Lincoln Anticline

Location

Northeastern Missouri and southern Calhoun and Jersey Counties, lliinois (H-2,3)

References

(selected) Keyes 1896, Krey 1924, McQueen et al. 1941, Rubey 1952, Cole 1961, Koenig 1961, Searight and Searight 1961, Tikrity 1968, McCracken 1971, Treworgy 1979a, Nelson and Lumm 1985

Description

This structure has been called the Lincoln Fold by most researchers, but the name Lincoln Anticline is more descriptive and thus seems preferable. The Lincoln Anticline is the most prominent structural feature in northeastern Missouri and follows the pronounced northwest to southeast structural grain of that region. It is at least 165 miles (265 km) long and as much as 15 miles (24 km) wide. It has structural relief of as much as 1,000 feet (300 m). The northeast limb is gentle, whereas the southwest limb is steep and faulted in places. The Cap Au Grès Faulted Flexure arises on the southwest flank of the Lincoln Anticline in Lincoln County, Missouri. Both fold and flexure then swing eastward into llinois and terminate in southernmost Jersey County. The south flank of the Lincoln Anticline in Illinois coincides with the Cap Au Grès Faulted Flexure, where bedding dips steeply and is overturned locally. In contrast, the north limb dips so gently as to be barely noticeable. The relationship of the Lincoln Anticline to the Cap Au Grès structure suggests that the anticline throughout its length is the surface expression of a fault in the Precambrian basement.

Most of the uplift of the Lincoln Anticline and Cap Au Grès Faulted Flexure took place in late Mississippian to early Pennsylvanian time. Additional uplift occurred after Pennsylvanian sedimentation in the area. Stratigraphic relationships indicate earlier, less pronounced upwarping of the structure from Middle Devonian through Kinderhookian time (Rubey 1952, Tikrity 1968). A final episode of uplift along the eastern part of the fold may have occurred late in the Tertiary Period (Rubey 1952).

See also Cap Au Grès Faulted Flexure.