G10 W. A. NELSON VOLCANIC ASH BED IN THE ORDOVTCIAN 



and from these facts it is considered that the volcano producing this ash 

 deposit must have been located either to the east of High Bridge, Ken- 

 tucky, or a short distance to the northeast. The fact that no ash deposits 

 or bentonite have been recognized in the Lowville formation, where it 

 has been studied in Maryland and Penns}dvania, would indicate that this 

 ancient volcano could not have been located northeast of the Kentucky- 

 West Virginia State line, for if such were the case thick ash deposits, 

 which could not have escaped observation, would have been found in the 

 Lowville rocks of West Virginia, Maryland, and Pennsylvania, even 

 though the prevailing winds at the time of the ash deposition were to the 

 southwest, as the present facts indicate. A study of the paleogeographic 

 maps of the Lowville and succeeding seas* shows that a volcano located in 

 eastern Kentucky in the late Lowville time would have been an island 

 volcano. 



Location of ancient Volcano 



It is therefore suggested that during Lowville time a great volcano 

 existed on an island (somewhere in the area between and including Fay- 

 ette County, Kentucky, on the west and to Elliott County, Kentucky, on 

 the east) lying 50 to 75 miles west of the long peninsula separating this 

 sea from the ancient Atlantic Ocean. We might visualize many low- 

 lying islands along the edge of the peninsula and extending out into the 

 shallow Lowville Sea, while far out to the west towered this volcanic peak. 

 In the warping of the earth's crust, so prevalent throughout the central 

 and eastern part of America at the close of Lowville time, this ancient 

 volcano exploded in one of the greatest eruptions which, so far as records 

 are decipherable, we know the earth has undergone. 



Amount of Ash ejected 



A volcano in this general locality, from the facts obtained to date, 

 erupted sufficient ash to form an irregular cone with an elliptical base, 

 having a long axis of possibly 850 miles and a maximum height of 5 feet. 

 Such a cone would contain about 100 cubic miles of material. But a vol- 

 canic ash deposit would not be in the form of a flat cone, but would form 

 a cone with a decidedly concave slope; so that it is arbitrarily estimated 

 that such an ash cone as it is thought was formed by this volcano would 

 contain only two-thirds the volume of the true cone, or 66 cubic miles of 

 ash. No account is taken of the considerable amount of volcanic dust 

 that must have fallen as a thin film much beyond the above limits; also, 



