连云港海域废黄河水下三角洲北翼的沉积特征与空间分布

基于连云港海域浅地层剖面资料解释和16个站位柱状岩心的剖面观察、粒度分析、微体化石鉴定、有孔虫和腹足类纹沼螺的AMS 14C年龄,分析废黄河水下三角洲北翼的沉积结构、厚度和沉积物组成,划分沉积单元及其分布范围;识别海侵沉积区的沉积相,认识其沉积环境特征。结果表明,水下三角洲沉积体可分为三角洲前缘和前三角洲两个沉积单元,两者沿连云港海岸线呈并置关系。三角洲前缘位于埒子口至新淮河口外,为一NNE向进积、NW向倾斜的扇形楔状体,可识别出灌河叶瓣及其以东的叶瓣两个沉积中心。该沉积单元以砂质沉积为主,两个叶瓣之间的分流间湾分布有泥和砂质泥。前三角洲位于三角洲前缘西北侧,大致从埒子口外侧沿海岸带向海州湾展布。该单元为泥质沉积,厚度较薄,其北部的两个柱状岩心所揭示的沉积厚度分别为1.8 m和1.5 m。水下三角洲以北,海侵沙席分布广泛,厚度通常在20 cm左右。其分布在本区具有普遍性,只是在连云港海域被黄河泥沙所覆盖,由此也构成了废黄河水下三角洲的底界面。该界面具有侵蚀残留地貌特征。海侵沙席之下为晚更新世MIS 3阶段中早期的海陆过渡相沉积。沉积物多由黄色粉砂或砂质粉砂组成,含有较丰富的有孔虫、介形虫等,可见淡水纹沼螺。     

论小坝梁铜矿床的海底火山热液成因

本文对内蒙古小坝梁铜矿床的成矿地质构造背景、成矿地质特征、同位素及矿床地球化学作了一系列研究，并与国外同类矿床进行对比，确定该矿床属海底火山热液型，成矿时代为晚华力西期。此项研究为该类矿床的勘查拓宽了思路，指出小坝梁矿区北部与东部为勘探铜矿床的远景区。     

西秦岭金矿化带中土壤与岩石实验室光谱相关性研究

通过西秦岭金矿化带中土壤与岩石实验室光谱的相关性分析与研究。探索该区表层壤覆盖条件下应用遥感信息寻找金矿床。研究表明,土壤与岩石两者光谱之间有很高的正相关性,并且在谱形上亦有相似性,使得利用该地区土壤光谱特征从遥感信息中提取出土壤覆盖层下的岩石光谱特征成为可能,为这种遥感技术找矿方法提供依据。     

Processes of magma/wet sediment interaction in a large-scale Jurassic andesitic peperite complex, northern Sierra Nevada, California

 The Middle Jurassic Tuttle Lake Formation in the northern Sierra Nevada, California, comprises a thick volcaniclastic sequence deposited in a submarine island-arc setting and penetrated by numerous related hypabyssal intrusions. A composite andesite-diorite intrusive complex ≥4.5 km long and ≥1.5 km thick was emplaced while the host Tuttle Lake sediments were still wet and unconsolidated. Large parts of the intrusive complex consist of peperite formed where andesitic magma intruded and intermixed with tuff, lapilli-tuff and tuff-breccia. The southern half of the complex consists of augite-phyric andesite containing peperite in numerous small, isolated pockets and in more extensive, laterally continuous zones. The peperites comprise three main types recognized previously in other peperite studies. Fluidal peperite consists of small (≤30 cm), closely spaced, at least partly interconnected, globular to amoeboid andesite bodies enclosed by tuff. This peperite type developed during intrusion of magma into fine-grained wet sediment along unstable interfaces, and fluidization of the sediment facilitated development of complex intrusive geometries. Blocky peperite and mixed blocky and fluidal peperite formed where magma intruded coarser sediment and underwent variable degrees of brittle fragmentation by quenching and dynamic stressing of rigid margins, possibly aided by small steam explosions. The northern half of the intrusive complex consists predominantly of a different type of peperite, in which decimetre-scale plagioclase-phyric andesite clasts with ellipsoidal, elongate, or angular, polyhedral shapes are closely packed to widely dispersed within disrupted host sediment. Textural features suggest the andesite clasts were derived from conduits through which magma was flowing, and preserved remnants of the conduits are represented by elongate, sinuous bodies up to 30 m or more in length. Disruption and dispersal of the andesite clasts are inferred to have occurred at least partly by steam explosions that ripped apart a network of interconnected feeder conduits penetrating the host sediments. Closely packed peperite is present adjacent to mappable intrusions of coherent andesite, and along the margin of a large mass of coarse-grained diorite. These coherent intrusions are considered to be major feeders for this part of the complex. Examples of magma/wet sediment interaction similar in scale to the extensive peperites described here occur elsewhere in ancient island-arc strata in the northern Sierra Nevada. Based on these and other published examples, large-scale peperites probably are more common than generally realized and are likely to be important in settings where thick sediment sequences accumulate during active volcanism. Careful mapping in well-exposed terrains may be required to recognize large-scale peperite complexes of this type. Received: 8 June 1998 / Accepted: 4 December 1998     

