油页岩原位开采地下冷冻墙缓冲距离研究

油页岩原位高温开采,需要在矿区周边建立地下冷冻墙以阻止地下水的流入,防止油气的泄漏。油页岩的高温开采区与地下冷冻墙的冷冻区之间的缓冲距离影响油岩页的开采效果及地下冷冻墙的制冷效果,也影响整个工程的施工成本及运行费用。采用理论计算、数值模拟分析的方法,以最低成本为目标,对合理的缓冲距离进行了详细计算与分析,确定出了合理的缓冲距离,为油页岩高温开采地下冷冻墙的设计提供了理论指导。     

成藏过程对天然气地球化学特征的控制作用

克拉2和阿克1天然气都具有组分明显偏干、碳同位素明显偏重的特征,如克拉2和阿克1天然气的干燥系数都接近于1.0,克拉2天然气的δ13C₁为-27.3‰～-31.1‰,阿克1天然气的δ13C₁为-21.9‰～-25.2‰,从“源控”的角度似乎这些天然气应该属于过成熟煤成气,这样计算所得到的天然气成熟度远大于实测和模拟计算的源岩成熟度。因此在解释克拉2和阿克1天然气数据的时候,除了“源控”的因素外,更应强调成藏过程的影响。分析认为晚期阶段聚气是造成克拉2和阿克1天然气都具有组分明显偏干、碳同位素明显偏重的主要因素。     

榆林风沙滩区水资源可持续利用对策与建议

本文在对榆林风沙滩区内水资源条件、开发利用现状及存在问题等调查研究资料进行深入分析的基础上,结合国民经济各业未来发展对水资源的需求情况,确定了未来不同水平年的需水量和供水量,并通过供需平衡分析,提出了解决水资源短缺的途径和实现水资源合理开发利用的建议.     

新疆阿尔金山清水泉-花泉子地区地球化学特征

在新疆阿尔金南缘断裂带中段的清水泉-花泉子地区,水系沉积物异常多呈带状沿断裂带分布,基性、超基性杂岩体是引起大而强异常的主要原因.通过对岩石化学特征和微量元素、稀土元素地球化学特征的剖析,表明其是同一岩浆结晶分异的产物,本区主要矿产应为铜,辉长辉绿岩是主要的含矿层位.经过加大了力度勘查,最终提交铜资源量15万 t.     

Inclusions in diamonds from the K14 and K10 kimberlites, Buffalo Hills, Alberta, Canada: diamond growth in a plume?

Analyses of mineral inclusions, carbon isotopes, nitrogen contents and nitrogen aggregation states in 29 diamonds from two Buffalo Hills kimberlites in northern Alberta, Canada were conducted. From 25 inclusion bearing diamonds, the following paragenetic abundances were found: peridotitic (48%), eclogitic (32%), eclogitic/websteritic (8%), websteritic (4%), ultradeep? (4%) and unknown (4%). Diamonds containing mineral inclusions of ferropericlase, and mixed eclogitic-asthenospheric-websteritic and eclogitic-websteritic mineral associations suggests the possibility of diamond growth over a range of depths and in a variety of mantle environments (lithosphere, asthenosphere and possibly lower mantle).

Eclogitic diamonds have a broad range of C-isotopic composition (δ¹³C=−21‰ to −5‰). Peridotitic, websteritic and ultradeep diamonds have typical mantle C-isotope values (δ¹³C=−4.9‰ av.), except for two ¹³C-depleted peridotitic (δ¹³C=−11.8‰, −14.6‰) and one ¹³C-depleted websteritic diamond (δ¹³C=−11.9‰). Infrared spectra from 29 diamonds identified two diamond groups: 75% are nitrogen-free (Type II) or have fully aggregated nitrogen defects (Type IaB) with platelet degradation and low to moderate nitrogen contents (av. 330 ppm-N); 25% have lower nitrogen aggregation states and higher nitrogen contents (30% IaB; <1600 ppm-N).

The combined evidence suggests two generations of diamond growth. Type II and Type IaB diamonds with ultradeep, peridotitic, eclogitic and websteritic inclusions crystallised from eclogitic and peridotitic rocks while moving in a dynamic environment from the asthenosphere and possibly the lower mantle to the base of the lithosphere. Mechanisms for diamond movement through the mantle could be by mantle convection, or an ascending plume. The interaction of partial melts with eclogitic and peridotitic lithologies may have produced the intermediate websteritic inclusion compositions, and can explain diamonds of mixed parageneses, and the overlap in C-isotope values between parageneses. Strong deformation and extremely high nitrogen aggregation states in some diamonds may indicate high mantle storage temperatures and strain in the diamond growth environment. A second diamond group, with Type IaA–IaB nitrogen aggregation and peridotitic inclusions, crystallised at the base of the cratonic lithosphere. All diamonds were subsequently sampled by kimberlites and transported to the Earth's surface.     

