(Table 1) Occurrence of ichthyoliths at DSDP Hole 56-436

Approximately 20 meters of the section near the bottom of Hole 436 was "unfossiliferous," overlain by middle Miocene mudstone with siliceous microfossils and underlain by Cretaceous chert. Therefore we attempt to determine the age of these pelagic clays on the basis of the ichthyoliths. Site 436 is at 39°55.96'N, 145°33.47'E, in a water depth of 5240 meters. The cores investigated here (Nos. 39 and 40) are from 359.5-378 meters below the sea floor. In addition, we studied one sample from Core 41, containing Late Cretaceous radiolarians (436-41-1, 26-31 cm).