Carbon in rocks and its rate of exchange with the exosphere is the least understood part of the carbon cycle. The amount of carbonate subducted as sediments and ocean crust is poorly known, but essential to mass balance the cycle. We describe carbonatite melt pockets in mantle peridotite xenoliths from Dalihu (northern China), which provide firsthand evidence for the recycling of carbonate sedi...

[1] We investigate the utility of adding a 365 nm ultraviolet (UV) light source to the ExoMars panoramic camera (PanCam) scheduled for launch in 2013. The modification makes it feasible to monitor rover drill cuttings for aromatic organic molecules and provide constraints on polycyclic aromatic hydrocarbons (PAH) as a function of depth to the 2-meter limit of the ExoMars drill. This non-destruc...

Abstract We present a summary of peridotite in the Subantarctic (46–60° S) surrounding Antarctic Plate. Peridotite xenoliths occur on Kerguelen Islands and Auckland Islands. The are underlain by plume, whereas part continental Zealandia, which is Gondwana-rifted fragment. Small amounts serpentinized has been dredged from fracture zones Southeast Indian Ridge, Southwest Ridge Pacific represent u...

We review physical and chemical constraints on the mechanisms of melt extraction from the mantle beneath mid-ocean ridges. Compositional constraints from MORB and abyssal peridotite are summarized, followed by observations of melt extraction features in the mantle, and constraints from the physical properties of partially molten peridotite. We address two main issues. (1) To what extent is melt...

Peridotite xenoliths in arc volcanoes are very rare, usually small and remain poorly studied. Much of the earlier work focused on peridotites affected by re-crystallization, metasomatism and veining that took place shortly before the eruption of the host magmas; such lithologies may not be widespread in the mantle wedge.This study reports petrographic, major and trace element data for 17 large,...

The role of the subducting lithospheric slab in the genesis of mantle-derived (primitive) magmas is investigated through a study of volcanic rocks formed in the tectonically strike-slip–dominated western Aleutian arc. Two types of chemically and petrologically distinctive primitive andesites have been found among the Miocene– late Pleistocene–age volcanic rocks in the western Aleutians. These a...

The oceanic crust, covering two-thirds of the Earth's surface, is formed along mid-oceanic ridges by crystallization at shallow levels melts depth partial melting mantle peridotite. Yet, process melt transport to ridge axis remains poorly understood. Ophiolites, which provide a window into uppermost mantle, contain dunite bodies often interpreted as relics flow conduits, pyroxene dissolution du...

With this Preface, we provide background information, a scientific overview of topics, and an annotated bibliography the 63 papers published in Journal Geophysical Research (JGR) Special Issue on “Ophiolites Oceanic Lithosphere, with Focus Samail Ophiolite,” collected online at https://agupubs.onlinelibrary.wiley.com/doi/toc/10.1002/(ISSN)2169-9356.SAMAIL1. Topics covered include formation alte...

We compressed and analyzed an undepleted natural peridotite—thought to be representative of the Earth’s upper mantle— from ∼25 to 110 GPa and heated to 2000–2500 K. Scatter in zero-pressure unit-cell volumes observed for high-pressure phases synthesized from peridotite, of ±0.4% for orthorhombic perovskite and ±0.8% for magnesiowüstite, can be ascribed to compositional heterogeneity in the natu...