Using tracks to correlate the Nugget Sandstone Formation of Dinosaur National Monument, Utah
Advisor Information
George Engelmann
Location
Milo Bail Student Center Ballroom
Presentation Type
Poster
Start Date
8-3-2013 1:00 PM
End Date
8-3-2013 4:00 PM
Abstract
The Nugget Sandstone Formation, in northeastern Utah has been considered to be Early Jurassic in age. Large-scale cross-bedded eolian dune sands characterize the Nugget. But the lower part of the Nugget consists of sediment that seems fluvial in origin, indicating a drastically different depositional environment than the higher, eolian-dominated sands. Ichnofossil localities with trackways that have been identified as the ichnotaxon Brachychirotherium have been found in and around Dinosaur National Monument. Brachychirotherium is characterized as a quadruedal trackway with manus (hand), and pes (foot) tracks in which the pes bears a distinctive tor claw. The aetosaur Typothorax coccinarum has been proposed as the trackmaker of the Brachychirotherium tracks. Brachychirotherium has been considered to indicate a mid to Late Triassic age. If the lower unit of the Nugget Sandstone can be shown to be Late Triassic in age, its relationship to the Glen Canyon Group and the underlying Chinle Group in the Colorado Plateau region to the south can be better resolved.
Using tracks to correlate the Nugget Sandstone Formation of Dinosaur National Monument, Utah
Milo Bail Student Center Ballroom
The Nugget Sandstone Formation, in northeastern Utah has been considered to be Early Jurassic in age. Large-scale cross-bedded eolian dune sands characterize the Nugget. But the lower part of the Nugget consists of sediment that seems fluvial in origin, indicating a drastically different depositional environment than the higher, eolian-dominated sands. Ichnofossil localities with trackways that have been identified as the ichnotaxon Brachychirotherium have been found in and around Dinosaur National Monument. Brachychirotherium is characterized as a quadruedal trackway with manus (hand), and pes (foot) tracks in which the pes bears a distinctive tor claw. The aetosaur Typothorax coccinarum has been proposed as the trackmaker of the Brachychirotherium tracks. Brachychirotherium has been considered to indicate a mid to Late Triassic age. If the lower unit of the Nugget Sandstone can be shown to be Late Triassic in age, its relationship to the Glen Canyon Group and the underlying Chinle Group in the Colorado Plateau region to the south can be better resolved.