818 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



Of the species which have been previously known in the New Albany shale at least three 

 are characteristic Genesee species; one is common to the Portage and the Genesee. The 

 presence in the New Albany shale of a Genesee fauna and a Portage fauna seems to justify the 

 conclusion that this formation is the western representative of both the Genesee and the Portage. 



The Styliola fissurella fauna does not bear any stronger evidence of the Genesee age of the 

 New Albany shale than does the Spathiocaris emersoni fauna of its Portage age; these two 

 faunas, however, are not intermingled in the New Albany shale. "While there is no evidence 

 that either one occupies a higher stratigraphic horizon than the other, they are found in unlike 

 sediments. The Styliola fissurella fauna is confined to the fissile black shale, while the Spathio- 

 caris emersoni occurs in a soft drab shale which is interbedded with the black shale in northern 

 Indiana. The New Albany shale of northern Indiana contains in its fissile black strata and 

 its drab sandy beds the lithologic elements of both the Genesee and the Portage, but neither 

 these beds nor the elements of the Genesee and Portage faunas which they contain are sharply 

 differentiated, as they are in the eastern Devonian province. 



The problem of the correlation of the Devonian Limestones with the New York scale is 

 much more difficult for some parts of the Indiana province than for others. In the vicinity of 

 the Falls of the Ohio we find two quite distinct and weU-marked faunas. These are the Spirifer 

 granulosus and the Spirifer acuminatus faunas and represent respectively the Hamilton and 

 Corniferous faunas of New York. Near the Falls of the Ohio the SeUersburg beds and the 

 Jeffersonville limestone which carry these faunas are sharply differentiated hthologicaUy, the 

 Jeflfersonville limestone being a nearly pure limestone and representing clear-water conditions 

 during its deposition, while the SeUersburg beds are composed of an impure argillaceous limestone. 

 In the northern part of the southern Indiana area these two formations cease to be sharply 

 differentiated lithologically and merge into each other in a limestone which is neither so pure 

 as the JeffersonAoUe limestone nor so argillaceous as the SeUersburg beds near the Falls. Asso- 

 ciated with the loss of individuaUty of these two formations occurs a mingUng of their two 

 faunas which renders them indistinguishable as separate faunas. 



In the Wabash area the faunas of the Devonian limestone are even more distinct than at 

 the FaUs of the Ohio. In the lower one Spirifer acuminatus is an abundant fossU and the fauna 

 does not differ greatly from that in the Jeffersonville limestone at the FaUs of the Ohio. The 

 upper fauna is a distinctly Hamilton fauna, but entirely different from the HamUton fauna of 

 southern Indiana. Two of the most abundant fossUs in it are Spirifer pennatus and Ohonetes 

 manitohiensis. Neither of these species is known in the southern Indiana area. 



Hopkins and Foerste *^^ follow Kindle's classification, with additional local 

 distinctions, and give the following description of the strata: 



In southern Indiana the New Albany black shale is exposed over considerable areas. It 

 is a black to blue-gray fissile shale containing much iron sulphide and a great deal of bituminous 

 matter. The bituminous matter is so plentiful in places that it will burn freely and the volatUe 

 gases have been distUled from it. The shale is 104 feet thick at New Albany, and elsewhere it 

 has been reported as much as 140 feet in thickness. The outcrop covers an area from 8 to 15 

 miles wide, as shown on the map. 



The SeUersburg limestone of Kindle includes both the crinoidal and the hydrauUc lime- 

 stones, but Siebenthal limits the term SeUersburg to the upper or crinoidal division and the 

 lower hydraulic limestone he caUs the SUver Creek hydrauHc limestone. The SeUersburg lime- 

 stone is a white to gray crystaUine limestone that lies between the overlying black shale and 

 the underlying hydrauUc limestone. Frequently the basal portions are sandy and sometimes 

 there is a layer of pebbly sandstone separating it from the underlying hydrauMc limestone. 

 The shining black pebbles are said to be rich in phosphates.. 



The SUver Creek hydraulic limestone Ues between the overlying SeUersburg Umestone and 

 the underlying JeffersonvUle limestone. It is a fine-grained, massively bedded argUlaceous 

 magnesian limestone, light to dark drab in color, becoming buff on exposure. It is 15 to 16 feet 

 thick at Silver Creek, 8 to 10 feet at Charlestown, and 5 to 6 feet in the vicinity of Lexington. 



