Impact glasses from Zhamanshin crater (U.S.S.R.) : chemical composition and discussion of origin
نویسنده
چکیده
have been analyzed for up to 40 major, minor, and trace elements. All data point to a clear distinction between these impact glasses and other tektites or impact glasses. e.g. from the Australasian strewn field. Halogens are generally enriched in the irghizites and zhamanshinites when compared to normal splash for tektites. with zhamanshinites enriched more than irghizites. The same holds also for the alkali metals and a number of other volatile elements like Sb and As. Nickel and cobalt are enriched in the irghizite sample IO a considerable degree, suggesting meteoritic
منابع مشابه
Blue glass: A new impactite variety from Zhamanshin crater, U.S.S.R
Aktmct-A new variety of impact giass has been discovered at Zhamansbin impact crater (U.S.S.R.). The crater has been known as the source of different impact glasses such as irghizites and Si-rich zhamanshinites @-rich varieties) and Si-poor (andesitic) zhamanshinites. The newly discovered impact glass is ofdistinct blue color and shows a layered structure with numerous small vesicles. The blue ...
متن کاملWhy are blue zhamanshinites blue? Liquid immiscibility in an impact melt
We report here a study of the cause of the coloration of blue zhamanshinites, which are glassy impact melt rocks from the Zhamanshin crater in the USSR. We find that the blue color results from Rayleigh scattering from spherical, 100 nm-diameter inclusions of a separate Ca-Fe-Mg-P-rich silicate glass. These observations can best be explained by the operation of liquid immiscibility in the zhama...
متن کاملSaltpan impact crater, South Africa: Geochemistry of target rocks, breccias, and impact glasses, and osmium isotope systematics
The Pretoria Saltpan crater is a well-preserved 220,000 year-old, 1.13 km-diameter, simple impact crater. The crater was formed in Nebo granites of the Bushveld Complex. Some minor intrusions thought to be younger than the Nebo granite are present at the crater and have earlier been believed to support a volcanic origin of the structure, but recent geological studies showed them to be part of t...
متن کاملShocked rocks and impact glasses from the El’gygytgyn impact structure, Russia
available online at http://meteoritics.org 1495 © Meteoritical Society, 2004. Printed in USA. Shocked rocks and impact glasses from the El’gygytgyn impact structure, Russia Eugene P. GUROV1 and Christian KOEBERL2* 1Institute of Geological Sciences, National Academy of Sciences of the Ukraine, 55b Oles Gontchar Street, Kiev 01054, Ukraine 2Department of Geological Sciences, University of Vienna,...
متن کاملGeochemistry of impact glasses from the K/T boundary in Haiti: Relation to smectites and a new type of glass
We have individually analyzed twelve black and seven yellow glasses from the K/T boundary section at Beloc, Haiti, plus three smectite mantles around black glasses. The main chemical differences between black and yellow glasses are higher S, Ca, Mg, Zn, As, Br, Sb, and Au, but lower K, Na, and Si abundances in the yellow glasses. We have found high-CaO yellow glasses with low S contents (0.08, ...
متن کامل