Geology Reports⌕ Search

Geology topics

Augustus K. Armstrong

Publications and source records attributed to Augustus K. Armstrong.

24 records · Page 2Linked to original sources
USGS1970

Foraminiferal zonation and carbonate facies of Carboniferous (Mississippian and Pennsylvanian) Lisburne group, central and eastern Brooks range, Arctic Alaska

The Lisburne Group carbonate rocks of the central and eastern Brooks Range contain foraminiferal assemblages assigned to zones of late Tournaisian (Osage) to early Moscovian (Atoka) age. Representatives of both Eurasiatic and American cratonic microfaunas permit correlation with the original Carboniferous type sections in western Europe as well as with the standard Mississippian and Pennsylvanian sequences in the Mid-Continent region of North America. Correlation anomalies in the lower part of the sequence are discussed.

Alaska↗
USGS1970

Biostratigraphy and dolomite porosity trends of the Lisburne Group

This preliminary study is based on measured and carefully collected sections of the Lisburne Group (fig. 1, sees. 1-29). The outcrops extend from Cape Lisburne (sec. 1) in the west to Egaksrak River (sec. 29) in northeastern Alaska and are used as the basic building blocks for the carbonate facies maps and the cross section. Lithologic and foraminifera samples were collected at 10-foot intervals and rugose corals were collected within each section where found. The rock material was cut into thin section, and petrographic and microfossil studies were made to determine environments of deposition, facies, diagenetic changes, and microfossil content. Coral collections were studied in thin section.

Alaska↗