南海再探可燃冰——“海洋六号”科考船开赴南海北部

近期,我国第一艘自主设计的"海洋六号"科考船再次开赴南海北部区域,对那里的可燃冰资源进行新一轮的精确调查,为下一步更加精确的勘探工作做准备。据悉,在我国南海北部神狐海域钻探目标区内圈定的11个可燃冰矿体,含矿区总面积约22平方公里,预测储量约194亿立方米。据相关人员介绍,南海北部的可燃冰储量     

南海北部天然气水合物气源系统与成藏模式

天然气水合物成矿成藏条件与油气成藏条件虽然存在差异,但亦存在共同之处,即均需要有充足烃源供给及烃源供给系统输送与有利聚集场所的时空耦合配置。为了深入研究天然气水合物与常规油气运聚成藏条件之差异,根据南海北部陆坡深水区构造沉积演化特点及油气地质条件与多年来油气及水合物勘探成果,综合剖析了油气及天然气水合物气源构成特点与流体运聚输导系统特征,同时根据地质地球物理及地球化学分析,初步研究了气源供给运聚通道系统类型与高压低温天然气水合物稳定带的时空耦合配置关系,并结合油气地质及天然气水合物成矿成藏基本地质条件,总结和建立了南海北部陆坡深水区“生物气源自生自储扩散运聚型”、“热解气源断层裂隙输导下生上储运移渗漏型”和“热解气源底辟及气烟囱输导下生上储运移渗漏型”等3种成因类型的天然气水合物成矿成藏模式,以期能为南海北部深水区天然气水合物资源预测及有利勘查目标评价优选等提供决策依据与指导。     

试论秦汉至唐时期封建王朝的治边方略

对秦汉至唐宋时期历朝的治边方略进行考察,可以发现,历朝的治边方略呈现出“守势政策”的特点.这一“守势政策”在不同王朝或同一王朝的不同时期具有不同的表现内容,大体可概括为两种类型,一为积极“守势政策”,一为消极“守势政策”.二者虽然在内容的表现形式上有差异,但本质上均含有保持中原王朝文化优势的“以夏变夷”的思想内容.受封建统治者思想认识水平及民族构成的影响,不同朝代对边疆少数民族或民族政权的认识具有差异性.     

Deep structure at northern margin of Tarim Basin

In this paper, a 2D velocity structure of the crust and the upper mantle of the northern margin of the Tarim Basin （TB） has been obtained by ray tracing and theoretical seismogram calculation under the condition of 2D lateral inhomogeneous medium using the data of seismic wide angle reflection/refraction profile from Baicheng to Da Qaidam crossing the Kuqa Depression （KD） and Tabei Uplift （TU）. And along the Baicheng to Da Qaidam profile, 4 of the 10 shot points are located in the northern margin of the TB. The results show that the character of the crust is uniform on the whole between the KD and TU, but the depth of the layers, thickness of the crust and the velocity obviously vary along the profile. Thereinto, the variation of the crust thickness mainly occurs in the middle and lower crust. The Moho has an uplifting trend near the Baicheng shot point in KD and Luntai shot point in TU, and the thickness of the crust reduces to 42 km and 47 km in these two areas, respectively. The transition zone between the KD and TU has a thickest crust, up to 52 km. In this transition zone, there are high velocity anoma- lies in the upper crust, and low velocity anomalies in the lower crust, these velocity anomalies zone is near vertical, and the sediment above them is thicker than the other areas. According to the velocity distributions, the profile can be divided into three sections： KD, TU and transition zone between them. Each section has a special velocity structural feature, the form of the crystalline basement and the relationship between the deep structure and the shallow one. The differences of velocity and tectonic between eastern and western profile in the northern margin of the Tarim Basin （NMTB） may suggest different speed and intensity of the subduction from the Tarim basin to the Tianshan orogenic belt （TOB）.     

Sea surface temperature and terrestrial biomarker records of the last 260 ka of core MD05-2904 from the northern South China Sea

This paper reports high-resolution biomarker records of the last 260 ka for core MD05-2904 from the northern South China Sea （SCS）. The sea surface temperature （SST） record using the U37^k＇, index reveals a minimum of 21.5℃（MIS 2） and a maximum of 28.3℃（MIS 5.5）, for a temperature difference of almost 7℃, and provides the longest high-resolution U37^k＇ SST record in northern SCS. The content of odd-number long chain n-alkanes and several n-alkanes indexes such as the CPI, ACL and the C31/C27 ratio, all reveal generally higher values during the glacials and lower values during the interglaclals. Terrestrial input as Indicated by n-alkane content was mostly controlled by sea-level changes： During the glacials, lower sea-level exposed the continental shelf to enable rivers to transport more terrestrial materials to the slope; and the situation reverses during the interglacials. The n-alkane indexes changes reveal more n-alkanes from contemporary vegetation during glacials as a result of the proximity of the core site to the source region, while the increases in ACL and C81/C27 ratio during glaclals indicate a change to more grassy vegetation. However, the highest values for CPI, ACL and the C81/C27 ratio all occurred during late MIS 3, and it was suggested that this period was characterized by a strong summer monsoon-dominated humid climate which resulted in a denser vegetation for the exposed continental shelf region.     

