Trace element and isotopic characteristics of western Pacific pelagic sediments; implications for the petrogenesis of Mariana Arc magmas

Saved in:
Online Access: Get full text
doi: 10.1016/0016-7037(92)90231-7
Authors:Lin, Ping-Nan
Author Affiliations:Primary:
Ohio State Univ., Byrd Polar Res. Cent., Columbus, OH, United States
Volume Title:Geochimica et Cosmochimica Acta
Source:Geochimica et Cosmochimica Acta, 56(4), p.1641-1654. Publisher: Pergamon, Oxford, International. ISSN: 0016-7037
Publication Date:1992
Note:In English. 73 refs.; illus. incl. 3 tables, sketch map
Summary:In order to constrain the source components for arc lavas, sediment from the sea floor being subducted beneath and proximal to the Mariana Arc was sampled and analysed for REE, and Sr and Nd isotope abundances. The samples were obtained from DSDP Sites 59.2, 195B, 198A and 199, just to the E of the Mariana Arc. All samples show a LREE enrichment within highly variable REE abundances, and a negative Eu anomaly; the lowest Eu anomaly occurs in volcanic ash which is found in some Mariana Arc lavas. The data for the Lower Cretaceous to Miocene pelagic sediments are used to calculate the Bulk Western Pacific Sediment (BWPS), characterized by low Sr/Nd (10), Ba/La (13), epsilon Nd (-5.2), and high 87Sr/86Sr (0.7078) compared to that of Mariana and Volcano arc melts. Higher Ba/La ratios in some Mariana lavas are attributed to multiple fluid fractionations in the mantle source. The mixing model indicates that minor sediment and metasomatic fluid fluxes the mantle source at a late stage when the sub-arc mantle is already highly metasomatized, and that the mantle source is affected more by metasomatic fluids than by melting or mixing of subducted sediments. [R.K.H.]
Subjects:Alkaline earth metals; Chemical composition; Deep Sea Drilling Project; Genesis; Geochemistry; Isotopes; Magmas; Marine environment; Marine sediments; Metals; Nd-144/Nd-143; Neodymium; Pelagic environment; Rare earths; Sediments; Sr-87/Sr-86; Stable isotopes; Strontium; Trace elements; DSDP Site 199; DSDP Site 592; IPOD; Leg 20; Leg 6; Leg 90; Mariana Trench; North Pacific; Northwest Pacific; Pacific Ocean; West Pacific; DSDP Site 195B; DSDP Site 198A; Ratios
Coordinates:N133047 N133047 E1561020 E1561020
S362825 S362823 E1652632 E1652631
N120000 N340000 E1570000 E1460000
Abstract Numbers:92M/4303
Record ID:1992053659
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
Tags: Add Tag
No Tags, Be the first to tag this record!