Abstract
A progressive change in the level of shock deformation is documented in autochthonous rocks from the central uplift of the Slate Islands impact structure, Lake Superior. Correlation of these observations, which are based mainly on the relative frequency of planar features of specific crystallographic orientation in quartz, with experimental data is used to estimate the average shock pressures recorded in the samples studied. Recorded pressures range from 5.8 to 15.3 GPa and generally increase towards the proposed shock centre. Variations in the shock response of quartz of different grain size and texture are observed within and between samples. It is apparent that large interlocking quartz grains in “eyes” record approximately 15–20% higher levels of shock deformation than small grains in mosaics or large isolated phenocrysts. These variations in shock deformation are attributed to the effect of shock wave reverberations between grains and length of shock pulse duration within grains.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
