yf the Country from II nelson's Bay to the Polar Sea. 375 
salt or muriatiferous clay, which afford the impregnating mate- 
rials to the springs. The springs on the Leave River afford, 
by spontaneous evaporation daring the short summers, a very 
large quantity of fine salt. 
4th, The secondary limestone appears generally to belong to 
the vast deposit which lies above the new red sandstone and un- 
der chalk, and which is known to form very extensive tracts of 
country, not only in other quarters of North America, but also 
on the Continent of Europe and in England. Some of the va- 
rieties may, on more minute examination, prove to belong to the 
mountain limestone of geologists. 
5th, The secondary trap and porphyry rocks, which occur so 
abundantly on the coast of the Arctic Sea, and throughout the 
whole extent of the Copper Mountains, are, to all appearance, 
connected with the new red sandstone. The frequency of na- 
tive copper in those rocks, both on the Copper Mountains and 
pn the sea coast, is a very interesting feature in their composi- 
tion 1 , and deserves the particular consideration of those w ho make 
the grouping or associations of simple minerals objects of atten- 
tion. Many of these trap and porphyry rocks presented the 
columnar structure which has been considered as indicative of 
a volcanic origin, but their other characters, and the horizontal 
strata upon which they reposed, seemed to give them a still 
greater claim to Neptunian origin. Our opportunities of obser- 
vation, however, were much too limited to permit us to offer a 
decided opinion upon this disputed point. 
Alluvial Deposites .— The extensive formation of these depo- 
sites in the line of our journey, afforded us numerous examples 
pf their different kinds. In the preceding notes, w T e have allu- 
.ded to extensive alluvial formations, occasioned by lakes which 
haye either gradually dried up, or have burst suddenly, and 
left their concavities more or less deeply covered with sand, 
gravel, and other alluvial matters. Other kinds have evidently 
had their origin from the action of rivers. Some formations on 
the sea-coast were occasioned by the conjoined action of the sea, 
and the -wasting influence of the weather. The peninsula be- 
tween. Point Turn-again and Melville Sound, is almost entirely 
composed of a low flat of this kind, a few trap-cliffs appearing 
at considerable distances only. The general wasting influence 
