Boundaries and Sedimentary Rocks
The basin is bordered on the northeast by the Kankakee Arch, on the southeast by the Cincinnati Arch, on the south by the Pascola Arch, on the southwest by the Ozark Dome, on the northwest by the Mississippi River Arch, and on the north by the Wisconsin Arch. The New Madrid Seismic Zone and the Wabash Valley Seismic Zone intersect the southern portion of the basin.
At its center beneath southern Illinois, the basin contains a thickness of about 15,000 feet of Cambrian through Pennsylvanian sedimentary rocks, predominantly marine, and mostly dolomite, limestone, shale, and sandstone.
The basement rocks deep below the sedimentary rocks of the basin are Proterozoic granites and rhyolite of the Eastern Granite–Rhyolite Province which dates to around 1.55 Ga.
Read more about this topic: Illinois Basin
Famous quotes containing the words boundaries and/or rocks:
“Ideas are not thoughts; the thought respects the boundaries that the idea ignores thereby failing to realize itself.”
—Franz Grillparzer (1791–1872)
“As a great buck it powerfully appeared,
Pushing the crumpled water up ahead,
And landed pouring like a waterfall,
And stumbled through the rocks with horny tread,
And forced the underbrush—and that was all.”
—Robert Frost (1874–1963)