重力中区地形改正系统的研制

从传统的重力地形改正方法入手,用Delphi语言编制了Windows程序,使得多年来重力中区地形改正繁重的手工数图工作能够用计算机完成,且计算精度得到明显提高.最后用甘肃1∶20万昌马幅的53个重力测点进行了试算.     

川西坳陷中段新场地区天然气研究及气源对比

经过大量学者多年的研究总结,川西坳陷中段新场地区具备良好的生、储、盖等成藏组合。结合地质背景及碳同位素、轻烃的研究,认为新场地区天然气主要是Ⅲ型干酪根的煤型气,气藏主要分布在上三叠系的须二段和须四段,以及中侏罗系、上侏罗系地层中。     

河套地区土壤矿物组成分析及与各元素的关系

通过对河套地区土壤中矿物组成的分析研究,土壤中矿物组成中砂质成分主要为石英、长石、方解石,黏土矿物组合主要为伊利石、绿泥石和高岭石,此外还有角闪石等少量矿物成分。在砂土、粉砂土中石英、长石含量较高,在黏土质为主的土壤中黏土矿物含量增加。黏土矿物与石英以及长石呈负相关关系,与大多数元素呈明显正相关关系,黏土矿物对各元素具有明显吸附性;石英、长石与各元素含量呈负相关关系,说明其对元素不具有吸附性。     

福建沿海地区土壤元素含量特征与地质背景研究

根据福建沿海深层土壤元素含量的统计分析,表明9大类地质体为背景的土壤元素含量存在差异,与均值对比Ag、Au、Sn、Co、Cu的含量受地质背景影响较小,B、Cr、Ni、Li、As、Sb、Hg、Mo、Bi、Cd、Br、C1、S、CaO、I、Na2O含量则影响明显。     

河北省蔚县矿区构造特征及断裂构造发育规律

运用现代构造地质研究方法，对蔚县矿区构造特征及断裂构造发育规律进行了研究。并揭示了矿区构造成因机制及演化历史。     

Division of Gas Accumulation System and Laws Controlling Distribution of Natural Gas in Typical Petroliferous Basins of China

Considering the existing problems of the petroleum system, this paper brings forward the concept of natural gas accumulation system and presents the dividing principles. Then detailed statistics on the accumulation factors of the 32 typical natural gas accumulation systems in China and studies on the laws controlling distribution of gas are collected. The research shows that the petroleum accumulation system is the basic unit controlling petroleum generation, migration and accumulation. Generating intensity, generating amount, accumulating efficiency and migration distance plays an important role in the distribution of natural gas. Through analysis on results of resources evaluation, discovered reserves and residual reserves, potential areas in middle-scaled petroliferous basins in China are forecasted in this paper. Ordos, Sichuan, Tarim and Qaidam basins are found out to be the main basins developing and enriching gas accumulation systems.     

Gold Mineralization and Occurrence of Sinter in the Hoshino Area, Fukuoka Prefecture, Japan

