Comment on ‘Tectonic setting for ophiolite obduction in Oman’ by Robert G. Coleman

Robert F. Coleman 1954–2014

1 Biography Robert F. Coleman, an extraordinarily original and creative mathematician who has had a profound influence on modern number theory and arithmetic geometry, died of a sudden heart attack in El Cerrito, CA, on the morning of March 24, 2014. He is survived by his wife Tessa, his sister Rosalind, and brother Mark, his nephew Jeffrey, and niece Elise, and his service dog Julep. The depth...

U-Pb zircon constraints on obduction initiation of the Unst Ophiolite: an oceanic core

7 The Unst Ophiolite is the best exposed of a chain of early Ordovician ophiolites in the 8 Scottish Caledonides and is widely regarded as having formed in a supra-subduction zone 9 setting within the Iapetus Ocean. Reinterpretation of sheeted dykes suggests that it formed 10 as an oceanic core complex, presumably during subduction roll-back immediately prior to 11 obduction onto the Laurentian...

Platinum-group Minerals in Podiform Chromitites of the Oman Ophiolite

Chromitite lenses rich in the platinum-group elements (PGE) have recently been discovered in the deeper part of the mantle section of the northern part of the Oman ophiolite. In terms of stratigraphic level, there are two types of chromitite: Moho transition zone (MTZ) and mantle types. The mantle type can be further classified into two subtypes: PGE-poor and PGE-rich. Platinum-group minerals (...

Comment (on Robert J. Gordon)

Comment on "A vestige of Earth's oldest ophiolite".

The claim by Furnes et al. (Reports, 23 March 2007, p. 1704) that Greenland metavolcanic rocks require Paleoarchean sea-floor spreading is incompatible with their own data. The purported sheeted dikes have the composition of pyroxenitic komatiite and could not have fed the adjacent ferroandesitic pillow lavas. Neither type has ophiolitic analogs, and both are likely ensialic.