WM. E. Wadsworth—Rocks of Newfoundland. 101 
ARGILLITE. 
a structure that might readily be taken for a fluidal one. This 
seems to be owing to the crystallization of the chloritic scales 
in vein-like deposits. The feldspathic fragments form the chief 
portion of the section and are much altered now, showin 
aggregate polarization, and having a fibrous kaolinized and tale- 
like structure. The quartz is in irregular fissured grains con- 
taining stone and fluid cavities bearing moving bubbles. The 
‘Melaphyr is much altered, retaining only its structure. While 
this rock is composed mostly of ordinary detritus it may in 
part be from volcanic ashes. . 
_ An argillite (868) coming from the southwest part of the 
island is greatly indurated, breaks with a conchoidal fracture, 
_ and is composed of a grayish green groundmass holding quartz 
_ grains. Under the microscope this is seen to be a distinctly 
_ ¢lastic rock like the preceding, and while in the main fine- - 
_ grained it contained some larger fragments like No. 863. 
4 t is now composed of greenish micaceous scales, quartz, 
feldspar, ferrite, microlites, ete. The quartz and feldspar (ortho- 
Clase) are both a fragmenta] and a secondary production, proba- 
bly through water action. A few broken crystals resembling 
zircons were seen. 
At Kaster Cove, Exploits Bay (on the main land, near 
Muddy Hole), the argillite is much indurated, although less 
so than the preceding. The strata here show a varying dip 
from 30° to 90° (usually 60° to 80°) to the southward. The 
Strata are much contorted and bent, and in one place a gen- 
eral northward dip was seen. A section of the argillite No. 
_ 869 closely resembles No. 868, being of similar character, but 
_ finer grained and-of lighter color. It is traversed by veins of 
quartz and calcite. Neat Welles’ Cove, Exploits Bay, the 
argillite is black, laminated like a shale, and cut by dikes of 
-diabase and porpbyrite. 
On the west side of Lawrence Harbor the shaly argillite 
Stands nearly vertical and carries graptolites. 
