Thermal history of SÃO JOÃO NEPOMUCENO (IVA) iron meteorite inferred from Ganguly? s cooling rate model and 57Fe MÖSSBAUER spectroscopy data.

DOS SANTOS E.; SCORZELLI ROSA,; VARELA, M.E

Meteoritics and Planetary Science

Wiley

Lugar: New York; Año: 2016

1945-5100

In spite of the extensive work performed on the IVA irons there is still no consensus about their origin and thermal history [1]. Their particular chemistry and range in metallographic cooling rates are difficult to explain under conventional models. Although IVA irons are extremely depleted in volatile siderophile elements (e.g., Ga, Ge) [1], the chemical trends within this group are consistent with an origin in a single metallic body that fractionally crystallized. Nonetheless, their large spread of metallographic cooling rates correlating inversely with Ni content argues against an origin in a mantled asteroidal core [2]. If this would be the case, uniform cooling rates should be expected.