滨海砂矿钻探的工艺特点

我国海岸线长，沿海有富集的砂矿资源。有玻璃砂、型砂、化学砂等。近年来，我局对砂矿资源进行了调查，并在部分矿区进行了钻探工作。本文将从钻探施工中总结滨海砂钻的一些工艺特点。     

滨海相砂矿床施工技术

我队在福建滨海进行滨海相型砂、玻璃砂矿床勘探。近两年共施工57个钻孔，完成工作量1143.78米，最大孔深51.50米，钻孔可利用率100％，优质孔率达86.5％，取得了满意的地质成果，掌握了滨海相砂矿施工技术。一、原始班报表普通岩心钻探班报表不适于作为砂钻班报表，我队专门设计了“砂钻施工原始班报表”，图1表明班报表各种数字间的关系。经矿区使用，它适用于砂钻施工，原始资料齐全，完全满足地质要求。二、套管鞋我队采用锥形和锯齿形套管鞋，如图2、3所示。锥形套管鞋用     

我国滨海砂矿及工作刍见

我国的海岸线长,有着利于滨海砂矿的成矿条件.滨海砂矿的研究始于五十年代,近年来,对滨海砂矿的分布特征、成矿带、成矿远景的研究,取得了新的进展.一、我国滨海砂矿的分布1.黄海、渤海滨海砂矿成矿区(1)辽东半岛东海岸金、钛铁矿、锆石成矿带:该区出露岩石主要为前寒武系片麻岩和花岗岩,有较多石英脉、含金破碎带,是本区滨海砂矿物质来源.砂金矿在旅顺等处,锆英石分布在庄河至金县沿海一     

滨海砂矿钻探的工艺特点

福建海岸曲折漫长,分布着丰富的砂矿资源。海砂质佳、品种多,有玻璃砂、型砂、化学砂等。近年来,我局对闽东南沿海约13400平方公里面积内的砂矿资源进行了调查,并对部分矿区进行了钻探工作。本文从钻探施工中遇到的问题,总结滨海砂钻的一些工艺特点。     

苏联砂金矿地质学的几个问题

苏联砂金矿床的主要地质－工业类型可分为：化学风化壳砂矿、弱分异堆积层的洪－冲积砂矿和洪－坡积砂矿、冲积砂矿、大陆古海岸线的滨海砂矿、工艺成因砂矿、其中冲积砂矿的工业价值最大，关于砂金矿的原生补给源、主要的有金－石英建造、金－硫化物－石英建造、金－硫化物建造、金－冰长石－石英建造，与它们有关的矿砂规模各不相同，其中金－石英建造的意义最大。砂金矿发育区的分类在砂矿的预测找矿中占有主导地位，在苏联可分为：老地盾和原地台砂金矿区，前中生代褶皱带砂金矿区、中生代褶皱区的砂金矿区、构造岩浆活化区的砂金矿区。对于砂金矿的地貌构造位置，可分为隆起区、稳定地貌区和坳陷区。坳陷区中的成矿后坳陷对成矿意义最大。     

福建近海砂矿类型及其分布特征

福建近海砂矿资源极为丰富，目前已发现各类近海砂矿10余种，初步探明具有工业价值的有回填用砂（建筑用砂）、石英砂（型砂、玻璃砂、标准砂等）和稀有、稀土砂（锆石、钛铁矿、金红石、独居石和磷钇等）9个矿种，各类矿床（点）42个，成因类型有海积、风积、冲洪积和洪积等。近海砂矿主要分布在闽江口及其以南近海地区，是福建极为重要的矿产资源。     

苏联砂金矿地质学的几个问题

苏联砂金矿床的主要地质-工业类型可分为:化学风化壳砂矿、弱分异堆积层的洪-冲积砂矿和洪-坡积砂矿、冲积砂矿、大陆古海岸线的滨海砂矿、工艺成因砂矿,其中冲积砂矿的工业价值最大。关于砂金矿的原生补给源,主要的有金-石英建造、金-硫化物-石英建造、金-硫化物建造,金-冰长石-石英建造。与它们有关的砂矿规模各不相同,其中金-石英建造的意义最大,砂金矿发育区的分类在砂矿的预测找矿中占有主导地位,在苏联可分为:老地盾和原地台砂金矿区、前中生代褶皱带砂金矿区、中生代褶皱区的砂金矿区、构造岩浆活化区的砂金矿区,对于砂金矿的地貌构造位置,可分为隆起区、稳定地貌区和坳陷区,坳陷区中的成矿后坳陷对成矿意义最大。     

