378 G. H. Stone—Terminal Moraines in Maine. 
pellicle of ice. In one instance a section displayed a pavement 
of hornblende enclosing a strip of serpentine with a plentiful 
sprinkling of magnetite, and in another example, an interesting 
illustration of the change of the hornblende to serpentine, was 
observed where a long fiber of the actinolite (?) was altered to 
serpentine at nearly equal lengths throughout its extent. The 
alteration started from minute transverse breaks and progressed 
on either side for a short distance into the substance of the 
crystal. The unchanged portions of the amphibole separating 
these serpentinized joints, gave the fragment the appearance of 
an equisetum (fig. 2). This was repeated less strikingly in the 
same section over its entire surface. Again ageregates of 
viridite or chlorite were seen scattered over the serpentine in 
one slide (fig. 4), a possible phase in the change of the horn- 
blende to serpentine or a secondary product of its alteration. 
The formation of the calcite in an interrupted manner seemed 
clearly shown in many instances, as where two irregularly 
interlocked areas of this mineral were seen with the cleavage 
lines of one section abruptly terminating at the margin of the 
other (fiz. 1). This would lead to the inference that the depo- 
sition of the two parts was not simultaneous and iend support 
to the view of the intermittent secretion of the calcite from 
aqueous solutions, in the interstices of the serpentinized horn- 
blende. Lacunz of calcite appear irregularly through the 
Serpentine, the ragged and spiculate edges of the serpentine 
yielding inwards, while in some instances a semi-dark line 
marking a change of thickness, separated an interior core of 
calcite from the border contiguous with the serpentine, an indi- 
cation of intermittent secretion. 
The examination of these sections leaves little room for 
doubt that a bed of hornblende rock has undergone a conver- 
sion more or less complete into serpentine, and that along lines 
of strain incident to its folding, where thermal conditions of an 
intense character were developed, accompanied, or perhaps suc- 
ceeded by the introduction of water, the change has been per- 
fected most rapidly and has been assisted by the elimination of 
lime carbonate as calcite, and probably in some cases the double 
carbonate of lime and magnesia as dolomite. 
Art. XXXIX.— Terminal Moraines in Maine; by GEORGE 
H. STONE. 
OnE of the most obvious features of the glacial drift of 
Maine is its unequal distribution. Many of the multiform 
ridges and heaps of till which abound in the State may par- 
