Premium
Annealing of shocked quartz during atmospheric re‐entry
Author(s) -
Croskell Michael,
Warner Mike,
Morgan Jo
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2001gl014382
Subject(s) - quartz , annealing (glass) , grain size , geology , materials science , mineralogy , composite material
The Chicxulub impact launched shocked quartz grains on ballistic trajectories outside the atmosphere, thus enabling their global dissemination. The shocked grains heated up during atmospheric re‐entry and the maximum temperature reached was related to their size, velocity and re‐entry angle. The extreme heating of some shocked quartz grains is likely to have resulted in the destruction of their planar deformation features (PDFs). A significant negative correlation exists between the palaeodistance from Chicxulub of a given K/T boundary locality and the size of the largest shocked quartz crystal found at that locality. The re‐entry annealing process can explain this correlation. The largest shocked quartz grain at a given locality followed the shallowest available trajectory and survived re‐entry without being thermally annealed. Larger crystals and those on steeper trajectories exceeded the annealing point and lost their PDFs.