基于水准剖面的山西断陷带现今活动性研究

根据跨山西断陷带的水准剖面观测资料,计算其垂直形变量和垂直形变速率,研究其现今垂直活动性。2006年以来的垂直形变揭示,山西断陷带东北段延怀盆地和蔚县盆地呈掀斜上升活动,北段阳原盆地和大同盆地以下降活动为主,晋中盆地为上下波动,临汾盆地呈现上升活动。2013年山西断陷带活动出现转折性变化,蔚县盆地大幅度下降,大同盆地、代县-定襄盆地、晋中盆地和临汾盆地均呈现不同程度的上升。     

耦合手机信令数据和房价数据的城市不同经济水平人群行为活动模式研究

有效分析城市不同经济水平人群的分布特征和活动模式对优化城市资源配置和揭示空间隔离现象有着极高的价值。但人群活动和社会经济等级数据较敏感,使得以往研究仅停留在宏观层面,难以合理划分人群经济等级并对其空间分布和活动模式进行定量分析。本研究以深圳为研究区,基于空间位置关联分析方法,耦合手机信令数据和细尺度房价数据实现了人群经济水平的准确划分,通过计算活动指标定量的分析了不同经济水平人群的空间分布和行为活动特征。研究表明：深圳市不同经济水平人群活动分布与各行政区经济发展相关,呈现“南高北低,西高东低”的格局;深圳市不同经济水平人群之间活动模式存在差异,活动范围、出行距离、出行速度与经济水平存在正向相关;高经济水平人群职住地点相距较远,存在跨行政区分布的现象。本研究分析了城市不同经济水平人群的空间分布特征和活动模式,对城市规划和解决社会不平等问题具有重要的参考价值。     

中哈俄阿尔泰稀有金属矿床时空分布、成因及成矿规律

中哈俄阿尔泰发育许多大型—超大型稀有金属矿床,是世界著名的稀有金属成矿省.该成矿省可分为3个稀有金属成矿带,自西南向东北依次为哈萨克斯坦Kalba-Narym、中国阿尔泰和俄罗斯山区阿尔泰等.这3个成矿带稀有金属矿床以伟晶岩型为主,但伟晶岩与花岗岩关系及其伟晶岩成因不一致:在哈萨克斯坦Kalba-Narym成矿带和俄罗...     

造山带中、新生代隆升作用构造年代学研究新进展

造山带中,新生代降 作用构造年代学研究在内容上强调隆升的细致过程和机制的研究,在方法上有４点值得重视：利用财核素测定年龄;利用ＭＤＤ模式定量研究山体隆升过程;利用磷灰石裂变径迹定年方法研究山脉的隆升与剥露;复地貌有关参数判断抬升机制。对大别造山带中,新生代隆升作用的构造年代学进行剖析后,得到一些规律性认识;隆升构造复杂多亲,可划分４类６型隆升构造;隆升作用在时间上显示缓慢和强烈或相间的节律性;空间     

赞比亚铜矿床类型及地质特征

赞比亚是世界著名的铜产地之一,其铜矿类型可分为层控型、沉积型、变质改造型及热液型,以沉积型为主。据现有大中型矿床铜资源量统计,沉积型矿产铜资源量占赞比亚铜总资源量的79%。各类型铜矿床总体受卢弗里安(Luflian)弧控制,层控型铜矿主要分布在穹窿核部边缘,含矿岩系为莫瓦(Muva)超群的黑云母片岩、二云石英片岩;沉积型铜矿主要分布在背斜或穹窿外缘周围,含矿岩系主要是加丹加(Katanga)超群下部的砂页岩层。     

Magnetite Dyke in Precambrian Banded Iron Formation,Singhbhum Craton,India: Mineralogical and Chemical Characteristics

Banded iron formation (BIF) of the Gorumahisani–Sulaipat–Badampahar (GSB) belt in Singhbhum Craton, India, consists predominantly of magnetite. This BIF is intruded by a magnetite dyke. The magnetite dyke is massive and compact with minor sulphide minerals while the host banded magnetite ore, a component of the BIF, shows thin lamination. The magnetite ore of the dyke is fine to medium grained and exhibits interlocking texture with sharp grain boundaries, which is different from the banded magnetite that is medium to coarse grained and show irregular martitised and goethitised grain boundaries. Relics of Fe–Ca–Mn–Mg‐carbonate and iron silicates (grunerite and cummingtonite) are observed in the banded magnetite. The intrusive magnetite is distinctly different in minor, trace and REE geochemistry from the banded magnetite. The banded magnetite contains higher amounts of Si, Al, Mn, Ca, Mg, Sc, Ga, Nb, Zr, Hf, Co, Rb and Cu. In contrast, the massive magnetite is enriched in Cr, Zn, V, Ni, Sr, Pb, Y, Ta, Cs and U with higher abundance of HREE. In the chondrite normalized plot, the massive magnetite shows a slight positive Eu anomaly while the banded ore does not show any Eu anomaly. Field disposition, morphology, mineralogy and chemistry show that the intrusive magnetite dyke is of igneous origin, while magnetite in BIF formed from a carbonate protolith through the process of sedimentation.     

