280 C. H. Hitchcock — Crystalline MocJcs of Alabama. 



mica schist. The first is developed at Chandler's Springs as 

 a heavy greenish chloritic schist : the second may be seen near 

 Millersville or Hillabe and is a garnetiferous argillaceous schist: 

 the first is like the familiar green rock east of the Green Moun- 

 tains in Canada, Vermont and Massachusetts, holding beds of 

 steatite and serpentine — the second is a genuine synclinal. 

 Passing farther along we find next a broad belt of well defined 

 gneiss between Pinckneyville and Alexander City. Part of it 

 is reticulated b}>" the segregated veins which are characteristic 

 of the Lake Winnipiseogee gneiss of New Hampshire. Another 

 portion is a genuine granite of oval shape about six miles in 

 length. It is much like the Amoskeag quarry granite of Man- 

 chester, N. H., and its presence is marked by immense bowlders 

 of decomposition, a novel sight to northern geologists. A few 

 miles beyond Alexander City, at the crossing of the Tallapoosa 

 River the rock is full of pyroxene, and farther along it is 

 associated with gneiss standing vertically. 



Midway between Alexander and Dadeville is a breadth of 

 one or two miles of the augen gneiss. Between this and 

 Auburn, gneiss of diversified aspect and considerable horn- 

 blende schist prevail. In the vicinity is a good locality of the 

 mineral corundum. At Ragen's mill on Songahatchie creek 

 near Loachapoka a massive gneiss is quarried for underpinning 

 and piers, and is cut by a dike of gabbro similar to that in the 

 White Mountains. 



Southeast from Auburn are repetitions of the augen gneiss. 

 Beyond them are the Chewackla quarries of limestone which 

 are associated with itacolumite. These are very like the quartz- 

 ites and limestone of Thomaston, Rockland and Camden in 

 Maine, and probably those of Smithfield, R. I. A large busi- 

 ness is done in the manufacture of quicklime at Chewackla 

 and other localities near by. These northern rocks were 

 referred to the Taconic system by Emmons. All of them, 

 including similar deposits in the Carolinas near the eastern 

 border of the crystallines, evidently originated in the same 

 geological period, whether that be Cambrian or Silurian. 



The remaining thirty miles of the section, from Opelika to 

 Columbus were traversed along a railroad. Gneisses predomin- 

 ate with variable dips. Midway and toward the southeastern 

 end the heavy massive gneiss near Auburn is repeated. At 

 Columbus, the exposures are closely similar to the saccharoidal 

 gneisses of Manchester, N. H., and to the thoroughly crystalline 

 schists of typical Laurentian areas. Between Alexander City 

 and Columbus, any geologist familiar with the Canadian or 

 Adirondack gneisses will constantly recognize the peculiar 

 features of that ancient fundamental gneiss. Our examinations 

 terminated at Columbus, as we here reach the Atlantic Tertiary 