莫桑比克中北部滨海锆钛砂矿成矿地质特征

莫桑比克东濒印度洋,沿海岸线赋存丰富的具有世界级规模的滨海砂矿资源,具有较好的勘探和开发投资前景。通过野外地质调查和室内综合研究,对莫桑比克中北部滨海砂矿的成矿地质背景、矿体特征、矿石特征及矿床成因进行总结。本区滨海锆钛砂矿赋存于第四系粉细砂层中,地貌上多为起伏砂地和平坦砂地,矿体沿海岸线呈条带状分布,延展连续性较好,形态较规则。沿倾向矿石品位较连续,矿体厚度总体上变化不大,各重矿物在矿体中的含量变化呈正相关关系。重矿物以钛铁矿为主,其次为锆英石、金红石、独居石,多以单矿物颗粒的状态散布在矿石中,粒度主要为0.096～0.15 mm,属易分选型矿石。矿床类型属滨海相机械沉积型矿床,其形成受成矿物质来源、气候和水动力、海岸地貌、构造运动与海岸变迁等多种因素影响,主要经历三个阶段,即重矿物原生赋存阶段、运移阶段和富集成矿阶段。本工作揭示了滨海砂矿形成规律,为莫桑比克中北部滨海砂矿矿床勘探和开发提供了参考。     

山东省近海砂矿资源类型划分及开发前景

山东省近海砂矿是仅次于油气的第二大近海矿产，目前已发现滨海海砂矿10多种，各类砂矿床近80个，初步查明具有工业价值的有锆石、建筑用砂、型砂、石英砂、贝壳、球石、砂金7种。近海砂矿主要是在海水动力条件下由于机械沉积分异作用，使陆源碎屑中的有用矿物富集而成的。海洋砂矿开发具有高投资、高风险、高收益的特点，开发前应充分论证海洋环境影响和采选技术条件，审慎地进行选区和可行性论证，避免盲目勘查、开发。     

广东滨海砂矿地质特征及评价方法

一滨海砂矿地质特征1.地貌:砂矿形成主要受地貌的制约。地貌形成与地壳运动、岩性、气候、水系……等因素有关。控制滨海砂矿赋存和富集的主要地貌单元有:(1)折曲的海岸及弧形海湾,常形成巨大的富集砂矿体,平直海岸矿体多窄狭零散;(2)海成平原。广阔的海成平原是生成砂矿床前提之一。许多矿区普查结果表明,大型砂矿床所在地海成平原一般宽达数至十余公里,顺海岸线连续长达百公里,窄狭长条状海岸线很少有工业砂矿存在。     

Zirconium-titanium placers of the Voronezh Anteclise: Types,epochs and factors of formation,and forecast

The early and late Frasnian, Barremian-Aptian, Cenomanian, early Santonian, early Campanian, and Oligocene-Miocene epochs of the formation of various types of zirconium-titanium placers are distinguished in the Voronezh Anteclise. The factors of their formation are considered, and a forecast of prospecting has been made. Lower Frasnian sedimentary rocks occur in the southeast, where the placers are related to the ilmenite-bearing volcanosedimentary rocks of the Yastrebovo Sequence. The upper Frasnian productive quartz sand of the Petino Sequence occurs in the central part of the Voronezh Anteclise. The Barremian-Aptian productive quartz sand and kaolinite clay occur in the northern and northeastern parts of the anteclise (Ryazan and Lipetsk oblasts). The placers formed in the Cenomanian are known in the Tambov oblast in the northeast of the Voronezh Anteclise and are related to phosphate-bearing glauconite-quartz sand. The early Campanian phosphorite-glauconite-quartz formation is widespread in the northwest of the Voronezh Anteclise at the junction with the northeastern wall of the Dnieper-Donets Basin (Bryansk oblast). The Oligocene-Miocene epoch was characterized by quartz sands abundant in the northwestern and south-western areas. The formation of zirconium-titanium placers is controlled by structural-tectonic, facies, volcanic, paleogeographic, stratigraphic, and evolutional factors. The indispensable condition for heavy mineral concentration is existence of positive forms of underwater topography. These are mostly structural elements of the third and fourth orders on the slopes of the Voronezh Anteclise at the boundaries of the adjacent negative structures. As concerns the facies factor, the occurrence of coastal and shallow-water marine facies with alternating and medium hydrodynamic activity and predominance of sand fractions 0.25–0.05 mm are criteria of elevated concentration of heavy minerals in sand. One of the conditions providing concentration of heavy minerals is a multiple rewashing of sands close to a relatively stable shoreline. The volcanic factor is determinant for the lower Frasnian marine placers fed by volcanic sources. The Cretaceous and Paleogene zirconium-titanium placers were formed owing to scouring of the older Paleozoic and Mesozoic sedimentary rocks of the Voronezh Anteclise, as well as the Baltic Shield, Moscow Syneclise, and the Volga-Ural Anteclise. The age of placers was estimated with accuracy up to substages (lower Aptian, lower Santonian, lower Campanian). The evolution factor is expressed in variation of localization and composition of placers in time and space. The forecast of potentially ore-bearing areas is based on optimal combinations of favorable factors.     

