STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 125 



mammals that the deposit is known as the " bone yard." Recent 

 land and freshwater shells as well as cones of a Picea, like those of 

 the Yukon spruces are associated with them. These silts and 

 gravels enclose beds of vegetable matter, one more than 20 feet 

 thick, in varied stages of conversion, from pliable wood to brittle 

 brown lignite. As a whole the similarity to recent peat is very 

 close. Collier's description suggests that the deposits mark sites 

 of flood-plain swamps, more or less forested and subject to over- 

 flows by floods which, like those of this day, left behind sands as 

 well as the trees from undermined sandy banks of the river, 



Haast^*^^ saw at several localities in New Zealand, deposits of 

 lignite or " lignitic brown coal," belonging to late Tertiary or in 

 some cases to early Quaternary. At one, the bed is 3 feet 2 inches 

 thick and the coal retains the woody structure ; at another, he 

 measured 14 feet of brown coal while at a third, the section shows 

 numerous beds, 2 inches to 5 feet thick, separated by fireclays, shales 

 and porphyritic tufas. Some lignites are distinctly ancient peat 

 bogs while others are composed chiefly of timber. Hutton^'''® recog- 

 nized undoubted Pliocene lignites at many places in southern New 

 Zealand, especially around the margins of old lake basins and in 

 river valleys, which existed prior to the great depression of the 

 newer Pliocene. Occasionally, one finds well-preserved stems and 

 usually the vegetable origin of the material is distinct to the unaided 

 eye ; but, at times, the mass is compact, brown, structureless and 

 cannot be distinguished from brown coal. The thickness at one 

 place is 30 feet ; but " like all hgnite beds " the deposits are local 

 and not connected. 



Hantken^*''* states that in Hungary the Pliocene frequently con- 

 tains lignite and that the deposits are freshwater, holding Uiiio and 

 Paludina. The beds are broken by irregular partings and vary 

 much, even abruptly, in thickness and quality. One bed has 8 

 benches of brown coal, in all 3.5 meters, with 7 partings of clay, 

 the whole thickness being 6.36 meters. The lower benches are 



1^" J. Haast, Rep. New Zealand Geol. Survey for 1873-4, PP- I4. I5- 

 168 p -y^. Hutton. " Geology of Otago," Dunedin, 1875, pp. 96, 98. 

 16^ M. Hantken, " Die Kohlenflotze und der Kohlenbergbau in den Liin- 

 dern der ungarischen Krone," Budapest, 1878, pp. 341, 343, 352, 353. 



