西沙西科1井元素地球化学特征与海平面升降的关系

以南海北部西沙群岛石岛碳酸盐岩台地为研究对象,对1268件碳酸盐岩样品进行全岩元素地球化学特征分析,并结合早中新世以来沉积学特征,研究其与海平面升降的响应关系。实验结果显示,该地区常量元素（Na2O/K2O、Na2O/SiO2、P2O5）及微量元素（B/Ga、Zr/Al、Li、V）分析的古盐度、古环境氧化还原状态和酸碱度及海平面变化,与岩石地层学和古生物学分析得到的结论基本一致,进而可应用于孤立海相碳酸盐岩台地的沉积层序划分;受限于复杂的白云岩化作用,Mg/Ca难以反映海平面变化。Na2O/K2O、Na2O/SiO2、P2O5 B/Ga、Zr/Al、Li、V等指标表明,早中新世初期三亚组水深逐渐加深,有利于生物礁的发育;中中新世早期梅山组二段海平面第1次达到最高值,礁盘随之扩大,形成较深水环境下的碳酸盐岩台地,以潟湖相和内侧滩相为主;随后水体于中中新世晚期梅山组一段逐渐变浅,持续至晚中新世早期黄流组二段,生物礁受淋滤剥蚀形成礁-滩相沉积;晚中新世晚期黄流组一段海平面再次持续上升,于上新世达到第2次最高值,直至更新世水深才逐渐变浅。     

Subduction metamorphism of serpentinite‐hosted carbonates beyond antigorite‐serpentinite dehydration (Nevado‐Filábride Complex,Spain)

At sub‐arc depths, the release of carbon from subducting slab lithologies is mostly controlled by fluid released by devolatilization reactions such as dehydration of antigorite (Atg‐) serpentinite to prograde peridotite. Here we investigate carbonate–silicate rocks hosted in Atg‐serpentinite and prograde chlorite (Chl‐) harzburgite in the Milagrosa and Almirez ultramafic massifs of the palaeo‐subducted Nevado‐Filábride Complex (NFC, Betic Cordillera, S. Spain). These massifs provide a unique opportunity to study the stability of carbonate during subduction metamorphism at P–T conditions before and after the dehydration of Atg‐serpentinite in a warm subduction setting. In the Milagrosa massif, carbonate–silicate rocks occur as lenses of Ti‐clinohumite–diopside–calcite marbles, diopside–dolomite marbles and antigorite–diopside–dolomite rocks hosted in clinopyroxene‐bearing Atg‐serpentinite. In Almirez, carbonate–silicate rocks are hosted in Chl‐harzburgite and show a high‐grade assemblage composed of olivine, Ti‐clinohumite, diopside, chlorite, dolomite, calcite, Cr‐bearing magnetite, pentlandite and rare aragonite inclusions. These NFC carbonate–silicate rocks have variable CaO and CO₂ contents at nearly constant Mg/Si ratio and high Ni and Cr contents, indicating that their protoliths were variable mixtures of serpentine and Ca‐carbonate (i.e., ophicarbonates). Thermodynamic modelling shows that the carbonate–silicate rocks attained peak metamorphic conditions similar to those of their host serpentinite (Milagrosa massif; 550–600°C and 1.0–1.4 GPa) and Chl‐harzburgite (Almirez massif; 1.7–1.9 GPa and 680°C). Microstructures, mineral chemistry and phase relations indicate that the hybrid carbonate–silicate bulk rock compositions formed before prograde metamorphism, likely during seawater hydrothermal alteration, and subsequently underwent subduction metamorphism. In the CaO–MgO–SiO₂ ternary, these processes resulted in a compositional variability of NFC serpentinite‐hosted carbonate–silicate rocks along the serpentine‐calcite mixing trend, similar to that observed in serpentinite‐hosted carbonate‐rocks in other palaeo‐subducted metamorphic terranes. Thermodynamic modelling using classical models of binary H₂O–CO₂ fluids shows that the compositional variability along this binary determines the temperature of the main devolatilization reactions, the fluid composition and the mineral assemblages of reaction products during prograde subduction metamorphism. Thermodynamic modelling considering electrolytic fluids reveals that H₂O and molecular CO₂ are the main fluid species and charged carbon‐bearing species occur only in minor amounts in equilibrium with carbonate–silicate rocks in warm subduction settings. Consequently, accounting for electrolytic fluids at these conditions slightly increases the solubility of carbon in the fluids compared with predictions by classical binary H₂O–CO₂ fluids, but does not affect the topology of phase relations in serpentinite‐hosted carbonate‐rocks. Phase relations, mineral composition and assemblages of Milagrosa and Almirez (meta)‐serpentinite‐hosted carbonate–silicate rocks are consistent with local equilibrium between an infiltrating fluid and the bulk rock composition and indicate a limited role of infiltration‐driven decarbonation. Our study shows natural evidence for the preservation of carbonates in serpentinite‐hosted carbonate–silicate rocks beyond the Atg‐serpentinite breakdown at sub‐arc depths, demonstrating that carbon can be recycled into the deep mantle.     

