Island Rock
The rock is nominally called c. I believe it is more specifically called green feldspathic sandstone (feldspathic protoquartzite arkose)
The rock has now been tilted to an angle of at 65 digress according to Map 2317, McGregor Bay North Channel of Lake Huron, Sudbury and Manitoulin Districts, Ontario Davison of Mines. (A copy of the map is at the Island)
The following definitions (from an odd Russian web site http://www.russiantext.com which is no longer in English and I can no longer find the references, 7/22/05)
protoquartzite: A well-sorted, quartz-enriched sandstone that lacks the well-rounded grains of an orthoquartzite; specif. a lithic sandstone intermediate in composition between subgraywacke and orthoquartzite. AGI
feldspathic: Said of a rock or other mineral
aggregate containing feldspar.
feldspathic sandstone: A feldspar-rich sandstone;
specif., a sandstone intermediate in composition between an arkosic sandstone and a quartz sandstone,
containing 10% to 25% feldspar and less than 20% matrix material of clay,
sericite, and chlorite. See also: arkos
arkose: A feldspar-rich sandstone, typically
coarse-grained and pink or reddish, that is composed of angular to subangular grains that may be either poorly
or moderately well sorted; usually derived from the rapid disintegration
of granite or granitic rocks, and often closely resembles granite; e.g.,
the Triassic arkoses of the Eastern United States. Quartz is usually the
dominant mineral, with feldspar (chiefly microcline) constituting at least
25%. Cement (silica or calcite) is commonly rare, and matrix material
(usually less than 15%) includes clay minerals (esp. kaolinite), mica, and
iron oxide; fine-grained rock fragments are often present. Arkose is
commonly a current-deposited sandstone of continental origin, occurring as
a thick, wedge-shaped mass of limited geographic extent (as in a fault
trough or a rapidly subsiding basin); it may be strongly cross-bedded and
associated with coarse granite-bearing conglomerate, and it may denote an
environment of high relief and vigorous erosion of strongly uplifted
granitic rocks in which the feldspar was not subjected to prolonged
weathering or transport before burial. Arkose may also occur at the base
of a sedimentary series as a thin blanketlike residuum derived from and
resting on granitic rock. Etymol: French, probably from Greek archaios,
ancient, primitive. Syn: arkosic
subarkose. Also spelled arcose. AGI
Rev 7/22/05