Research to utilize rhyolite lava as a new paleomagnetic recorder

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05313
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: Okayama University
• Principal Investigator: Uno Koji 岡山大学, 教育学研究科, 准教授 (10510745)
• Co-Investigator(Kenkyū-buntansha): 古川 邦之 愛知大学, 経営学部, 准教授 (20440620)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 古地磁気学 / 岩石磁気学 / 火山学 / 流紋岩 / 残留磁化方向 / 磁化率異方性

Outline of Final Research Achievements

Natural remanent magnetization of volcanic rocks gives quantitative information to various earth scientific phenomena such as plate motion and eruption temperature; however it seems that the accuracy of magnetization direction acquisition of rhyolite has been hampered because of its high viscosity. In this study, we observed the natural remanent magnetization direction of a thick rhyolite lava and investigated whether the rhyolite has the ability to record the expected remanent magnetization direction. Rhyolite lava showing significant deviation from the expected direction of the Earth's geomagnetic field was observed in part, while rhyolite lava samples mostly show similarity in the direction with the expected one. At present, there appears to be no tendency that the deviation in direction correlates with the degree of development of the flow structure.

Free Research Field

古地磁気学