Carboniferous formations and faunas of central Montana

Abstract

___________________ Analysis of previous work ____________________________ Papers dealing primarily with equivalents of the Big Snowy group in Montana--_-__-____-____-__--_ Incidental reports.______________________________ Resume__ _ _____________________________________ Carboniferous systems._____________________________ Mississippian system ____________________________ Madison group_____________________________ Mission Canyon limestone_______________ Charles formation_______________________ Lower part of Big Snowy group._.____________ Kibbey sandstone.._____________________ Otter formation-._______________________ Heath formation._______________________ Mississippian or Pennsylvanian system ____________ Middle part of Big Snowy group.._____________ Cameron Creek formation_________ ______ Alaska Bench limestone__________________ Pennsylvanian system ___________________________ Upper part of Big Snowy group._--___________ Devils Pocket formation. ________________ Beds overlying Big Snowy group________ ____________ Pennsylvanian (?), Permian (?), or Triassic(?) undiff erentiated-_ _______________________________ Jurassic system-________________________________ Unconformities. ____________________________________ Faunal analysis,____________________________________ Preservation ____________________________________ Distribution.. __________________________________ Paleontological characteristics of the formations Interregional and intercontinental correlation problems_ ____________________________________ Chester series of Illinois._____________________ Springer formation of Oklahoma._____________ Moscow basin._____________________________ Cordilleran geosyncline______________________ Rocky Mountains___________________________ Brazer limestone________________________ Sacajawea formation of Branson (1936)____ CARBONIFEROUS FORMATIONS AND FAUNAS OF CENTRAL MONTANA

Pelecypoda and Rostroconchia of the Amsden Formation (Mississippian and Pennsylvanian) of Wyoming

“…24) as Septimyalina n. sp. The specimens from the Cameron Creek Formation of Montana referred by Easton (1962) to Septimyalina n. sp. may belong to a different species than those from the Amslen of Wyoming; in the Montana specimens the angle between the dorsal margin and the umbonal ridge (angle alpha) is greater than the same angle in the Wyoming specimens.…”

Parasitic polychaetes in the Early Cretaceous Hydrocarbon seep-restricted brachiopod Peregrinella Multicarinata

“…Our single complete shell shows some external similarity to Leiorhynchoidea carbonifera (Girty, 1911) described from the Chesterian of Idaho (Butts 2007). Other specimens from Muhua show also evident simi− larity to L. carbonifera from the Heath Formation (Mississip− pian) of Montana, USA (see Easton 1962). Paucity of the present material, however, does not allow for a more detailed determination.…”

Stratigraphy and geologic history of the Amsden Formation (Mississippian and Pennsylvanian) of Wyoming

“…This analysis of the relations between Late Mississippian and Pennsylvanian rocks of Wyoming and Montana has been made by comparing our data with the lithostratigraphic synthesis of Maughan and Roberts (1967) and by reinterpreting the fossils listed and described by Gardner and others (1946) and Easton (1962) from the Montana sequence. Our data include not only fossils and stratigraphic sections from Wyoming but also similar data, much of it not previously published, collected in Montana.…”

“…Correlations of the Wyoming and Montana sequences with the miogeosynclinal sequence of southeast and south-central Idaho are based on integra- tion of our data from Wyoming, southwest Montana, and Idaho with the lithostratigraphic synthesis of Maughan and Roberts (1967) in Montana and restudy of the fossils listed and described in Gardner and others (1946) and Easton (1962). Much of the biostratigraphic evidence for the present interpretations can be found in reports by Dutro and Sando (1963a, b), Huh (1967), Sando (1967b), Sando and others (1969), and Mamet and others (1971).…”