Mississippian conodonts, Lisburne Group, St. Lawrence Island, Alaska
Late Mississippian conodonts recovered from two sections of the Lisburne Group exposed along the Ongoveyuk River, western St. Lawrence Island, are few, poorly preserved, yet relatively diverse. At the West Fork and East Fork Ongoveyuk sections, the lower, dark-colored, cherty beds yield conodonts that belong in the upper part of Lane Faunal Unit 8. They are correlatives of the upper St. Louis Formation in the Mississippi River Valley and, in northwest Alaska, are equivalent to the upper Nasorak and Kogruk Formations (Lisburne Group) along Nasorak Creek near Point Hope, and the Kogruk Formation at the Trail Creek, De Long Mountains, Misheguk Mountain quadrangle. The upper, light-colored, thicker-bedded interval at the West Fork exposure yields conodonts assignable to Lane Faunal unit 9 of latest Meramecian and earliest Chesterian age. This fauna occurs widely over North America in beds that correlate with the St. Genevieve Limestone in the Mississippi River Valley. On the Lisburne Peninsula, this interval correlates with at least a portion of the Kogruk Formation exposed at Niak Creek and Cape Lewis north of Point Hope. Conodont alteration indices (CAI) are very high and variable, ranging from 5.5 to 8.0, suggesting they resulted from contact rather than regional metamorphism.
- Research Organization:
- Amoco Production Co., Tulsa, OK
- OSTI ID:
- 5962436
- Report Number(s):
- CONF-8505215-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 69:4; ISSN AAPGB
- Country of Publication:
- United States
- Language:
- English
Similar Records
Redefinition of the Osagean-Meramecian boundary in the Mississippian stratotype region
Conodont biostratigraphy and biofacies of the Lisburne Group