Geochemistry and mineralogy of REY-rich mud in the eastern Indian Ocean

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doi: 10.1016/j.jseaes.2014.07.005
Author(s): Yasukawa, Kazutaka; Liu, Hanjie; Fujinaga, Koichiro; Machida, Shiki; Haraguchi, Satoru; Ishii, Teruaki; Nakamura, Kentaro; Kato, Yasuhiro
Author Affiliation(s): Primary:
University of Tokyo, Department of Systems Innovation, Tokyo, Japan
Waseda University, Japan
Japan Agency for Marine-Earth Science and Technology, Japan
Fukada Geological Institute, Japan
Volume Title: Journal of Asian Earth Sciences
Source: Journal of Asian Earth Sciences, Vol.93, p.25-36. Publisher: Elsevier, Oxford, United Kingdom. ISSN: 1367-9120
Note: In English. Includes appendices. 75 refs.; illus., incl. 1 table
Summary: Deep-sea sediments in parts of the Pacific Ocean were recently found to contain remarkably high concentrations of rare-earth elements and yttrium (REY) of possible economic significance. Here we report similar REY-rich mud in a core section from Deep Sea Drilling Project Site 213 in the eastern Indian Ocean. The sediments consist mainly of siliceous ooze, with subordinate zeolitic clay that contains relatively high REY concentrations. The maximum and average total REY (ΣREY) contents of this material are 1113 and 629 ppm, respectively, which are comparable to those reported from the Pacific Ocean. The REY-rich mud at Site 213 shows enrichment in heavy rare-earth elements, negative Ce anomalies, and relatively low Fe2O3/ΣREY ratios, similar to those in the Pacific Ocean. In addition, the major-element composition of the Indian Ocean REY-rich mud indicates slight enrichment in lithogenic components, which probably reflects a contribution from southern African eolian dust. A volcaniclastic component from neighboring mid-ocean ridges or intraplate volcanoes is also apparent. Elemental compositions and X-ray diffraction patterns for bulk sediment, and microscopic observation and elemental mapping of a polished thin section, demonstrate the presence of phillipsite and biogenic apatite, such as fish debris, in the REY-rich mud. The strong correlation between total REY content and apatite abundance implies that apatite plays an important role as a host phase of REY in the present deep-sea sediment column. However, positive correlations between ΣREY and elements not present in apatite (e.g., Fe2O3, MnO, and TiO2) imply that the REY-rich mud is not formed by a simple mixture of REY-enriched apatite and other components. Abstract Copyright (2014) Elsevier, B.V.
Year of Publication: 2014
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 06 Petrology, Sedimentary; Arabian Sea; Chemical composition; Clastic sediments; Clay; DSDP Site 213; DSDP Site 223; DSDP Site 236; DSDP Site 238; DSDP Site 259; DSDP Site 267; Deep Sea Drilling Project; Eastern Indian Ocean; Enrichment; Framework silicates; ICP mass spectra; Indian Ocean; Leg 121; Leg 22; Leg 23; Leg 24; Leg 27; Leg 28; Marine sediments; Mass spectra; Metals; Mineral composition; Mud; Ninetyeast Ridge; ODP Site 758; Ocean Drilling Program; Ooze; Perth abyssal plain; REY; Rare earths; Sediments; Silicates; Somali Basin; Spectra; X-ray diffraction data; X-ray fluorescence spectra; Yttrium; Zeolite group
Coordinates: S101243 S101242 E0935347 E0935346
Record ID: 2014102050
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands