Li_2O-(Mg、Zn、Ni)O-V_2O_5三元体系的相平衡

对Li_2O-(Mg、Zn、Ni)O-V_2O_5三元体系在500—800℃相图的研究表明,在每个系统内部都出现了一个依端员组分摩尔比为1:2:1的化合物。即橄榄石型的LiMgVO_4,硅铍石型的LiZnVO_4和尖晶石型的LiNiVO_4。不同的是,Li_2O-MgO-V_2O_5中发现了第二个三元相和一个固溶体。LiO_2-NiO-V_2O_6中得出一个固溶体,而LiZnNO_4中未得固溶体。     

东天山白山钼矿地球化学特征及地质意义

白山钼矿赋矿岩体为花岗斑岩,其主量、微量及稀土元素地球化学特征研究表明,岩体属过铝质高钾钙碱性系列,并相对富集大离子亲石元素(Rb,Th,Sr等),亏损高场强元素(Nb,Ce,Zr等),以及具有LREE富集的右倾稀土元素分布模式。根据矿物稀土元素作为示踪剂提供的信息表明,含钼矿物的石英脉稀土元素组成和分布模式与壳幔同熔型花岗岩有众多相似之处,推测该成矿物质来源与花岗岩岩浆有关,来自同一源区,形成于碰撞后演化阶段向板内转化的构造环境,并具相同的成岩方式与成岩成矿同期。     

煤矿开采在煤系砂岩中形成现代陷落柱的实例

通 过 钱家 营井 田 203泥石 流 突发 事故 ,对 陷落 柱 的形 成机 理 作进 一步 的 研究 ,巷 道临 空 空间 、构 造破 碎带 、高压 地下 水 的存 在是 煤 系砂 岩地 层 中形 成现 代 陷落 柱的 主 要控 制因 素 。     

小莱河麻粒岩相铁建造的矿物组合—变质过程p、T变化的探讨

小莱河太古宙麻粒岩相铁建造的矿物组合有：①斜方辉石（Fs87）＋钙铁辉石＋石英＋磁铁矿±莱河矿；②铁闪石＋铁浅闪石质角闪石＋石英＋磁铁矿＋碳酸盐±Fe－镁川石（云辉闪石）。辉石的出溶显示了它形成的不同阶段：片晶发育的OpxⅡ－CpxⅡ是最后稳定产物，计算的平衡温度是742℃，按相图获得的压力是7×108～7．8×108Pa；钙铁辉石中“001”片晶是易变辉石片晶转变的，Opx－Cpx－Pig（片晶）阶段据相图推测可能形成于近820℃，8×108Pa的条件下。原始均一相的OpxⅠ－CpxⅠ阶段矿物成分按估算的片晶含量计算，它们的形成温度接近820℃，可能的压力范围是11×108～13×108Pa。由此得到ITD型麻粒岩相p－T－t轨迹。莱河矿无氧化成因的证据，认为它是在麻粒岩相条件下生成的。云辉闪石的Si—O链重复周期是3×，其Fe／（Fe＋Mg）＝0．85，是接近富铁端元的Fe－镁川石，它与闪石一起在640到近700℃条件下交代了辉石。     

提高测井曲线纵向分辨率的方法

常规处理方法往往漏掉一些有价值的薄油气储层。利用频率域反槽积方法、贝叶斯反褶积方法、反褶积与光滑滤波组合（ＤＦＳＮ）方法和分辨率匹配与非线性拟合方法对测井曲线进行了提高纵向分辨率处理，测井曲线的纵向分辨率可提高１～４倍，一些结果得到了证实，为准确地定量评价薄储居提供了较可靠的参数     

中国中、新生代含油气盆地构造和动力学背景

中国有大约26个含油气盆地。盆地主要有两种类型:(1)伸展盆地;(2)前陆(或挠曲)盆地。第一种伸展盆地主要位于东部,第二种前陆盆地主要位于中部和西北地区。本文讨论了伸展和前陆盆地的以下特征:(1)沉降史;(2)热史;(3)构造样式和运动学。结合深部地球物理和火山岩资料,确定了盆地的地球动力学背景,并且推测盆地形成与西太平洋板俯冲作用和特提斯洋闭合有关。     

Effect of melt composition on basalt and peridotite interaction: laboratory dissolution experiments with applications to mineral compositional variations in mantle xenoliths from the North China Craton

