November 13, 2013: Day 8, Sonsela Member
Sonsela at blue mesa
(1) Sonsela Member at Blue Mesa.

The Sonsela Member of the Chinle Formation is one of the most interesting units in the formation.
In addition to having most of the petrified logs in the Park (1) it is also the unit that contains the largest magnitude faunal and floral change in the Chinle. Note log weathering out of slope.

During the evening the night ship (2. 4) saw coring into the Jim Camp Wash Beds of the Sonsela. This interval (2) appears to be the right age to correlative with the giant Manicoagan impact structure (3) based on U-Pb dates. This same interval records the largest faunal and floral change in Chinle Formation.

Red Silcrete
(2) Prominant red silcrete within transition between the Adamanian and Revueltian in the south park.
Manicouagan impact structure
(3) Manicoagan impact structure
(Wikipedia Link)
Driling Sonsela at night shift
(4) Night drilling
Next (11-14-13)