A more generally applicable impact-diagnostic method is the detection of traces of the meteoritic projectile in target rocks. This allows to establish the impact origin for a crater structure. The meteoritic projectile undergoes vaporization in the early phases of crater formation. A small amount of the meteoritic vapor is incorporated with the much larger quantity of target rock vapor and melt, which later forms impact melt rocks, melt breccias, or glass. In most cases, the contribution of meteoritic matter to these impactite lithologies is very small (commonly <<1%), leading to only slight chemical changes in the resulting impactites. Only elements that have high abundances in meteorites, but low abundances in terrestrial crustal rocks, can be used to detect such a meteoritic component. During the last two decades, studies of the abundances and interelement ratios of the siderophile elements, such as Cr, Co, Ni, and, especially, the platinum group elements (PGEs) have been used for these investigations (see, e.g., Morgan et al., 1975; Palme, 1982; Evans et al., 1993; and references therein). However, the use of elemental abundances does not necessarily lead to unambiguous results, as ultramafic rocks or ore minerals may be present among the target rocks, resulting in elevated PGE abundances. Another complication is the possible fractionation of the siderophile elements in the impact melt while it is still molten. This effect may be significant in larger craters, because there the melt can stay hot for many thousand years. Different mineral phases, such as sulfides or oxides (e.g., magnetite, chromite), may take up various proportions of the PGEs or other siderophile elements, leading to an irregular distribution of these elements and possibly fractionated interelement ratios and patterns. Such irregular distribution of siderophiles is known from, for example, the East and West Clearwater impact structures (Palme et al., 1979), or the Chicxulub impact structure (Koeberl et al., 1994c; Schuraytz et al., 1996). Hydrothermal processes associated with the hot impact melt may also change PGE abundances.

Now, remember that spq and others have found very significant Chromium which is the first element mentionned in here. Of course, the reference to "especially, the platinum group elements (PGEs)" is very interesting with today's release.

If indeed this is a meteor strike as JohnDefur hypothesized and this scientific article seems to agree with, than DE1 is just the tip of a very large ICEBERG.

Glorieux