BH250-181
Title
BH250-181
Subject
Gabbro
Description
Major Minerals: clinopyroxene, orthopyroxene, olivine
Minor Minerals: hornblende, plagioclase, biotite, oxides, serpentine, chlorite
BH250-181 is a peridotite composed of olivine (mostly altered), orthopyroxene (Opx), and clinopyroxene (Cpx) in roughly equal proportions. This mineral assemblage is most consistent with a harzburgite, a specific variety of peridotite.
The presence of biotite and hornblende in the peridotite indicates hydrous metasomatism — enrichment of the mantle peridotite by fluids or hydrous melts introduced from external sources, typically associated with subduction zones or deep lithospheric processes.
The minerals in this rock show strong alteration, with extensive serpentinization of olivine and pyroxenes visible throughout the thin section.
Minor Minerals: hornblende, plagioclase, biotite, oxides, serpentine, chlorite
BH250-181 is a peridotite composed of olivine (mostly altered), orthopyroxene (Opx), and clinopyroxene (Cpx) in roughly equal proportions. This mineral assemblage is most consistent with a harzburgite, a specific variety of peridotite.
The presence of biotite and hornblende in the peridotite indicates hydrous metasomatism — enrichment of the mantle peridotite by fluids or hydrous melts introduced from external sources, typically associated with subduction zones or deep lithospheric processes.
The minerals in this rock show strong alteration, with extensive serpentinization of olivine and pyroxenes visible throughout the thin section.
Creator
Bereket Haileab
Source
From the rock collection of Bereket Haileab. Sample BH250-181.
Housed at Carleton College in Minnesota.
Housed at Carleton College in Minnesota.
Type
Hand sample and thin section
Relation
Collection
Citation
Bereket Haileab, “BH250-181,” BH250 Mineralogy Teaching Collection, accessed April 25, 2026, https://bereket-haileab.geology.sites.carleton.edu/items/show/216.