Lherzolite is a type of ultramaficigneous rock. It is a coarse-grained rock consisting of 40 to 90% olivine along with significant orthopyroxene and lesser amounts of calcic chromium-rich clinopyroxene. Minor minerals include chromium and aluminiumspinels and garnets. Plagioclase can occur in lherzolites and other peridotites that crystallize at relatively shallow depths (20 – 30 km). At greater depth plagioclase is unstable and is replaced by spinel. At approximately 90 km depth, pyropegarnet becomes the stable aluminous phase. Garnet lherzolite is a major constituent of the Earth's upper mantle (extending to ~300 km depth). Lherzolite is known from the lower ultramafic part of ophiolite complexes (although harzburgite is more common in this setting), from alpine-type peridotite massifs, from fracture zones adjacent to mid-oceanic ridges, and as xenoliths in kimberlite pipes and alkali basalts. Partial melting of spinel lherzolite is one of the primary sources of basalticmagma.
The name is derived from its type locality, the Lherz Massif (an alpine peridotite complex, also known as orogenic lherzolite complex), at Étang de Lers, near Massat in the FrenchPyrenees; Étang de Lherz is the archaic spelling of this location.
The Lherz massif also contains harzburgite and dunite, as well as layers of spinelpyroxenite, garnet pyroxenite, and hornblendite. The layers represent partial melts extracted from the host peridotite during decompression in the mantle long before emplacement into the crust.
The Lherz massif is unique because it has been emplaced into Paleozoic carbonates (limestones and dolomites), which form mixed breccias of limestone-lherzolite around the margins of the massif.
Blatt, Harvey and Robert J. Tracy, 1996, Petrology: Igneous, Sedimentary and Metamorphic, 2nd ed., Freeman, ISBN0-7167-2438-3
January 26, 2023
lherzolite, type, ultramafic, igneous, rock, coarse, grained, rock, consisting, olivine, along, with, significant, orthopyroxene, lesser, amounts, calcic, chromium, rich, clinopyroxene, minor, minerals, include, chromium, aluminium, spinels, garnets, plagiocla. Lherzolite is a type of ultramafic igneous rock It is a coarse grained rock consisting of 40 to 90 olivine along with significant orthopyroxene and lesser amounts of calcic chromium rich clinopyroxene Minor minerals include chromium and aluminium spinels and garnets Plagioclase can occur in lherzolites and other peridotites that crystallize at relatively shallow depths 20 30 km At greater depth plagioclase is unstable and is replaced by spinel At approximately 90 km depth pyrope garnet becomes the stable aluminous phase Garnet lherzolite is a major constituent of the Earth s upper mantle extending to 300 km depth Lherzolite is known from the lower ultramafic part of ophiolite complexes although harzburgite is more common in this setting from alpine type peridotite massifs from fracture zones adjacent to mid oceanic ridges and as xenoliths in kimberlite pipes and alkali basalts Partial melting of spinel lherzolite is one of the primary sources of basaltic magma Lherzolite Lherzolite at Etang de Lers Ariege France Garnet lherzolite a xenolith from a kimberlite pipe Kimberley South Africa Field of view 1 6 cm across Purplish red pyrope garnet Bright green chromian diopside Dark greenish black orthopyroxene Olive green olivine The name is derived from its type locality the Lherz Massif an alpine peridotite complex also known as orogenic lherzolite complex at Etang de Lers near Massat in the French Pyrenees Etang de Lherz is the archaic spelling of this location The Lherz massif also contains harzburgite and dunite as well as layers of spinel pyroxenite garnet pyroxenite and hornblendite The layers represent partial melts extracted from the host peridotite during decompression in the mantle long before emplacement into the crust The Lherz massif is unique because it has been emplaced into Paleozoic carbonates limestones and dolomites which form mixed breccias of limestone lherzolite around the margins of the massif The Moon s lower mantle may be composed of lherzolite 1 References Edit Wikimedia Commons has media related to Lherzolite Vita Finzi Claudio 2005 Planetary Geology Harpenden Terra Publishing page 31 ISBN 1 903544 20 3 Blatt Harvey and Robert J Tracy 1996 Petrology Igneous Sedimentary and Metamorphic 2nd ed Freeman ISBN 0 7167 2438 3 Retrieved from https en wikipedia org w index php title Lherzolite amp oldid 1039265244, wikipedia, wiki, book, books, library,
