040 EIGHTH PACIFIC SCIENCE CONGRESS 



Owing to a faulty construction of the clockwork used with the 

 "y\lbatross" geo thermometer only two dependable values were obtained 

 for the geothermal gradient, both from the equatorial Pacific Ocean, 

 viz. an increase of 1°C in 22 and in 26 metres, i.e., considerably higher 

 than the average value for the continents, whereas for general reasons 

 one would have expected a lower value. A third value found in the 

 beginning of 1948 in the E. Indian Ocean, which at that time appeared 

 suspiciously high, was 1° in 4 metres. 



High values of the geothermal gradient in deep-sea sediments have 

 recently been found also by Revelle on the "Capricorn" Expedition, 

 where a thermo-electric geothermometer of smaller depth range, due 

 to Bullard, was used. The high values for the geothermal current com- 

 puted from these measurements is highly puzzling. It may possibly be 

 explained through a wide-spread although latent volcanism of the deep- 

 sea floor, for which much independent evidence exists. 



Regarding diagenetic changes in the deep-sea sediments Arrhenius 

 has proved induration due to silica, diffusing from dissolving silica- 

 skeletons to occur in cores from the Eastern Pacific. Also the diffusion 

 of manganese may lead to a formation of surface crusts, as has been 

 observed already from the Challenger Expedition. That a consider- 

 able vertical migration of various components in the sediment takes 

 place is evident. Special interest adheres to the cases of deep-sea sand, 

 such as we from the "Albatross" found in great depths, especially in the 

 Romanche Deep in the equatorial region of the Atlantic Ocean. There 

 coarse sand, consisting of angular fragments of mafic rocks, testified to 

 a contribution to the sediments from the substratum. The great rug- 

 gedncss of the deep-sea floor indicates that tectonic forces are active, 

 leading to differential movements at which a crushing or mylonisation 

 of the rock material may well occur. Other- instance of deep-sea sand 

 obtained in cores taken further west in the same ocean indicate a quite 

 different origin, viz. from the coastal plateau of a continent or of a 

 large island. Also a displaced shallow-water benthonic fauna and frag- 

 ments of vegetation remains speak for a continental or island origin. 

 The great distance of the place of the find, some 500 nautical miles 

 from the coast of S. America, makes the transportation problem highly 

 puzzling. 



These feiv instances of the results found from extensive investiga- 

 tions of the "Albatross" cores prove how extremely rich in promising 

 results is the new science of deep-sea geology in the development of 

 which American and British investigators, like Ewing, Tolstay, She- 

 pard, Phleger, Bullard a. o., have taken such a prominent part. Here 

 obviously is a field for international cooperation like that established 

 half a century ago with the International Council for the study of the 



