We report Li isotopic compositions of olivine from the mantle sequence of the Luobusa ophiolite, southern Tibet. The olivine in the Luobusa ophiolite has Li concentrations from ~0.1 to 0.9 ppm and a broad range of δ(7)Li (+14 to -20‰). An inverse correlation of Li concentration and δ(7)Li in olivine from harzburgite suggests recent diffusive ingress of Li into the rock. Olivine from dunite enve...

The extension of subduction processes into the Eoarchaean era (4.0-3.6 Ga) is controversial. The oldest reported terrestrial olivine, from two dunite lenses within the ∼3,720 Ma Isua supracrustal belt in Greenland, record a shape-preferred orientation of olivine crystals defining a weak foliation and a well-defined lattice-preferred orientation (LPO). [001] parallel to the maximum finite elonga...

Chromite is widely distributed in the east and southeast of Afghanistan, especially in Logar Province. Chromite mineralization is podiform-type and is hosted in the stratigraphically lowest ultramafic rocks of the Logar Ophiolite Complex. This ophiolite complex represents a remnant of an early Cretaceous oceanic crust that was thrusted over a late Permian to Mid-Jurassic platform-type sequence ...

During the early stages of an impact a small amount material may be jetted and ejected at speeds exceeding velocity. Jetting is important process for producing melt during relatively low velocity impacts. How angle affects jetting has yet to fully understood. Here, we simulate oblique impacts using iSALE shock physics code. Assuming both target impactor have same composition (dunite), examine w...

the subduction of the northern part of the tethys is documented by arc magmatism from upper triassic to lower eocene crosscutting the sanandaj-sirjan zone and from upper eocene to plio-quaternary in the urumieh-dokhtar magmatic zone, situated north of the ssz. neyriz ophiolite is part of middle eatern neo-tethyan ocean of mesozoic that geographically is related to ophiolites of nw-se iran, alon...

Mantle xenoliths in a nephelinite the Little Lottery River provide insight into Miocene mantle adjacent to Australia-Pacific plate boundary N Canterbury. The comprise peridotite and pyroxenite extracted from depths of ∼ 40 60 km. olivine Mg# < 89, lack spinel occurrence ilmenite, elevated bulk Cr Al, light rare Earth element (REE)-enriched clinopyroxene, 87Sr/86Sr15 Ma clinopyroxene populations...

We report here the results of a petrographic and geochemical study of remarkably well-preserved kimberlites from the Kangamiut region in Greenland. The samples contain between 5 and 45% of olivine in the form of rounded “nodules”, each 1 to 5 mm in diameter. Most originally were single crystals but many consist of polycrystalline, monomineralic aggregates. Olivine compositions vary widely from ...