along with its high Cu/Pd ratio at an R-factor varying from 100 to 1,200. The mineralization at Poshi and Poyi has very high γOs (at 280 Ma) values (+30 to +292) that are negatively correlated with the abundance of Os in 100 % sulfide (5.81–271 ppb) and positively correlated with the Re/Os ratios; this indicates that sulfide saturation was triggered by the assimilation of crustal sulfide with both high γOs and Re/Os ratios. When compared to other Permian mafic–ultramafic intrusions with sulfide mineralization in the East Tianshan, the Poyi and Poshi ultramafic bodies were formed from more primitive magmas, and this helps to explain why the sulfide mineralization has high Ni tenor.  相似文献   

Growth of ringwoodite reaction rims from MgSiO3 perovskite and periclase at 22.5 GPa and 1,800 °C     

Akira Shimojuku  Asmaa Boujibar  Daisuke Yamazaki  Takashi Yoshino  Naotaka Tomioka  Junshan Xu 《Physics and Chemistry of Minerals》2014,41(7):555-567

The growth rate of ringwoodite reaction rims between MgSiO₃ perovskite and periclase was investigated at 22.5 GPa and 1,800 °C for 1–24 h using the Kawai-type high-pressure apparatus. The reaction was likely to proceed by a diffusion-controlled mechanism in which the dominant diffusion mechanism was grain-boundary diffusion. The reaction constant (the width of the ringwoodite reaction rim squared divided by time) determined from these experiments was between 1.3 × 10^?15 and 5.6 × 10^?15 m²/s. A Pt inert marker experiment indicated that the MgO component migrated faster than the SiO₂ component in ringwoodite. Thus, either Mg or O having the slower diffusion rate controlled the reaction. Because previous diffusion studies have shown that diffusion rates of O are slower than those of Mg, O would be a rate-controlling element for ringwoodite formation from MgSiO₃ perovskite and periclase. The growth rate appeared to be too fast to explain the observed topographic rise (~10 km) inside mantle plumes at the 660-km discontinuity.  相似文献   

山西新阳矿太原组下组煤层底板岩溶水突水安全性评价     

徐树媛  刘大伟 《中国煤炭地质》2014,(10):44-48

新阳矿9-10-11号煤层底板低于奥灰岩溶水位,承受水压较高,存在带压开采问题。依据矿区水文地质勘查资料,通过对9-10-11号煤层底板隔水岩层隔水性能、奥灰岩溶水富水程度、底板断裂构造发育情况、煤层底板承压大小以及采煤扰动底板破坏深度等突水因素分析,表明井田西南部断裂构造发育地段为突水危险区。分别采用突水系数法和突水危险度法对全井田9-10-11号煤层底板突水危险性进行评价,评价结果显示井田南部及断裂构造发育地段为突水危险区。理论分析与定量评价结果基本一致。针对9-10-11号煤层底板突水安全评价结果,提出了相应的防突水对策。  相似文献   

页岩气地震勘探数据采集参数选择的研究     

徐永清 《中国煤炭地质》2014,(7):63-68

我国页岩气重点开展区域为南方海相沉积地层,地震地质条件相对复杂,数据采集难度较大。贵州凤冈某页岩气勘查区块,属典型的喀斯特低山地貌,地形起伏大,地震施工困难,同时寒武系下统牛蹄塘组页岩层埋藏较深,反射波能量较弱,原始资料信噪比偏低。参考邻区地震勘探经验,采用二种方法论证野外施工参数:一是在勘探区选取论证点设计物理模型进行理论计算;二是以勘查区内向斜部位设计地质模型进行正演模拟求取。在此基础上通过进行不同岩性、井深、药量等激发接收参数的试验,确定了该区块的野外施工方案。该区页岩气地震勘探野外施工参数的选择方法,有效保障了其页岩气地震勘探效果。  相似文献   

新郑矿区地热资源潜能分析与保护建议     

朱永飞  ;徐连利  ;景学建  ;樊振丽  ;石勇丽 《中国煤炭地质》2014,(9):43-48

基于新郑矿区以平均每年0.0813×108m3的涌水量向地表排放热水,造成的地热资源损失和污染环境的现实,在分析地温地质条件基础上,利用热储资源量公式、卡明斯基公式和弹性储存量公式,分别计算了矿山开采前和开采后不同类型地热资源量,并对当前矿区地热潜能进行了评估。在此基础上,提出了选择煤层底板加固技术,保持岩溶裂隙水一定的水位、减少地下水排放和利用识别模型,选择适宜区段作为地热资源开采区,以调减矿山日常的排水量,尽可能维持渗流场基本不变,进而提高热储的潜能,实现节能减排,达到保护与利用地热资源的效果的建议。  相似文献   

陕北煤矿区地质环境保护与恢复治理措施——以神府矿区郭家湾煤矿为例     

李永红  何意平  康金栓  张新宇  李辉  滕宏泉  丁佳 《中国煤炭地质》2014,(4):41-45,57

郭家湾煤矿地处神府矿区新民采区西北部,为生态环境脆弱区。井田七层煤三个煤组开采后引发地面塌陷、含水层疏干、土地结构变化等地质环境问题,严重制约了地方经济的发展。为了煤炭资源可持续发展,研究陕北煤矿区地质环境保护与恢复治理措施,以1∶10000野外详细调查为依据,首先进行现状评估,然后针对矿山工程建设可能遭受、加剧、引发的矿山地质环境问题进行预测评估,最后提出了以移民搬迁、回填裂缝、生态恢复、建立矿山地质环境监测体系等为主的防治措施,让煤矿开采与矿山地质环境问题恢复治理并行。旨为陕北地区乃至全国煤矿,在保护地质环境中开发利用矿产资源提供依据和示范。  相似文献   

利用地震模拟技术研究逆断层的断点位置     

徐忠华 《中国煤炭地质》2014,(3):59-63,69

在地震资料解释阶段,可根据解释结果进行正演模拟,以验证解释结果的可靠性,并通过模型正演方式了解地下波场的细微变化,提高解释精度。依据内蒙古鄂托克前旗沙章图矿区DF2逆断层的赋存形态,建立的地质模型,并围绕其逆断层的断点位置、埋深、地层速度等,对各种接收排列进行射线追踪实验。通过改变开动的道数、道距及偏移距,观察各种参数下射线追踪的分布情况及模拟时间剖面的面貌。正演结果表明利用射线模型追踪的模拟地震反射剖面与实际时间剖面完全吻合,其确定的逆断层断点位置及断面倾角合理。  相似文献