Yang Tao, Gao Jintian, Gu Zuowen, Dagva Baatarkhuu, Tserenpil Batsaikhan
Institute of Geophysics, China Earthquake Administration, Beijing 100081, China.
ScientificWorldJournal. 2013 Nov 7;2013:791918. doi: 10.1155/2013/791918. eCollection 2013.
Petrophysical properties of 585 rock samples from the Suhbaatar-Ulaanbaatar-Dalandzadgad geophysical profile in Mongolia are presented. Based on the rock classifications and tectonic units, petrophysical parameters (bulk density, magnetic susceptibility, intensity of natural remanent magnetization, and Köenigsberger ratio) of these rocks are summarized. Results indicate that (1) significant density contrast of different rocks would result in variable gravity anomalies along the profile; (2) magnetic susceptibility and natural remanent magnetization of all rocks are variable, covering 5-6 orders of magnitude, which would make a variable induced magnetization and further links to complex magnetic anomalies in ground surface; (3) the distribution of rocks with different lithologies controls the pattern of lithospheric magnetic anomaly along the profile. The petrophysical database thus provides not only one of the keys to understand the geological history and structure of the profile, but also essential information for analysis and interpretation of the geophysical (e.g., magnetic and gravity) survey data.
本文展示了蒙古苏赫巴托尔-乌兰巴托-达兰扎德嘎德地球物理剖面585个岩石样本的岩石物理性质。基于岩石分类和构造单元，总结了这些岩石的岩石物理参数（体积密度、磁化率、天然剩余磁化强度和科尼希斯贝格尔比）。结果表明：（1）不同岩石显著的密度差异会导致沿剖面的重力异常变化；（2）所有岩石的磁化率和天然剩余磁化强度都是可变的，涵盖5-6个数量级，这会产生可变的感应磁化，并进一步与地表复杂的磁异常相关联；（3）不同岩性岩石的分布控制了沿剖面岩石圈磁异常的格局。该岩石物理数据库不仅为理解剖面的地质历史和结构提供了关键线索之一，也为地球物理（如磁法和重力法）测量数据的分析和解释提供了重要信息。
