21. These consist of alkali-feldspar porphyritic quartz-trachyte and trachyte. 22. A similar phenomenon takes place also in selective alteration of alkaline feldspar . 23. Because of this phenomenon, physical disintegration of alkaline feldspar takes place. 24. In the batholiths there are quartz-feldspar porphyry and dolerite dykes. 25. These pale rocks are rich in feldspar and may contain some quartz. 26. There is less feldspar and more calcite than the adjacent Bringelly Shale. 27. Less quartz content would lead to " quartz alkali feldspar syenite ". 28. Other rocks includes clinopyroxene, titanite, apatite and feldspar . 29. These include the amphibole, biotite, feldspar and zircon. 30. This sediment, composed of quartz, mica and feldspar , became brownstone.
