9. MADISON TOWN- 1 IIP. F\ 263 



of dark shale diminishes. The gray calcareous shale at the 

 base of the group gives place to an alternation of dark shales 

 and limestone, the latter in very solid, hard beds, as shown 

 in the preceding sections. These beds have yielded numer- 

 ous fossils for an account of which the reader is referred to 

 the volume on the palaeontology. 



The Marcellus black shale, (VIII.) 



Good exposures of this rock may be found in Madison 

 township. It is thrown out by the low folds of which men- 

 tion has already been made, and made be found exposed by 

 the wayside in many places between Bixler's mills and 

 Sandy hill. It presents, however, no unusual features and 

 calls for no further remark at this outcrop. 



A strong sulphur spring issued at Sandy hill, at H. Kep- 

 ner's, probably from black slate. At * * in Fig. 3, plate 

 XXIV, the Marcellus limestones make a good show along 

 the roadside, but in a passing examination I saw no fossils. 



The Marcellus Iron ore. 



This ore crops out near sandy hill and makes a very fine 

 display along the roadside. Many tons might readily be 

 gathered up and an abundant supply obtained by mining. 

 But without railway carriage it is of little or no present 

 value. 



T?te Hamilton lower shale and sandstone. ( VIII.) 



These beds make but an insignificant show in Madison 

 township entering it from Saville, and there is no occasion 

 to do more than refer the reader to the report on that town- 

 ship for all necessary details. 