青海省达肯达坂山地区化探元素组合分区探讨

文章对青海省达肯达坂山地区1∶5万水系沉积物测量所得数据进行R型因子分析,提取了5种具有代表性的因子组合类型,对各因子元素组合得分归类,绘制了测区地球化学分区图。通过判读分析,地球化学分区图反映了不同地质体中以相应元素组合类型为主的地球化学异常。研究对比组合分区与因子得分异常,有利于推断相关元素的浓集部位,也为确定找矿靶区提供了方向。     

陕西省宁陕县太山庙金矿床地质特征及找矿标志

太山庙金矿床位于胭脂坝岩体南接触带附近,近东西向的断裂带控制着含金构造带及金矿体的分布。矿区圈出3个金矿体,金矿物为微粒金,以包裹金为主。金矿石自然类型主要为黄铁矿化石英脉型、褐铁矿化石英脉型、黄铁矿化蚀变绢云母石英片岩型。地球化学异常、石英片岩、次级断裂、石英脉、褐铁矿化蚀变带等为本区主要找矿标志。     

软岩井巷喷射混凝土抗渗机制及模拟试验研究

针对豫西滑动构造区软岩巷道在喷射混凝土支护条件下的抗渗性能问题,从立方定律基本理论着手,结合地下水层流渗透特点,按照不同的施工条件进行了黏结面渗透性能的模拟试验,并导出了相应的计算公式。通过试验结果的对比和分析,可以清晰了解到岩性、粗糙度、界面剂和大型刻槽等各种影响因素之间相互作用的过程和机理。即：（1）黏结面作为结构上的薄弱面,其渗透性要远远大于岩体和混凝土本体的渗透性,而粗颗粒软岩黏结面的渗透性也要远远大于相应的细颗粒软岩;（2）限制岩体结构面的粗糙度、使用各种界面剂以及布置适当的人工刻槽均能提高黏结面的抗渗性能;（3）岩体结构的荷载条件是黏结面渗透性能的一个重要影响因素。     

水库渗流影响文物遗址安全发掘研究——以湖南里耶秦代古城遗址为例

与古遗址相邻的江、河由于后期的工程活动,如水库、大坝的修建和蓄水,水位上升,将对遗址区地下水的运动规律及渗流场产生较大影响。在其影响下,古遗址可能产生各种环境地质灾害并对其发掘安全产生不利影响。论文以国家重点文物——湖南里耶秦代古城遗址安全发掘深度研究为例,在分析水库蓄水诱发的环境地质灾害的基础上,对遗址在不同库水位下的安全发掘深度及发掘方案进行了研究,提出了保障发掘安全的工程措施。研究成果为国家重点文物的保护和进一步发掘提供了科学依据。对类似文物工程的保护和发掘具有借鉴意义。     

Unravelling the evolution of an Alpine to post-glacially active fault in the Swiss Alps

The Gemmi fault is a prominent NW–SE striking lineament that crosses the Gemmi Pass in the central Swiss Alps. A multidisciplinary investigation of this structure that included geological mapping, joint profiling, cathodoluminescence and scanning electron microscopy, stable isotope measurements, luminescence- and U-TH-dating, 3D ground penetrating radar (GPR) surveying and trenching reveals a history of fault movements from the Miocene to the Holocene. The main fault zone comprises a 0.5–3 m thick calcite cataclasite formed during several cycles of veining and brittle deformation. Displaced Cretaceous rock layers show an apparent dextral slip of 10 m along the fault.A detailed study of a small sediment-filled depression that crosses the fault provides evidence for a post-glacial reactivation of the fault. A trench excavated across the fault exposed a Late-Glacial-age loess layer and late Holocene colluvial-like slope-wash deposits that showed evidence for fault displacement of a few centimeters, indicating a recent strike-slip reactivation of the fault. Focal mechanisms of recent instrumentally recorded earthquakes are consistent with our findings that show that the fault at the Gemmi Pass, together with other parallel faults in this area, may be reactivated in today's stress field. Taking together all the observations of its ancient and recent activity, the Gemmi fault can be viewed as a window through geological space and time.