Interaction between basaltic melts and peridotites has played an important role in modifying the lithospheric and asthenospheric mantle during magma genesis in a number of tectonic settings. Compositions of basaltic melts vary considerably and may play an important role in controlling the kinetics of melt–peridotite interaction. To better understand the effect of melt composition on melt–peridotite interaction, we conducted spinel lherzolite dissolution experiments at 2 GPa and 1,425 °C using the dissolution couple method. The reacting melts include a basaltic andesite, a ferro-basalt, and an alkali basalt. Dissolution of lherzolite in the basaltic andesite and the ferro-basalt produced harzburgite–lherzolite sequences with a thin orthopyroxenite layer at the melt–harzburgite interface, whereas dissolution of lherzolite in the alkali basalt produced a dunite–harzburgite–lherzolite sequence. Systematic variations in mineral compositions across the lithological units are observed. These mineral compositional variations are attributed to grain-scale processes that involve dissolution, precipitation, and reprecipitation and depend strongly on reacting melt composition. Comparison of mineral compositional variations across the dissolution couples with those observed in mantle xenoliths from the North China Craton (NCC) helps to assess the spatial and temporal variations in the extent of siliceous melt and peridotite interaction in modifying the lithospheric mantle beneath the NCC. We found that such melt–rock interaction mainly took place in Early Cretaceous, and is responsible for the enrichment of pyroxene in the lithospheric mantle. Spatially, siliceous melt–peridotite interaction took place in the ancient orogens with thickened lower crust.     

Early Cretaceous adakitic granites in the Northern Dabie Complex, central China: Implications for partial melting and delamination of thickened lower crust

To date, few adakitic rocks have been reported in direct association with contemporary intra-continental extensional structures, which has cast doubt on genetic models involving partial melting of the lower crust. This study presents Early Cretaceous (143-129 Ma, new Sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb ages) adakitic granites, which are directly associated with a contemporary metamorphic core complex (i.e., the Northern Dabie Complex in the Dabie area). These granites exhibit relatively high Sr contents, negligible to positive Eu and Sr anomalies, high La/Yb and Sr/Y ratios, but very low Yb and Y contents, similar to subducted oceanic crust-derived adakites. They are also characterized, however, by very low MgO or Mg^# and Ni values, and Nd-Sr isotope compositions (ε_Nd(t) = −14.6 to −19.4 and (⁸⁷Sr/⁸⁶Sr)_i = 0.7067-0.7087) similar to Triassic continent-derived eclogites subducted in the Dabie-Sulu Orogen. Additionally, late granitic dikes in the adakitic intrusions exhibit low Sr contents, clearly negative Eu and Sr anomalies, low La/Yb and Sr/Y ratios, but relatively high Yb and Y contents, similar to 118-105 Ma granites in the Northern Dabie Complex. Based on composition and geochronology data of Neoproterozoic amphibolites and orthogneisses, Triassic high- to ultra-high pressure metamorphic rocks, and Early Cretaceous mafic-ultramafic intrusive rocks, and the constraints provided by experimental melt data for tonalites, metabasaltic rocks and eclogites, we suggest that the adakitic granites were most probably generated by partial melting of thickened amphibole or rutile-bearing eclogitic lower crust as a consequence of Triassic-Middle Jurassic subduction and thrusting. The late dikes probably originated from plagioclase-bearing intermediate granulites. Moreover, we suggest that late Mesozoic delamination or foundering of thickened eclogitic lower crust is also a more plausible mechanism for the petrogenesis of Early Cretaceous mafic-ultramafic intrusive rocks in the Dabie area, and probably involved partial melting of a mixed source comprising eclogitic lower crust that had delaminated or foundered into upper lithospheric or asthenospheric mantle peridotite. Asthenospheric upwelling in response to post-collisional delamination of lithospheric mantle was likely to have provided the heat source for the Cretaceous magmatism.     

山东临朐山旺新生代玄武岩中超镁铁岩包体的研究

山旺新生代玄武岩中的超镁铁质包体分为五类:尖晶石纯橄榄岩、尖晶石二辉橄榄岩、尖晶石方辉橄榄岩、尖晶石石榴石二辉岩和石榴石二辉橄榄岩。对它们的地质学,岩相学、岩石化学,造岩矿物的化学成分,稀土配分模式及热力学计算的研究表明,前三种岩石属原始地幔岩,后二种是地幔中岩浆作用的产物。     

Spatial Database of Geological Survey Extent in 20th Century in China

During the whole 20th century in China, especially the latest 50 years, we have gotten much geological information about geological mapping, geophysics, geochemistry, mineral exploration,remote sensing, environmental geology, hydrogeology, engineering geology and oceanic geology etc. by our geologists and explorers. All the information has been accmnulated and can be used as a dcision-making foundation for the future plan of geological survey. The spatial database of geological survey ex-tents has been established by using computer technology. The database contained all kinds of exploration sections and collected about 160 000 records in this database. This paper introduces the data construc-tion ,contents and applying systemof this database, and trys to let people know what kinds of geological survey were finished, when the exploration were carried out, and how and where you can get this infor-mation.