Gabbro refers to a large group of dark, often phaneritic (coarse-grained), mafic intrusive igneous rocks chemically equivalent to basalt. source
Gabbro refers to a large group of dark, often phaneritic (coarse-grained), mafic intrusive igneous rocks chemically equivalent to basalt.
Gabbro forms when molten magma is trapped beneath the Earth's surface and slowly cools into a holocrystalline mass. source
Gabbro forms when molten magma is trapped beneath the Earth's surface and slowly cools into a holocrystalline mass.
Much of the Earth's oceanic crust is made of gabbro, formed at mid-ocean ridges. source
Much of the Earth's oceanic crust is made of gabbro, formed at mid-ocean ridges.
Gabbro is also found as plutons associated with continental volcanism. source
Gabbro is also found as plutons associated with continental volcanism.
Due to its variant nature, the term "gabbro" may be applied loosely to a wide range of intrusive rocks, many of which are merely "gabbroic". source
Due to its variant nature, the term "gabbro" may be applied loosely to a wide range of intrusive rocks, many of which are merely "gabbroic".
The term "gabbro" was used in the 1760s to name a set of rock types that were found in the ophiolites of the Apennine Mountains in Italy. source
The term "gabbro" was used in the 1760s to name a set of rock types that were found in the ophiolites of the Apennine Mountains in Italy.
In 1809, the German geologist Christian Leopold von Buch used the term more restrictively in his description of these Italian ophiolitic rocks. source
In 1809, the German geologist Christian Leopold von Buch used the term more restrictively in his description of these Italian ophiolitic rocks.
The calcium rich plagioclase feldspar (labradorite-bytownite) and pyroxene content vary between 10% - 90% in gabbro. source
The calcium rich plagioclase feldspar (labradorite-bytownite) and pyroxene content vary between 10% - 90% in gabbro.
The quartz content in gabbro is less than 5% of total volume. source
The quartz content in gabbro is less than 5% of total volume.
Gabbro is generally coarse grained, with crystals in the size range of 1 mm or greater. source
Gabbro is generally coarse grained, with crystals in the size range of 1 mm or greater.
Gabbro may be extremely coarse grained to pegmatitic. source
Gabbro may be extremely coarse grained to pegmatitic.
Gabbro is usually equigranular in texture, although it may be porphyritic at times. source
Gabbro is usually equigranular in texture, although it may be porphyritic at times.
Gabbro can be formed as a massive, uniform intrusion via in-situ crystallisation of pyroxene and plagioclase. source
Gabbro can be formed as a massive, uniform intrusion via in-situ crystallisation of pyroxene and plagioclase.
Cumulate gabbros are more properly termed pyroxene-plagioclase adcumulate. source
Cumulate gabbros are more properly termed pyroxene-plagioclase adcumulate.
Gabbro is an essential part of the oceanic crust, and can be found in many ophiolite complexes as parts of zones III and IV (sheeted dyke zone to massive gabbro zone). source
Gabbro is an essential part of the oceanic crust, and can be found in many ophiolite complexes as parts of zones III and IV (sheeted dyke zone to massive gabbro zone).
Gabbro often contains valuable amounts of chromium, nickel, cobalt, gold, silver, platinum, and copper sulfides. source
Gabbro often contains valuable amounts of chromium, nickel, cobalt, gold, silver, platinum, and copper sulfides.
