Poster Number 77
See more from this Division: General Discipline Sessions
See more from this Session: Mineralogy/Crystallography; Petrology, Experimental; Igneous; Metamorphic (Posters)
Abstract:
The Crabtree Pegmatite and country rock were variably affected by a brittle-ductile deformation event. Weakly formed pegmatite contains plagioclase that has developed strongly curved and kinked deformation twins, cordierite with sweeping extinction, and some quartz exhibiting well formed deformation lamellae and prismatic subgrains. Weakly deformed granofels displays Type I calcite twins and sparse deformation twinning in plagioclase. Strongly sheared pegmatite contains fragmented feldspar, cordierite, quartz and tourmaline. Strongly sheared granofels displays fragmented and fractured feldspar and cordierite with fractures healed with small equant quartz grains. In both rock types a matrix consisting of variable amounts of epidote, sericite, and quartz occurs between the fragments. This matrix is well foliated and crenulated. Calcite, chlorite, and tremolite are absent in the strongly sheared granofels. Surprisingly, the schist appears not effected by this deformation even though proximal to the nearby pegmatite and granofels.
See more from this Division: General Discipline Sessions
See more from this Session: Mineralogy/Crystallography; Petrology, Experimental; Igneous; Metamorphic (Posters)