Dunite
Dunite ( group of mantle-derived rocks.
Dunite and other peridotite rocks are considered the major constituents of the
subduction zone have been thrust onto continental crust by obduction during continental or island arc collisions (orogeny). It is also found in alpine peridotite massifs that represent slivers of sub-continental mantle exposed during collisional orogeny. Dunite typically undergoes retrograde metamorphism in near-surface environments and is altered to serpentinite and soapstone
.
The type of dunite found in the lowermost parts of ophiolites, alpine peridotite massifs, and
upper mantle. However, a more likely method of dunite formation in mantle sections is by interaction between lherzolite or harzburgite
and percolating silicate melts, which dissolve orthopyroxene from the surrounding rock, leaving a progressively olivine-enriched residue.
Dunite may also form by the accumulation of olivine crystals on the floor of large basaltic or
Skaergaard complex in Greenland. The largest layered mafic intrusions are tens of kilometers in size and almost all are Proterozoic in age, e.g. the Stillwater igneous complex (Montana), the Muskox intrusion (Canada), and the Great Dyke (Zimbabwe). Cumulate dunite may also be found in ophiolite complexes, associated with layers of wehrlite, pyroxenite, and gabbro
.
Dunite was named by the Austrian geologist
Dun Mountain Ophiolite Belt
.
A massive exposure of dunite in the United States can be found as
Troodos mountains of Cyprus. In southern British Columbia, Canada dunite rocks form the core of an ultramafic rock complex located near the small community of Tulameen. The rocks are locally enriched in platinum group metals, chromite and magnetite
.
Carbon sequestration potential
Dunite could be used to
References
Wikimedia Commons has media related to Dunite.
- S2CID 129776536.
- ^ Danae A. Voormeij, George J. Simandl, Bill O'Connor - A systematic assessment of ultramafic rocks and their suitability for mineral sequestration of CO2 Archived 2015-02-12 at the Wayback Machine
- ^ Peter Köhler, Jens Hartmann, and Dieter A. Wolf-Gladrow. 2010. Geoengineering potential of artificially enhanced silicate weathering of olivine. PNAS ∣ November 23, 2010 ∣ vol. 107 ∣ no. 47 | 20228–20233
- Dunite
- Blatt, Harvey and Robert J. Tracy, 1996, Petrology, 2nd ed., W. H. Freeman, ISBN 0-7167-2438-3
