Monchiquite

Monchiquites: From Sierra de Monchique in Southern Portugal. A monchiquite is a porphyritic alkaline (shoshonitic) lamprophyre, dominated by essential olivine, titan-augite and brown hornblende.

lamprophyre2020(3).jpg

Monchiquite dyke with altered mantle xenoliths (with brownish-weathering), Wawa, northern Ontario, Canada. From James St. John.

Bibliography

• Mitchell, R. H. (1994). The lamprophyre facies. Mineralogy and Petrology, 51(2), 137-146.
• Rock, N. S. (1977). The nature and origin of lamprophyres: some definitions, distinctions, and derivations. Earth-Science Reviews, 13(2), 123-169.
• Rock, N. M. S. (1986). The nature and origin of ultramafic lamprophyres: alnöites and allied rocks. Journal of Petrology, 27(1), 155-196.
• Rock, N. M. (1987). The nature and origin of lamprophyres: an overview. Geological Society, London, Special Publications, 30(1), 191-226.

Photo
Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)	Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)	Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)
Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)	Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)	Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)
Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)	Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)	Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)
Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)	Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)	Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)
Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)	Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)	Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)
Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)	Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)	Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)
Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)	Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)	Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)
Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)	Augite crystals (embedded in a groundmass rich in microphenocrystals of augite) in a monchiquite from Libia. PPL image, 2x (Field of view = 7mm)	Augite crystals in a Monchiquite from Libia. XPL image, 2x (Field of view = 7mm)