^8 THE PERMO-CARBONIFEROUS RED BEDS OF 



Williston and Weller, though the existence of just such deposits, the Merom 

 sandstone, in closely adjacent regions in Indiana lends considerable support 

 to the suggestion. The later recognition that the age of the vertebrate fos- 

 sils is much greater than was originally supposed, and that they must be 

 considered as Permo-Curboniferous rather than Permian, removes the need 

 for such an hypothesis, in large measure. Concerning these beds, I quote 

 from a letter from Dr. Williston, of April i8, 1912: 



"We found fossils on practically the same horizon, about 300 feet distant, lying 

 above a limestone layer, whose horizon was definitely fixed as Pennsylvanian. The 

 fossils occur in a clay bed almost precisely like that of the Baldwin quarry [a black, 

 soapy clay — Case], near the water's edge and about 100 feet below the top of the 

 bank of the river. In my inspection I felt pretty confident that the fossils lie in 

 their original undisturbed position. Weller is inclined to believe that the clay beds 

 have slipped down from a higher altitude. If they are in their original position they 

 certainly are 200 or 300 feet, at least, below horizons which are clearly Pennsylvanian. 

 There is not the slightest evidence of an unconformity or any old 'Permian' river 

 channel. If Weller is correct, the fossils may have come from near the top of the 

 Pennsylvanian, but still distinctly Pennsylvanian. If my opinion is correct, they 

 are a considerable distance below the top of the Pennsylvanian." 



INDIANA. 

 It would be idle in the present state of our knowledge to speculate upon 

 the condition of the eastern part of the Mississippi Valley in late Pennsyl- 

 vanian and Permian times, but we can at least be certain that it was exposed 

 to erosion, and deeply trenched in places by large streams. Definite remains 

 of such are found in Indiana. Some of these old stream-channels preserved 

 as the Merom sandstone have been described by Blatchley and Ashley" in 

 the Annual Reports of the Indiana Geological Survey. 



"The Merom Sandstone: Division /.Y.— Just as the main body of the Coal Meas- 

 ure is underiain with unconformability by a massive sandstone, so it is also overiain 

 with unconformability by a massive sandstone. In the earlier reports this sandstone 

 was designated the 'Merom Sandstone,' from its excellent exposure at that point. 

 It there, as in the covmties to the south, lies on an eroded surface of the Coal Meas- 

 ures, its' lowest member consisting of a calcareous conglomerate containing shale, 

 coal! pebbles of sandstone, etc. To the north, in Parke and Fountain Counties, and 

 Vermilion County, Illinois, occur a number of extensive channels cut down into the 

 Coal Measures to a depth ranging up to 200 feet, and filled with a sandstone very 

 similar in many respects to the sandstone at Merom, Sullivan County. Though 

 no such readily distinguishable channels were found in the southern part of the coal 

 field, the position of the sandstone there, relative to the coal below it, indicates 

 extensive erosion. If we are correct in correlating the massive sandstone of the 

 channel fillings in the north part of the coal area with the overlying massive sand- 

 stone of the southern part of the area, it would appear that this sandstone was laid 

 down at no inconsiderable time after the laying down of the Coal Measures proper. 

 The great depth and width of the stream-channels cut out of the Coal Measures 

 prior to its deposition suggest a long time interval. So far as known, no fossils have 



» Blatchley and Ashley, Geological Survey Indiana, vol. 23, pp. 80, 81. 



