琼东南盆地物源和沉积环境变化的重矿物证据

基于11口钻井岩心样品的重矿物数据,结合古生物学、元素地球化学和地震资料,对琼东南盆地的物源及沉积环境演变进行了分析.结果表明,盆地基底沉积以陆相沉积为主,自渐新世起,盆地逐渐接受海侵,大致经历了海陆过渡→滨浅海→浅海→半深海的沉积环境演变过程,水深总体呈逐渐增大的趋势且在同一时期南部区域水深整体上大于北部.随着沉积环境的变化,各地层(崖城组至莺歌海组)物源呈现出多源性特征,经历了原地→近源→远源的演变过程.在渐新世早期,物源以近源玄武质火山碎屑和邻区陆源碎屑为主,之后演变为远源的陆壳碎屑,物源区包括北部海南岛、南部永乐隆起、东北部神狐隆起、西部红河、西南部中南半岛乃至更广的区域.海南岛物源自早渐新世便开始发育,至中中新世成为盆地最主要的物源,并持续至现今;永乐隆起和神狐隆起物源在晚渐新世至早中新世期间最为发育,于中中新世逐渐消退;红河物源于晚中新世大规模加入,为中央峡谷的主要沉积物源,影响至上新世结束;中南半岛莺西物源自上新世发育,影响至更新世时期.此外,自生组分对盆地(尤其是南部区域)的沉积贡献也不容忽视.     

Heavy minerals clustering provenance analysis of Kong analysis in application of 2 Member in Kongnan area

The main task of provenance analysis is to determine the source of sediments and the position of parent rocks. Provenance analysis may find out the relationship between erosion districts and sediment zone, between the uplift and the depression in the process of basin development. The authors use the method of heavy mineral clustering analysis and estimate the provenance direction of Huanghua Depression in the Paleogene Kong 2 Member. Research shows that there were five provenance areas of Kong 2 Member in Kongnan area. They are western （Shenusi）, northwestern （Cangzhou）, eastern （Ganhuatun）, northeastern and southeast- ern. The main provenance areas were northwestern and western, while the southern provenance could not be ruled out. And these areas are consistent with the known provenance areas.     

Water solubility in nominally anhydrous minerals measured by FTIR and 1H MAS NMR: the effect of sample preparation

Samples of enstatite and forsterite were crystallized in the presence of a hydrous fluid at 15 kbar and 1100 °C. Water contents in quenched samples were measured by ¹H MAS NMR and by FTIR. If the samples were prepared in the same way, similar water concentrations were obtained by both methods. There is no evidence that one or the other method would severely over or underestimate water contents in nominally anhydrous minerals. However, measured water contents vary by orders of magnitude depending on sample preparation. The lowest water contents are measured by polarized FTIR spectroscopy on clear, inclusion-free single crystals. These water contents probably reflect the real point defect solubility in the crystals. Polycrystalline material shows much higher total water concentrations, presumably due to hydrous species on grain boundaries, growth defects, and in submicroscopic fluid inclusions. Grinding the sample in air further increases water concentration. This effect is even more pronounced if the sample is ground in water and subsequently dried at 150 °C. Polarized FTIR measurements on clear single crystals of enstatite saturated at 15 kbar and 1100 °C give 199 ± 25 ppm by weight of water. The spectra show sharp and strongly polarized bands. These bands are also present in spectra measured through turbid, polycrystalline aggregates of enstatite. However, in these spectra, they are superimposed on much broader, nearly isotropic bands resulting from hydrous species in grain boundaries, growth defects, and submicroscopic fluid or melt inclusions. Total water contents for these polycrystalline aggregates are between 2000 and 4000 ppm. Water contents measured by FTIR on enstatite powders are 5300 ppm after grinding in air and 12 600 ppm after grinding under water und subsequent drying at 150 °C. Received: 25 June 1999 / Revised, accepted: 4 October 1999     

广西德保铜锡矿床氧化带产出的砷酸盐矿物

广西德保矿区是我国最重要的砷酸盐矿物产区 ,已发现有 17种砷酸盐矿物 ,其中钡毒铁石、砷铜矾等 12种为在国内首次发现。文中提供了其中一些重要新发现矿物较详细的矿物学数据 ,初步阐述了该类矿物在德保铜锡矿床氧化带的共生组合特征 ,指出该类矿物是矽卡岩型铜 -锡矿床以及铜铅锌等多金属硫化物矿床的重要找矿标志     

