1. a Institute of Oceanography, National Taiwan University , P. O. Box 23-13, Taipei, Taiwan
2. b R. O. C. Der-Duen Sheu , Institute of Marine Geology, National Sun Yat-Sen University , Taipei, R. O. C., Taiwan
3. c Institute of Marine Geology, National Sun Yat-Sen University , P. O. Box 23-13, Taipei, R. O. C., Taiwan