Geology and geochemistry of the Bingdaban ophiolitic mélange in the boundary fault zone on the northern Central Tianshan Belt,and its tectonic implications

The properties and tectonic significance of the fault bound zone on the northern margin of the Central Tianshan belt are key issues to understand the tectonic framework and evolutionary history of the Tianshan Orogenic Belt. Based on the geological and geochemical studies in the Tianshan orogenic belt, it is suggested that the ophiolitic slices found in the Bingdaban area represent the remaining oceanic crust of the Early Paleozoic ocean between the Hazakstan and Zhungaer blocks. Mainly composed of basalts, gabbros and diabases, the ophiolites were overthrust onto the boundary fault between the Northern Tianshan and Central Tianshan belts. The major element geochemistry is characterized by high TiO₂ (1.50%–2.25%) and MgO (6.64%–9.35%), low K₂O (0.06%–0.41%) and P₂O₅ (0.1%–0.2%), and Na₂O>K₂O as well. Low ΣREE and depletion in LREE indicate that the original magma was derived from a depleted mantle source. Compared with a primitive mantle, the geochemistry of the basalts from the Bingdaban area is featureded by depletion in Th, U, Nb, La, Ce and Pr, and unfractionated in HFS elements. The ratios of Zr/Nb, Nb/La, Hf/Ta, Th/Yb and Hf/Th are similar to those of the typical N-MORB. It can be interpreted that the basalts in the Bingdaban area were derived from a depleted mantle source, and formed in a matured mid-oceanic ridge setting during the matured evolutionary stage of the Northern Tianshan ocean. In comparison with the basalts, the diabases from the Bingdaban area show higher contents of Al₂O₃, ΣREE and HFS elements as well as unfractionated incompatible elements except Cs, Rb and Ba, and about 10 times the values of the primitive mantle. Thus, the diabases are thought to be derived from a primitive mantle and similar to the typical E-MORB. The diabases also have slight Nb depletion accompanying no apparent Th enrichment compared with N-MORB. From studies of the regional geology and all above evidence, it can be suggested that the diabases from the Bingdaban area were formed in the mid-oceanic ridge of the Northern Tianshan ocean during the initial spreading stage. Supported by the Major State Research Program of PRC (Grant No. 2001CB409801), the National Natural Science Foundation of China (Grant Nos. 40472115 and 40234041) and the State Research Program of China Geological Survey (Grant No. 2001130000-22)     

>0.3 MeV高能电子注入辐射带槽区事件的分析与预报

本文利用低高度太阳同步轨道系列卫星NOAA/POES从1996年到2006年的>0.3 MeV高能电子观测数据,分析了>0.3 MeV高能电子注入辐射带槽区的特征,研究了注入槽区事件与行星际条件、太阳活动和地磁扰动之间的联系.研究表明>0.3 MeV高能电子注入辐射带槽区事件与磁暴的发生密切相关,注入事件的发生与太阳活动的强度有一定的相关性.在此研究的基础上,本文通过分析辐射带槽区>0.3 MeV高能电子通量和Dst指数的相关性,提出了利用Dst指数推算辐射带槽区>0.3 MeV高能电子通量的方法,继而给出了可行的辐射带槽区高能电子辐射环境的预警模式.     

桐柏老湾金矿带成矿构造体系演化研究及其地质意义

通过对老湾成矿带各期构造作用、区域变质作用、岩浆作用、矿化富集作用研究,将老湾成矿带成矿构造体系演化分为三个阶段:加里东-华力西期深层次韧性剪切作用,形成的NNW向构造控矿因素深远,起初始富集作用;从印支晚期(236～214 Ma)开始,在燕山期或期前(132.5Ma)为脆-韧性剪切-右行走滑体系,矿液再次充填控矿形成现在的富矿体;燕山末期后发生了浅层次脆、韧性构造和构造推覆。并建立了老湾金矿带"早期老湾韧性剪切成矿构造系统"与"中期高角度右型走滑脆韧性断裂构造系统叠加"和"晚期构造掩盖或破坏"三期成矿构造演化体系。三期成矿构造演化体系的建立和"晚期老湾岩体推覆于龟山岩组上"的认识,极大地拓展了赋矿地层空间,为取得找矿突破提供重要理论依据。     

The surface composition of Trojan asteroids: constraints set by scattering theory

We present the results of spectral modeling of 17 Trojan asteroids. The surface composition of this group of objects (located just beyond the main belt, trapped in Jupiter's stable Lagrange points) remains uncertain due to an absence of diagnostic absorption features in their spectra. We quantitatively analyze spectra of these objects covering the range 0.3-4.0 μm using the formulation for scattering in a particulate medium developed by Hapke. Since the widest spectral range possible is desired to provide the most robust results, recently measured near-IR spectra are combined with previously published visible and near-IR data. These composite spectra are converted to and modeled in terms of geometric albedo to provide the additional constraint of the absolute brightness of the asteroids. It is important that this modeling is performed for a large number of objects, and results are derived based on trends among best-fit models. Under this rigorous examination, we find that it is unlikely that the red spectral slope is a result of organics on the surfaces, due mainly to the lack of absorptions in the L-band. Instead, anhydrous silicates adequately describe the spectral characteristics of this group of objects. A significant fraction of carbonaceous material is also likely present, but is not responsible for the red spectral slope in these models. Also, using these models, we estimate that these surfaces contain at most a few wt% of H₂O ice and no more than 10-30 wt% of hydrated silicates.