Climato-hydrological environment inferred from Lake Baikal sediments based on an automatic orbitally tuned age model

We propose a new automatic orbital tuning algorithm to adjust climatic signals to insolation. This can tune two signals with periodicity only without shape similarity. A Genetic Algorithm (GA) is used as an optimizing method. The new age model for the Brunhes epoch in Lake Baikal core BDP98 defined climatic shifts at about 250 kyr B.P., 350 kyr B.P. and 700 kyr B.P. The sedimentation rate for the interval from 350 kyr B.P. to 700 kyr B.P. was comparatively low and stable. This new model also indicates that there was a stadial during the super interglacial period (MIS 11), and that the terrestrial response to climate change was complex in this period.     

江苏省露采矿山地质环境综合评价研究

本文以江苏省露采矿山地质环境调查资料为基础,采用层次分析法,通过露采矿山地质灾害易发性和自然环境影响程度两方面的12个评价指标,建立江苏省露采矿山地质环境综合评价体系。在确定各评价指标权重和评价分级标准的基础上,以ARCGIS作为系统运行平台,生成江苏省露采矿山地质灾害易发性区划图、自然环境影响程度区划图、矿山地质环境综合区划图。     

水电工程地质信息管理系统的开发探讨

从西南某大型水电工程地质研究及管理系统现状入手,在充分分析水电工程地质数据信息的基础上,提出了较为合理的水电工程地质信息管理系统结构,并将信息管理系统设计为系统维护、数据库查询、图形图像管理、统计分析、报表等五大模块。系统的成功开发不仅为水电工程地质研究工作节约了大量的人力和物力,还为主管部门的决策提供了方便,也为水电工程地质数据信息的共享奠定了基础。     

内蒙古二连盆地岩性圈闭早期形成和多期形成特征分析

根据盆地内部储层和盖层的临界条件,利用盖层排替压力曲线和储层物性曲线联合确定了岩性圈闭的发育层段,发现多个层位可发育岩性圈闭。如果盖层排替压力和储层物性随埋深的变化是按现今各曲线有规律地演化,则可以推测在盆地的埋藏早期就可以形成岩性圈闭,并且在演化过程中存在多个圈闭形成时期。二连盆地若干凹陷的实际资料也证实了岩性圈闭存在早期形成和多期形成的基本特征。岩性圈闭形成期与油气运聚史相结合对研究岩性圈闭成藏过程十分重要。     

四川盆地地质构造演化特征与可地浸砂岩型铀矿找矿前景

本文通过对四川盆地地质构造演化特征的分析,指出由于该盆地基底、盖层结构横向分块的不均一性,在盆地中构造活化弱的地段或抬升剥蚀较早的地段构造形变弱,深埋时间相对短,岩石固结程度较低;其隆坳过渡部位有条件形成较大范围的自流斜坡,有利于形成长期渗入的水文地质条件,是寻找可地浸砂岩型铀矿的目标区。赋存疏松砂体的三叠纪和侏罗纪地层是找矿的目的层。     

河南省西部四道沟银-铅矿区地质特征及找矿远景分析

通过对河南省西部熊耳山地区四道沟银-铅矿区区域地质背景、矿区地质特征和矿体特征、矿化富集特点的分析,综合该区地球物理、地球化学特征,提出四道沟银-铅矿区具有大型银-铅矿的找矿前景.     

浙江省长兴县煤山盆地地球化学异常特征及环境质量初步评价

农业地质环境调查是新兴的地学研究领域。文章以长兴县农业地质环境调查结果为依据，结合区域浅层、深层土壤及浅层地下水测试分析数据的统计特征，圈定了煤山盆地土壤中Cd、Hg、As、Ni、Pb等重金属和与采煤有关的S、Br、Cl、F等不同元素的地球化学异常图，重点分析了异常的空间表现特征，并对土壤、浅层地下水环境质量进行初步评价。结果表明由于大量的煤矸石露天堆放，随着雨水的冲刷，煤矸石中的有毒、有害元素已进入土壤并发生表层富集现象，致使煤山镇、葆青煤矿一带15．5k^2土壤达到轻度一中度污染程度；煤矿矿灯厂虽然已在20世纪80年代停产关闭，但在长达30多年的生产过程中残渣、废液的排放，与之有关的Cu、Pb等有害元素对其周围1km^2左右范围内的土壤造成的重度污染，至今仍然存在。另一方面，盆地中虽然大量煤矸石的堆放已对局部土壤环境质量造成污染，但与煤矸石有关的有毒、有害物质尚未对浅层地下水造成影响。     

隧道中的地质雷达技术应用效果

地质雷达勘探技术以其独有高分辨率、高效率、无损检测的特点可满足超前地质预报施工要求，在隧道施工，能够准确预报掌子面前方岩体构造情况和不良地质体，对隧道混凝土衬砌常见的问题如：衬砌和围岩的结合部的缺陷、局部裂缝、衬砌厚度不足、土衬砌与围岩出现的脱空、回填欠实、富水区等进行有效的检测。     

