The global pattern of trace-element distributions in ocean floor basalts

Nature ◽  
2012 ◽  
Vol 491 (7426) ◽  
pp. 698-704 ◽  
Author(s):  
Hugh St C. O’Neill ◽  
Frances E. Jenner
Keyword(s):  
Trace Element ◽  
Ocean Floor ◽  
Global Pattern

scholarly journals 1,135 ionomes reveals the global pattern of leaf and seed mineral nutrient and trace element diversity in Arabidopsis thaliana

2021 ◽  
Author(s):  
Ana Carolina A. L. Campos ◽  
William F.A. Dijk ◽  
Priya Ramakrishna ◽  
Tom Giles ◽  
Pamela Korte ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Trace Element ◽  
Mineral Nutrient ◽  
Global Pattern

Geochemical patterns in Norwegian greenstones

1982 ◽  
Vol 19 (3) ◽  
pp. 385-397 ◽  
Author(s):  
G. H. Gale ◽  
J. A. Pearce
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Trace Element ◽  
Tectonic Setting ◽  
Major Elements ◽  
Island Arc ◽  
Ocean Floor ◽  
Spreading Axis ◽  
Southern Norway ◽  
Representative Samples

Representative samples of Caledonian greenstones from the Grong, Joma, Løkken, Støren, Stavenes, and Bømlo areas in central and southern Norway have been analysed for major elements and over 20 trace elements. Ocean-floor tholeiite-normalized trace-element patterns and chondrite-normalized rare-earth patterns both provide clues to the genesis, original tectonic setting, petrologic character, and effects of alteration of these greenstones. We conclude that the Støren, Stavenes, and Løkken greenstones were generated at spreading axes within the Caledonian ocean, the Grong and possibly the Bømlo submarine greenstones were erupted in an island-arc system, and the Joma and Bømlo subaerial greenstones were erupted in a within-plate setting. The Løkken greenstones may have been generated in a marginal basin, whereas those from Støren and Stavenes were probably generated at a rapidly spreading axis in a major ocean.

Geochemical investigations of basalts and associated rocks from the ocean floor and their implications

1971 ◽  
Vol 268 (1192) ◽  
pp. 469-486 ◽  
Keyword(s):  
Trace Element ◽  
Deep Sea ◽  
Major Element ◽  
Sea Water ◽  
Ocean Floor ◽  
Low Grade ◽  
Basaltic Magmas ◽  
Trace Element Contents ◽  
Element Contents ◽  
Possible Cause

Variations in trace element contents and inter-element ratios of deep-sea basalts are much more marked than variations in major element contents. This paper explores possible reasons for the variations which have been discovered. Inadequacy of sampling techniques may be responsible for some reported differences, but variations due to this cause are unlikely to approach the magnitude of reported variations. Some variation in samples from restricted areas of the ocean floor can be correlated with variation in the degree of silica saturation of the basalts. Submarine alteration of lavas by reaction with sea water is another possible cause of variation. Studies of metamorphosed deep-sea basalts suggest that very low-grade metamorphism may cause some, though slight, elemental migration. Studies on ultrabasic rocks show variations in trace element contents which, to some degree, appear to complement the variations encountered in basalts, suggesting that the extent of partial melting in the mantle during basaltic genesis influences the trace element contents of the products of melting. However, when such possible explanations have been considered, there remain variations in trace element contents of otherwise comparable basalts from different parts of the ocean floor, which appear to represent real variations in the trace element contents of the erupted basaltic magmas. In view of the difficulty of explaining such differences by contamination of magmas on their way to the surface, it is suggested that variations exist in the trace element contents of mantle material at the levels of basaltic genesis. Geochemical provinces exist in oceanic areas just as they do in continental regions.

Trace-element geochemistry of metabasaltic rocks from the Yukon-Tanana Upland and implications for the origin of tectonic assemblages in east-central Alaska

1999 ◽  
Vol 36 (10) ◽  
pp. 1671-1695 ◽  
Author(s):  
Cynthia Dusel-Bacon ◽  
Kari M Cooper
Keyword(s):  
Trace Element ◽  
Continental Margin ◽  
Ocean Floor ◽  
Late Triassic ◽  
Geochemical Data ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
East Central ◽  
The North ◽  
Augen Gneiss

We present major- and trace- element geochemical data for 27 amphibolites and six greenstones from three structural packages in the Yukon-Tanana Upland of east-central Alaska: the Lake George assemblage (LG) of Devono-Mississippian augen gneiss, quartz-mica schist, quartzite, and amphibolite; the Taylor Mountain assemblage (TM) of mafic schist and gneiss, marble, quartzite, and metachert; and the Seventymile terrane of greenstone, serpentinized peridotite, and Mississippian to Late Triassic metasedimentary rocks. Most LG amphibolites have relatively high Nb, TiO2, Zr, and light rare earth element contents, indicative of an alkalic to tholeiitic, within-plate basalt origin. The within-plate affinities of the LG amphibolites suggest that their basaltic parent magmas developed in an extensional setting and support a correlation of these metamorphosed continental-margin rocks with less metamorphosed counterparts across the Tintina fault in the Selwyn Basin of the Canadian Cordillera. TM amphibolites have a tholeiitic or calc-alkalic composition, low normalized abundances of Nb and Ta relative to Th and La, and Ti/V values of <20, all indicative of a volcanic-arc origin. Limited results from Seventymile greenstones indicate a tholeiitic or calc-alkalic composition and intermediate to high Ti/V values (27-48), consistent with either a within-plate or an ocean-floor basalt origin. Y-La-Nb proportions in both TM and Seventymile metabasalts indicate the proximity of the arc and marginal basin to continental crust. The arc geochemistry of TM amphibolites is consistent with a model in which the TM assemblage includes arc rocks generated above a west-dipping subduction zone outboard of the North American continental margin in mid-Paleozoic through Triassic time. The ocean-floor or within-plate basalt geochemistry of the Seventymile greenstones supports the correlation of the Seventymile terrane with the Slide Mountain terrane in Canada and the hypothesis that these oceanic rocks originated in a basin between the continental margin and an arc to the west.

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