Lonsdale Limestone Member

Lithostratigraphy: McLeansboro Group >>Modesto Formation >>Lonsdale Limestone Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Desmoinesian Series
Allostratigraphy: Absaroka Sequence

Primary source

Willman, H. B., Elwood Atherton, T. C. Buschbach, Charles Collinson, John C. Frye, M. E. Hopkins, Jerry A. Lineback, and Jack A. Simon, 1975, Handbook of Illinois Stratigraphy: Illinois State Geological Survey Bulletin 95, 261 p.

Contributing author(s)

M. E. Hopkins and J. A. Simon

Name

Original description

The Lonsdale Limestone Member of the Modesto Formation (Worthen, 1873, p. 328).

Derivation

Named for the old Lonsdale quarries, Peoria County.

Type section

Type location

The original type section in the old quarry (N 1/2 6, 8N-7E) is no longer accessible, and an outcrop near by (14, 8N-7E) is a supplementary type section (Wanless, 1957, p. 194).

Extent and thickness

The Lonsdale is a well developed limestone in western and northern Illinois, where it averages 6-8 feet thick and locally is as much as 25 feet thick.

Lithology

It is a very fine-grained, light gray limestone, conglomeratic in part. Throughout much of its area of occurrence the upper part is nodular.

Fossils

It contains a large and diversified marine fauna locally rich in fusulinids.

Age and correlation

It is correlative with at least a part of the West Franklin Limestone of southeastern Illinois, the Cooper Creek Limestone of Iowa, and the Madisonville Limestone Member of western Kentucky.

References

WANLESS, H. R., 1957, Geology and mineral resources of the Beardstown, Glasford, Havana, and Vermont Quadrangles: Illinois State Geological Survey Bulletin 82, 233 p.
WORTHEN, A. H., 1873, Geology and paleontology: Geological Survey of Illinois, v. 5, 619 p.

ISGS Codes

Stratigraphic Code	Geo Unit Designation
2370	--