西南印度洋脊龙旂热液区富铝蚀变黏土矿物类型和地球化学特征研究

产出于不同地质背景下的热液成因黏土矿物组成、晶体结构及化学成分等信息,可指示与海底热液作用有关的水-岩反应过程和流体的物理化学条件变化。但目前对于以西南印度洋脊为代表的超慢速扩张脊热液区的黏土矿物研究程度较低,尚未了解其经历的热液蚀变作用及形成过程。本文综合应用SEM-EDS、XRD、FT-IR、EPMA和LA-ICP-MS等多种分析测试手段对采自龙旂热液区矿化蚀变角砾的形貌结构、矿物组成及其化学成分进行系统表征。研究表明:该蚀变角砾中的共生矿物相主要由具二八面体结构、富Al端元的蒙皂石族矿物贝得石与蛋白石组成,角砾中可见呈细粒浸染状的TiO_2。蚀变黏土矿物的化学成分较为单一,具有富Al、贫Mg和贫Fe的特征;其稀土元素总量普遍不高(2. 43～43. 45μg/g),配分模式呈负Eu异常(0. 31～0. 53)而未显示Ce异常(1. 09～1. 16)。推断产出于硫化物堆积丘体边部的矿化角砾长期受酸性、相对还原的、低温热液流体持续叠加和淋滤改造,除Al和Ti以外大部分元素被活化迁移,形成矿物组成简单的富铝黏土矿物相。本研究查明了龙旂热液区新的蚀变黏土矿物类型及其元素地球化学特征,反映该区广泛发育低温热液蚀变作用,为进一步探讨西南印度洋超慢速扩张脊热液成矿系统的水-岩反应过程提供了一定依据。     

Formation of the Devonian Fengtai Hydrothermal Brine Basin and the Metallogeny of Gold and Lead-Zinc Mineralizations in Shaanxi

The study of the relationships between the hydrothermal sedimentary formations and the gold andlead-zinc mineralizations in the Devonian Fengtai basin in Shaanxi shows that there was a hydrothermal brine sedimentary event which was inserted into the normal sedimentary background from the late Middle Devonian to the early Late Devonian. This event is closely related to gold and lead-zinc mineralizations in this area.     

元坝高研磨性地层提速提效集成钻井技术

四川元坝地区陆相下沙溪庙组—须家河组地层岩性复杂、可钻性差、研磨性强、地层压力高,使用牙轮钻头、PDC钻头等常规钻井技术钻速慢、周期长、效率低,引进扭力冲击器+PDC钻头、孕镶金刚石钻头+涡轮等进口提速工具费用昂贵,提速效果明显,但经济效益差。为降低钻井成本,结合地层地质特性,开展了个性化钻头及配套提速工具的研制及优选,形成了元坝高研磨性地层提速提效集成钻井技术,即自流井组珍珠冲段以上地层采用研制的KS1362ADGR型PDC钻头+国产大扭矩螺杆马达;珍珠冲及须家河组地层优选国产NR826M型孕镶金刚石钻头+高转速螺杆马达。通过3口井现场试验表明：同比2012—2013年完钻井指标,平均机械钻速提高64.7%;在井段长度增加8.7%的情况下,平均钻井周期缩短36.3%。该技术将对川东北、川西须家河组等高研磨性地层钻井具有指导作用。     

高研磨性地层复合式钻头的研制与应用

金山气田、龙凤山构造、长岭断陷等登娄库组以下深部地层可钻性差,研磨性强,导致钻头磨损严重,使用效率低。在对牙轮钻头、PDC钻头及孕镶金刚石钻头在高研磨性地层中的适应性进行细致和全面分析的基础上,提出了把PDC钻头机械钻速高和孕镶金刚石钻头进尺多的技术优势相结合的研制思路,开展PDC+孕镶复合式钻头设计。现场应用取得了良好的试验效果。提出了合理化的建议。     

海底热水活动与海相富有机质层形成的关系——以华北新元古界青白口系下马岭组为例

对华北新元古界青白口系下马岭组富有机质层段的常量元素、微量元素和有机质含量进行了系统分析，其基本特征是富有机质沉积层段的SiO2含量明显高于泥质岩中的含量，SiO2含量与TOC成正相关系，与TiO2含量成反比，Si／(Si Al Fe)比值与TOC成正相关关系；与海底热水流体活动有关的P、Cu、Zn、Co、Ni、V等元素含量明显富集，Ba／Sr比值远远大于1，且与TOC之间成正相关关系。在下马岭组剖面上，从Qb1x^3向上纹层～薄层状硅质岩夹层蹭多，有机质含量也开始急剧增高。地质地球化学特征表明，在下马岭组富有机质沉积层段形成时，盆地拉张沉降作用强烈，海底热水活动与之紧密相伴，而且海底热水流体活动是导致该富有机质沉积层段形成的主要原因。     

川中地区上三叠统须家河组气田异常高压演化研究

根据川中地区上三叠统须家河组典型气田的现今实测地层压力分析了异常高压发育的特征。以现今实测压力为约束,利用流体压实耦合方法恢复了须家河组气田主要储层的压力演化史。研究结果表明：上三叠统须家河组储层超压的发育在总体上是逐渐增大的,其地层压力演化可划分为三个阶段：（1）150 Ma之前为常压阶段,地层压力等于静水压力;（2...     

