Three-component magnetic logging in the Outokumpu deep drillhole

奥托昆普深钻孔三分量磁测井

• 批准号: 65348769
• 负责人: Professor Dr. Andreas Hördt
• 金额: --
• 依托单位: Institut für Geophysik und Extraterrestrische Physik
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/65348769?language=en
• 关键词: Three; component; magnetic; logging; Outokumpu

One of the aims of the Outokumpu deep drilling project in Finland is to obtain an understanding of the deep structure of the Cu-Co-Zn ore deposits. The ore is hosted by the Outokumpu formation, consisting of black shales, serpentinite and skarn rocks, which was transsected by the drillhole between 1300 and 1500 m depth. We carried out threecomponent magnetic logging and we will derive the rock magnetisation from the measured magnetic field. The integrated interpretation of our results with data from laboratory investigations carried out in a parallel project, will enable us to test various hypotheses on the tectonic evolution of the Outokumpu assemblage. We aim at an estimation of the magnetisation vector, and in particular its declination, which is generally considered difficult. We use the Göttingen borehole magnetometer (GBM), which is equipped with fiber-optic gyros allowing an independent orientation of the tool. The favourable conditions at the Outokumpu hole, an open section between 40m and 2500m, continuous coring, cool temperatures and a highly magnetised section embedded between weakly magnetised layers, will allow an unprecedented accuracy. The detailed evaluation of the results based on data redundancy and laboratory measurements, and the identification of the most critical error sources will have important implications for the application of borehole magnetometers in general.

芬兰Outokumpu深钻项目的目的之一是了解Cu-Co-Zn矿床的深层结构。该矿石由Outokumpu地层托管，由黑色阴影，蛇形和Skarn岩石组成，该岩石被1300至1500 m深度之间的钻孔超越。我们进行了三分之一的磁性记录，我们将从测得的磁场中得出岩石磁化。通过在平行项目中进行的实验室研究的数据对我们的结果进行了综合解释，这将使我们能够在Outokumpu组合的构造演化上检验各种假设。我们的目标是估算磁化载体，尤其是其偏斜，这通常被认为是困难的。我们使用Göttingen钻孔磁力计（GBM），它等效于光纤陀螺仪，允许该工具的独立方向。 Outokumpu孔的有利条件，在40m至2500m之间的开放截面，连续的加油，凉爽的温度以及嵌入弱磁性层之间的高度磁性截面，将允许前所未有的精度。基于数据冗余和实验室测量以及最关键的误差源的识别对结果的详细评估将对总体上的钻孔磁力计应用具有重要意义。