93 



Continuation of Column No. 2. 

 TABLE II. 



17 



i 



f 



'03 



c 



B 



< 

 - 



3h 



is 



h 

 B 



o 



i z 



JO 



18 



19 



20 



Upper Silurian. 



Upper Ludlow, 



(micaceous gray sandstone.) 

 Aymestry Limestone, 



(argillaceous limestone.) 

 Lower Ludlow Shale with 



concretions of Limestone. 



1. Wenlock Limestone, 



(concretionary limestone.) 



2. Wenlock Shale. 



(argillaceous shale.) 



Lower Silurian. 



1. Caradoc Sandstone, Flags and 



Shelly Limestone. 



2. Sandstone thickly bedded. 



3. White Freestone. 



Llandelo Flags. 



1. Dark colored Calcareous Flags 



These rocks are what the older Geologists 

 termed Transition and Graywacke, they con- 

 tain numerous marine fossil shells, plants, 

 Zoophytes, and Crustacea, (Trilobites,) but 

 no remains of the higher order of animals 

 have as yet been found. The Lingula Ovata I 

 of Conrad appears to be the oldest fossil ', 

 known. 



ALL FOSSILS END HERE. 



Volcanic Rocks. 



These are termed unconformable 

 rocks and consist of : 



1. Volcanic Ashes and Scoria. 



2. Tuff. 



3. Pumice Stone. 



4. Lava. 



5. Trap and Greenstone. 



6. Basalt and Dykes. 



7. Sienite. 



8. Trachyte. 



9. Porphyry. 

 10. Amygdaloid. 



These rocks have many varieties of form and 

 are generally vertical, (the Palisades of the 

 Hudson River is one example,) they contain 

 many minerals imbedded. Being thrown up 

 by volcanic action they are found in all situ- 

 ations, sometimes above and sometimes be- 

 low any of the others. 



