Pliocene to Pleistocene planktonic foraminiferal datum levels in the North Pacific

Continuous late Neogene planktonic foraminiferal records have been studied in the deep-sea cores of DSDP Sites 173, 310, and 296 across mid-latitudes of the North Pacific. These three sites have been correlated on the basis of planktonic foraminiferal events and major paleoclimatic/paleoceanographic intervals and tied to diatom, radiolarian, and nannofossil datum levels, and paleomagnetic and isotopic stratigraphy. Ten planktonic foraminiferal datum levels have been recognized within these Pliocene to Pleistocene sections; two of these are recognizable within the Pleistocene and eight within the Pliocene. Six planktonic foraminiferal zones are proposed which combined with the foraminiferal datum levels provide a high resolution biostratigraphic correlation for the mid-latitudes of the North Pacific.

Hydrochemistry measured on water bottle samples during the METEOR International Indian Ocean Expedition 1964/65

The present volume gives the observed physical and chemical data obtained by R.V. "Meteor" in the Indian Ocean during cruise 1964/65. The tables are based on the computations made by the National Oceanographic Data Center (NODC) in Washington. In addition to the normally communicated data, the tables contain four chemical parameters: alkalinity, ammonia, fluoride, and calcium.

Petrology and geochemistry of Quaternary tephras of the Izu-Bonin Arc

Quaternary marine tephras in the Izu-Bonin Arc offer significant information about explosive volcanic activities of the arc. Visual core descriptions, petrographic examinations, and chemical and grain-size analyses were conducted on tephras of backarc, arc, and forearc origin. Tephras are black and white and occur in simple and multiple modes with mixed and nonmixed ashes of black and white glass shards. The grain size distributions of the tephras are classified into three categories: coarse, white pumiceous, and fine white and black well-sorted types. The frequency of occurrence of the white and black tephras differs within the tectonic settings of the arc. Chemically, the Quaternary tephras in this region belong to low-alkali tholeiitic series with lower K2O and TiO2 than normal ordinary arc volcanic materials. Several tephras from different sites along the forearc correlate with each other and with tephras in the Shikoku Basin site and with Aogashima volcanics. These volcanic ashes resemble those in other backarc rifting areas, such as in the Fiji, Okinawa (Ryukyu), and Mariana regions.