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.     

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。     

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).     

中分辨率成像光谱仪图像积雪反射特性的初步分析研究

通过对中分辨率成像光谱仪图像２６个连续波段的同点采样,获得从可见到红外光谱一个完整的积雪反射特性系列,在背景气候,气象数据信息的支持下,进行图像积雪反射特性与同类积雪实测反射特性的对比分析。结果表明：本研究所使用的中分辨率成像光谱仪图像积雪反射特性反映了积雪变化的过程,同时与地面光谱仪实测数据有一定的对应关系,同类积雪在可见光波谱区的光谱反射基本吻合,据此,反演积雪类型的图像分类是可行的。     

边坡灾害及其防治研究新进展--"香港边坡灾害及其防治讨论会"简介

概要介绍了边坡灾害及其防治研究方面的一些新进展 ,主要内容涉及边坡岩土特性与参数、边坡稳定性计算方法与模拟、边坡稳定性评价、边坡监测及预测、边坡分析、管理与决策以及边坡灾害防治等。     

成矿构造物理化学场结构预测法及其应用——以山东河东金矿为例

以“构造－物性－物质组合控矿”理论为方法学基础,提出并讨论了隐伏矿体定位预测中的成矿构造物理化学结构预测方法,并以典型脉状金矿床为例,进行山东河东金矿成矿构造应力场结构,激电异常场结构,原生晕异常场结构,成矿构造物理化学场组合结构分析和矿区外围找矿靶区优选及深部隐伏矿体定位预测准则的实例剖析。     

矿物学研究从资源属性到环境属性的发展

资源与环境是地球科学的两大主题,在回顾矿物资源属性的基础上,提出了矿物学环境属性的研究。在矿物形成和变化的过程中,不同时间和空间的环境变化都会在矿物中留下烙印,使得矿物成为记录 环境演变信息的载体。利用矿物能被防止分解的一面,采取相应的措施防止矿物的破坏与分解,就有可能减少甚至避免由于矿物的破坏与分解所造成的对人体健康的影响和生态环境的破坏。类似于有机生物处理方法,利用无机矿物处理污染物的方法,体现了天然自净化作用的特色。天然矿物对污染物的净化功能主要体现在环境矿物材料基本性能方面。 矿物与生物的交互作用研究,是无机界与有机界交叉渗透性研究课题。纳米矿物所表现出的超乎寻常的化学性质是其有效参与纳米生物作用的关键。     

溢油物理化学性质灰色模式的研究

应用灰色系统理论对海面溢油物理化学性质(蒸发率、溶解率、表面张力、黏度和密度)在风化过程中的变化进行研究,建立了溢油物理化学性质在风化过程中的预测模式GM(1,1)和GM(0,m).结果表明,在风化过程中,溢油物理化学性质的GM(1,1)和GM(0,m)模式预测精度令人满意,皆符合统计学检验的要求;在风化过程中,溢油物理化学性质所具有的灰色相关性可用GM(0,m)模式的灰色辨识参数来表征;在风化过程中,溢油的蒸发率和溶解率可分别用表面张力、黏度和密度作为预报因子。     

Hydrogeological framework of the Deccan basalt groundwater systems, west-central India

Deccan basalts of west-central India are hydrogeologically inhomogeneous rocks. A proper understanding of the physical framework of the basalts within which groundwater resides and moves is a key to the hydrogeology of these rocks. Two types of basalt, the vesicular amygdaloidal basalt and the compact basalt, occur as alternate layers in the volcanic pile. Although the rocks are generally inhomogeneous, structures in the basalt, such as sheet joints and vertical joints, serve as zones of groundwater flow. In the shallow subsurface, two groundwater systems are operative. Groundwater system A consists of a vesicular amygdaloidal basalt underlain by a compact basalt, whereas groundwater system B consists of a vesicular amygdaloidal basalt overlain by a compact basalt. Groundwater system A has a better developed network of openings and, as a consequence, this system has a higher transmissivity and storage coefficient than groundwater system B. Wells tapping groundwater system A have higher yields on average and irrigate more hectares of cropland than do wells tapping groundwater system B. This simple systems concept offers a practical methodology for understanding the geometry of the physical framework that contains groundwater in the Deccan basalts. The efficacy of the concept is in its widespread utility for the region. The concept may also be extrapolated to help understand the hydrogeology of deeper Deccan basalt groundwater systems.