Markham Silt Member

Lithostratigraphy: Roxana Silt >>Markham Silt Member
Chronostratigraphy: Cenozoic Erathem >>Quaternary System >>Pleistocene Series

Primary source

Willman, H. B., and John C. Frye, 1970, Pleistocene Stratigraphy of Illinois: Illinois State Geological Survey Bulletin 94, 204 p.

Contributing author(s)

H. B. Willman and John C. Frye

Name

Original description

Markham Silt Member (Willman and Frye 1970).

Derivation

The Markham Silt Member is named for Markham, a village on the Norfolk and Western Railroad 4 miles west of Jacksonville, Morgan County.

Other names

The Markham Member previously was called Roxana Zone la (Frye and Willman, 1963b). It is the same as "upper story Sangamon" in recent Iowa literature (Ruhe et al., 1968).

Type section

Type location

Its type section is the Chapin Section (table 6) in roadcuts along Illinois Highway 104, 1.5 miles northwest of Markham, on the west side of Mauvaise Terre Creek, SW NE NW Sec. 8, T. 15 N., R. 11 W.

Table 6 -- Stratigraphic Sections (partial)
The following stratigraphic sections describe exposures in Illinois and illustrate many aspects of Pleistocene stratigraphy, including type localities and analytical sample data.

• 
  Chapin Section and Cottonwood School Section

Stratigraphic relationships

Its spatial relations are shown in figure 8.

• 
  Fig. 8 -- Diagrammatic cross section showing the relations of formations and members of Wisconsinan age in northern and western Illinois.

Lithology

In many places the Markham is a colluvium of silt and some sand with small pebbles, and locally it is entirely within the A-zone and B-zone of the Chapin Soil. Along the Illinois River Valley it commonly contains some loess admixed with the colluvium, and so has a mineral composition different from that of the underlying Sangamon Soil (Frye, Glass, and Willman, 1962; Glass, in Frye and Willman, 1965b), but along the Mississippi River Valley its mineral composition is commonly indistinguishable from that of the underlying Sangamon Soil B-zone. Other stratigraphic sections with this report describing the Markham Member are the Campbells Hump, Cottonwood School, Gale, Jubilee College, and Tindall School Sections (table 6). Its mineral composition is given in table 5.

Table 6 -- Stratigraphic Sections (partial)

• 
  Cache Section and Campbells Hump Section
• 
  Chapin Section and Cottonwood School Section
• 
  Cottonwood School Section (cont.) and Enion Section
• 
  Flat Rock Section (cont.), Gale Section, and Jubilee College Section
• 
  Jubilee College Section (cont.), Lewistown Section, and Malden South Section
• 
  Pulleys Mill Section, Rochester Section, and Tindall School Section
• 
  Tindall School Section (cont.) and Toulon Section

Selected analyses from stratigraphic sections (X-ray analyses by Illinois State Geological Survey).

• 
  Table 5 -- Continued.

Age and correlation

The Markham Member is in the earliest part of the Altonian Substage of the Wisconsinan Stage.

References

FRYE, J. C, H. D. GLASS, and H. B. WILLMAN, 1962, Stratigraphy and mineralogy of the Wisconsinan loesses of Illinois: Illinois State Geological Survey Circular 334, 55 p.
FRYE, J. C, and H. B. WILLMAN, 1963b, Loess stratigraphy, Wisconsinan classification and accretion-gleys in central western Illinois: Midwestern Section Friends of the Pleistocene, 14th Annual Meeting, Illinois State Geological Survey Guidebook Series 5, 37 p.
FRYE, J. C, and H. B. WILLMAN, 1965b, Illinois, in Guidebook for field conference G— Great Lakes- Ohio River Valley (R. F. Black and E. C. Reed [organizers]; C. B. Schultz and H. T. U. Smith [eds.]): International Association of Quaternary Research 7th Congress, Nebraska Academy of Science, p. 5-26; Illinois State Geological Survey Reprint 1966-B (supplemental data, H. D. Glass, p. G-S1 - G-S4), 26 p.
RUHE, R. V. (et al.), W. P. DIETZ, T. E. FENTON, and G. F. HALL, 1968, Iowan drift problem, northeastern Iowa: Iowa Geological Survey Report of Investigations 7, 40 p.

ISGS Codes

ISGS Code and Symbol

Stratigraphic Code	Geo Unit Designation
0710	--