PRELIMINARY REPORT OF GEOLOGICAL AND GEOPHYSICAL SURVEYS OFF QUEEN MAUD LAND, EAST ANTARCTICA

• Main Authors: サキ タカオ, タムラ ヤスオ, トクハシ シュウイチ, コダト トシオ, ミズコシ イクロウ, アマノ ヒロシ, Takao SAKI, Yasuo TAMURA, Shuichi TOKUHASHI, Toshio KODATO, Ikuro MIZUKOSHI, Hiroshi AMANO
• Format: Report
• Language: English
• Published: Technology Research Center, Japan National Oil Corporation:(Present address)Technical Department, Japan National Oil Corporation 1987
• Subjects: East Antarctica; Syowa Station; Queen Maud Land; Gunnerus Ridge; Antarc*; Antarctica
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2530; http://id.nii.ac.jp/1291/00002530/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2530&item_no=1&attribute_id=18&file_no=1

The geological and geophysical surveys off Queen Maud Land, East Antarctica were carried out during the 1985-1986 season using R/V HAKUREI-MARU. The survey covered areas of Gunnerus Ridge and the upper continental rise to the abyssal plain off Syowa Station. The basement of Gunnerus Ridge is supposed to be continental crust by magnetic data, gravity data, sonobuoy data and dredged rocks. The oceanic basement is confirmed in seismic and gravity data to have a deepening trend and to form a thickening sedimentary basin toward the foot of the continental slope. The maximum depth and thickness exceed 9.0s in two-way time from sea level and 3.0s in two-way time between sea bottom and acoustic basement, respectively on seismic lines. The age difference of the oceanic crust is discussed using seismic character difference of the top of acoustic basement. The sediment section of the basin is divided into three prominent sequences and discussed in terms of seismic stratigraphy. The heat flow data show slightly lower values than a world ocean average value, and this may suggest that the age of the oceanic basement in this area is relatively old.