上升洋流与陆缘坻

通过对中国三大成磷期（也是世界８大成磷期中的３个）成矿构造－古地理单元的研究，提出了“陆缘坻”的新概念。陆缘坻不是一般意义上的台地、盆地，而是一个连接深海并与海岸平行的峡长水下槽地，它具有以断垒构造为主的活动性和地貌上的复杂性，甚至高耸地带可以出露水面。形成具有工业意义的大规模的磷块岩必需具备上升洋流和陆缘坻这两个基本条件，二者缺一不可。可以说陆缘坻的提出丰富和发展了上升洋流理论     

班公湖—怒江结合带南侧弧-盆系时空结构与演化特征

本文在1：25万邦多区幅、措麦区幅填图成果基础上，运用多岛弧造山模式分析了班公湖—怒江结合带南侧弧-盆系时空结构与演化特征。认为中晚侏罗世—早白垩世，伴随班公湖—怒江洋向南俯冲消亡，其南侧形成多岛弧—盆系的空间配置格局；早白垩世晚期—晚白垩世，残余海盆沉积、闭合消亡及其随后的碰撞造山，完成了班公湖—怒江带南侧弧-盆系时空演化史。     

东秦岭商丹带北侧新元古代埃达克质花岗岩及其地质意义

东秦岭商丹构造带北侧的商南花岗岩体和吊庄花岗岩体属于钙碱性系列,具有岛弧花岗岩特征。这些岩石富Na2O(3.54％～5.52％)、贫K2O(0.75％～3.46％)、Na2O/K2O比值为1.09～6.16,SiO2含量＞56％(61.84％～74.57％),Al2O3含量变化于13.41％～19.01％,多数≥15％,MgO含量均小于3％(0.65％～2.41％),Mg#为43.87～66.12,低Y(＜18×10-6, 为1.90×10-6～18.4×10-6)和Yb(＜1.9×10-6为0.27×10-6～2.27×10-6),Sr含量高(350×10-6～830×10-6),多数大于400×10-6,Sr/Y比值在25.29～216.71之间,大于20～40;LREE富集,HREE亏损,多数La/Yb比值＞20(47.60～110.93),(La/Yb)N＞20(32.09～99.13),不显Eu异常或有弱的Eu正异常,大离子亲石元素(Rb、Ba、Th、Sr)相对富集,高场强元素(如Nb、Ta、Zr、Hf、Ti)相对亏损。同位素组成表明,花岗岩体具有相对低的143Nd/144Nd比值(0.512127～0.512134),与商南松树沟蛇绿岩的143Nd/144Nd比值(0.512651～0.512917)比较接近,εNd(t)为正值(+1.23～+2.51),暗示源岩以N-MORB为主。这些地球化学特征与洋壳俯冲MORB的部分熔融形成的埃达克质岩相似,表明这些晋宁期的花岗岩类可能属于埃达克质岩。研究表明,商丹地区埃达克质花岗岩类与新元古代沿商丹带-线曾发育有一个以松树沟蛇绿岩和黑河玄武岩为代表的古洋盆(古秦岭洋)向北发生俯冲消减作用有关,造成古洋壳俯冲板片MORB岩石部分熔融而形成。     

Estimates of Anthropogenic CO_2 Uptake in a Global Ocean Model

A global ocean general circulation model (L30T63) is employed to study the uptake and distribution of anthropogenic CO2 in the ocean. A subgrid-scale mixing scheme called GM90 is used in the model. There are two main GM90 parameters including isopycnal diffusivity and skew (thickness) diffusivity. Sensitivities of the ocean circulation and the redistribution of dissolved anthropogenic CO2 to these two parameters are examined. Two runs estimate the global oceanic anthropogenic CO2 uptake to be 1.64 and 1.73 ...     

Seasonal variation in the three-dimensional structures of coastal thermal front off western Guangdong

The seasonal structure and dynamic mechanism of oceanic surface thermal fronts(STFs) along the western Guangdong coast over the northern South China Sea shelf were analyzed using in situ observational data, remote sensing data, and numerical simulations. Both in situ and satellite observations show that the coastal thermal front exhibits substantial seasonal variability, being strongest in winter when it has the greatest extent and strongest sea surface temperature gradient. The winter coastal thermal front begins to appear in November and disappears after the following April. Although runoff water is more plentiful in summer, the front is weak in the western part of Guangdong. The frontal intensity has a significant positive correlation with the coastal wind speed,while the change of temperature gradient after September lags somewhat relative to the alongshore wind. The numerical simulation results accurately reflect the seasonal variation and annual cycle characteristics of the frontal structure in the simulated area. Based on vertical cross-section data, the different frontal lifecycles of the two sides of the Zhujiang(Pearl) River Estuary are analyzed.     

