A seismic reflection and GLORIA study of compressional deformation in the Gorringe Bank region, eastern North Atlantic

Seismic reflection and GLORIA side-scan sonar data obtained on RRS Charles Darwin cruise CD64 reveal new information on the styles of deformation in the Gorringe Bank region, at the eastern end of the Azores–Gibraltar plate boundary. Previous studies suggest that Gorringe Bank was formed by the overthrusting of a portion of the African plate upon the Eurasian plate. The new seismic data show, however, that the most intensely deformed region is located south of Gorringe Bank, on the northern flanks of a NW–SE-trending submarine ridge which includes the Ampere and Coral Patch seamounts. The deformation is expressed as long-wavelength (up to 60  km), large-amplitude (up to 800  m) folds in the sediments and underlying acoustic basement, which in places are associated with one or more reverse faults, and as a fabric of short-wavelength folds (up to 3  km) with a NE trend. In contrast, the same sedimentary units when traced beneath the flanking plains are undeformed, except for some faults with a small throw (~30  m), some of which offset the seafloor. GLORIA data show that recent deformation is broadly distributed over the region. Structural trends rotate from 45° in the west to 70° in the east of the region, nearly perpendicular to the NW-verging plate motion vectors as determined from plate kinematic models. Flexure modelling suggests that a portion of Gorringe Bank has loaded 152  Ma oceanic lithosphere and that a maximum of 50  km of shortening has occurred at Gorringe Bank since the mid-Miocene. Our observations support a model in which there is no single plate boundary in the region, rather that the deformation is distributed over a 200–330  km wide zone.     

海底热液硫化物——深海采矿前沿探索

结合深海采矿的现状,以海底热液硫化物这一潜在开采对象为基础,对国内外的相关研究与开发动态情况进行了介绍,分析了海底热液硫化开采远景,在剖析海底热液硫化物开采研究现实意义的基础上,提出海底热液硫化物是我国海洋采矿发展的新契机.并建议相关部门结合大洋战略逐步完善我国深海基础机电产品及工程装备研发体系.结合海底热液硫化物探测技术的发展,同步开展开采系统的前期研究工作,从而引导并推进我国深海采矿及海洋工程技术的发展.     

Dynamic Analysis of the Seafloor Pilot Miner Based on Single-Body Vehicle Model and Discretized Track-Terrain Interaction Model

In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with some subsystems to form the complete integrated deep ocean mining pilot system and perform dynamic analysis,a new method for the dynamic modeling and analysis of the miner is proposed and developed in this paper,resulting in a simplified 3D single-body vehicle model with three translational and three rotational degrees of freedom,while the track-terrain interaction model is built by partitioning the track-terrain interface into discrete elements with parameterized force elements built on the theory of terramechanics acting on each discrete element.To evaluate and verify the correctness and effectiveness of this new modeling and analysis method,typical comparative studies with regard to computational efficiency and solution accuracy are carried out between the traditional modeling method of building the tracked vehicle as a multi-body model and the new modeling method.In full consideration of the particular structure design of the pilot miner,the special characteristics of the seafloor soil and the hydrodynamic force of near-seafloor current,the dynamic simulation analysis of the miner is performed and discussed,which can provide useful guidance and reference for the practical miner system in design and operation.This new method can not only realize the rapid dynamic simulation analysis of the miner but also make possible the integration and rapid dynamic analysis of the complete integrated deep ocean mining pilot system in further researches.     

Dynamic Analysis of the Seafloor Pilot Miner Based on Single-Body Vehicle Model and Discretized Track-Terrain Interaction Model

In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with some subsystems to form the complete integrated deep ocean mining pilot system and perform dynamic analysis, a new method for the dynamic modeling and analysis of the miner is proposed and developed in this paper, resulting in a simplified 3D single-body vehicle model with three translational and three rotational degrees of freedom, while the track-terrain interaction model is built by partitioning the track-terrain interface into discrete elements with parameterized force elements built on the theory of terramechanics acting on each discrete element. To evaluate and verify the correctness and effectiveness of this new modeling and analysis method, typical comparative studies with regard to computational efficiency and solution accuracy are carried out between the traditional modeling method of building the tracked vehicle as a multi-body model and the new modeling method. In full consideration of the particular structure design of the pilot miner, the special characteristics of the seafloor soil and the hydrodynamic force of near-seafloor current, the dynamic simulation analysis of the miner is performed and discussed, which can provide useful guidance and reference for the practical miner system in design and operation. This new method can not only realize the rapid dynamic simulation analysis of the miner but also make possible the integration and rapid dynamic analysis of the complete integrated deep ocean mining pilot system in further researches.     

