FOSSIL AND ARTIFACT COLLECTING REPORT July 2013 Daniel A. Woehr and Family and ...

479 Pages·2013·57.76 MB·English

FOSSIL AND ARTIFACT COLLECTING REPORT
July 2013
Daniel A. Woehr and Family and Friends

July 3, 2013: Upper Cretaceous Marine Outing with a Holocene Bonus
The holiday week afforded me the liberty of a little travel time on a work night, so I seized the
opportunity to push farther along an exposure of Pecan Gap Formation marine chalk to see what else
might be catching daylight for the first time in 73 million years.
I pushed over a mile downstream through dry stream bed gravels and it became clear to me that the
float was composed of the various lithologies present within the Austin Chalk (84 MYA). Rock units
could in places be seen bedded in the stream bottom and ranged from blocky to nodular to marly.
There was much hematite strewn throughout the float. I could see partial ammonite fragments and
impressions, mostly in the orange colored, flaggy limestones peppered with shell fragments. But no
whole ammonites were found in situ. Instead I was rewarded with one cute little nautiloid from the
nodular Austin float just downstream of its source bedded in the stream bottom.
FIGS 1-2: Eutrephoceras (?) nautiloid from the Austin Chalk this and next page (Site 668)
The return leg of my hike found me weaving a path other than where my initial steps had fallen, eyes
scanning all new sections of bedded limestones and gravels. A large bluff that ended abruptly
instinctively put my artifact detection system on high alert. I guess I’m finally learning to read
topography for potential Indian campsites. I reasoned that the flat spot on top of the stream terrace at
the downstream foot of the bluff would have been a great campsite, affording a rapid uphill retreat in
the event of attack, rising flood waters, etc.
I had seen little or no flint in the stream gravel along the course of my hike, then the first piece I
encountered was about 2/3 of a flint blade, not far downstream of said bluff. I had the self control to
shoot an in situ photo before grabbing it. It was quite gratifying to actually find a point in an area that
my instincts identified as having artifact potential. Who knows how many I’ve walked by over the years,
oblivious to the clues around me, and more recently, focusing more on bedrock outcrops for fossils than
on the signs of pre historic habitation. I still have much to learn.
FIGS 3-5: Flint blade this and next 2 pages (Site 668)

The contact between the Austin and Pecan Gap formations here is overwashed by alluvial gravels, but I
soon found my way back to the small stretch of bedded Pecan Gap Chalk. I did a little more blind mining
and turned up a couple Hemiaster echinoids, a Gyrodes gastropod, and a few Neithea scallops, but no
ammonites this time.
FIGS 6-7: Pecan Gap echinoid Hemiaster c.f. texanus this and next page (Site 154)

FIG 8: Pecan Gap Formation gastropod Gyrodes sp. (Site 154)