Abstract
Reconciliation of Pennsylvanian stratigraphic nomenclature in the Midcontinent, USA
Abstracts with programs - Geological Society of America, Vol.54(5)
Geological Society of America, 2022 annual meeting; GSA connects 2022
10/2022
DOI: 10.1130/abs/2022AM-382965
Abstract
The harmonization of Pennsylvanian stratigraphic nomenclature in the Midcontinent of the US (KS, OK, MO, NE, IA) has been hindered by the varied establishment of formal units by individual states. To come to a unified understanding of Pennsylvanian stratigraphy, a regional working group was created. Here we report working group findings from stratigraphic analysis of the upper Desmoinesian and lower Missourian stages together with proposed nomenclatural revisions for this interval. Extant stratigraphic nomenclature was developed primarily from outcrop studies. We improve upon these works by incorporating extensive subsurface petrophysical data, drillers logs, and new drill cores. We also re-evaluate the original outcrops. These data include a network of subsurface-to-outcrop petrophysical transvers sections that span 36 adjoining counties. We include over 160 type, principal, and neostratotype sections, spanning 452 miles ( approximately 727 km; >120 located in Kansas) from Seminole County, OK, to Appanoose County, IA. Sixteen group and subgroup boundary-defining units were assessed as well as 10 proximal type sections. Together, these data revealed numerous discrepancies in previous correlations. We proposed significant changes in stratigraphic nomenclature. The Pleasanton Group is demoted in rank to formation and included within the redefined Marmaton Group (MG). The lower boundary of the MG is established at the base of an unnamed limestone that immediately underlies the Excello Shale Member. The redefined MG comprises the Fort Scott, Appanoose/Oologah, and Holdenville subgroups. These subgroups, as presently used by individual states, are either raised in rank or have boundaries extended or restricted to coincide with regionally mappable units, and honor seniority. The Fort Scott Subgroup now includes the Little Osage Formation (raised in rank) and Labette Formation. The Appanoose/Oologah Subgroup includes the Pawnee, Bandera, and Altamont formations. The Holdenville Subgroup includes the Nowata, Lenapah, Memorial, and Pleasanton formations. Due to an inability to map regional boundaries between the Lost Branch, Shale Hill, and Hepler lithostratigraphic units, these units are demoted to members of a redefined Pleasanton Formation and will be retained on a state-by-state basis.
Details
- Title: Subtitle
- Reconciliation of Pennsylvanian stratigraphic nomenclature in the Midcontinent, USA
- Creators
- Stephan Oborny - Kansas Geological Survey Lawrence, KS USA United StatesAnthony L. LayzellJon J. SmithFranek HasiukPatrick MulvanyDavid BridgesR. M. JoeckelThomas StanleyCarla M. EichlerAlyssa M. BancroftRyan Clark
- Resource Type
- Abstract
- Publication Details
- Abstracts with programs - Geological Society of America, Vol.54(5)
- Conference
- Geological Society of America, 2022 annual meeting; GSA connects 2022
- Publisher
- Geological Society of America (GSA)
- DOI
- 10.1130/abs/2022AM-382965
- ISSN
- 0016-7592
- Alternative title
- Geological Society of America, 2022 annual meeting; GSA connects 2022
- Language
- English
- Date published
- 10/2022
- Academic Unit
- Earth and Environmental Sciences; Iowa Geological Survey; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984702714102771
Metrics
1 Record Views