华北地块沁水盆地下三叠统刘家沟组古地磁倾角浅化研究

• Published in: Beijing da xue xue bao Vol. 54; no. 3; pp. 521 - 534
• Main Authors: Zhou, Tinghong, Huang, Baochun, Jia, Shufei, Liang, Yalun, Zhang, Donghai, Zhao, Qian, Zhang, Ye, Yan, Yonggang
• Format: Journal Article
• Language: Chinese
• Published: Beijing Acta Scientiarum Naturalium Universitatis Pekinenis 20.05.2018; 造山带与地壳演化教育部重点实验室, 北京大学地球与空间科学学院, 北京 100871%岩石圈演化国家重点实验室,中国科学院地质与地球物理研究所, 北京 100029
• Subjects: Fabrics; Magnetic susceptibility; Magnetism; Magnetite; China; 古地磁; 华北地块; inclination shallowing; 早三叠世; 刘家沟组; 磁倾角浅化; Early Triassic; paleomagnetism; North China Block; Liujiagou Formation
• ISSN: 0479-8023
• DOI: 10.13209/j.0479-8023.2017.100

A combined paleomagnetic, rock magnetic and magnetic fabrics study is conducted on the redbeds of Early Triassic Liujiagou Formation from Qinshui Basin, North China Block (NCB). The E/I (elongation/inclination) method indicates that the characteristic remanent magnetizations (ChRM) was significantly affected by inclination shallowing with a flattening factor f=0.6. Rock magnetic analysis indicates that hematite and magnetite are the main magnetic carriers. Anisotropy of magnetic susceptibility (AMS) result shows typical depositional fabrics in water. The chRM has been successfully isolated from 15 sites with tilt-corrected mean direction of Ds=318.8°, Is=30.9° (α95=6.9°) and a corresponding paleomagnetic pole at 49.3°N, 5.5°E (A95=6.7°). The pole after E/I correction is 53.5°N, 18.0°E. Combining with published high quality Early Triassic pole (Q≥4) for NCB, the mean Early Triassic pole for NCB before and after inclination shallowing correction is 55.3°N, 357.1°E (A95=5.5°) and 60.8°N, 13.4°E (A95=5.8°), respe