鼎湖山自然保护区土壤的矿物组成

鼎湖山自然保护区土壤的矿物组成,由山脚到山顶,2∶1型粘粒矿物和结晶态氧化铁矿物渐增,高岭石渐减;粗粒矿物以石英为主,其次是云母或叶腊石,并伴有钾长石、高岭石或蛭石。0.1毫米以上粒级全部由原生矿物组成。     

桂林地区岩溶水中矿物和气体溶解量计算

本文在对桂林地区７４个岩溶水水样化学分析结果进行综合、归纳和分析之后认为，该区岩溶水化学成分是在当地雨水化学成分的基础上，经过水对岩石中的石膏、方解石及白云石和大气中的ＣＯ_２发生溶解作用而形成的。为了验证这一推论，笔者还运用质量守恒计算法，对上述水化学分析结果相对于当地雨水的矿物和ＣＯ_２气体溶解量进行了计算。文中还对岩溶水形成环境进行了分析和讨论。     

东秦岭北部斑岩岩浆作用的物理化学条件

本文是在东秦岭北部斑岩岩石学、矿物学研究的基础上,应用多种地质温度压力计方法,计算了岩浆的物理化学条件,岩浆结晶的P—T途径为P≥6.5～0.3kb;T≈970～860～770℃;Logfo_2=-12.25—-14.23;岩浆源的深度为32km左右,初始岩浆的温度小于1000℃。斑晶矿物稳定的PH_2O=1.156～0.197,熔体相中水的溶解度XH_(20)=0.3545～0.1105mol％。文中还讨论了含矿岩体与不含矿岩体的岩浆在物理化学条件上的差异及评价其含矿性的物理化学标志。     

Marine Minerals in the Mexican Pacific: Toward Efficient Resource Management

Abstract

Vast reserves of marine minerals are known to occur within the Mexican Exclusive Economic Zone. These reserves include: (1) heavy mineral placers rich in titanium and iron along the coast of San Antonio del Mar, Baja California and the southern States of Oaxaca and Guerrero; (2) phosphorites, which represent the only source for superphosphate fertilizers along the Pacific coast off the Baja California peninsula and the Gulf of Tehuantepec; and (3) manganese oxide deposits in nodule and crusts located adjacent to the Clarion-Clipperton Zone and containing high concentrations of Cu + Ni + Co (up to 1.9%), which are essential for the steel and super-alloy industries. Few but important efforts toward surveying these deposits have been carried out by Mexican and international researchers. Relevant data generated by these investigations are reviewed here and put together in a single document. Adequate knowledge of Mexican mineral resources is essential for the development of management strategies when offshore mining starts during this century. Thus, the review discusses the economics inherent to ocean mining in Mexico, setting baselines for future exploration and development activities in the Mexican Exclusive Economic Zone.     

Provenance Signature of Pre-Cambrian and Mesozoic Rocks in the Nearshore Placers of Konkan,Central West Coast of India

Heavy mineral studies of the nearshore placer deposits of the Konkan Coast reveal a dominant assemblage comprised of garnet and kyanite along with other accessory minerals like epidote, olivine and rutile. The heavy mineral assemblage of the study region shows a characteristic suite of 17 types of heavy minerals. Their abundance shows hardly any drastic variation in the four bays studied. Overwhelming presence of minerals like garnet and kyanite in the studied four bays points to the source as metamorphic rocks. The presence of etched garnets, overgrown zircons and etched kyanites corroborate the recycling of paleo-sediments into the bay. Characterization of opaques under the microscope also corroborates the influence of a metamorphic source, rather than the adjoining basaltic rocks. However, the absence of metamorphic rocks in the hinterland suggests the possibility of deposition of sediments predominantly from offshore. Factor analysis results also corroborate the overwhelming influence of metamorphic rocks in the present study region rather than the abutting basalts.     

Technology developments for the strategic Indian blue economy

Abstract

With the land-based resources depleting faster, effective exploration and sustained harvesting of the Ocean resources, taking into account the economic growth, social needs and the health of the Ocean environment is essential. India with a 7600?km long coastline and an exclusive economic zone of 2.3 million km² and spear heading the blue economic growth and security of all the countries in the Indian Ocean region have initiated policies for leveraging the growth of the Indian economy through the blue economy. The paper discusses the strategic technology developments undertaken in India by the National Institute of Ocean Technology-Ministry of Earth Sciences (MoES), Government of India for the harvesting of the living and non-living blue economic resources, and for protecting the ocean ecosystems.