Capreol area - Geology Ontario

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Locally, pyroclastic breccias consisting cf subrounded to rounded
blocks of very fine to fine-grained felsic material (volcanic?) that
contain sparse, rounded^ quartz phenocrysts, are present within
lapilli tuff (see Photo 7). These blocks commonly range from fist
size to 5 B in diameter ) although scie were as large as 30 m long and
up to 10 m in width, large blocks of Huronian sandstone up to afcout
30 m were also observed by the writer. Both typ^s of large blocks
are slightly more common in the lower part of th9 Green Member but
wera also found by the writer within the lower part of the Black
Member.
In outcrops, some rounded to subrounded, U cm to 50 cm diameter
fragments cf granitic rocks (commonly containing microcline
phenocrysts), quartzite, .rare argillite and other unidentified rock
types are irregularly scattered in various proportions. When stained
for potassium minerals, many vclcanic anc sedimentary fragments
became noticeably yellow.
A poorly defined 'zcne 1 across the nap-area bears a significantly
increased proportion of pink fragments of sandstone and granitic
rocks. This may represent a tinse-stratigraphic layer.
A very fine-grained rock similar to that described at the end of the
Section on the Gray Member was fcund 180 IB from the base of the Green
Member; it is tertatively believed to be a flow or a sill. Except for