Print this pageWeird Scenes Inside the Gold Mine; Finding Debris from the Avak Impact
By
A.C. Banet (Bureau of 
Land
Management)
The Geologic Materials Center (GMC) in Eagle River is
the Alaska repository for cores and cuttings from numerous petroleum and mineral
exploration activities. The GMC is a valuable storehouse of hard data without
which so much logging and geophysical data are merely measurements. In addition
to petroleum and exploration data, the GMC repository also provides insights
geological questions. The Avak impact is the northernmost impact feature of the
known Cretaceous seaway impacts. Core and cuttings from the Cape Simpson area
show allochthonous lithologies, including coarse and angular fragments of
sandstone and argillite that are similar in appearance to the debris described
from the Avak well core. These sandstone and argillite fragments are suspended
in a matrix of soft gray clay. Well correlations and paleo data show this unit
is the upper Cretaceous Seabee Shale (shale of the Colville Group). If the
debris found in the Simpson area proves to correlate to the Avak impact, its
level within the Seabee Formation could provide a more precise age estimate than
previous workers.
AAPG Search and Discovery Article #90008©2002 AAPG Pacific Section/SPE Western Region Joint Conference of Geoscientists and Petroleum Engineers, Anchorage, Alaska
, May 18–23, 2002.