PART I Ill. IV. >. VI. VII. VIII. IX. X. XI. XII. PART II XIII. XIV. Chemical composition of sediments in the GH78-1 area . . . . . . . . . . . . . Mukoto Yuasa, Komi Kato and Tomoyuki Moritani 216 Metal contents of manganese nodules from the GH78-1 area . . . . . . . . . Seizo Nakao, Tsunekazu Mochizuki, Shigeru Terashima, Makoto Yuasa and Tomoyuki Moritani 226 X-ray mineralogy of manganese nodules from the GH78-1 area . . . . . .  Mehmet Fakioglu, Makoto Yuasa and Tomoyuki Moritani 237 XV. Outline of the GH78-1 cruise and its results 1. . . . . . . . . . . . . . . . Tomoyuki Moritani, Koji Onodera, Keiji Handa, Takemi Ishihara, Yasumasa Kinoshita, Kiyokazu Nishimura, l Taisuke Suzuki, Katsuya Tsurusaki and Makoto Yuasa II. Positioning by NNSS and OMEGA system in the GH78-1 cruise 25 . . . Submarine topography by 12 kHz PDR in the GH78-1 area 44 . . . . .  Tomoyuki Moritani, Koji Onodera and Kiyokazu Nishimura 51 Gravity survey in the GH78-1 area . . . . . . . . . . . . Takemi Ishihara Geomagnetic survey in the GH78-1 area 55 . . . . . . . . . . . . . . . . . . . . . . . Takemi Ishihara and Kiyokazu Nishimura Continuous seismic reflection profiling survey in the GH78-1 area 57 . . . . . .  Kiyokazu Nishimura, Tomoyuki Moritani and Seizo Nakao Bottom sediments in the GH78-1 area 75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seizo Nakao and Taisuke Suzuki Geotechnical properties of deep sea sediments from the western part of Central Pacific Basin (GH78-1 area) . . . . . . . . . . . . . . . . . . . . . . . . Katsuya Tsurusaki and Keiji Handa 103 Description, types and distribution of manganese nodules in the GH78-1 area .  . 116 Tsunekazu Ajiki and Eiji Kuboki Manganese nodule occurrence and benthonic activities observed from deep sea photographs in the GH78-1 area . . . . . . . . . . . . . . . . . . Yasumasa Kinoshita and Tomoyuki Moritani 172 Relation between manganese nodule abundance and acoustic stratigraphy in the GH78-1 area . . . . . . . . . . . . . . . . Tomoyuki Moritani and Kiyokazu Nishimura 201 S.T.D. observation in the GH78-1 area . . . . . . . . . . . . . . . . . . . . . . Keiji Handa and Katsuya Tsurusaki 206 Manganese in the interstitial water of pelagic sediments from the XVI. GH78-1 area . . . . . . . . . Masashi Kusakabe, Masatoshi Yamada, Shizuo Tsunogai 243 and  Tomoyuki  Moritani Radiochemical studies on the pelagic sediments collected in the east XVII. of Marshall Islands (GH78-1 area) . . .  Shizuo Tsunogai, Masatoshi Yamada and Tomoyuki Moritani 246 APPENDIX I. A PPENDIX Appendix   Il. A PPENDIX III. Appendix IV. Notes on test of new sampling instruments in the GH78-1 cruise . . .  Yasumasa Kinoshita, Keiji Handa, Katsuya Tsurusaki, Seizo Nakao and Tomoyuki Moritani 251 Test of a submersible type 3.5 kHz transducer in the GH78-1 cruise . . . . . . . . . . . . . Masato Joshima and Kiyokazu Nishimura 258 Magnetic and gravity data between Japan and survey area and between survey area and Fiji Islands in the GH78-1 cruise . . . . . .  Takemi Ishihara and Kiyokazu Nishimura 263 Results of continuous seismic reflection profiling survey off Fiji Islands in the GH78-1 cruise . . . . . . . . . . . . . . . . . . Kiyokazu Nishimura, Seizo Nakao and Tomoyuki Moritani 266