alkali-feldspar granite of Cumberland (Devonian? or Mississippian?)
alkali-feldspar granite of Cumberland - Gray to blue-gray. medium- to coarse-grained, equigranular to porphyritic alkali-feldspar granite (phenocrysts of perthite). Massive to locally foliated. Contains perthite, quartz, abundant accessory riebeckite and aegerine, and lesser astrophyllite, anegmatite, zircon, allanite, fluorite, and opaque minerals. Plagioclase is notably absent. Hypersolvus, strongly peralkaline granite. Includes rock mapped formerly as Rhode Island Quincy Granite.
Scituate Igneous Suite - alkali-feldspar granite (Devonian)
Scituate Igneous Suite - alkali-feldspar granite - Gray to pink, medium- to coarse-grained, porphyritic to subporphyritic alkali-feldspar granite (phenocrysts of perthite). Contains perthite, quartz, and accessory biotite, hornblende, and lesser riebeckite, aegerine, zircon, allanite, sphene, fluorite, and opaque minerals. Plagioclase is sparse to absent. Secondary muscovite, chlorite, and calcite. Ovoid clots of mafic and accessory minerals are locally prominent. Rock is a hypersolvus, mildly peralkaline granite. Fabric ranges from massive to locally lineated and foliated. Includes rock mapped formerly in part as Scituate Granite Gneiss, Cowesett Granite, and perthitic Cowesett Granite.