A detailed rock magnetic study was conducted on the top six cores (above 57.5 meters below seafloor) at Site 1007. The calcareous nannofossil biostratigraphy assigns the studied intervals to an age ranging from early Pleistocene to Holocene. We found two significant conversion points in the Pleistocene based on isothermal remanent magnetization (IRM) acquisition and on alternating field demagnetization of anhysteretic remanent magnetization and IRM. These conversion points correlate strongly with changes in sedimentation rate and lithology. We conclude that the paleomagnetic signals reflect changes of rate of sediment supply and of paleoenvironment on the western edge of the Great Bahama Bank.
1
Swart, P.K., Eberli, G.P., Malone, M.J., and Sarg, J.F. (Eds.), 2000. Proc.
ODP, Sci. Results, 166 [Online]. Available from World Wide Web:
<http://www-odp.tamu.edu/publications/166_SR/166TOC.HTM>. [Cited YYYY-MM-DD]
2 Marine Geology
Department, Geological Survey of Japan, 1-1-3 Higashi, Tsukuba, Ibaraki,
305-8567, Japan. ko-arai@aist.go.jp
3 Institute of
Applied Earth Sciences, Mining College, Akita University, Tegata Gakuencho 1-1,
Akita 010, Japan.
Date of
initial receipt: 13 August 1998
Date of acceptance: 28 August 1999
Ms 166SR-121