Integrating Cavity Absorption Meter measurements of dissolved substances and suspended particles in ocean water

We have developed a new device to measure the separate contributions to the spectral absorption coefficient due to a pure liquid, due to the particles suspended in it, and due to the substances dissolved in it. This device, the Integrating Cavity Absorption Meter (ICAM), is essentially independent of scattering effects in the sample. In April 1993, a prototype of the ICAM was field tested on board the research vessel USNS Bartlett. A major part of the cruise track included criss-crossing the area where the Mississippi flows into the Gulf of Mexico at various ranges from the mouth of the river; thus samples were collected from areas of blue, green, and brown/black water. We evaluated 35 seawater samples collected with 5-l Niskin bottles from 22 locations to determine absorption spectra (380–700 nm) of suspended particles and dissolved substances (gelbstoff). Results validate the ICAM as a viable tool for marine optical absorption research. Gelbstoff absorption at 432.5 nm ranged from 0.024 to 0.603 m⁻¹. Over the spectral region 380→560 nm, gelbstoff absorption by each of the samples could be accurately fit to a decaying exponential. The particle absorption spectra are generally characteristic of those of phytoplankton and exhibit a local maximum at 430–440 nm. Absorption values at 432.5 nm ranged from zero to 1.0 m⁻¹. Some samples with moderate particulate absorption, however, did not show the characteristic local maximum of phytoplankton in the blue and instead resembled the characteristic decaying exponential of detritus with a shape similar to that observed in the gelbstoff. The ratio of gelbstoff to particulate absorption at 432.5 nm ranged from 0.46 to 152.     

Silicate perovskite analogue ScAlO3: temperature dependence of elastic moduli

The elastic moduli of ScAlO₃ perovskite, a very close structural analogue for MgSiO₃ perovskite, have been measured between 300 and 600 K using high precision ultrasonic interferometry in an internally heated gas-charged pressure vessel. This new capability for high temperature measurement of elastic wave speeds has been demonstrated on polycrystalline alumina. The temperature derivatives of elastic moduli of Al₂O₃ measured in this study agree within 15% with expectations based on published single-crystal data. For ScAlO₃ perovskite, the value of (∂K_S/∂T)_P is −0.033 GPa K⁻¹ and (∂G/∂T)_P is −0.015 GPa K⁻¹. The relative magnitudes of these derivatives agree with the observation in Duffy and Anderson [Duffy, T.S., Anderson, D.L., 1989. Seismic velocities in mantle minerals and the mineralogy of the upper mantle. J. Geophys. Res. 94, 1895–1912.] that |(∂K_S/∂T)_P| is typically about twice |(∂G/∂T)_P|. The value of (∂K_S/∂T)_P for ScAlO₃ is intermediate between those inferred less directly from V(P,T) studies of Fe-free and Fe- and Al-bearing MgSiO₃ perovskites [Wang, Y., Weidner, D.J., Liebermann, R.C., Zhao, Y., 1994. P–V–T equation of state of (Mg,Fe)SiO₃ perovskite: constraints on composition of the lower mantle. Phys. Earth Planet. Inter. 83, 13–40; Mao, H.K., Hemley, R.J., Shu, J., Chen, L., Jephcoat, A.P., Wu, Y., Bassett, W.A., 1991. Effect of pressure, temperature and composition on the lattice parameters and density of (Mg,Fe) SiO₃ perovskite to 30 GPa. J. Geophys. Res. 91, 8069–8079; Zhang, Weidner, D., 1999. Thermal equation of state of aluminum-enriched silicate perovskite. Science 284, 782–784]. The value of |(∂G/∂T)|_P for ScAlO₃ is similar to those of most other mantle silicate phases but lower than the recent determination for MgSiO₃ perovskite [Sinelnikov, Y., Chen, G., Neuville, D.R., Vaughan, M.T., Liebermann, R.C., 1998. Ultrasonic shear wave velocities of MgSiO₃ perovskite at 8 GPa and 800K and lower mantle composition. Science 281, 677–679].

Combining the results from the previous studies and current measurements on ScAlO₃ perovskite, we extracted the parameters (q and γ₀) needed to fully specify its Mie–Grüneisen–Debye equation-of-state. In this study, we have demonstrated that acoustic measurements of K_S(T), unlike V(P,T) data, tightly constrain the value of q. It is concluded that ScAlO₃ has ‘normal’ γ₀ (1.3) and high q (3.6). The high value of q indicates that ScAlO₃ has very strong intrinsic temperature dependence of the bulk modulus; similar behaviour has been observed in measurements on Fe- and Al-bearing silicate perovskites (Mao et al., 1991; Zhang and Weidner, 1999).