Noble gases from oceanic island basalts do not require an undepleted mantle source

Nature ◽  
1985 ◽  
Vol 316 (6030) ◽  
pp. 716-718 ◽  
Author(s):  
David E. Fisher
Keyword(s):  
Mantle Source ◽  
Noble Gases ◽  
Oceanic Island ◽  
Oceanic Island Basalts

Strontium Isotopes in some Seamount Basalts from the Northeastern Pacific Ocean

1973 ◽  
Vol 10 (10) ◽  
pp. 1479-1484 ◽  
Author(s):  
K. V. Subbarao ◽  
G. S. Clark ◽  
R. B. Forbes
Keyword(s):  
Chemical Composition ◽  
Pacific Ocean ◽  
Mantle Source ◽  
Strontium Isotopes ◽  
Oceanic Island ◽  
Lava Flows ◽  
Northeastern Pacific ◽  
Oceanic Island Basalts ◽  
Isotopic Variations ◽  
Source Materials

87Sr/86Sr ratios in seven seamount basalts from the northeastern Pacific Ocean range from 0.7022 to 0.7034 and correlate significantly with chemical composition as expressed by the ratio K2O/(K2O + Na2O). These basalts seem to be similar to oceanic island basalts in alkali element concentrations, 87Sr/86Sr and K2O/(K2O + Na2O) ratios suggesting similar mantle source materials, possibly least depleted in dispersed elements. However, in places, seamount basalts also appear to resemble ridge tholeiites. Large differences in 87Sr/86Sr and Rb/Sr ratios for the samples from the Cobb seamount appear to indicate isotopic variations in the source materials, perhaps resulting in the formation of different lava flows within the seamount.

Oceanic Island Basalts

2016 ◽  
pp. 1-5 ◽  
Author(s):  
Matthew Gerard Jackson
Keyword(s):  
Oceanic Island ◽  
Oceanic Island Basalts

Archean, highly unradiogenic lead in shallow cratonic mantle

Geology ◽  
2020 ◽  
Vol 48 (6) ◽  
pp. 584-588 ◽  
Author(s):  
Jun-Bo Zhang ◽  
Yong-Sheng Liu ◽  
Mihai N. Ducea ◽  
Rong Xu
Keyword(s):  
Pressure Dependence ◽  
Mantle Source ◽  
Negative Pressure ◽  
Upper Mantle ◽  
Partition Coefficients ◽  
North China ◽  
Oceanic Island ◽  
Isotopic Data ◽  
The North ◽  
Cratonic Mantle

Abstract Here, we present coupled geochemical and Sr-Nd-Pb-S isotopic data of Early Cretaceous primitive gabbros from the North China craton. Strikingly, these rocks have highly unradiogenic lead compositions (206Pb/204Pb = 16.58 ± 0.24) and anchor one extreme end member (low 206Pb/204Pb and 143Nd/144Nd) in the global array of oceanic-island volcanics. Our study shows that they originated from an Archean fluid-metasomatized refractory peridotite source, in which highly unradiogenic lead was preferentially released with subducted Archean seawater and sequestered into recrystallized sulfides at shallow mantle depths. Sulfide/silicate partition coefficients for lead show a negative pressure dependence: Lead is more enriched in sulfide with decreasing pressure. Sulfide-bearing and iron-poor harzburgite as well as dunite residues at shallow mantle are expected to develop low U/Pb (and thereby low time-integrated 206Pb/204Pb) relative to a deeper upper-mantle source. Our preferred interpretation is that an Archean, highly unradiogenic lead reservoir may be stored in the spinel-facies refractory cratonic mantle.

Frequency spectrum of the electrical properties of seawater-saturated ocean crust and oceanic island basalts

1978 ◽  
Vol 15 (9) ◽  
pp. 1489-1495 ◽  
Author(s):  
M. J. Drury
Keyword(s):  
Electrical Properties ◽  
Frequency Spectrum ◽  
Conduction Mechanism ◽  
Oceanic Island ◽  
Pore Fluid ◽  
Membrane Polarization ◽  
Conduction Mechanisms ◽  
Metallic Mineral ◽  
Dominant Conduction Mechanism ◽  
Oceanic Island Basalts

The frequency spectrum of electrical properties of seawater-saturated oceanic crust and oceanic island basalts has been studied. All samples showed at least two of three possible polarization mechanisms: dielectric, membrane, and electrode. The membrane polarization appears to result from the presence of clay minerals, which frequently line or block pores and cracks in the samples. The dominant conduction mechanism in the samples is pore fluid (seawater) conduction, but the electrical properties of samples containing clay are modified by the clay. The results support the suggestion by Drury that a model of three conduction mechanisms acting approximately in parallel—pore fluid, clay mineral, and metallic mineral conduction—describes the electrical properties of seawater-saturated basalts.

Noble gas and nitrogen isotopic components in Oceanic Island Basalts

2009 ◽  
Vol 266 (1-2) ◽  
pp. 29-37 ◽  
Author(s):  
R.K. Mohapatra ◽  
D. Harrison ◽  
U. Ott ◽  
J.D. Gilmour ◽  
M. Trieloff
Keyword(s):  
Noble Gas ◽  
Oceanic Island ◽  
Oceanic Island Basalts

Noble gases in pyrites from the Guocheng-Liaoshang gold belt in the Jiaodong province: Evidence for a mantle source of gold

2018 ◽  
Vol 480 ◽  
pp. 105-115 ◽  
Author(s):  
Jun Tan ◽  
Junhao Wei ◽  
Huaiyu He ◽  
Fei Su ◽  
Yanjun Li ◽  
...  
Keyword(s):  
Mantle Source ◽  
Noble Gases

An overview of oceanic island basalts in accretionary complexes and seamounts accretion in the western Central Asian Orogenic Belt

2019 ◽  
Vol 179 ◽  
pp. 385-398 ◽  
Author(s):  
Gaoxue Yang ◽  
Yongjun Li ◽  
Lili Tong ◽  
Zuopeng Wang ◽  
Fenghao Duan ◽  
...  
Keyword(s):  
Oceanic Island ◽  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Central Asian ◽  
Oceanic Island Basalts

Constraints on genetic models for the Ballantrae complex, SW Scotland

1984 ◽  
Vol 75 (2) ◽  
pp. 189-191 ◽  
Author(s):  
P. Stone
Keyword(s):  
Continental Margin ◽  
Strike Slip ◽  
Oceanic Island ◽  
Island Arc ◽  
Genetic Models ◽  
Transform Zone ◽  
Oceanic Island Basalts

ABSTRACTThe distribution of Arenig graptolite faunas and zones of differing metamorphic fades help to establish a polyphase imbrication history for the complex. A further complication is introduced by the presence within the imbricate stack of lava sequences of comparable age but with contrasting geochemical signatures of island-arc and oceanic island basalts, and oceanic island sequences of markedly different Arenig ages. Strike-slip mechanisms appear the most likely means of introducing such a disparate assortment of elements into the Ballantrae complex and an origin in a continental margin transform zone is preferred.

Sign in / Sign up

Export Citation Format

Share Document