| Title | Microscopic lamellar deformation features in quartz: discriminative characteristics of shock - generated varieties |
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| Author | Alexopoulos, J S; Grieve, R A F; Robertson, P B |
| Source | Geology vol. 16, no. 9, 1988 p. 796-799, https://doi.org/10.1130/0091-7613(1988)016<0796:mldfiq>2.3.co;2 |
| Year | 1988 |
| Alt Series | Geological Survey of Canada, Contribution Series 54187 |
| Publisher | Geological Society of America |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Alberta; Ontario; Quebec; Newfoundland and Labrador |
| NTS | 31F/05; 31F/12; 13M/14; 82P |
| Area | Scollard Area; Labrador; Canada; United States of America; Haiti; China; Indonesia |
| Subjects | igneous and metamorphic petrology; extraterrestrial geology; deformation; quartz; nuclear explosions, undergrd; metamorphism; igneous rocks; intrusive rocks; volcanic rocks; meteorite craters; Mistastin
Lake Complex; Cretaceous Clays; Cretaceous; Tertiary; Mesozoic; Cenozoic |
| Abstract | The appearance and orientation of microscopic lamellar deformation features in quartz have been examined in samples from different geologic environments. Lamellar deformation features from known shock
and/or impact environments are sharp, parallel, closely spaced, and tend to extend in a continuous manner across entire grains. They have specific, well-documented orientations and occur in multiple sets per grain. Lamellar deformation features from
other geologic environments, including tectonic and explosive volcanic, only superficially resemble shock features. They are generally less well defined, slightly curved, wider spaced, and tend to extend in a discontinuous manner across parts of
grains. They have relatively random orientations, only some of which correspond to known shock orientations, and generally occur as single sets per grain. On the basis of these observations, we conclude that there is a characteristic set of
microscopic deformation features produced in quartz by shock. These so-called planar features differ from microscopic lamellar deformation features produced by other dynamic processes; therefore, the case for the formation of characteristic planar
features in quartz by natural processes other than impact is still not proven. |
| GEOSCAN ID | 123772 |
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