Logging requirements: Please verify your visit by sending the
answer to the following questions. Please do not post the answers
in your log, even if encrypted.
(1) What is the color of the deepest layer of soil along the
riverbank?
(2) What is happening to this layer?
(3) What is being created as a result?
(4) What color is the bedrock in the bottom of the river?
OPTIONAL logging requirement: (1) A photo of you in the park with
(or without) a fossil you found. We would LOVE to hear about what
you found, and how much fun you had!
---> IMPORTANT: Submitting a photo is OPTIONAL -- answering the
questions above IS NOT. A photo IS NOT a substitute for answering
the earth science questions.
The North Sulphur River is a unique place steeped in irony. In
an effort to improve water flow from storm runoff and to curtail
erosion, a 20-foot wide, 10-foot deep river channel was dug in the
1930s. While water flow through this new channel drastically
improved, erosion unexpectedly accelerated, eventually collapsing a
railroad bridge that had spanned the river. That 20-foot wide
channel from 1930 is now well over 200-feet wide in places, due
primarily to erosion caused by the old project.
But if not for the unintended consequences of this failed water
project, the river itself would still be in a very narrow and
shallow channel, and none of the fossils the North Sulphur River is
famous for now would have ever come to light.
This stretch of the river could be submerged in a decade or so
if the proposed dam to create Lake Ralph Hall is completed just
downstream.
The North Sulphur River is well-known in paleontological circles
for the wide variety of excellent fossils from different eras that
can be found in its river bed and along its sand bars. Fossils from
both the Pleistocene and late Cretaceous periods can be found in
the riverbed of the North Sulphur River. It is not uncommon to find
fossil hunters parked along bridges over the North Sulphur, waiting
in the rain for the river to recede after a thunderstorm or heavy
rain event.
The late Cretaceous period began approximately 100 million years
ago and lasted for about 35 million years. Cretaceous era fossils
are mostly of marine creatures: mosasaurs, giant oysters, clams,
shark teeth, ammonites (straight and curved), plus the occasional
shark and fish vertebra. Many dedicated North Sulphur River fossil
hunters have added mosasaur jaws with teeth to their
collections.
The Pleistocene epoch began 2 million years ago and ended fairly
recently, geologically speaking: a mere 12000 years ago.
Pleistocene fossils are primarily of mammals, including mammoths,
sloths, and bison. An entire mammoth skeleton was discovered in the
river and donated to the Dallas Museum of Natural History decades
ago. It has now disappeared.
For now, the North Sulphur remains a fossil hunter's paradise.
The City of Ladonia has thoughtfully provided a carport and steps
down to the river at this rudimentary park, ending what used to be
a congestion problem along the SH 34 bridge and a
take-your-life-into-your-hands descent into the riverbed.
Take plenty of water with you, especially in the summer. There
is NO DRINKING WATER available at the site.