SUPPLEMENTAL REPORT 



GEOLOGY OF THE HANGING ROCK DISTRICT. 



PRCV.J.S.'S-BMVRV.RRYj'ChieJ Geologist:- - » <- •/ 



Dkar Sir: I hercTvilU transmit a brief snpplemental l-epSrt on the "Geology of tt'e ' 

 Hanging Rock District. Tlie report is based on an examination of the field which I 

 made daring the summer of 1877, the examination being nndertaken under your author- 

 ity as chief of the survey, but at my own instance and without compensation. 



The object which I proposed was to trace if possible some of the well-known strata of 

 the Hocking Valley southward to the Ohio River, or, to staite my object more definitely, 

 it was to f.illow the great coal seam of the Hocking Valley, and the most important bed 

 of iron ore worked there, viz., the Baird Ore, as far southward as they extend within 

 the limits of the State. 



I think that I have accomplished this Object in such a manner as to remove all ques-* 

 tion in regard to the points involved. ^ 



In Executing this specific task, Ihav^ had occasion to review to some extent thestrvio- 

 ture ol the lowest Coal Mleasurcs'of the district) but fhfs' portion of my work. I cbrintf 

 iAcidentai. In regard to it, I have to confess that I lave raised more questions thanlhave 

 been ^ble to fettle. There is no peculiar complication or difiiculty in the field, but more 

 time most be spent on tbe strata that underlie the Zoar Limestone before a full and 

 connected account of them can be given. 



The work that I have done on this portion of the series has obliged me, in some In- 

 stacces, to form conclusions at vaiiauce with those announced in the previous voluibes' 

 of our report. The main points of difference are as follows : 



1. The Conglomerate of Pike and Jackson counties which holds within It workable 

 coal— is the Conglomerate of the Hocking Valley which has been proved ib be of Sub- 

 carboniferous age. Thefe are several divisions of this Conglomerate, but tbey are all ' 

 included within two hundred feet of > ertical "range and they all belong to dnfe main , 

 seiriesL 



'2; The Jatkson Shaft Coal belongs within the limits of this conglomerate and is 

 therefore of Snb-caiboniferous age. The same thing is probably true of several other 

 workable coal seams of the district. 



3. The Maxville Limestone does not constitute the base of the Coal Measures Of ' 

 Southern Ohio, but its placte is from fifty to one hundred feet above the lowest coal 

 seams. The Sub-carboniferons age of the limestone is not hereby questioned, but tbi" 

 same age is asserted for the lowest Coal Measures of this district. 



Upon these and kindred points, I have accumulated a large number of facts, which 

 the proper, limitsflfjhe present volume, already overrun, forbid me to make use of here. 



