Observations on the Burrows and Burrowing Behaviour of the Red Band-Fish, Cepola rubescens L.

Abstract. The red band-fish, Cepola rubescens L., lives in burrows in sublittoral muddy sediments. The authors first presented information on the burrows of this species in the 1970s. The present paper presents new information on burrow structure, describes the method of excavation, and comments on the bioturbatory significance of the species. The work derives from field and laboratory studies. A burrow typically consists of a vertical shaft which opens into an expanded terminal chamber. In some cases a side shaft may be added. The paper includes a size analysis of 130 burrows measured in the field and detailed morphological information from a selection of burrows which were cast with polyester resin. The fish burrows are frequently intersected by the burrows of other species and interspecific associations may develop. Burrow size reflects the size of the occupant and may approach 1 m in depth. The biogenic movement of water and particles to this depth is often overlooked in bioturbation studies and is discussed. Burrow distribution is aggregate, which has implications for the bioturbatory impact of the species. Burrows are constructed by mouth excavation and this is described in detail. Fish transport fine material within their mouths and coarse material is grasped in the jaws. Large spoil heaps occur at burrow openings. One obvious effect of this bioturbatory activity at the field site was the redistribution of coarse material (shell gravel) from depth to the sediment surface.     

广东红海湾、珠江口及电白—阳江近海第四纪沉积

根据物探和钻探资料，研究区内第四纪沉积物可分为两部分，下部地震反射结构复杂，斜层理发育，粒度较粗，为晚更新世产物；上部的地震反射结构简单，呈水平状或近水平状结构，粒度较细，为全新世沉积。     

Southern Segment of the European Geotraverse — a wide-angle seismic refraction experiment in the Sardinia Channel

The Sardinia Channel dataset was collected as part of the European Geotraverse (EGT)—a 4000 km seismic refraction line running from Northern Norway to the Sahara, designed to investigate the structure of the lithosphere beneath Europe. Wideangle seismic data recorded by ocean bottom seismometers deployed in the Sardinia Channel as part of the Southern Segment of the EGT, together with gravity data, were used to constrain the final crustal model. In the centre of the Channel the crust is identified as thinned continental in nature, with a crystalline thickness of 10 km overlain by 4 km of sediments and 2.5 km of water in the most extended region. High velocities in the lower crust in the central region are thought to represent an area of underplating or intrusion by igneous material caused by extension related to the opening of the Tyrrhenian Sea. The crust overlies an anomalously low velocity upper mantle.     

A technique for conducting seismic refraction experiments on the ocean bed using bottom shots

A technique has been devised for firing arrays of bottom shots on the ocean bed in depths upto 4000 m or more. Ten kilogram explosive charges are dropped from the surface while the shooting ship is navigated acoustically. They are detonated at preset times by an electronic timer which initiates an electrical detonator, detonating cord and cast PETN/TNT explosive. Ranges to ocean bottom seismographs, and the shot instants, can be calculated from the arrival-time differences of the direct and surface-reflected water waves. The accuracy, which is dependent on water-depth and range, was better than 22 m in range and 14 msec in shot instant for our experiments.     

冲绳海槽天然气水合物BSR的地震研究

根据多道地震反射资料分析,在冲绳海槽南部和中部发现了拟海底反射层(BSR)现象。通过对海底异常反射层的振幅特征、速度异常和AVO属性分析,说明该BSR可能反映了天然气水合物的存在,并发现冲绳海槽断层与天然气水合物的形成有密切关系。     

东营北部凸起带古冲沟储层分布规律研究

在油田勘探与开发中 ,充分认识古冲沟油气藏的勘探与开发是十分重要和有意义的。本文利用东营北部凸起带的地质、钻井、航磁和地震等资料 ,对古冲沟在地震剖面上的特征和古冲沟储层预测方法等进行了研究与探讨     

GPS技术在山区石油地震勘探测量中的应用

针对GPS技术在山区石油地震勘探测量中的工作方式,结合2007年度南盘江一桂中地区二维地震大剖面资料采集应用GPS的工程实例,介绍GPS技术应用的新进展。通过GPS静态测量和应用RTK技术放样物理点,从测前准备、数据处理、精度分析等方面,阐述提高作业精度、有效进行质量控制的方法,旨在最大限度地发挥GPS技术在山区施工中的作用。     

东海陆坡及邻近槽底天然气水合物成藏条件分析及前景

在西太平洋边缘海中,东海是唯一没有获得天然气水合物样品的边缘海。利用已有的地震资料、海底温度资料等,从沉积物来源、沉积地层厚度、烃源岩条件、沉积速率、海底温度—压力条件等方面对东海水合物成藏条件进行了分析。认为冲绳海槽沉积物源丰富,沉积厚度大,且发育烃源岩地层。冲绳海槽较高的沉积速率主要分布于冲绳海槽槽底沉积中心,以及西部陆坡连接海底峡谷底部的三角洲区域。根据冲绳海槽实测的海底温度数据,整个冲绳海槽地区600m以深的范围都能够满足水合物发育的温度、压力条件。以温度梯度为30℃/km计算,冲绳海槽中水合物稳定域的最大厚度为650m。冲绳海槽盆地中普遍发育的底辟构造、背斜构造等局部构造,以及网格状断裂系统,为烃类气流体的向上及侧向运移创造了有利条件,成为天然气水合物发育的有利区带。根据已经发现的BSR特征来看,东海地区天然气水合物前景广阔。