冀东地区元古宙多金属硫铁矿矿床地质及其成矿作用

通过对冀东地区元古宙多金属硫铁矿床成矿构造环境背景、喷气沉积岩地球化学以及矿床中大量矿化嗜热微生物的发现与研究 ,以及采用分子生物学对沉积记录中的生物标志物的研究。得知冀东地区多金属硫铁矿的形成主要由海底喷气沉积与嗜热微生物富集成矿作用所致。运用海底喷气成矿热流体活动 嗜热微生物吸附与新陈代谢 多金属硫铁矿床形成的成矿理论 ,指导该区硫铁矿找矿工作已见成效。     

Eolian evidence from the Chinese Loess Plateau: the onset of the Late Cenozoic Great Glaciation in the Northern Hemisphere and Qinghai-Xizang Plateau uplift forcing

On the basis of a newly-constructed record of magnetic susceptibility (SUS) and the depositional rate change of eolian loess-red clay sequences in the last 7.2 Ma BP from the hea Plateau, together with a cornperison of a record of °¹⁸O values from the equatorial East Pacific Ocean and eolian Quartz flux variations fmm the North Pacific Ocean, the evolutiomuy process of the Late Cenozoic Great Glaciation in the Northern Hemisphere can be divided into three stages: the arrival stage around 7.2–3.4 Ma BP, the initial stage at about 3.4—2.6 Ma BP, and the Great Ice Age since 2.6 Ma BP. The evolution of the East Asian monsoon is characterized by paid winter and summer monsoons, and it is basically composed of the initial stage of weak winter and summer monsoons, the transitional stage of simultaneous increase in intensity of winter and summer monsoons, and the prevailing stage of strong winter and week summer monsoons, or weak winter and strong summer monsoons. The Late Cenowic global tectonic uplift, paaicdarly the Qinghai-Xizang Plateau uplift and the associated CO₂ concentration variation, controls the dng processes of the onset of Great Glaciation and the long-term changes of East Asian monsoom climate in the Northern Hemisphere to a large extent. The accelerating uplift of the Qinghai-Xizang Plateau between 3.4 and 2.6 Ma BP provided an important driving force to global climiatic change. Project supported by the foundation of Chinese Academy of Sciences (Grant No. KZ951-A1-402), the State Science and Technology Committee (Grant No. 95-pre-40)and the Chinese Nature Science Foundation (Grant No. 49672140)     

小秦岭金矿床的成矿物质来源

研究表明,太华群是小秦岭地区金矿床的矿源层。通过对比混合岩化、花岗岩化、围岩蚀变和成矿作用过程中的微量元素的分布情况,发现Au和Pb、Cu、Ag、Zn等在这一系列过程中始终表现出变化的一致性,说明Au等成矿物质来源于太华群变质岩,同位素证据也表明Au等成矿物质来源于太华群。     

湖南银成矿系列的划分及与构造演化的关系

本文在全面分析湖南省银矿床和伴生银矿床的地质特征和地球化学特征的基础上,按照矿床形成过程中的主导地质作用,将省内银矿床和伴生银矿床划分为两个成矿系列,即与岩浆侵入作用有关的成矿系列和与沉积-成岩作用有关的成矿系列。两个成矿系列分别进一步划分成三个成矿业系列。文中对各成矿系列的主要地质特征、时空分布特点进行了论述,并分析了成矿系列形成与构造演化的关系。     

超大型金矿床成矿流体某些特征及其找矿

具有重要意义的金─石英脉型矿床可作为研究超大型金矿床成矿流体特征及其找矿问题的良好实例。研究和对比分析表明：（１）在超大型和非超大型金─石英脉型矿床间,在成矿流体包裹体方面尚未发现有意义的区别。似乎不存在能形成上述类型的超大型金矿的任何独特流体。（２）有利的大地构造和区域地质背景,良好的导矿、配矿和容矿构造,适宜的围岩,丰富的成矿物质,大量富含ＣＯ＿２的流体活动,多期、多次、多成因的地质作用的叠加,强烈而又广泛的围岩蚀变是形成某些内生超大型金矿的必要条件。系统扎实的基础地质工作、先进的科学手段和物化等方法的综合运用以及宏观和微观的结合对寻找超大型金矿十分必要。     

中国及邻区石炭纪构造古地理及生物古地理

本文包括3部分:（1）扼要回顾了中国及邻区晚海西阶段的地质构造背景和构造古地理特征。根据全球构造活动论和地壳发展阶段论的观点,把中国及邻区晚海西阶段的大地构造单元分为4个构造域,10个亚构造域。（2）论述中国和世界石炭纪生物古地理分区。根据四射珊瑚和腕足动物群分析,把全球早石炭世生物古地理区系分为两个生物大区、6个生物区和8个生物亚区。在中国境内对生物亚区内部生物地方中心的分异作了进一步划分。（3）简述中国石炭纪古地理和某些有关的沉积矿产。中国石炭系矿产除了重要的煤以外,还有石膏矿、铝土矿和不同类型的铁矿。这些沉积矿产的分布主要受到古气候、古地理和构造条件的控制。