Mathematics – Logic
Scientific paper
Jul 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994metic..29r.477i&link_type=abstract
Meteoritics (ISSN 0026-1114), vol. 29, no. 4, p. 477
Mathematics
Logic
Chemical Composition, Glass, Meteorite Craters, Micrometeoroids, Tektites, Geochronology, Morphology, Spatial Distribution, Stratigraphy
Scientific paper
Zhamanshin is the only impact structure in the world where microtektites are found together with impact glasses. Muong-Nong-(MN)-type layered tektites, and splash-form tektites-irghizites. Microtektites are closely associated with the tektites-irghizites, which commonly have numerous smaller glass spherules agglutinated to the surface. When separated, these spherules are undistinguishable from common sea-bottom microtektites. Relative to MN zhamanshinites, the irghizites are richer in MgO; however, both belong to adjacent families. Compositional equivalents for tektites-irghizites and associated microtektites are unknown among the Zhamanshin Crater target rocks. The imagined mixture of target and stone-meteorite materials evaporated and condensed together has no proof, and appears to be an ad hoc assumption. The total absence of any basic glass spherules originated from the impact melts is remarkable. Therefore, an impact origin for the microtektites must be precluded when applied to the Zhamanshin Crater realities. The problem of the relationship between microtektites and tektites so far has no satisfactory solution. The absence of microtektites on the land within the Australasian tektite strewn field (AATSF) cannot be explained traditionally as a result of ground corrosion or demolition during redeposition, as the Zhamanshin example shows. On the other hand, the irghizite-like morphological type of tektite is also absent along the AATSF, with the Darvin Glass as a meaningful exception. The age paradox forces us to assume specific extraterrestrial conditions for irghizite-micritekite formation. If so, the spatial distribution of microtektites, like all other tektite morphological types and compositional families, depends on the projectile structure and composition, and its fragmentation and trajectory relative to the Earth's surface. If the extraterrestrial origin of tektites and microtektites is taken as a reality, then something can be assumed to be wrong with the sea-bottom microtektite stratigraphy and/or radiogenic ages, and with the correlation between sea-bottom microtektites and land tektites. They have different strewn-field orientation, and different stratigraphy and if all this is true, they must both belong to different tektite falls, with possibly various-age paradox spans.
No associations
LandOfFree
Microtektites of the Zhamanshin impact crater: Key facts to the microtektite problem does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Microtektites of the Zhamanshin impact crater: Key facts to the microtektite problem, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microtektites of the Zhamanshin impact crater: Key facts to the microtektite problem will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-822320