The geology of Hardin County, and the adjoining part of Pope County . ., E. 10 E>. (see figures 11 and 12). In a shallow ravineone-fourth mile farther west, not more than six or eight feet of this portionof the section is covered. The exposures are such as to indicate that thesandstone succeeds the limestone abruptly, with no intergradation of sedi-ments. There can be no doubt of the existence of an unconformable surface —10 G 146 GEOLOGY OF HAKDIN COUNTY between the two formations, indicating a withdrawal and succeeding readvanceof the sea in the Hardin County area at this time. At the fir
The geology of Hardin County, and the adjoining part of Pope County . ., E. 10 E>. (see figures 11 and 12). In a shallow ravineone-fourth mile farther west, not more than six or eight feet of this portionof the section is covered. The exposures are such as to indicate that thesandstone succeeds the limestone abruptly, with no intergradation of sedi-ments. There can be no doubt of the existence of an unconformable surface —10 G 146 GEOLOGY OF HAKDIN COUNTY between the two formations, indicating a withdrawal and succeeding readvanceof the sea in the Hardin County area at this time. At the first localitydescribed above, six to eighteen inches of fragmental material is presentbetween the limestone and the overlying sandstone. This layer is composedof flat pebbles, slabs more or less irregularly disposed, much lime-sand, quartzsand of large rounded grains, and many fragments of fossils, some of whichare worn and rounded. The layer is plainly a beach formation which has beenaccumulated by the waves and currents. The exposure is shown in figures11 and Fig. 11.—Photograph of the unconformable contact of the Renault limestoneand the overlying Bethel sandstone, in the bluff 3 miles east of Cave in Rock, onthe line between sees. 16 and 17, T. 12 S., R. 10 B. West of Hardin County, in the Cache River bluffs about five and one-halfmiles south of Vienna, Johnson County, there are other exposures exhibitingunconformity at this same horizon. In this section, which is exposed in therailroad cut on the Chicago, Burlington and Quincy Railway, the Renaultlimestone is followed by a sandstone formation 12 feet thick, in the base ofwhich there is a calcareous conglomerate bed, while two miles to the eastthere is no sandstone present, and the Paint Creek shales with thin limestonelayers, rest upon the Renault with a conglomerate bed in the base of theupper formation. UPPER MISS1SSIPPIAX SERIES, CHESTER GROUP 147 PALEONTOLOGY Although some of the beds of limestone in the Renault
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectgeology, bookyear1920
