Lueders Formation
The Lueders Formation is a geologic formation in Texas. It is the top formation of the Albany Group and preserves fossils dating back to the Permian period.
[Image:Helicoconchus elongatus.jpg|thumb|Helicoconchus elongatus, a microconchid from the Lueders Formation of Texas.]
Description
Paleogeography
At the time of deposition, a broad sea connected to the Panthalassic Ocean covered much of the central United States, including Texas. The Lueders Formation would have been located in the northern tropics or subtropics. Climatically, after the retreat of an early Artinskian glacial maximum, the deserts of the North American craton experienced fluctuation and growth during this time period, and the associated aridity decrease impacted seabed deposition in localities across the basin.
Depositional environment
The Lueders Formation represents a deltaic environment, with terrestrial sediments being deposited onto the muddy bottom of a shallow estuary by shifting freshwater streams. In the Maybelle Member, the dolomite likely represents marine deposits, preserving marine sharks and fish, whereas darker terrestrial sediments and freshwater shale deposits contain remains of land animals and freshwater fish respectively.
Fossil content
Fish
Acanthodians
Cartilaginous fish
Invertebrates
Arthropods
Bivalves
Bryozoans
Cephalopods
Echinoderms
Plants