The area is dominated by NNW and WNW trending microgranite
dykes and NNW-trending quartz and siderite veins.
An undeformed microgranite
dyke, located approximately 2 km east of Tower Hill, yielded a U-Pb zircon age of 409 [+ or -] 2 Ma (Davis et al.
The rocks are sparingly porphyritic and contain dykes and veins of microgranite
, aplite and quartz; pegmatites are rare and simple.
Follow up in the Frazer Stream area "identified several drainages with similar microgranite
float and some outcrops with a true width of up to 20 metres.
Of the identified assemblage, quartz dominates numerically (77%), followed by rhyolitic ignimbrite (18%), granite (3%), microgranite
and felsic dykes (1%) and volcanic (1%).
Medium to coarse-grained, possibly granite or microgranite
Ruan(12) investigated this with a traverse of soil and soil air samples crossing scheelite and arsenopyrite mineralization in minor intrusive sheets of microgranite
and quartz porphyry at Ballinglen, Ireland.
Pegmatites appear to be associated with kilometre scale microgranite
bosses within the license area.
2a), and subsidiary phases of medium-grained equigranular granite, equigranular to quartz-feldspar-phyric microgranite
, melanocratic biotite granite, and minor aplite and pegmatite (MacLellan et al.
The final phases of magmatism are represented by mafic and rhyolite dykes and their contemporaneous rare microgranite
A sample from the porphyritic microgranite
yields 280 + 16 Ma year U-Pb age on zircon.
They range from aplite to porphyritic microgranite
, and rhyolite to quartz trachyte in composition (Jan et al.