English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Sediments recovered by drilling during Legs 58, 59, and 60 in the North and South Philippine Sea have been analyzed by X-ray diffractometry. The CaCO3 content was measured separately. The sites encompass several volcanic ridges and intervening inter-arc basin troughs as well as sites on the Mariana arc fore-arc sediment prism and the Mariana Trench. The sediments at all sites received major volcanogenic input from the various arcs; they tend to be rich in volcanic glass, with associated quartz, feldspar, pyroxenes and amphibole. Carbonate is a major component only at Site 445 at the southern end of the Daito Ridge, and at Site 448 on the Palau-Kyushu Ridge. All other sites were either deep relative to the carbonate compensation depth or had very high non-carbonate sedimentation rates. Clay minerals are mainly smectite and illite with lesser variable proportions of chlorite and kaolinite. Smectite predominates over illite except at sites in the Shikoku Basin and the Daito Ridge, and at one site in the Mariana Trench. At several sites, smectite increases and illite decreases with depth. Principal zeolites are phillipsite and clinoptilolite. Analcime occurs in some samples. INTRODUCTION This chapter reports the results of X-ray diffraction analyses of sediments recovered from Deep Sea Drilling Project Legs 58, 59, and 60. Site locations are shown on Figure 1. Leg 58 drilling included three sites—Sites 442 through 444—in the Shikoku Basin, and two sitesSites 445 and 446—in the Daito Ridge and Basin Province. Legs 59 and 60 were primarily an east-west transect with holes drilled on successively younger ridges and back-arc spreading troughs. From west to east, the ridges are the Palau-Kyushu Ridge (Site 445), the West Mariana Ridge (Site 451), and the Mariana arc (Sites 458 and 459). The basins are the West Philippine Sea (Site 447), the Parece-Vela Basin (Sites 449 and 450), and the actively spreading Mariana Trough (Sites 454, 455, and 456). Two additional sites—Sites 460 and 461— were drilled in the Mariana Trench and one on the Pacific plate in the Mariana Basin (Site 452). This report lists data from all these sites but Sites 452, 455, and 457. METHODS X-ray diffraction procedures as described by Mann and Muller (1980) have been employed. Carbonate contents were determined by the "Karbonat-Bombe" method of Muller and Gastner (1971). RESULTS X-ray diffraction results are listed in Table 1 (Leg 58), Table 2 (Leg 59), and Table 3 (Leg 60). The data are plotted versus depth and summary lithologies on Figures 1-5 (Leg 58), Figures 6-9 (Leg 59), and Figure 10 Initial Reports of the Deep Sea Drilling Project, Volume 60. (Leg 60). A brief synopsis of the results from each site is given in the following paragraphs. LEG 58 Site 442 (see Fig. 2) The Quaternary period is characterized by a dark greenish gray mud and a clay sequence with scattered ash zones. Clay minerals (and amorphous components) represent about 60 percent of the bulk mineralogy. Quartz is the most abundant mineral of the non-clay fraction (-20%), and three specimens (Samples 442A2-2, 103-105 cm, 442A-4-2, 84-86 cm, and 442A-15-2, 16-18 cm) contain calcite in amounts ranging between 3 and 5 percent. The lowest part of the Quaternary yields decreasing illite contents (from -60 to 34%), whereas smectite rises from -27 to 53 percent. Kaolinite and chlorite remain almost constant. Pliocene samples contain -70 percent clay minerals (and amorphous material). Again the >2-μm fraction is dominated by quartz (-20%). No differences between samples of the yellow and dark brown mud have been observed. Clay minerals become more abundant in Miocene samples (from -70 to -80%), whereas quartz decreases to < 5 percent. Feldspar has been found throughout Hole 442A, but its content does not vary as much as that of quartz; all samples contain at least 2 percent and the maximum is 12 percent (Sample 30-2, 24-26 cm). Sample 29-2, 23-25 cm of an interbedded ash and clay sequence is light gray in color and has 2.5 percent feldspar and 2 percent quartz; its main components ( — 95%) are volcanic ash and clay minerals with smectite, which comprises -81 percent of the <2-μm fraction. The early Miocene, dark brown zeolithic clay of Unit IV contains minor amounts of quartz (-4%) in addition to feldspar, smectite, and amorphous material.

Mineralogy of Sediments Cored during Deep Sea Drilling Project Legs 5860 in the North and South Philippine Sea: Results of X-Ray Diffraction Analyses

Mineralogy of Sediments Cored during Deep Sea Drilling Project Legs 5860 in the North and South Philippine Sea: Results of X-Ray Diffraction Analyses