内蒙古河套地区高氟水成因分析

根据内蒙古生态地球化学调查结果，结合大量的水质测定资料，编制了河套地区地下水氟离子含量分级图，分析研究了区内高氟水的形成与富集的原因。包括当地气候条件等自然因素，研究区内岩性、土壤性质、地下水物化条件、湖泊沉积物类型等地质因素和人类活动二个方面。其中起主导作用的是自然因素、地质因素，而像包头市近郊潜水氟污染是由于包钢的废渣和废水排放等人类活动引起的。对治理河套地区氟中毒的区域环境问题提出了相应的建议。     

坚硬地层NBS高效孕镶金刚石钻头的研究与应用

介绍了一种NBS高效孕镶金刚石钻头,该类型钻头通过向胎体配方引入一种NBS材料,该材料与胎体结合强度强,晶型锐利,室内微钻试验及野外试验结果显示,该类型钻头可大幅提高钻进中弱风化坚硬岩石的钻进效率,且钻头寿命较以往技术有很大提高。     

托普台区块高渗透地层随钻堵漏剂配方优化

托普台区块上部地层以砂泥岩层、砾质砂岩为主,容易发生漏点不明确、漏失段长的高渗透性漏失。通过对堵漏材料的配伍性评价及合理级配,优选出了一种适合高渗透性漏失地层的随钻堵漏剂。该堵漏剂对钻井液流变性影响小,可降低钻井液API滤失量,对沙床封堵后承压能力＞10 MPa,在TP328X井的应用表明,高强度弹性石墨颗粒复合凝胶堵漏对于高压差、高渗透漏失的工况,可以有效封堵漏层,特别适用于对于漏层不明、漏涌同层、裸眼等复杂井况。     

鄂尔多斯盆地延安组层序地层格架与煤层形成

研究鄂尔多斯盆地延安组的煤层发育特征,首先建立延安组等时的层序地层格架,进而分析可容空间变化对煤层形成的控制作用。通过分析野外露头、钻孔、测井等资料,识别延安组中发育的关键层序地层界面,将延安组划分为3个三级层序;层序由低位正常湖退、湖侵、高位正常湖退和强迫湖退4个体系域组成,并建立了全盆地范围等时的层序地层格架。研究发现:在等时层序地层格架中,煤层主要发育在层序I、层序Ⅱ湖侵和高位正常湖退体系域的中、晚期和层序Ⅲ的湖侵体系域的晚期;在区域上,盆地北部地势较为平坦,发育中等厚度、区域稳定性较好的煤层,盆地南部发育稳定性较差的厚-巨厚煤层;从滨湖平原到三角洲平原再到河流泛滥平原,厚煤层从位于四级基准面上升半旋回的底部逐渐过渡到中上部。综上可知,不同沉积区可容空间增加速率与泥炭堆积速率达到平衡的位置不同,厚煤层主要发育在二者近似处于平衡状态的位置,并且发育随着沉积相带变化有规律地迁移。     

Geochemical constraints on the modes of carbonate precipitation in peridotites from the Logatchev Hydrothermal Vent Field and Gakkel Ridge

