OccurRRING CHIEFLY ALONG THE AXIS OF THE SYNCLINE, BUT ALSO
AT OTHER STRATIGRAPHIC woHiaene, A STRING OF ULTRAMAFIC BODIES INTRUDE THE
SYLVESTER GROUP INTERMITTENTLY FOR 70 Mites. THESE ARE THE McDAME
InTRUSIONS. MOST HAVE BEEN CONVERTED TO SERPENTINE AND CONTAIN CHRYSOTILE

ASBESTOS BUT SO FAR ONLY ONE, THE CASSIAR DEPOSIT, HAS PROVEN ECONOMIC.

8. GEQLOGY OF THE CASSIAR OREBODY

a) Country Rocks

THe CASSVAR MINE .1S HIGH ON THE WESTERN FLANK- OF McDAME
MOUNTAIN, A HIGH SERRATED RIOGE, EIGHT MILES LONG, AT AN AVERAGE
ELEVATION OF 6,600 FEET, SURMOUNTED BY PEAKS UP TO 7,000 FEET IN
ELEVATION. THE UPPER SLOPES ARE PRECIPITOUS AND CONTAIN MANY

GLACIAL CIRQUES.

THE EASTERN EDCE OF THE CASSIAR GRANITIC BATHOLITH FOLLOWS
THE CREST OF ANOTHER MOUNTAIN RANGE, ONE TO TWO MILES WEST OF THE
MINE. METAMORPHOSED Proterozoic AND Lower CAMBRIAN SEDIMENTS FORM

THE EASTERN SLOPES OF THIS RANGE.

LiMyY ARGILLITES AND DOLOMITES OF ORDOVIGIAN ANO SILURIAN
AGES UNDERLIE THE Lower sLopes OF McDAmMe MounTAIN, WHILE THE SYLVESTER
GROUP OF INTERBEDDED ARGILLITES AND VOLCANICS FORM. THE UPPER PART.

BoTH FORMATIONS DIP UNIFORMLY EAST INTO THE REGIONAL SYNCLINE.

THE UPPERMOST UNIT OF THE SANDPILE GROUP IS A VERY PROMINENT
WHITE-WEATHERING BAND OF MASSIVE BLACK DOLOMITE, EXPOSED FOR SEVERAL
MILES ALONG THE MOUNTAINSIDE, EXCEPT IN THE VICINITY OF THE MINE,

WHERE THE DOLOMITES ARE OVERLAIN BY LIMY BLACK ARGILLITES. THE