The Mineral Resources of Greenland. 9 
copper deposits now known originated from heated waters of magmatic 
origin. Of considerable theoretical interest is the presence at several 
localities of two generations of pegmatites, derived from a single magma, 
the younger as a rule being richer in commercial minerals. Slightly 
cupriferous pyritized zones, occurring at many parts along the coast, 
were likewise formed by magmatic waters. As minerals of secondary 
origin, derived from basic igneous rocks, may be mentioned asbestos, 
tale and steatite. Contact metamorphic deposits are unimportant, but 
include certain pyrrhotite masses and graphite beds on Disco Island. 
Graphite has also originated through the regional metamorphism of 
carbonaceous sediments. Of sedimentary origin are the coal beds and 
unimportant iron carbonate seams in the Disco Island region. 
The apparent absence of large bodies of iron ore is at first sur- 
prising, in view of the fact that the predominant rocks are of pre-Cambrian 
age, and that certain of the rocks are similar to those of Norway, Sweden, 
Canada and the Lake Superior region. The absence of large iron ore 
deposits is, however, due to the fact that granite gneiss is the pre- 
dominant rock and that pre-Cambrian sedimentary rocks and lava 
flows are of unimportant development. The general geology is not 
particularly favorable to the occurrence of large bodies of other metals, 
and from the mining standpoint, hereafter, as in the past, Greenland 
will presumably be of particular importance as a producer of cryolite 
and non metallic minerals, particularly graphite. 
Effect of climate on ore bodies. 
Greenland has been recently most severely glaciated and now has 
humid arctic climate. The pre-Glacial secondarily enriched portion of 
veins situated in valleys, where glacial erosion was most intense, has 
been almost completely removed. Glaciation has also scoured off the 
softened disintegrated rock, which doubtless once existed in Greenland 
and which, in the Southern Appalachian states and other regions of 
relatively deep disintegration, renders the mining of certain non-metallic 
minerals, such as mica and felspar, less costly; and the same agency 
has scattered widely the concentrated material of alluvial and detrital 
deposits, if such ever occurred. As a result of glaciation, the gravels 
have not been subjected to a high degree of concentration with the 
exception of small tonnages of beach gravels and little patches of pre- 
glacial gravel protected from glacial scouring. In consequence, exploit- 
able placers do not exist. 
Although sulphide ores are usually found practically at the surface, 
post-glacial oxidation is locally present. Films of chrysocolla, derived 
from the slightly cupriferous pyrite of amphibolite, are exceedingly 
