NATURAL REMANENT MAGNETIZATION OF SOME ROCKS FROM SOUTHERN SRI LANKA

• Main Authors: フナキ ミノル, ヨシダ マサル /, Minoru FUNAKI, Masaru YOSHIDA, P.W. VITANAGE
• Format: Report
• Language: English
• Published: National Institute of Polar Research 1990
• Subjects: East Antarctica; Queen Maud Land; Antarc*; Antarctica
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2636; http://id.nii.ac.jp/1291/00002636/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2636&item_no=1&attribute_id=18&file_no=1

The first detailed paleomagnetic studies were performed for the samples from southern Sri Lanka. The stable NRM components were recognized in the Tonigala granite, pink granite, Gallodai dolerite and some gneisses. The reliable NRMs were obtained by the AF demagnetization 30 or 35mT from the Tonigala granite, pink granite and Gallodai dolerite. The VGP positions were elucidated as the latitude (Lat)=6.1°S, longitude (Lon)=28.0°E, α_<95>=6.2°, Lat=27.1°N, Lon=38.5°E, α_<95>=11.0° and Lat=8.5°N, Lon=152.9°E, α_<95>=6.4° respectively. Sri Lanka is rotated around a pole position (Lat=5.3°S, Lon=23.8°E, with -100.5° of counterclockwise angle) which was decided by adjusting the VGPs of both Cambro-Ordovician and the latest Jurassic periods from the Tonigala granite, Gallodai dolerite of Sri Lanka and the previous results from East Antarctica. Thus, the location of Sri Lanka is settled in Gondwana in the offing of eastern Queen Maud Land. A model of juxtaposition of Sri Lanka with Lutzow-Holm Bay was shown, taking into account the conformity of declinations of Cambro-Ordovician NRMs of the two areas.