冷涡对过境台风的响应研究

利用多源卫星遥感资料及再分析资料,对台风泰利(Talim)对中尺度冷涡的影响进行了分析研究。结果表明,台风泰利过境中尺度冷涡时,冷涡显著增强。最大海面高度异常出现在冷涡中心区域,达到-32.7cm,最大海表温度降幅达到3°C以上,叶绿素平均浓度增长了10倍。通过计算冷涡海域的罗斯贝数、水体拉伸度和离散度等动力学参数,可以进一步发现,台风过境冷涡所在海域时,局地非地转效应和混合效应显著增强,罗斯贝数、水体拉伸和离散度均增加了2倍以上,最大水体拉伸度和离散度发生在冷涡南侧靠近台风路径的区域。本研究对深入理解涡-台风相互作用,以及由此产生的海洋生态环境效应具有重要的意义和作用。     

The significance of Mn‐rich ilmenite and the determination of P–T paths from zoned garnet in metasedimentary rocks from the western Cape Breton Highlands,Nova Scotia

The Jumping Brook Metamorphic Suite in the western Cape Breton Highlands of Nova Scotia is part of an inverted Barrovian sequence that formed during a Late Silurian–Early Devonian promontory–promontory collision in the Canadian Appalachians. In this study, systematic discrepancies between geochemical observations and thermodynamic model predictions led to the discovery of a systematic relationship linking the style of garnet core isopleth intersection (GCII) to the pyrophanite (MnTiO₃) component of co‐existing ilmenite. Samples that yielded tight GCIIs at or near the garnet‐in curve were found to contain ilmenite with negligible pyrophanite components, whereas samples yielding GCIIs far removed (up to 105°C) from the garnet‐in curve were found to contain ilmenite with significant pyrophanite and/or ecandrewsite (ZnTiO₃) components. Based on petrographic and geochemical observations, Mn(±Zn)‐rich ilmenite are interpreted to have sequestered Mn throughout prograde metamorphism due to sluggish intracrystalline diffusion. The amount of reactive Mn input into the thermodynamic models from whole‐rock analyses were, in some cases, overestimated, resulting in garnet‐in curve topologies that extend to erroneously low P–T conditions. Modifications to the whole‐rock chemistry that account for Mn sequestration into ilmenite, however, yielded robust model results. Our results show that, in addition to uncertainties in thermodynamic data sets and phenomenon related to reaction kinetics, Mn‐rich ilmenite may superimpose additional complexities related to the interpretation of predicted equilibria involving garnet. Numerical simulations of garnet crystallization were used to infer P–T paths of metamorphism for one sample from the garnet zone (Mn corrected) and two samples from the staurolite zone (Mn uncorrected) of the inverted sequence. Model results are remarkably similar among the three samples and indicate that garnet crystallization occurred along relatively steep (31–37°C/km) clockwise P–T paths. The peak conditions of garnet crystallization and metamorphism (560–590°C, 7.4–8.0 kbar) are interpreted to have been attained approximately simultaneously, such that the paths are characterized by tight prograde‐to‐retrograde transitions. The hairpin nature of the P–T paths is interpreted to represent the onset of thrust‐related exhumation and isograd inversion along ductile shear zones, consistent with available field and geochronological constraints.     

贵州及邻区二叠系锰矿地质特征及成矿作用探讨

本文在系统收集和分析了近年来贵州锰矿资源评价工作及以往锰矿工作资料的基础上,获得了对贵州及邻区二叠系锰矿更深入系统的认识。主要成果为：认为该区中二叠世茅口期含锰岩系可大致对比,可沿用遵义锰矿产出地区所使用的名称——中二叠统茅口组白泥塘层（P2m^b）;水城纳雍锰矿与宣威格学锰矿特征及成矿机制十分相似,均为第四纪氧化富集成矿,矿床类型属于风化矿床类的锰帽型锰矿床亚类,矿质来源于原始沉积的含锰岩系——白泥塘层,而白泥塘层的锰质来源于中二叠世茅口期峨眉山玄武岩喷发;将贵州及邻区二叠系各类型锰矿床的特征及含锰岩系、物质来源、成矿作用等方面作了有机联系和系统分析,并建立了统一的成矿模式。     

初探扬子地台东南缘优质锰矿地质特征及其成矿条件--以乐华锰矿为例

文章以乐华锰矿床地质特征为例,初探了扬子地台东南缘低磷优质锰矿的地质特征和成矿条件,并对在赣东北地区寻找该类型矿床的前景提出了自己的看法.     

内蒙古狼山后山地区海相火山岩特征及找矿前景

内蒙古狼山后山地区为一转换拉伸盆地,其演化过程及伴随的火山活动可划分出4个阶段,分别为拉伸盆地初始演化阶段、盆地强烈拉伸阶段、裂谷晚期双峰式海相火山岩形成阶段和裂谷闭合岩浆侵入活动阶段.那仁宝力格～查干楚鲁海相火山岩的原岩分异较好,产出构造环境为大陆-大洋过渡的岛弧环境.海相火山岩的常量元素和微量元素特征表明,霍各乞地区矿床的物质来源与火山岩(绿片岩及角闪岩)关系密切,该海相火山岩系具有一定的成矿潜力.