The felsic dykes are subequigranular to, locally, subporphyritic, hypidiomorphic
, and fine- to fine medium-grained.
Most rocks under the microscope are medium-grained hypidiomorphic to allotriomorphic subequigranular and composed of plagioclase hornblendic amphibole opaque iron oxide quartz and in some biotite titanite and rare perthite.
The porphyritic granite is coarsely medium- grained and hypidiomorphic to locally allotiomorphic.
The texture is medium to coarse-grained hypidiomorphic or allotriomorphic (2-10 mm crystal size).
Sample Fm Rock type Texture ANC1 RaFm Dacitic vitric-tuff (+C+Lc) ANC10 RaFm Granite/ Qz-syenite Allotriomorphic ANC3 RaFm Greywacke ANC4 RaFm Gabbro Subophitic ANC5 RaFm Gabbro Ophitic ANC6 RaFm Dacitic vitric-tuff (+C+Lc) ANC7 RaFm Rhyolitic ash-tuff ANC8 RaFm Microgabbro Ophitic ANC9 RaFm Bt-Granite Hypidiomorphic AN47 RaFm Bt-Granite Hypidiomorphic AN48 RaFm Basalt Doleritic AN49 RaFm Dacitic crystal-rich tuff (+Vc) AN50 RaFm Dacitic/Rhyolitic crystal-rich tuff (+Vc) AN51 RaFm Andesite Porphyritic [AN51.
Wehrlite is medium-coarse-grained and shows granular porphyritic and hypidiomorphic texture (Fig.
Granular porphyritic and hypidiomorphic texture in wehrlite with large and small subhedralgrains of clinopyroxene in the groundmass of clinopyroxene, orthopyroxene and olivine; (f).
In thin section, large perthitic K-feldspar megacrysts are in a hypidiomorphic
granular matrix of normal to oscillatory zoned oligoclase, perthitic orthoclase-microcline, quartz, dark brown to orange-brown biotite, pinitized cordierite, and minor muscovite.
The gabbro-norites are sub- equigranular, medium- to coarse-grained, hypidiomorphic
to idiomorphic and massive, i.
Texture is typically hypidiomorphic
equigranular and, locally, inequigranular to porphyritic, especially near the margins as described above.
The rocks are typically fine to medium grained with hypidiomorphic
granular to locally ophitic texture involving amphibole and plagioclase (Fig.
The Baring Granite is coarse-grained, hypidiomorphic
, granular, and is composed of microcline, plagioclase, quartz, hornblende, and biotite.