常德-张家界高速公路某大桥桥基砂土液化评价

结合常德张家界高速公路某大桥桥基工程,在DSD160型电磁式振动三轴试验仪上,通过往返加荷三轴试验,对饱和砂土进行了液化试验研究,探讨了基于动三轴液化试验结果判断饱和砂土液化的方法。并尝试了这种室内研究反应分析的液化可能性估计方法与地震剪应力时程相结合的综合判断方法。在该高速公路大桥桥基的饱和砂土液化评价中,采用这种综合判断方法,对大桥桥基砂土液化进行了判断。在判断场地是否液化后,对其液化危害程度进行了等级划分,给出了该工程场地在未来遭受到不同超越概率下的地震作用时发生液化的危害程度,得到了一些有工程实用意义的结果。     

Sedimentary processes controlling ultralong cells of littoral transport: Placer formation and termination of the Orange sand highway in southern Angola

This study focuses on the causes, modalities and obstacles of sediment transfer in the longest cell of littoral sand drift documented on Earth so far. Sand derived from the Orange River is dragged by swell waves and persistent southerly winds to accumulate in four successive dunefields in coastal Namibia to Angola. All four dunefields are terminated by river valleys, where aeolian sand is flushed back to the ocean; and yet sediment transport continues at sea, tracing an 1800 km long submarine sand highway. Sand drift would extend northward to beyond the Congo if the shelf did not become progressively narrower in southern Angola, where drifting sand is funnelled towards oceanic depths via canyon heads connected to river mouths. Garnet–magnetite placers are widespread along this coastal stretch, indicating systematic loss of the low‐density feldspatho‐quartzose fraction to the deep ocean. More than half of Moçamedes Desert sand is derived from the Orange River, and the rest in similar proportions from the Cunene River and from the Swakop and other rivers draining the Damara Orogen in Namibia. The Orange fingerprint, characterized by basaltic rock fragments, clinopyroxene grains and bimodal zircon‐age spectra with peaks at ca 0·5 Ga and ca 1·0 Ga, is lost abruptly at Namibe, and beach sands further north have abundant feldspar, amphibole‐epidote suites and unimodal zircon‐age spectra with a peak at ca 2·0 Ga, documenting local provenance from Palaeoproterozoic basement. Along with this oblique‐rifted continental margin, beach placers are dominated by Fe–Ti–Cr oxides with more monazite than garnet and thus have a geochemical signature sharply different from beach placers found all the way along the Orange littoral cell. High‐resolution mineralogical studies allow us to trace sediment dispersal over distances of thousands of kilometres, providing essential information for the correct reconstruction of ‘source to sink’ relationships in hydrocarbon exploration and to predict the long‐term impact of man‐made infrastructures on coastal sediment budgets.     

Gold in the beach placer sands of Chavakkad-Ponnani,Kerala Coast,India

Although sporadic mining of placer gold from river beds is not uncommon in India, there is no documented literature on the occurrence of gold in the beach placer sand deposits of the country. While characterizing the heavy minerals of the Chavakkad-Ponnani (CP) beach placer sands along the North Kerala coast, the association of gold with the pyriboles in these sands has been observed. A native gold grain of about 25 μm was seen to occur as an inclusion within an amphibole of hornblendic composition. The pyriboles of the CP deposit are angular to sub-angular indicating a nearby provenance that may be in the upstream reaches of the Ponnani River in the districts of Malappuram and Palakkad or further north in the auriferous tracts of the Wynad-Nilambur or Attapadi regions. It is argued that the occurrence of native gold in CP deposit is not a freak occurrence and that it warrants thorough investigation of all the pyribole-ilmenite-rich placers to examine the possible presence of gold and its abundance in the beach placers of northern Kerala coast.     

基于静力触探试验的液化判别新方法

近来地震液化灾害频发,再次成为研究重点,发展具有良好应用前景的基于静力触探试验（CPT）的液化判别方法对预防液化灾害具有重要意义。以Boulanger数据库171组数据为回归样本,分析既有方法存在的问题,提出了基于CPT液化判别的双曲线模型和计算公式,并通过提取2011年新西兰地震147组液化新数据,对该方法进行对比检验。研究表明,我国岩土工程勘察规范的CPT液化判别方法对浅埋砂层偏于保守,对深层土又明显偏于危险,而国际上具有代表性的Robertson方法,其液化临界线存在低烈度区不合理回弯、高烈度区又偏于保守的问题。提出的新公式在不同地震动强度和砂层埋深下均可给出合理判别结果,克服了国内外既有方法的缺点,并纳入到具有样板规范性质的《建筑工程抗震性态设计通则》修订稿中,可为我国相关规范修订和工程应用提供支持。     

