Spectrum gamma ray borehole logging wire data of MeBo sediment core GeoB16601-7

Logging was performed with the sea floor drill rig MARUM-MeBo70 in a borehole drilled with a 103 mm diameter bit. The 1460 Slimhole Memory SGR instrument developed by ANTARES Datasystems GmbH was used. A CsI(Na) crystal with outer diameter of 37 mm and 250 mm length is used as detector. The probe provides Natural Gamma Ray counts and analyses the spectrum for the concentrations of the natural gamma ray emitters potassium, thorium and uranium with an accuracy of about 10%. The probe was deployed in the memory mode with the logging string being inserted into the drill string. The measurement was conducted as upcast by hooking up the probe inside the drill string with a wire. The trip out speed was about 3 cm/s and the logging frequency was 1 Hz. Data processing was conducted using the Antares software GeoBase5 including an environmental correction compensating for the attenuation of the gamma ray signal by the drill pipe.

本测井作业依托MARUM-MeBo70型海底钻探钻机，在直径103 mm钻头钻进的钻孔内开展。本次作业采用由ANTARES数据系统有限公司（ANTARES Datasystems GmbH）研发的1460型Slimhole Memory SGR测井仪，其探测器采用外径37 mm、长度250 mm的钠激活碘化铯（CsI(Na)）晶体。该探头可采集自然伽马计数，并针对天然伽马发射体钾、钍、铀的浓度开展能谱分析，测量精度约为10%。本次作业将测井串接入钻柱内部，使探头以内存模式运行；测量采用起升测井模式，通过测井钢缆将探头挂接于钻柱内部完成数据采集，起钻速度约为3 cm/s，测井采样频率为1 Hz。数据处理采用ANTARES公司的GeoBase5软件完成，内置环境校正模块，可补偿钻柱对伽马射线信号的衰减影响。