新疆且末县米特河地区1:5万水系沉积物地球化学特征及找矿意义

根据1:5万水系沉积物地球化学测量工作成果,对采集的3138件样品中Cu,Pb,Zn,Au,Ag,W,Sn,Mo,Bi,As,Sb,Cr,Co,Ni共14种元素进行分析测试。研究结果表明,Au,Ag,Cu,Ni是区内最有找矿潜力的成矿指标元素;聚类分析所划分的4类元素簇群,主要与中低温成矿元素、阿尔金南缘断裂、蛇绿混杂岩相关,通过因子分析得到Ni-Cr-As-Sb-Cu-Bi,W-Bi-As-Cu,Bi-W,As,Ag-Zn-Pb,Cu-Bi-As共6类元素组合。其中Cr,Ni,Sb,Cu,As,Bi组合反映出与低温热液活动和断裂构造活动有关;Cr,Ni元素的富集主要与研究区内叶桑岗蛇绿混杂岩带关系密切;Ag,Pb,Zn组合则与地层低温热液元素局部富集和断裂构造活动密切相关。在综合异常分析和查证的基础上,结合区域成矿地质条件、区内矿产地质特征,圈定、划分出2个找矿远景区,并指出了研究区内以金、铜、银、镍为主要优势矿种,铅、锌为潜力矿种。     

暗云L1211的C~（18）O（J＝1－0）分子发射谱线的观测

本文作者首次对暗云Ｌ１２１１的Ｃ~（１８）Ｏ（Ｊ＝１－０）分子发射谱线进行了观测，发现了暗云Ｌ１２１１致密核的Ｃ~（１８）Ｏ（Ｊ＝１－０）的宽翼发射谱线和它的结构，得到了核区Ｃ~（１８）Ｏ（Ｊ＝１－０）分子的谱线轮廓图、强度分布图、速度分段积分等高图、速度位置图。     

SHORT COMMUNICATION SOL1:A PROGRAM FOR THE SIMULATION OF COMPLEX EQUILIBRIA USING A PERSONAL COMPUTER

The program SOL1,written in Turbo-PASCAL for use on a personal computers(IBM-PC orcompatible),has been developed for calculating the equilibrium concentrations of the species inmulticomponent ligand-metal mixtures of up to 21 components and 150 species.The main features arethe easy data input system,the possibility of three different tasks(calculating the composition of a singlesolution,simulating titration curves and calculating the species distribution as a function of pH)andprocedures for drawing the calculated curves on Roland DXY plotters.The program has been tested by astudy of six different complex systems.     

以基线长度变化率为约束估算VLBI站的垂直形变率

基于NNR-NUVEL-1A地球板块运动模型和ITRF2000地球参考架的三维VLBI站速度矢量,采用实测的VLBI基线长度变化率作为约束,重新估计了部分国际VLBI站的局部或区域性地壳的垂直形变,并与国际地球参考架ITRFs解和VLBI全球解GLB2003,VTRF2003和VTRF2005的结果进行了比较。结果表明,欧亚板块的URUMQI站和太平洋板块的KWAJAL26站,南极OHIGGINS站的垂直形变率、ITRFs解和VLBI全球解存在6-15mm/a的差异,北美YUMA站可能有15-31mm/a 的垂直形变率,而美国西部太平洋板块的San Francisco(PRESIDIO)站的垂直形变率还有待进一步的研究。此外,SC-VLBA,CRIMEA和EFLSBERG站的垂直形变率、ITRFs解和VLBI全球解的差约为1-6mm/a。用不同方法得到的VLBI站的水平形变率解有较好的一致性。     

用于2.4m望远镜的网络气象站

在进行天文观测时,天气因素的影响是很大的,为适应天文观测技术发展的要求,在2.4m镜附近需要建立一个网络气象站,一方面可以对天气状况实时监测,另一方面其他设备可以从网上查询并使用这些数据,以满足2.4m望远镜必须要有气象状况输入才能正常地在RoboticMode下工作的要求。文中介绍了1 wirenet气象站的原理以及软硬件设计。     

我国重要城市间信息作用的系统分析

本文依据城市间长途电话资料,借助因子分析方法,对我国三十个重要城市间信息作用的集聚场和扩散场进行了系统分析,着重分析了核及其影响范围、等级结构和地域结构,发现我国重要城市间的信息作用场深受中央集权行政管理体制的影响,网络结构也不合理.对此,本文也提出初步的发展依据和设想.