The ultramafic-hosted Logatchev Hydrothermal Field (LHF) at 15°N on the Mid-Atlantic Ridge and the Arctic Gakkel Ridge (GR) feature carbonate precipitates (aragonite, calcite, and dolomite) in voids and fractures within different types of host rocks. We present chemical and Sr isotopic compositions of these different carbonates to examine the conditions that led to their formation. Our data reveal that different processes have led to the precipitation of carbonates in the various settings. Seawater-like ⁸⁷Sr/⁸⁶Sr ratios for aragonite in serpentinites (0.70909 to 0.70917) from the LHF are similar to those of aragonite from the GR (0.70912 to 0.70917) and indicate aragonite precipitation from seawater at ambient conditions at both sites. Aragonite veins in sulfide breccias from LHF also have seawater-like Sr isotope compositions (0.70909 to 0.70915), however, their rare earth element (REE) patterns show a clear positive europium (Eu) anomaly indicative of a small (< 1%) hydrothermal contribution. In contrast to aragonite, dolomite from the LHF has precipitated at much higher temperatures (~ 100 °C), and yet its ⁸⁷Sr/⁸⁶Sr ratios (0.70896 to 0.70907) are only slightly lower than those of aragonite. Even higher temperatures are calculated for the precipitation of deformed calcite veins in serpentine–talc fault schists form north of the LHF. These calcites show unradiogenic ⁸⁷Sr/⁸⁶Sr ratios (0.70460 to 0.70499) indicative of precipitation from evolved hydrothermal fluids. A simple mixing model based on Sr mass balance and enthalpy conservation indicates strongly variable conditions of fluid mixing and heat transfers involved in carbonate formation. Dolomite precipitated from a mixture of 97% seawater and 3% hydrothermal fluid that should have had a temperature of approximately 14 °C assuming that no heat was transferred. The much higher apparent precipitation temperatures based on oxygen isotopes (~ 100 °C) may be indicative of conductive heating, probably of seawater prior to mixing. The hydrothermal calcite in the fault schist has precipitated from a mixture of 67% hydrothermal fluid and 33% seawater, which should have had an isenthalpic mixing temperature of ~ 250 °C. The significantly lower temperatures calculated from oxygen isotopes are likely due to conductive cooling of hydrothermal fluid discharging along faults. Rare earth element patterns corroborate the results of the mixing model, since the hydrothermal calcite, which formed from waters with the greatest hydrothermal contribution, has REE patterns that closely resemble those of vent fluids from the LHF. Our results demonstrate, for the first time, that (1) precipitation from pure seawater, (2) conductive heating of seawater, and (3) conductive cooling of hydrothermal fluids in the sub-seafloor all can lead to carbonate precipitation within a single ultramafic-hosted hydrothermal system.     

高压水热体系中氧逸度/活度测量与控制技术的回顾与展望

高压水热体系在科学实验、工业过程和自然界中广泛存在.氧逸度/活度是高压水热体系最基本的物理化学参数之一,经常控制着体系的物质形态、性状以及过程的发生与发展,因此对高压水热体系氧逸度/活度的测量与控制具有极为重要的意义.本文首先对目前国际上流行的各种高压水热体系氧逸度/活度测量与控制技术从原理和基本特点等方面作了详细的介绍,接着对各种技术的优、缺点作了比较与评价,文末对未来高压水热科学与技术领域氧逸度/活度测量与控制技术的发展趋势作出了展望.     

上扬子地块北缘灯影组硅质岩系地球化学特征及其成因

通过野外调研, 表明大巴山构造带和米仓山构造带震旦系灯影组发育多套硅质岩系, 并与海相碳酸盐岩相伴产出。微量、稀土元素分析结果表明, 硅质岩系具有热水成因特征。其中, Ba含量较高, Ba/Sr值大于1;Th/U值小于1, Th-U图解中所有样品均投到热水沉积物区;Zr元素较为富集, Zr-Cr图解中样品全部投到热水沉积物趋势线附近;硅质岩系REE总量低, Ce总体为负异常, Eu正异常明显, 硅质岩HREE富集, 硅质白云岩HREE富集不明显。Ce/Ce*、LaN/CeN、V/Y值表明灯影组硅质岩形成于大洋盆地到大陆边缘的过渡地带;Th/Sc、Th/U、V/Cr、V/(V+Ni)值表明硅质岩主要形成于还原环境中, 部分形成于氧化环境中。综合硅质岩稀土、微量元素特征并结合震旦纪区域地质构造演化, 本区硅质岩应形成于复杂大陆边缘富氧的浅海陆棚环境及缺氧的陆内裂陷槽环境中。     

南大西洋中脊26°S热液区成矿物质来源探讨

南大西洋中脊的26°S热液区广泛发育多金属硫化物、底泥、枕状熔岩、非活动性烟囱体和活动性烟囱体。为了有效探索硫、铜等成矿物质的来源以及成矿作用过程,分别以玄武岩、烟囱体残片及块状多金属硫化物为研究对象,开展了熔融包裹体、硫同位素和铜同位素研究。结果显示：区内玄武岩新鲜未蚀变且斑晶中产出大量熔融包裹体;熔融包裹体气泡壁附着黄铜矿、黄铁矿及磁铁矿等子矿物,说明在岩浆作用过程中可从熔浆中分离出成矿所需的金属元素和硫,这些成矿元素随着岩浆去气作用进入挥发分中,并随着脱气作用迁移出来。通过对烟囱体残片及块状多金属硫化物中黄铁矿的硫同位素组成进行比对分析,发现26°S热液区内硫化物的硫同位素与大西洋各热液区硫化物的硫同位素变化范围相一致,但δ³⁴S_V-CDT值略低（3.0‰~3.9‰）。低的δ³⁴S_V-CDT值指示硫以岩浆硫源为主,海水硫酸盐还原硫占比低。黄铜矿呈现略微富铜重同位素特征且分馏程度较低,其δ⁶⁵Cu值（0.171‰~0.477‰）趋近于大洋中脊玄武岩的铜同位素值（0）。综合硫同位素及铜同位素特征,表明热液流体经历了岩浆和海水的混合过程,成矿物质主要来自于岩浆热液,成矿作用过程中可能有少量海水混入。     

