Resolving atmospheric contaminants in mantle noble gas analyses

Numerical models, geochemistry and the zero-paradox noble-gas mantle.

Numerical models of whole-mantle convection demonstrate that degassing of the mantle is an inefficient process, resulting in ca. 50% of the (40)Ar being degassed from the mantle system. In this sense the numerical simulations are consistent with the (40)Ar mass balance between the atmosphere and mantle reservoir. These models, however, are unable to preserve the large-scale heterogeneity predic...

Noble gases in mantle plumes.

Trieloff et al. (1) provided neon isotope data to argue that mantle neon originates as a trapped component in meteorites rather than having a pristine solar composition. That finding, if true, has important consequences for understanding the mechanism of volatile input into the mantle, because it rules out models involving direct incorporation of solar gases. The main argument that Trieloff et ...

A model to explain the various paradoxes associated with mantle noble gas geochemistry.

As a result of an energetic accretion, the Earth is a volatile-poor and strongly differentiated planet. The volatile elements can be accounted for by a late veneer ( approximately 1% of total mass of the Earth). The incompatible elements are strongly concentrated into the exosphere (atmosphere, oceans, sediments, and crust) and upper mantle. Recent geochemical models invoke a large primordial u...

Atmospheric noble gas signatures in deep Michigan Basin brines as indicators of a past thermal event

Noble Gas Anomalies and Synthesis

There are two types of planetary noble gases. One containing isotopically " anomalous: argon ,krypton and xenon but isotopically " normal " helium and neon, was derived from outer stellar regions. The other, consisting almost entirely of isotopically " normal " argon, krypton and xenon with little or no helium or neon, was derived from inner stellar regions. Mixing of nucleosynthesis products f...