Using 137Cs tracing technique to estimate wind erosion rates in the typical steppe region,northern Mongolian Plateau

Wind erosion is one of the major factors of land degradation in the typical steppe region, northern Mongolian Plateau. Using ^137Cs tracing technique, we estimated the wind erosion rates of different pastures and abandoned farmland at Bayannur and Karakorum in Mongolia. The pastures and cutting grassland at Bayannur were slightly eroded by wind, with the rates of 64.58-169.07 t·km^-2.a^-1. The abandoned farmland in Karakorum, however, was strongly eroded by wind, with annual surface soil loss of 4.05 mm. a^-1, and wind erosion rates up to 6723.06 t· km^-2. a^-1. The total loss of surface soil due to wind erosion has been 17.4 cm since the cultivation of the steppe land in the 1960s. The wind ero- sion rate at the abandoned farmland was much higher than that at the typical steppe sites, showing that the cultivation led to serious wind erosion in the typical steppe region, northern Mongolian Plateau. By contrast, traditional livestock grazing resulted in less disturbance to the surface soil, and did not induce to devastating wind erosion, which plays an important role in maintaining the stability of the steppe ecosystem in the northern Mongolian Plateau.     

从能源短缺的角度看广东海洋新能源开发前景

广东省是海洋大省,蕴藏着潜力巨大的海洋新能源——天然气水合物。其良好的开发前景,对解决广东能源短缺,实现经济、社会可持续发展,具有重要战略意义和现实意义。广东省十分有必要积极参与到这种新型能源的研究和开发工作中,为调查研究和评价南海北部天然气水合物资源,早日实现商业性开采做出重要贡献。     

历史上廉州、钦州与越南北部地区的文化互动

历史上廉州、钦州与越南北部有着密切的文化互动关系,文化互动的内容包括廉州、钦州与越南北部地区的海路交通;廉州、钦州与越南北部地区的人员互迁;廉州、钦州人到越南北部为官的情况;而廉州所藏越南昭光寺钟及钟铭、越南在廉州修建的东山寺和唐朝宰相姜公辅的籍贯等等更进一步证明不应该把近现代意义上所谓的"国家"、"民族"的意义生硬地套到当时的历史时代,只有这样,研究才有可能相对客观。     

南海北部陆缘多金属结核的内部显微构造特征及其地质意义

多金属结核在形成过程中因环境不同而产生显微构造与物质成分的差异.选取采自南海北部陆缘的多金属结核,运用高倍率偏反光显微镜对其显微构造进行了初步的研究,显微构造呈现:层纹状、叠层状、柱状、颗粒状、掌状、斑状、条带状、裂隙充填状及脉状等丰富的形态,反映了边缘海多金属结核生长过程中古海洋环境变化的多样性与复杂性.     

珠江口盆地白云凹陷珠海组碎屑岩储层特征及成因机制

通过岩石铸体薄片、粒度分析和压汞分析等手段,分析白云凹陷珠海组储层的岩石学特征和物性演化特征,研究沉积环境和成岩演化过程对储层特征的影响机制。研究结果表明:储层主要以长石质石英砂岩和长石岩屑质石英砂岩为主,颗粒支撑并以碳酸盐、自生石英和黏土矿物接触式胶结。储层物性总体具有中低孔中低渗特征,以粒间溶蚀扩大孔为主,其次为珠海组底部黏土膜保护的原生孔隙,分选好的中-粗喉型喉道使孔隙连通性良好;在凹陷西斜坡,珠海组上部和底部分别发育钙质砂岩夹层和铁泥质砂岩夹层。三角洲前缘环境是珠海组储层物性良好的先决条件;酸性流体的溶蚀溶解作用和绿泥石黏土膜保护是储层物性较好的根本原因,压实作用是粒间孔隙损失的主要原因,而部分储层渗透率较低是因为自生石英和黏土矿物充填喉道;钙质砂岩夹层物性差是胶结作用所致,而铁泥质砂岩夹层物性差是压实和胶结共同作用的结果。