中国海洋国土的确定及矿产资源

我国是有辽阔海洋国土的海洋大国,海陆总国土面积约1 260×104km2。中国海处于大陆边缘,其海底地貌可分为大陆架、大陆坡、岛弧、海沟和深海海盆五大类。本文按地体构造分析我国海域及邻区的构造,其主体处于欧亚板块的华北亚板块、扬子亚板块、华南亚板块、南海亚板块和东南亚亚板块,其中亚板块可分为若干地体。台湾海岸山脉及其以东区域位于菲律宾海板块。三叠纪以来,这些板块、亚板块和地体处于不断拼合、增生或离散之中。按照联合国海洋法公约,渤海是内海。黄海的西部海域,东海和南海的大部分海域都是我国国家管辖的专属经济区,都是中国海洋国土,根本不是什么公海。我国海洋矿产资源极其丰富,海洋油气资源的勘探与开发居最重要的地位。除了已开采海滨砂矿、铜、煤等固体矿产之外,应特别要重视海洋多金属结核、天然气水合物等资源的勘探和开发。     

中国地质学会公布第三届科普奖评选结果

为推动中国地质学会地学科普研学工作的开展,根据 《中国地质学会精品地学研学路线、课程评选办法(试行)》, 学会组织开展了第二批精品地学研学路线、第一批精品地学 研学课程的申报、推荐和评审工作。     

Mount Woolnough: the submerged volcano,SE of Sydney,NSW

Part of a larger investigation of the sea bed off Sydney was a study of the extinct submarine volcano Mount Woolnough. It is located approximately 41 km east of Kurnell, NSW, and protrudes 175 m above the sediment cover at depths of approximately ?550 to ?375 m. Volcanic rock, approximately 2.2 km in diameter, is exposed above the sediment sea floor and is much smaller than its magnetic expression (approximately 13 km in diameter). Samples dredged from Mount Woolnough were conglomerates with phosphatic nodules and volcanic fragments set in a fine foraminiferal sediment matrix. Zircons within the mafic fragments yielded a minimum age of 261 Ma.     

内蒙古西乌旗下二叠统寿山沟组海底扇的发现及意义

西乌珠穆沁旗地区下二叠统寿山沟组沉积环境的认识尚缺乏确凿证据.对塔宾庙林场剖面寿山沟组的研究认为是一套海相碎屑岩沉积,岩石类型以长石岩屑砂岩为主,发育粒序层理和平行层理,属于鲍马序列中的A和B段,并伴有Zoophycos相遗迹化石组合,属于海底扇沉积.根据岩石类型、砂岩的单层厚度、砂岩和泥岩的比值,划分出内扇、中扇、外扇3个亚相,内扇亚相发育水道砾岩,外扇亚相发育复理石相遗迹化石.该区寿山沟组厚层暗色泥岩,是良好的烃源岩,而扇体可以作为有效的储层,具有很好的油气勘探前景.     

Morphogenesis of Congo submarine canyon and valley: implications about the theories of the canyons formation

The bottom and edges of the Congo submarine canyon are made of deposits which show morphologies of superposed terraces associated with lense side slope. Using 3D seismic, 3.5 kHz acoustic profiles and core datas, these geometries are interpreted as being mainly the result of the polyphase processes due to the activity of turbidity currents. All the turbidite deposits located below the canyon floor and the actual Congo fan belong to a unique depositional sequence which begun at the early Pliocene. Probably, this sequence has been initiated by an important uplift of the West Africa margin.     

浅谈海缆追踪系统及其应用

海底电缆的监测和维护已成为海洋工程勘察的一个重要组成部分,其精确跟踪定位更是世界性难题.文章首先对比分析了3种海缆追踪方法及相应的商业化系统,接着详细论述了有源系统TSS350国内首次对高压海缆的追踪应用效果.海缆追踪系统在国外小电流及断点电缆追踪上的成功应用已经证明了系统的性能;而国内湛江高压电缆实验高精度的路由追踪和埋深定位又为海缆追踪系统开辟了更广泛的应用空间.海缆追踪系统的原理、技术指标及其应用为国内海缆的监测和维护提供了解决办法,也为弥补国内研究空白提供了方法基础.     