辽宁省典型地区高氟地下水的分布特征及成因分析

在前人研究的基础上,通过水文地质调查、综合物探法、水化学及水质检测方法,探测辽宁省典型地区水化学特征,分析了水化学特征与地下水氟离子的含量关系;不同地貌单元地下水氟离子含量分布不同;主要从高氟地下水形成的物质基础,水文地质环境对氟离子变化的制约,粘性土层是富集氟离子最好场所等方面分析辽宁高氟地下水的形成原因,通过研究了解到高氟地下水一般存在于潜水的上部及粘土层中,这一研究为今后寻找低氟水源提供前期有力资料奠定基础。     

Hydrothermal and resedimented origins of the precursor sediments to banded iron formation: sedimentological evidence from the Early Palaeoproterozoic Brockman Supersequence of Western Australia

The Early Palaeoproterozoic Brockman Supersequence comprises banded iron formation (BIF), bedded chert, limestone, mudrock, sandstone, breccia, tuffaceous mudstone, ashfall tuff and, in sections not reported here, basalt and rhyolite. Density current rhythms are preserved in sandstones, mudrocks, tuffaceous mudstones and limestones. Relics of similar rhythms in BIF imply that its precursor sediments were also deposited by density currents. Hemipelagic deposits are siliciclastic or mixed siliciclastic–volcaniclastic mudstones. Bedded chert, chert nodules and the chert matrix of BIF preserve evidence for formation by diagenetic replacement. For bedded chert (and chert nodules), silica replacement occurred before compaction close to or at the sediment–water interface, indicating that it is siliceous hardground. The chert matrix of BIF formed during compaction but before burial metamorphism. Original sediments were resedimented from two sources: (1) limestone, mudrock, sandstone, breccia and tuffaceous mudstone from a shelf; and (2) BIF from within the basin realm. Shelf sediments were resedimented to basin-floor fans during third-order lowstands. The precursor sediments to BIF are interpreted to have been granular hydrothermal muds, composed of iron-rich smectite and particles of iron oxyhydroxide and siderite that were deposited on the flanks of submarine volcanoes and resedimented by density currents. Resedimentation occurred by either bottom currents or gravity-driven turbidity currents, and the resulting sediment bodies may have been contourite drifts. The concept that BIF records high-frequency alternating precipitation from ambient sea water of iron minerals and silica is negated by this study. Instead, it is postulated that the precursor sediments to BIF originated in much the same way as modern Red Sea hydrothermal iron oxide deposits, implying that at least the particles of iron oxyhydroxide originated from the oxidation of vent fluids by sea water. Several orders of cyclicity in basin filling establish a relationship between rising to high sea levels, episodic sea-floor hydrothermal activity and BIF that is reminiscent of the link between eustacy and spreading-ridge pulses.     

高瓦斯涌水超厚煤系复杂地层的钻进施工

在瓦斯含量极高的煤层（厚）和不同地层段涌水的超厚水敏性地层中钻进施工,合理设计钻孔结构、选择设备、钻进方法、钻进参数和正确操作,是顺利完成钻进施工的前提,正确使用泥浆是孔内事故预防措施的关键。正确使用“高密度”水基成膜泥浆,既能保持孔内液柱与孔壁之间的压力平衡,也能降失水抑制水敏性地层水化膨胀和分散脱落,从而达到防止孔壁坍塌,起到稳定孔壁的作用。介绍了这些技术措施在贵州扬寨煤矿高瓦斯涌水超厚煤系复杂地层中的应用及效果。     

粤西古水剖面震旦系顶部层状硅岩的热水成因属性:岩石学和地球化学证据

古水剖面震旦系顶部硅岩主要发育层状构造、纹理状构造、块状构造和假角砾状构造,化学成份以ＴｉＯ_２、Ａｌ_２Ｏ_３和大部分微量元素亏损（相对地壳克拉克值）为特征。但Ｂａ、Ａｓ和Ｓｂ等少数已知的热水沉积特征元素显示富集。在Ａｌ－Ｆｅ－Ｍｎ三元图上,古水硅岩投映在“热水沉积”域内。因子分析和对应分析显示了大部分金属元素在代表热水淋滤作用的因子上均有反映。稀土元素以低含量为特征,在对北美页岩组合样（ＮＡＳＣ）正规化后的稀土配分模式落在典型热水沉积的上、下限之间,而在正常沉积的之外。各种岩性和地球化学证据表明,古水硅岩具有热水成因。     

高压旋喷水泥浆护壁技术的研究与应用

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