What is meant by depleted mantle?

What is meant by depleted mantle?

Depleted mantle: The depleted mantle is the part of Earth’s mantle from which basaltic melt has been extracted in one or multiple melting events at, for example, mid-ocean ridges, hot spots, or island arcs.

What is enriched mantle?

Enriched Mantle – region in the mantle that is enriched in incompatible trace elements with respect to a primitive mantle model. EM1 – “Enriched Mantle 1”; OIBS plotting in the lower left-hand column in Sr-Nd. isotope array (see lecture notes); often interpreted to represent derivation from recycled.

What is MORB and OIB?

mid-ocean ridge basalts (MORB) and intra-plate ocean island basalts (OIB) have differences in their geochemical characteristics. These differences were instrumental in formulating the mantle plume hypothesis (Morgan, 1971, 1972).

Why is morb depleted?

Abstract. The depleted chemical signature of MORB has been commonly thought to be a consequence of the progressive extraction of continental crust from the upper mantle, although few attempts have been made to evaluate the exact nature of the depletion process.

What is HIMU geology?

Subduction of oceanic and continental crust (and associated sediments) into the mantle over geologic time generates mantle domains with geochemically distinct signatures, referred to as HIMU (high “μ”, where μ = 238U/204Pb) and EM (enriched mantle) domains.

What is bulk silicate Earth?

In geochemistry, the primitive mantle (also known as the bulk silicate Earth) is the chemical composition of the Earth’s mantle during the developmental stage between core-mantle differentiation and the formation of early continental crust.

What is OIB in geology?

Ocean island basalt (OIB) is a volcanic rock, usually basaltic in composition, erupted in oceans away from tectonic plate boundaries.

What is Nmorb?

al 2013 proposes the use of the term NMORB to refer to the most likely basalt composition encountered along the global ridge system distant from hotspots. The NMORB is given by the lognormal mean of the compositions of ridge segments more than 500 km away from plumes excluding back-arcs.

What is Chur geology?

The CHondritic Uniform Reservoir or CHUR is a scientific model in astrophysics and geochemistry for the mean chemical composition of the part of the Solar Nebula from which, during the formation of the Solar System, chondrites formed.

How do chondrites form?

A chondrite /ˈkɒndraɪt/ is a stony (non-metallic) meteorite that has not been modified, by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids.

Which is the dominant rock type of OIB?

Is ND 142 radioactive?

Nd is the decay product of radioactive 147Sm….Neodymium.