This nodule is located near Trinidad, Colorado. The nodule formed around the root ball of a Cretaceous palm tree. Two feet above the root ball, the tree trunk was truncated by the erosive forces of the newly formed fluvial channel.
The top of the nodule and surrounding the tree trunk is a thin layer of black carbonaceous material.
Huw Williams from across the pond describes it best: Looks like shallow lake shale/paleosols with composite crevasse splay events coming in.
The ultimate nodule!
The Fountain Formation makes contact with Precambrian rocks of the Laramide Orogeny along the Front Range of the Colorado Rockies across a 1.4 billion year unconformity. Well-known outcrops from Boulder (the “Flatirons“) to Morrison (Red Rocks Park) and Colorado Springs (Garden of the Gods) make this arguably the most photographed rock unit in Colorado.
So to speak… that is, photographing and documenting them in a way that helps tell their stories. That’s what this new site is all about. Join us as we explore Colorado geology (for starters) and introduce some favorite localities.
Rock Focus 