The metamorphic sole rocks at the base of mantle peridotites from the Mersin ophiolite consist of amphibolites and metasedimentary lithologies. Mineral parageneses in the metamorphic sole rocks exhibit amphibolite and greenschist facies assemblages. Geothermobarometric studies based on mineral assemblages and chemical compositions of minerals indicate that average metamorphic temperature during...

Over millions of years, the interaction marine basalt with percolating seawater in low-temperature ocean floor hydrothermal systems leads to formation calcite and aragonite. The presence these minerals basalts provides evidence for substantial CO2 fixation rocks. Here, we report on laboratory experiments study this process under enhanced partial pressures (pCO2) at 130 °C. Mid-ocean-ridge-basal...

Experimental petrology and major element chemistry are used to infer the melting processes that operate in the upper oceanic mantle to yield basaltic magma, and the subsequent cooling processes by which these magmas chill to form the oceanic crust. THE PRIMARY MAGMAS OF MID-OCEAN RIDGE BASALTS This paper reports experiments carried out between 9 and 16 kbar (0.9 1.6 GPa) using natural, primitiv...

We analyzed stable carbon (δC) and radiocarbon (ΔC) isotopes of ocean crustal fluid samples from two low-temperature environments on and near the Juan de Fuca Ridge (JDFR), a seafloor spreading center in the northeastern Pacific Ocean. Themajor goals of this work were to resolve relative dissolved inorganic carbon (DIC) sources and removal processes, and characterize the isotopic signatures of ...

The decay of (187)Re to (187)Os (with a half-life of 42 billion years) provides a unique isotopic fingerprint for tracing the evolution of crustal materials and mantle residues in the convecting mantle. Ancient subcontinental mantle lithosphere has uniquely low Re/Os and (187)Os/(188)Os ratios due to large-degree melt extraction, recording ancient melt-depletion events as old as 3.2 billion yea...

Abstract Continental formation models invoke subduction or plume‐related processes to create the buoyant, refractory character of continental lithospheric mantle (CLM). From similarities in melt depletion, major element composition, modal clinopyroxene, and Os isotope systematics it has been proposed that oceanic lithosphere is likely protolith non‐cratonic CLM, however, a direct link between t...

1208 The Ninetyeast (or East Indian) Ridge is one of the longest aseismic volcanic ridges in the World Ocean and one of the longest linear structures of the Earth. It is 200 km wide on average, and it extends in the merid ional direction via the entire eastern part of the Indian Ocean for almost 5000 km (Fig. 1). The ridge is dis tinctly expressed in the bottom topography from its intersection ...

Abstract Bimodal volcanism occurs in a range of extensional environments that are characterized by distinctive but overlapping, lithogeochemical and isotopic signatures lithological assemblages. Where basaltic magmatism is associated with ferroan (A‐type) rhyolites, it typically the lithogeochemistry systematics rocks most beneficial constraining tectonic evolution. This study presents geochemi...

[1] Two fore‐arc magmatic belts exist in Kodiak Island, the granitic Kodiak batholith and the basaltic trenchward belt. Both are part of the 2100 km long Sanak‐Baranof belt, interpreted to result from trench‐ridge‐trench (T‐R‐T) triple‐junction migration. In this hypothesis, trenchward belt basaltic rocks formed as the spreading ridge first entered the accretionary prism, and the larger Kodiak ...