Merom Sandstone Member


Mattoon Formation,

Pennsylvanian System

Type locality and use of name: Sandstone that crops out at Merom, Sullivan County, Ind., was first described by John Collett in 1871 (p. 199-200). He stated that "the stone work of the college edifice at Merom was quarried from massive ledges of the 'Merom Sandstone' north of town...." The Merom Sandstone was assigned member status in the Mattoon Formation by Wier and Gray (1961). The type locality as designated by Wier (1961, 1965) is at Merom Bluff in secs. 7 and 18, T. 7 N., R. 10 W.

Description: The sandstone ranges from 10 to 35 feet (3 to 11 m) in thickness at most exposures and is not known to exceed a thickness of 40 feet (12 m). The Merom Sandstone Member consists of two distinct lithologies: an upper crossbedded medium- to coarse-grained sandstone and a lower conglomerate that is gray to brown and composed of a mixture of rounded to subrounded pebbles of limestone, coal, and clay cemented with calcium carbonate. In Indiana the Merom is recognized only near its type area in Sullivan County and in the Mumford Hills area in Posey County.

Correlation: The Merom has been incorrectly correlated with numerous outcrops of other units in southern Indiana. Collett (1874, p. 321-338) erroneously called the Inglefield Sandstone Member and some higher sandstones in Knox County the Merom, and Ashley (1899, p. 1051-1079) repeated this error. Other workers (Logan, 1932; Culbertson, 1932; Malott, 1948; and Friedman, 1954) followed Ashley and mistakenly identified the lnglefield as the Merom in southern Indiana.

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