Study on the quantitative relationship between soil in situ strength and drilling parameters

The rational use of drilling parameters is a hot issue in the field of geotechnical engineering and geological engineering. A new method, for evaluating the bearing capacity of soils using drilling parameters was proposed. First, through the mechanical analysis of the drill bit, the preconditions and theoretical formulas for calculating the bearing capacity of soils using the bit’s torque are clearly defined. Next, drilling tests and dynamic cone penetration tests were performed on miscellaneous fill, silty clay, sandy clay, medium coarse sand and gravel sand, and the empirical formula for calculating the bearing capacity of these soils were given. Then, using the new method and the empirical formula, the bearing capacity of the soil under the roadbed was examined. The test results show that the bit’s torque is a good parameter for the evaluation of the bearing capacity of the soil. Finally, the application scope of the new method and the empirical formula is discussed, and the subsequent research directions are pointed out.     

Fine and ultrafine gold in placers of northeastern Russia

The main features of the migration and accumulation of fine and ultrafine gold during the evolution of placer-forming processes in northeastern Russia are discussed. The results of loose sediment sampling (over 2000 samples) with a screw separator and strake facilities have been taken into consideration. The approximate grades and potential resources of gold were estimated for various genetic types of placers. The most favorable conditions for the mobilization and accumulation of fine and ultrafine gold in the placers of northeastern Russia prevailed during the Paleogene to Miocene stage of the evolution of orogenic morphostructures, when the residual (illuvial and alluvial) placers were formed. During the Pliocene to Quaternary stage, the tectonic activation caused the reworking of placers by slope and fluvial processes and resulted in the formation of new hillside and alluvial placers. At this stage, the dispersal of fine gold fractions prevailed over accumulation. Under conditions of the periglacial lithogenesis of the Pliocene to Quaternary tectonic activation, the formation of new placers with fine and ultrafine gold derived from primary sources was suppressed due to the low rate of metal release in the process of physical weathering. In terms of the economic importance of placers with fine and ultrafine gold, residual, eluvial, or hillside placers, as well as alluvial stratal placers located in low-order (and partly medium-order) stream valleys, are the most attractive in northeastern Russia. The primary sources of such placers comprise gold-bearing porphry copper, gold-sulfide-quartz, and other hydrothermal deposits with similar placer-forming capability, as well as gold-quartz stockworks. The grade of fine and ultrafine gold in such placers may be as high as a few g/m³. The placers located in the constratal alluvium of graben-type valleys and the bar and floodplain placers in the areas with stockwork-like orebodies containing fine (<0.25 mm) gold are regarded as prospective objects.     

中国近海建筑砂矿床特征

分析研究了我国现已探明的近海建筑砂矿床勘查资料,对建筑用海砂矿床进行了地质分类和工业分类;对我国已探明的近海建筑砂矿床的分布、矿体特征和矿石特征进行了综述。并就不同类型近海建筑用砂矿床矿例进行了解剖,为今后建筑用砂矿的找矿及资源评价工作提供了依据和借鉴,对建筑用海砂矿床的对比研究以及开发环境保护等方面具有较大的现实意义。     

砂土地震液化的模糊概率评判方法

利用模糊数学中的模糊概率理论,建立了砂土地震液化的模糊概率综合评判模型。在此模型中,提出了模糊权重的概念,可充分考虑权重的模糊性,从而避免权重取值带来的不确定性。结合砂土地震液化特点,选取地震烈度、标准贯入击数、平均粒径和上覆有效压力作为主要评价影响因子,同时将液化程度划分为不液化、轻微液化、中等液化和严重液化4个等级,进而使其评判结果更为精细化。通过算例分析,表明文中方法对砂土液化评判的合理性与有效性。     

利用测井曲线的洛伦兹系数评价地层的非均质性

简要介绍了测井资料洛仑兹系数的原理和计算方法,将洛仑兹系数和含砂比引入到测井数据处理当中。将常规测井曲线的洛仑兹系数与含砂比结合能够对钻井剖面的非均质性进行有效评价,为地层非均质性的定量评价提供了一种新思路。首先根据地层资料信息选择了对地层非均质性较为敏感的自然伽马曲线作为地层非无质性评价曲线;然后计算出地层的含砂比和洛伦兹系数;最后针对自然伽马测井曲线的洛伦兹系数结合含砂比给出了钻井剖面地层的层内非均质性,进一步挖掘地层的砂体结构信息。根据多井评价结果做出了鄂尔多斯盆地苏里格气田召60区块地层和含砂比的平面分布图,可以看出盒8^上与盒8^下段地层中部较为均质,储层分选性较好。