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author Murray, Richard W
Leinen, Margaret W
author_facet Murray, Richard W
Leinen, Margaret W
collection Datos científicos de ciencias marinas y ambientales
contents We have analyzed the major, trace, and rare earth element composition of surface sediments collected from a transect across the Equator at 135°W longitude in the Pacific Ocean. Comparing the behavior of this suite of elements to the CaCO3, opal, and Corg fluxes (which record sharp maxima at the Equator, previously documented at the same sampling stations) enables us to assess the relative significance of the various pathways by which trace elements are transported to the equatorial Pacific seafloor. The 1. (1) high biogenic source at the Equator, associated with equatorial divergence of surface water and upwelling of nutrient-rich water, and 2. (2) high aluminosilicate flux at 4°N, associated with increased terrigenous input from elevated rainfall at the Intertropical Convergence Zone (ITCZ) of the tradewinds, are the two most important fluxes with which elemental transport is affiliated. The biogenic flux at the Equator transports Ca and Sr structurally bound to carbonate tests and Mn primarily as an adsorbed component. Trace elements such as Cr, As, Pb, and the REEs are also influenced by the biogenic flux at the Equator, although this affiliation is not regionally dominant. Normative calculations suggest that extremely large fluxes of Ba and P at the Equator are carried by only small proportions of barite and apatite phases. The high terrigenous flux at the ITCZ has a profound effect on chemical transport to the seafloor, with elemental fluxes increasing tremendously and in parallel with Ti. Normative calculations, however, indicate that these fluxes are far in excess of what can be supplied by lattice-bound terrigenous phases. The accumulation of Ba is greater than is affiliated with biogenic transport at the Equator, while the P flux at the ITCZ is only 10% less than at the Equator. This challenges the common view that Ba and P are essentially exclusively associated with biogenic fluxes. Many other elements (including Mn, Pb, As, and REEs) also record greater accumulation beneath the ITCZ than at the Equator. Thus, adsorptive scavenging by terrigenous paniculate matter, or phases intimately associated with them, appears to be an extremely important process regulating elemental transport to the equatorial Pacific seafloor. These findings emphasize the role of vertical transport to the sediment, and provide additional constraints on the paleochemical use of trace elements to track biogenic and terrigenous fluxes.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_76291
institution PANGAEA
language en
publishDate 1993
publisher PANGAEA
record_format pangaea
spellingShingle Biogenic components, major, trace and rare earth elements of equatorial Pacific Ocean surface sediments (Table 1)
Murray, Richard W
Leinen, Margaret W
Accumulation rate, mass; Aluminium oxide; Arsenic; Barium; Calcium carbonate; Calcium oxide; Calculated; Carbon, organic, total; Cerium; Cerium/Cerium ratio; Chromium; Department of Geology, Oregon State University; DEPTH, sediment/rock; Dysprosium; Elevation of event; Erbium; Europium; Event label; Gadolinium; GC; Gravity corer; Holmium; Iron oxide, Fe2O3; Lanthanum; Latitude of event; Lead; Longitude of event; Loss on ignition; Lutetium; Magnesium oxide; Manganese oxide; Neodymium; Niobium; Opal, biogenic silica; Opal, normative calculation; Leinen, 1977; OSU; Phosphorus pentoxide; Potassium oxide; Praseodymium; Praseodymium/Ytterbium ratio; Rubidium; Samarium; Silicon Cycling in the World Ocean; Silicon dioxide; SINOPS; Sodium oxide; Strontium; Terbium; Thulium; Titanium dioxide; W8803B; W8803B-T-23; W8803B-T-31; W8803B-T-36; W8803B-T-42; W8803B-T-47; W8803B-T-52; W8803B-T-57; W8803B-T-62; W8803B-T-68; W8803B-T-69; W8803B-T-89; W8803B-T-9; W8803B-T-92; Wecoma; X-ray fluorescence (XRF); Ytterbium; Zirconium
We have analyzed the major, trace, and rare earth element composition of surface sediments collected from a transect across the Equator at 135°W longitude in the Pacific Ocean. Comparing the behavior of this suite of elements to the CaCO3, opal, and Corg fluxes (which record sharp maxima at the Equator, previously documented at the same sampling stations) enables us to assess the relative significance of the various pathways by which trace elements are transported to the equatorial Pacific seafloor. The 1. (1) high biogenic source at the Equator, associated with equatorial divergence of surface water and upwelling of nutrient-rich water, and 2. (2) high aluminosilicate flux at 4°N, associated with increased terrigenous input from elevated rainfall at the Intertropical Convergence Zone (ITCZ) of the tradewinds, are the two most important fluxes with which elemental transport is affiliated. The biogenic flux at the Equator transports Ca and Sr structurally bound to carbonate tests and Mn primarily as an adsorbed component. Trace elements such as Cr, As, Pb, and the REEs are also influenced by the biogenic flux at the Equator, although this affiliation is not regionally dominant. Normative calculations suggest that extremely large fluxes of Ba and P at the Equator are carried by only small proportions of barite and apatite phases. The high terrigenous flux at the ITCZ has a profound effect on chemical transport to the seafloor, with elemental fluxes increasing tremendously and in parallel with Ti. Normative calculations, however, indicate that these fluxes are far in excess of what can be supplied by lattice-bound terrigenous phases. The accumulation of Ba is greater than is affiliated with biogenic transport at the Equator, while the P flux at the ITCZ is only 10% less than at the Equator. This challenges the common view that Ba and P are essentially exclusively associated with biogenic fluxes. Many other elements (including Mn, Pb, As, and REEs) also record greater accumulation beneath the ITCZ than at the Equator. Thus, adsorptive scavenging by terrigenous paniculate matter, or phases intimately associated with them, appears to be an extremely important process regulating elemental transport to the equatorial Pacific seafloor. These findings emphasize the role of vertical transport to the sediment, and provide additional constraints on the paleochemical use of trace elements to track biogenic and terrigenous fluxes.
title Biogenic components, major, trace and rare earth elements of equatorial Pacific Ocean surface sediments (Table 1)
topic Accumulation rate, mass; Aluminium oxide; Arsenic; Barium; Calcium carbonate; Calcium oxide; Calculated; Carbon, organic, total; Cerium; Cerium/Cerium ratio; Chromium; Department of Geology, Oregon State University; DEPTH, sediment/rock; Dysprosium; Elevation of event; Erbium; Europium; Event label; Gadolinium; GC; Gravity corer; Holmium; Iron oxide, Fe2O3; Lanthanum; Latitude of event; Lead; Longitude of event; Loss on ignition; Lutetium; Magnesium oxide; Manganese oxide; Neodymium; Niobium; Opal, biogenic silica; Opal, normative calculation; Leinen, 1977; OSU; Phosphorus pentoxide; Potassium oxide; Praseodymium; Praseodymium/Ytterbium ratio; Rubidium; Samarium; Silicon Cycling in the World Ocean; Silicon dioxide; SINOPS; Sodium oxide; Strontium; Terbium; Thulium; Titanium dioxide; W8803B; W8803B-T-23; W8803B-T-31; W8803B-T-36; W8803B-T-42; W8803B-T-47; W8803B-T-52; W8803B-T-57; W8803B-T-62; W8803B-T-68; W8803B-T-69; W8803B-T-89; W8803B-T-9; W8803B-T-92; Wecoma; X-ray fluorescence (XRF); Ytterbium; Zirconium
url https://doi.org/10.1594/PANGAEA.76291