Silurian System

Type and reference sections and use of name: The Liston Creek Limestone Member, originally having formation rank, was named by Cumings and Shrock (1927, p. 75) for its type exposure on Liston Creek in southwestern Wabash County, Ind. (NE¼SW¼ sec. 24, T. 26 N., R. 5 E.). At this section, which is now under water in the Mississinewa Reservoir, the member consists of about 30 feet (9 m) of cherty limestone and dolomitic limestone that is light gray and tan, fine to medium grained, fossil fragmental, and slabby bedded and that rests with sharp, but probably conformable, contact on the Mississinewa Shale Member (Wabash Formation). (See photograph in Shaver and others, 1961, fig. 6.) In some western, less eroded sections, the Liston Creek is more than 100 feet (30 m) thick, and Pinsak and Shaver (1964, p. 38-39 and 80) designated one of these as a reference section, namely, the 83-foot (25-m) section of rocks cored in the Northern Indiana Public Service Co. Gale M. and Glada Skinner No. 1 well near Royal Center, Cass County (NW¼NW¼ sec. 10, T. 28 N., R. 1 W.). At the same time the rank of this unit was reduced to member (upper part of the Wabash Formation). Usage of the term Liston Creek was extended to the subsurface of southwestern Indiana, where this unit has, wherever recognizable, a vertical cutoff against rocks in the upper part of the Bainbridge Group. In the far southwest corner of the state, therefore, the Liston Creek is absent (Becker, 1974, p. 21, and Becker and Droste, 1978). It is also absent from the Silurian outcrop area of southeastern Indiana because of erosional cutout in the subsurface below the Muscatatuck Group (Middle Devonian).

Description: Except for slabby bedding, which is surficial, the type lithology is predictably present in the few-county area surrounding the type locality, but Mississinewa-like rocks are intimately intercalated in places. Like the Mississinewa, the Liston Creek has a reef facies (Huntington Lithofacies) that continues stratigraphically upward without break from the Mississinewa into the Liston Creek. These three lithologies (Mississinewa, Liston Creek, and reef facies) are so intimately mixed in many areas that the Wabash members are not separable in their type relations. In its typical area of distribution in north-central Indiana, the basal Liston Creek is made up of the 1- to 3-foot (0.3- to 0.9-m) glauconitic Red Bridge Limestone Bed.

The Liston Creek is underlain conformably by the Mississinewa member, and it underlies Middle Devonian rocks unconformably (except in the outcrop area) in some places in the area of Kokomo distribution, however, a thin Liston Creek member underlies the Kokomo member. (For example, see Droste and Shaver, 1982, p. 40.)

Liston Creek distribution as a distinctly separate member is poorly known in southern Indiana, but there, for example, Becker (1974, p. 21) referred to a 65-foot (20-m) section, and in far western Indiana sections nearly 200 feet (61 m) thick are known (Pinsak and Shaver, 1964, p. 86). Characteristic sections in northern Indiana are about 100 feet (30 m) thick (noted above), but here both thickness and areal distribution are greatly complicated because of complex facies within the Wabash. The Liston Creek, therefore, has complementary relationships with the Mississinewa (lower Wabash) and the Kokomo and Kenneth Limestone Members (upper Wabash). Northward the Liston Creek as an objectively defined unit terminates in the reef facies of the Fort Wayne Bank, north of which cherty lithologies are scarcely present. (See Droste and Shaver, 1982, p. 23.)

Correlation: The Liston Creek is a near equivalent of the Bailey Limestone in the Illinois Basin parts of Indiana, Kentucky, and Illinois. It also corresponds to upper Racine rocks in northern Illinois and eastern Wisconsin, to upper Salina rocks (above the C unit) in the Michigan and Appalachian Basins, and to Salina rocks above the Vernon Shale in New York. Considering the intimate intra-Wabash relations as described, parts of the Liston Creek variably correlate with Mississinewa, Kokomo, and Kenneth rocks in Indiana. Probably only in the Illinois Basin does the relatively uneroded Liston Creek and Liston Creek-equivalent rocks have an age as young as that of the Bass Islands Group of the Michigan Basin and as that of the New York Silurian section ranging upward from the Bertie Dolomite.

The Liston Creek interval of upper Wabash rocks is characterized, although sparsely, by the conodonts Polygnathoides siluricus, Spathognathodus primus, and S. eosteinhornensis. (See Pollock and Rexroad, 1973, p. 80; and Yoder, 1982, p. 22.) In the pentamerid brachiopod lineage, Kirkidium cf. K. laqueatum is characteristic, along with rarer occurrences of similar taxa known only m Late Silurian rocks. (See Shaver and others, 1971, p. 56-57, and Indiana University Paleontology Seminar, 1980, p. 119-120). These fossil indicators are compatible with a late Ludlovian to Pridolian age in European terms or Cayugan in North American terms.