Historical:North Hill Group

Lithostratigraphy: Mammoth Cave Limestone Megagroup >>North Hill Group
Chronostratigraphy: Paleozoic Erathem >>Mississippian Subsystem >>Kinderhookian Series
Allostratigraphy: Kaskaskia Sequence

Authors

Elwood Atherton, Charles Collinson, and Jerry A. Lineback

Name Origin

The North Hill Group (Laudon, 1931, p. 344) is named for the North Hill area of Burlington, Iowa. The name was introduced for the oldest member of the Hampton Formation, but Laudon later (1935) made the unit a formation. Workman and Gillette (1956) made it a group to include the McCraney Limestone at the base, the Prospect Hill Siltstone, and the Starrs Cave Limestone.

Type Section

The type section of the North Hill Group is located near the North Hill area of Burlington, Iowa.

Correlation

Conodonts and other fossils indicate that the North Hill Group correlates with the Chouteau Limestone (Collinson, 1961).

Extent and Thickness

These formations (the McCraney Limestone, the Prospect Hill Siltstone, and the Starrs Cave Limestone), extensive in Iowa, are confined in Illinois to a narrow belt east of the Mississippi River in extreme western Illinois (fig. M-9), where they have a maximum thickness of about 110 feet.

Fig. M-9 -- Thickness of Chouteau Limestone and areal extent of formations of the North Hill Group (after Buschback, 1952; Workman and Gillete, 1956).

Stratigraphic Position

The group is conformable on the Hannibal Shale but is overlain unconformably by the Burlington Limestone.

References

COLLINSON, CHARLES, 1961, Kinderhookian Series in the Mississippi Valley, in Northeastern Missouri and west-central Illinois: Kansas Geological Society Guidebook, 26th Annual Field Conference, Missouri Geological Survey Report of Investigations 27, p. 100-109; Illinois State Geological Survey Reprint 1961-U.
LAUDON, L. R., 1931, Stratigraphy of the Kinderhook Series of Iowa: Iowa Geological Survey, v. 35, p. 333-451.
LAUDON, L. R., 1935, Supplemental statement on the Mississippian System in Iowa: Kansas Geological Society 9th Annual Field Conference Guidebook, p. 246-247.
WORKMAN, L. E., and TRACEY GILLETTE, 1956, Subsurface stratigraphy of the Kinderhook Series in Illinois: Illinois State Geological Survey Report of Investigations 189, 46 p.

ISGS Codes

Stratigraphic Code	Geo Unit Designation
5440	--