板块运动规律梳理及其源动力实验计算研究

洋中脊是大洋的胚胎,从洋中脊为地堑式中央裂谷的形态特征来看,大洋是拉张应力的产物,因此必须依据大陆漂移造成海底被动扩张这一结论来分析研究板块运动的动力源问题.大陆漂移的方向是有规律的,根据世界大洋年龄图等资料进行逆推,还原不同阶段的洋陆展布状态,可以看出,白垩纪以来南半球大陆分解向北运动、北半球大陆分解向南运动,大陆在...     

青海德尔尼铜矿床成因最新研究进展

德尔尼铜矿床位于青海省玛沁县积石山中段德尔尼山南坡,是一个以铜为主,钴、锌等多元素可以综合利用的大型矿床。矿床成因存在较大分歧,因此,笔者运用宏观观察、矿相学研究及电子探针测试分析相结合的方法,重点对该矿床金属矿物矿相学、矿石矿物组合及矿床成因进行了系统研究,首次在德尔尼铜矿床中发现重晶石和石膏。石英-碳酸盐-重晶石-石膏为海底热液矿床的典型低温矿物组合。通过构造成矿环境、成矿物质来源研究,结合草莓状结构、矿体顶部的硅质岩、重晶石和石膏的发现等,种种迹象表明该矿床为海底热液喷流沉积矿床。     

可变角度换能器在海底沉积物声学原位测量应用的探讨

海底沉积物的声学测量是海底测深的关键技术之一,应用于海底地形地貌测量、海洋矿产资源开采和海底工程建设等。海底沉积物声学测量方法中的原位测量方法可以避免保真采样法的强扰动性和遥测法的准确度、精度及灵敏度的不确定性等缺点,如何改进原位测量系统渐成为海底探测的研究热点。通过分析现有海底沉积物原位测量设备测试换能器的工作原理,针对垂直压入方式换能器测量深度有限,提出了一种通过改变换能器压入沉积物的角度来增加测量深度的方法。在理论上论证出在不低于换能器接收阈值时,测量深度随着掠射角的增加而增加。在不增加压入深度的前提下提供了一种增加测量深度方法。     

东太平洋海隆热液活动区原位观测数据的小波分析和热液指标的周期性变化

洋中脊热液流体供养了特殊的生物群落.热液扩散流中的生物群从流体中汲取基本代谢组分(如H₂S,CH₄,CO₂,O₂等),将它们供给共生菌,通过共生菌将它们转化成机体能够利用的有机质[1-2].热液中的硫化氢一方面提供营养给化学自养菌,另一方面对许多海底生物又具有毒性[3-4],因此热液中溶解硫化氢的浓度是制约生物群空间分布和组合特征的重要因素[5-8].     

基于地形的海底热液区沉积物分布趋势预测方法研究

热液区沉积物接受了大量热液物质的输入,其矿物组成及地球化学空间分布特征是多金属硫化物勘探的有效指标。由于重力作用,洋中脊区域沉积物主要分布于低洼和平坦地形区。为了探索地形因素对热液区沉积物分布的影响规律,本文通过ArcGIS提出了一种基于地形数据的海底热液区沉积物分布趋势预测方法,并对西南印度洋中脊龙角区地形数据进行了分析,包括沉积物重力搬运方向提取、沉积物汇集量估算、海底沟谷提取和沉积物源区划分。通过与研究区底质解译结果进行对比验证发现,预测结果与研究区内沉积物的实际分布范围较为吻合,表明本方法在一定程度上可以有效地指示地形影响下海底热液区沉积物的分布情况。本方法对海底硫化物矿产勘探工作具有一定指导意义,可为海底沉积物取样站位设置与海底硫化物成矿远景区圈定提供参考依据。     

Shape from shading—a method of integration of sonar images and bathymetric data for ocean mapping

Shape from shading is one of the methods that derive geometric information of objects from analysis of monocular images. Application of this technique to underwater sonar images enables the conversion of imposed reflectance characteristics in sonar images to shape information, namely, slopes, about the seafloor surface. A combination of this shape information and available sparse distributed depth points results in improved dense bathymetric data.

The reconstruction of shape models of seafloor surfaces from sonar images is treated as an inverse problem and is solved by the regularization theory. Sparse gridded points are used for boundary constraints. The regularization is implemented as a relaxation procedure with a hierarchical structure of multiresolution grids.