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Deposition and diagenesis of the Mississippian Lodgepole Formation, central Montana
The lower Mississippian Lodgepole Formation is exposed in central Montana in the anticlines which form the Big Snowy and Little Belt Mountains. Four sections averaging 130 feet in length were measured at the base of the ...
Origin and silica-carbonate relations of cherts of the Upper Cretaceous of Venezuela
Petrographic and chemical studies were made on the black cherts of the San Antonio formation (eastern Venezuela) and of the Ftanita del Tachira member (western Venezuela), both of Upper Cretaceous age. The AI2O3, Fe2 ...
Provenance and paleotectonic setting of conglomerates in the Virgilian Holder Formation, northern Sacramento Mountains, New Mexico
The Late Pennsylvanian (Virgilian) Holder Formation of the Sacramento Mountains, south central New Mexico, is composed of clastic and carbonate rocks cyclically deposited on the narrow Sacramento Shelf. Coarse channel fill ...
Late Pleistocene stratigraphy and geologic development of Cozumel Island, Quintana Roo, Mexico
Knowledge of the depositional history of Cozumel Island is important for an understanding of the tectonics of the block-faulted eastern Yucatan and Belize continental margin. Basic information was derived from field ...
Paleo-environments of Middle Pennsylvanian Chaetetes lithotopes, Texas and New Mexico
Detailed field studies and petrographic analyses of Chaetetes-bearing sections reveal Chaetetes in the presence of Profusulinella in the La Tuna and Berino Formations (Morrowan-Atokan) of the Magdalena Group in the Northern ...
Patch reefs off Bermuda
Patch reefs living on the Bermuda Platform provide excellent models for detailed investigation of bioclastic sediment dispersion. Skeletal debris is shed from the reef top to form a wedge of reef flank sediments which ...