Gabbro Thin Section

There are several phenocrysts of brown to green pyroxene magnetite and plagioclase.

Gabbro thin section. Appendix 2 of ms thesis 1979 suny albany created date. Photomicrograph of a thin section of gabbro gabbro ˈɡæbroʊ is a phaneritic coarse grained mafic intrusive igneous rock formed from the slow cooling of magnesium rich and iron rich magma into a holocrystalline mass deep beneath the earth s surface. Igneous textures in thin section.

Igneous rocks with similar composition are basalt extrusive equivalent of gabbro and diabase the same rock type could be named dolerite or microgabbro instead. The name norite is derived from the norwegian name for norway. Cumulate gabbros are more properly termed pyroxene plagioclase orthocumulate.

The colors are dark gray black and green. Dolerite and diabase are mafic igneous rocks having the same mineralogical composition but differing in formation. Frieda l malcolm scanned and assembled to pdf by william kidd subject.

Norite may be essentially indistinguishable from gabbro without thin section study under the petrographic microscope. Properties rock group igneous classification intrusive plutonic composition mafic texture phaneritic extrusive counterpart basalt common minerals clinopyroxenes e g augite ca rich plagioclase feldspars e g labradorite bytownite olivine amphibole gabbro gigapans gabbro plag rich gabbro from fetlar shetland gabbro in thin section thin section gigapans gabbro plane polars gabbro. It means that it formed as magma cooled slowly in the crust.

It is an intrusive rock. Descriptions of petrographic thin sections of rock samples recovered during alvin dives author. Gabbro is a coarse grained and usually dark colored igneous rock.

And hard to see with all the air bubbles entrained in the epoxy bubbles in epoxy have thin birefringent rims. The relatively coarse grained nature of many of the gabbros and their low modal olivine content question the significance of distinguishing between gabbro and olivine gabbro based on sampling a volume represented by a thin section. Photomicrograph of thin section showing large deformed plagioclase phenocryst embedded in finer matrix of ferromagnesian minerals in gabbro haldar and tišljar 2014.