STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 141 



United States and the quantity of coal in some fields is enormous, 

 there being 198 feet in the Alberta section of the Crowsnest field. 

 But the formation thins eastwardly and it has not been recognized 

 in Manitoba. 



The distribution of coal in the several formations of the Cretace- 

 ous is wholly similar to that of peat deposits on coastal plains. 



2. Structure mid Other Characteristics of the Accompanying 

 Rocks. — Information respecting these topics is lacking for many 

 districts but details given by observers in many others are all in ac- 

 cord and are sufficient. 



The Wealden sandstones of England contain driftwood and 

 often have rippled surfaces ; the shales have sun cracks, while lime- 

 stone slabs, in many cases, are rippled and are marked by trails. 

 Stems of trees, replaced with silica or oxide of iron, abound in the 

 rocks between coal seams. Grains of coal are in Wealden sand- 

 stones of Westphalia. The Upper Cretaceous of Borneo and 

 Queensland has grains of coal in the sandstones. In Queensland, 

 sun cracks, worm burrows and trails are notable features of the 

 sandstones, which are cross-bedded at many places. Fragments of 

 tree stems, usually silicified, characterize the sandstones of Queens- 

 land, New Zealand and Greenland. 



Many observers report that the Laramie deposits in Colorado 

 and Wyoming are extremely irregular, sandstones and shales being 

 lenses. In Montana, the sandstones assigned to this formation are 

 often cross-bedded, rippled and contain fossil wood. The Fox Hills 

 sandstones are much cross-bedded in parts of Colorado and Mon- 

 tana. Fossil wood is reported from one locality in southern Colo- 

 rado, where cross-bedding is not uncommon. 



The Pierre sandstones show cross-bedded layers in the Cerillos 

 field, where some of the beds are locally conglomeratic. Cross- 

 bedded and rippled sandstones are in the southwestern part of the 

 San Juan Basin, and petrified stumps and logs abound at at least 

 one locality on the eastern border of the basin. In the Grand Mesa 

 portion of the Uinta Basin, the sandstones and shales are so irreg- 

 ular in distribution that many times sections, separated by only a 

 short interval, are unlike ; cross-bedding in sandstones was observed 

 frequently. Within Montana, the sandstones of Electric and Liv- 