湘西北海相含铀磷块岩中硒汞矿和晶质铀矿的发现及其地质意义

在扬子陆块东南缘湘西北武陵地区下寒武统牛蹄塘组海相黑色岩系下部鲕粒磷块岩中,首次发现了似纳米级的硒汞矿和晶质铀矿。通过电子探针化学成分测定和微区解剖,显示海相磷块岩中硒汞矿和晶质铀矿的产出状态、形态特征和占位特征。研究认为,同沉积期伴随火山热液喷出形成海相沉积鲕粒状磷块岩(鲕粒中包含球滴状硒汞矿),似纳米级硒汞矿在海相磷块岩中占位于鲕粒磷结核的内部和中心。其形成后期,海底热液作用持续,磷块岩经部分溶蚀、热液脱碳,在磷块岩的微裂隙中晶质铀矿、石英共沉淀析出。海相磷块岩中硒汞矿和晶质铀矿的发现和空间占位特征的研究,对探讨磷块岩中硒汞矿和晶质铀矿的形成与海底喷流(热水)沉积作用的发生方式和成因联系有启示意义,进一步佐证扬子陆块东缘陆缘裂陷喷气沉积是发生大规模铀成矿作用的机制。     

湘西北下寒武统黑色页岩伴生元素研究新进展

湖南大庸慈利的镍钼多金属矿床是湘西北下寒武统黑色页岩中伴生元素镍钼及铂族元素等富集最好地段。该矿床中的硅岩应属典型的喷气岩；特殊的筒状富矿体，以及Ｎｉ、Ｍｏ、Ｃｕ、Ｚｎ、Ｓｅ、Ａｓ、Ｂａ、Ａｕ、Ａｇ、Ｐｔ族元素特殊组合；矿石中金属硫化物呈胶状产出，显示快速堆积特征。     

Characteristics of the Submarine Topography and its Profile Type of the Coast of China

Based on the latest submarine topography data of the China 908 Project （China offshore marine environmental comprehensive investigation and assessment）,we analyzed the general China offshore submarine topographical characteristics and the factors influencing its development.The submarine topography off the coast of China follows the NW-SE trend of the land topography.The gradient of the submarine topography ranges from 0.2％ to 1.6％ with an average gradient of about 0.8％.The depth contours run mostly parallel to the coast,and extend out to sea in estuary areas.The submarine topography is dominated by the geological structure,which shows the typical characteristics of two uplifts and two subsidence events from north to south.The geological structure combined with the different sedimentary environments and complex hydrodynamic conditions produced topography that can be characterized by three types：sedimentary basins,compressionuplift,and transition form.In the sedimentary basin and compression-uplift regions,the topographical undulation is small,sediments are fine-grained,and the currents flow in a single direction,leading to bays with sedimentary plains and underwater accumulation slopes,which are of the same tectonic origin.Transition-type topography is characterized by strong undulations and mixed-size sediment particles,terraces and scarps inshore and shelf plains and erosion-deposition landforms offshore.This is a result of incomplete fault block development and repeated transgressions.In the deposition reformation regions （transition form type）,the topography has strong undulations,the sediments are coarse,tidal sand ridges are well-developed at terrigenoussupplied estuaries and convergence zones,and the Holocene sediments are thick,transformed by tides,river runoff,and currents.     

西秦岭岷县地区二叠纪裂陷带斜坡沉积及其构造意义

秦岭造山带西段，二叠纪裂陷作用非常活跃。位于西秦岭中部的岷县红崖、梅州一带，二叠系以粉碎屑沉积为主，泥质较少。根据对其岩石类型、沉积构造、岩石组合和生物特征的分析，认为这套地层主要形成于海底扇体系的内扇和中扇环境，外扇不发育，系由碎屑流和浊流沉积组成，包括内扇的水道和水下天然堤沉积及中扇的网状水道和朵叶体沉积。这套地层沿中秦岭南缘呈ＮＷＷ－ＳＥＥ方向延伸，代表了二叠纪西秦岭裂谷的存在及其继续裂陷的活动特征。