Home > Iowa Academy of Science > Journals & Newsletters > Proceedings of the Iowa Academy of Science > Volume 71 (1964) > Annual Issue
Document Type
Research
Abstract
Conodonts are rare in the Shell Rock Formation, but they support the previous assignment of this formation to the lower part of the Upper Devonian. Conodont species diagnostic of the Lower Palmatolepis gigas Zone (Upper Devonian, toIγ) occur in the upper part of the Juniper Hill and in the lower Cerro Gordo members of the Lime Creek Formation. The ranges of conodont species occurring in the Sheffield Formation are indicative of zones toIδ -tollα. The conodont faunas from the Aplington Formation is meager but may indicate zone toIV or toV. Conodonts from the "English River Siltstone" and the Maynes Creek Member of the Hampton Formation are distinctive of zones upper cuI through cuII. The Devonian-Mississippian boundary in north-central Iowa occurs between the Aplington Formation and either the "English River Siltstone", which is not everywhere present, or the Hampton Formation. At one locality the "Maple Mill Shale" overlies the Aplington Formation and here the boundary is between the "Maple Mill" and the overlying "English River Siltstone".
Publication Date
1964
Journal Title
Proceedings of the Iowa Academy of Science
Volume
71
Issue
1
First Page
320
Last Page
334
Copyright
©1964 Iowa Academy of Science, Inc.
Language
en
File Format
application/pdf
Recommended Citation
Anderson, Wayne I.
(1964)
"Upper Devonian and Lower Mississippian Conodont faunas, north-central Iowa,"
Proceedings of the Iowa Academy of Science, 71(1), 320-334.
Available at:
https://scholarworks.uni.edu/pias/vol71/iss1/49