Origin of tlie ArcJican Igneous Rocks. — WincJicll. 309 
in sec. 31, T. 65-6. The fragmental character is most evident, 
and many of the pebbles are rounded. There is no short 
transition, but the whole rock over a certain belt acquires the 
granitic texture by the secondary development of interlocking 
minerals. The original, clastic, feldspars were mainly in frag- 
ments, but some were nearly complete as crystals. They are 
cemented together by fresh feldspars and by quartz. As 
grains they never interlock with one another. 
The facts, taken ensemble, seem to warrant the conclusion 
that the same rock is both clastic and intrusive, and therefore 
that as an intrusive it is derived from the clastic beds in situ, 
and had no deep seated source. This is not an isolated case 
of the observed recrystallization and intrusive action of clastic 
strata. In the Adirondacks, according to numerous observ- 
ers, the limestones have been made to intrude the adjoining 
quartzytes and gneisses, and to surround isolated portions of 
them much in the same manner as igneous rocks. This fact 
led Emmons and some of the early geologists to class crystal- 
line limestone amongst the igneous rocks. 
If this source of the granitic rocks be admitted in the case 
of the Kekequabic lake granite, it is likely to have been 
equally efficient in other localities, and, indeed, it rises to 
the importance of a general cause applicable, in the absence of 
other sufficient source, to all the granites of the state. 
It remains only to call attention to one of the conse- 
quences of this hypothesis, should it be accepted. It is nec- 
essary to find in the elastics which accumulated between the 
epoch of the .basal greenstones and the intrusion of the gran- 
ites, the excess of silica and the potash which characterize 
the alkaline magma. That the schists and sedimentarv 
gneisses contain a large amount of free silica, and also much 
orthoclase and microcline, is a fact which only needs to be 
mentioned to be admitted by every petrographer. In case 
those rocks suffer refusion it is inevitable that the rock pro- 
duced would contain the same elements. 
We know of no way, other than erosion and volcanic ac- 
tion, and the chemical precipitations provoked by such action, 
by which the sedimentary products of the Archean could have 
accumulated. As erosion of the ferro-magnesian rocks that 
seem to have constituted the first crust could not, as alreadv 
