146 STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 



Rhine region. The important localities are Deutz, at a short dis- 

 tance west from Cologne, Bruhl and Unkel, about 25 and 45 miles 

 south from Cologne. Other areas are as far as Linz, a few miles 

 beyond Unkel. Three types of coal are found in this region ; Blat- 

 terkohle or Dysodil, Alum brown coal and the Earthy brown coal 

 which is manufactured into briquets. The first and second, limited 

 chiefly to the upper portions of the basin in the Siebengebirge, ex- 

 tend northward on the left bank of the Rhine to Friesdorf near 

 Bonn, while on the right bank they are found as far as Spick in the 

 Deutz-Runderoth district. Heusler asserts that the difference in 

 these coals has no relation to age and is due merely to local 

 conditions. 



Blatterkohle occurs in isolated patches near Linz, Orsburg, 

 Oedingen as well as on the Hardt, especially near Rott. The de- 

 posits are irregular and alternate with clay, sand and ordinary brown 

 coal. Near Linz, three layers were seen, i.i, 0.78 and 4 meters thick, 

 each containing more or less of lignite-like coal and many remains 

 of aquatic animals, 10 species having been recognized. Near Orsburg, 

 three layers were seen, separated by clay and poor coal ; batrachians 

 of several genera are abundant in the coal. In an isolated basin, this 

 section was obtained : Hard earthy brown coal with lignite, 0.94 ; 

 bituminous clay, 0.63 to i.io; laminated siliceous beds, with leaf im- 

 pressions, 0.16 to 0.26; Blatterkohle and Polischiefer, 0.26 to 0.78; 

 lignite, pyritous, with leaf impressions and remains of fish, 0.63 to 

 i.io; semi-opal, 0.16; Blatterkohle, laminated, pyritous, some lignite, 

 nests of Polischiefer, fragments of plants, insects, fish remains, 0.31 ; 

 gray, pyritous clay, 0.31. 



The measurements are in meters. The association with diatoma- 

 ceous earth is by means unusual. Near Oedenberg, the Blatterkohle 

 is very thick, but is so mixed with infusorial earth as to be of little 

 value. In the Rott area, at the Krautgarten mine, the finely laminated 

 Blatterkohle, at the bottom, is separated by almost 2 meters of gray- 

 ish-white clay from a meter-thick bed of ordinary brown coal above. 

 In this mine, the coals contain remains of mammals, amphibia, fish, 

 insects of six orders, with crustaceans, mollusks and polyps as well 

 as abundant plant fragments of many types. Heusler's description 



