Summer Coon Dikes

 

-> Dike segment azimuths were recorded by Moats (1990) for 12 of the 20 labeled dikes (see figure on previous page)

note dike breaking into en echelon segments in the right half of the photo

-> Eight of the 12 dikes show the rotation amount of dike segments increasing with distance from the central intrusive complex

-> The rotation may have two causes:

  1. With distance from the center of the volcano the paleodepth of exposure decreases, so the rotation may be caused as the dikes near the surface
  2. With distance from the center of the volcano pressures exerted by the magma chamber decrease, and rotation may result as the dikes adjust to the regional stress field away from the magma chamber

-> Unfortunately, the two causes may not be distinguished because paleodepth data is presently unavailable

-> Analysis of the four dikes with rotations that decrease with distance from the central intrusive complex shows interesting correlations with other dikes