Red Bed Plains

Red Bed Plains
Name	Red Bed Plains
Type	Sedimentary formation
Period	Permian to Triassic (primarily)
Primary lithology	Sandstone, siltstone, mudstone
Other lithology	Conglomerate, evaporite
Namedfor	Red coloration
Country	Various

Red Bed Plains are extensive sedimentary sequences notable for their red beds occurring across multiple continents during the late Paleozoic and early Mesozoic. They are recognized in stratigraphic frameworks from basins linked to the Ural Mountains orogeny, the Appalachian Mountains, the Himalayan foreland, and rift basins such as the Siberian Traps margins. These units have been studied in correlation with global events including the Permian–Triassic extinction event and regional episodes like the Variscan orogeny.

Geology and Stratigraphy

Red Bed Plains comprise continental clastic successions dominated by oxidized iron-bearing minerals within sandstone and siltstone lithofacies deposited in synrift, foreland, and intracratonic settings. Stratigraphically they often occupy time-equivalent packages to marine sequences such as the Zechstein and the Chengjiang-age successions but are distinct for their nonmarine provenance. Key stratigraphic markers include unconformities tied to the Alleghanian orogeny and sequence boundaries synchronous with the Anisian–Ladinian interval. Regional correlation uses magnetostratigraphy aligned with records from the Deccan Traps and isotope chemostratigraphy compared with the Greenland siliciclastic successions.

Paleoenvironments and Sedimentology

Sedimentological interpretation emphasizes fluvial, alluvial fan, playa-lake, and aeolian depositional systems consistent with arid to semi-arid climates documented during Permian and Triassic continentalization. Facies associations parallel models from the Newark Basin and the Karoo Basin and are contrasted with lacustrine deposits in the Ordos Basin. Red oxidation states are tied to diagenetic processes involving meteoric fluids and authigenic hematite comparable to mineralogical trends in the Bambui Group and Cedar Mesa Sandstone. Paleosol horizons and calcrete crusts align with paleoclimate reconstructions derived from comparisons to the Chupadera Mesa and Ischigualasto Formation records.

Geographic Distribution and Major Formations

Red bed sequences are widespread: in Europe (e.g., the Mercia Mudstone Group, the Germanic Trias), North America (e.g., the Dockum Group, the Chinle Formation), South America (e.g., the Santa Maria Formation), Africa (e.g., the Karoo Supergroup), Asia (e.g., the Xingshikou Group), and Australia (e.g., the Sydney Basin red beds). Major basins hosting these units include the Permian Basin, the Paris Basin peripheries, the Ordos Basin, and the Eromanga Basin. Correlation of these formations has been undertaken alongside records from the Buntsandstein and the Molasse Basin successions.

Fossils and Paleontology

Fossil assemblages in red bed settings frequently preserve tetrapod tracksites, archosauriform skeletal remains, plant macrofossils, and palynological assemblages useful for biostratigraphy. Notable comparisons are drawn with vertebrate faunas of the Ischigualasto Formation, the Chañares Formation, the Lystrosaurus-bearing Karoo Basin, and the Chinle Formation phytosaurs and aetosaurs. Trace fossils such as those correlated with the Grallator ichnofacies occur alongside impressions attributed to Ginkgoales and Cycadales-type flora. Paleontological work integrates taphonomic studies similar to those in the Silesian coal measures and taxonomic revisions parallel to research on Postosuchus and Euparkeria.

Economic Resources and Uses

Red bed plains host reservoir sandstones exploited for hydrocarbons in the Permian Basin and unconventional plays analogous to the Bakken Formation. They contain aquifers tapped by municipal supplies in regions like the Great Artesian Basin, and host aggregates and building stone quarried near the Cotswolds and the Adirondack Mountains margins. Evaporite intervals linked with red beds are mined for evaporitic minerals comparable to deposits in the Bursa region and the Khewra Salt Mine analogues. Geothermal and carbon sequestration studies reference porosity-permeability frameworks developed for the North Sea red-bed reservoirs.

History of Study and Nomenclature

Early recognition of red beds dates to 19th-century mapping by geologists working on the Appalachian Mountains and the Scottish Highlands, with stratigraphic names later formalized during continental syntheses by authors working on the Geological Society of London publications and national surveys such as the United States Geological Survey and the British Geological Survey. Classic monographs comparing red beds with contemporaneous marine facies were produced in the context of debates following the Plate tectonics revolution and studies of the Permian–Triassic boundary. Ongoing research programs link field mapping initiatives in the Tibetan Plateau, sediment provenance studies led from the University of Cambridge and the Chinese Academy of Sciences, and international collaborations including the International Union of Geological Sciences.

Category:Sedimentary formations Category:Permian geology Category:Triassic geology