Abstract. Several epithermal gold deposits occur in the Hoshino area, which is located in the western end of the late Cenozoic Hohi volcanic zone, north‐central Kyushu, Japan. The area is characterized by intermediate to felsic extrusive rocks of Pliocene age. In the Hoshino area, the shallow manifestation of the hydrothermal activity is exposed on the surface. Several outcrops of sinter are still preserved on the top of hydro thermally altered volcanic rocks, and high‐grade gold‐bearing quartz veins occur on the surface at lower levels. The hydrothermal alteration resulted into well‐developed alteration zones. The zonal alteration pattern, primarily of near‐neutral pH type, is characterized by the outer smectite zone of a lower temperature, and the inner mixed layer minerals zone of a higher temperature. Quartz vein‐related or fracture‐controlled alteration, is represented by the occurrence of interstratified illite/smectite and K‐feldspar, suggesting a potassium‐enriched alteration. The mineralization in the Hoshino area is recognized on the surface by the occurrence of gold‐bearing quartz veins distributed mainly in the mixed layer minerals zone. The fracture system related to the gold mineralization is mainly characterized by NW‐SE trend. The alteration pattern and the mineralogical composition of the veins suggest that the mineralizing fluids had near‐neutral pH and the mineralization is of low‐sulfidation‐type. Fluid inclusion data and textures observed in quartz veins indicate that gold precipitated during boiling. The chemical composition of quartz veins shows that high‐grade gold‐bearing quartz veins are characterized by higher content of Al₂O₃, K₂O and Rb. Several outcrops of silica‐sinters are distributed on the top of the mixed layer minerals zone. Although their structures are not very well preserved, because of later silicification, the Hoshino sinters still show characteristic textures identical to those observed in modern sinters, such as the presence of plant fossil incorporated into the sinters, the strongly developed depositional laminations and the columnar structures perpendicular to the depositional surfaces. Quartz is the only silica mineral constituting the Hoshino sinters presently. The conversion of amorphous silica into quartz was probably governed by higher temperatures resulting from later hydrothermal activity. This later hydrothermal activity is reflected by the intense silicification affecting mainly the lower parts of the sinters and also by the presence of quartz veins cutting the sinters. The distribution of sinters in the Hoshino area is very significant. The presence beneath the sinters of concealed high‐grade gold‐bearing quartz veins should be highly considered and exploration work is strongly suggested.     

Phytolith assemblages as a promising tool for reconstructing Mediterranean Holocene vegetation

The reliability of phytolith assemblage analysis for characterizing Mediterranean vegetation is investigated in this study. Phytolith assemblages are extracted from modern and buried Holocene soils from the middle Rhône valley (France). The relation between modern phytolith assemblages and the surrounding vegetation, as well as between fossil assemblages and contemporaneous vegetation, already reconstructed through other proxies, is discussed. We demonstrate that the main northwestern Mediterranean biomes are well distinguished by soil phytolith assemblage analysis. In particular, the density of pine and nonconiferous trees (densities expressed relatively to the grass cover) and the overall degree of opening of the vegetation appear well recorded by three phytolith indexes. North Mediterranean vegetation changes during the Holocene period, mainly tree line shifts, pine wood development and deforestation are poorly documented, due to the scarcity of proxy-preserving sites. Phytolith assemblage analysis of soils, buried soils, and sediments appears to be a promising technique to fill this gap.     

鲁中南岱崮地貌的成因及演化——以抱犊崮为例解析

鲁中南抱犊崮地区,山体陡峭挺拔,风景秀丽,以有鲁南小泰山之称的抱犊崮为代表,山体顶部主要由古生代寒武纪九龙群张夏组灰岩组成,其下分布由长清群馒头组砂岩、砂质页岩、泥质灰岩、薄层灰岩及朱砂洞组灰岩、泥质灰岩等。“崮”的成因主要是古生代寒武纪灰岩经受了强烈的地壳切割和抬升运动,并遭受长期的侵蚀、溶蚀、重力崩塌和风化剥蚀等多重地质作用而形成抱犊崮所具有的岱崮地貌,作为地质遗迹和地质地貌景观,具有重要的地学研究价值,也是潜力巨大的旅游资源。     

滇西变泥质岩的白云母b_0值及其构造－地层意义

据３３３个白云母ｂ０值，结合区域地层和构造的研究成果，提出：（１）原称昌宁－孟连变质带解体为西盟－勐统变质带（加里东期中压变质带）和澜沧双变质带的高压亚带，两期高压变质作用分别与海西－印支期的洋壳消减和陆－陆碰撞有关；（２）石鼓变质带是三个逆冲岩片的叠置，各岩片内岩石的变质作用各具特色；（３）金沙江洋盆为地块间小洋盆，其消减及嗣后的弧－弧碰撞可能不产生高压变质作用。在此基础上探讨了白云母ｂ０值在造山带研究中的意义。