Troctolite/ˈtrɒktəlaɪt/ (from Greek τρώκτης 'trout' and λίθος 'stone') is a
maficintrusive rock type. It consists essentially of major but variable amounts of
olivine and calcic
plagioclase along with minor
pyroxene. It is an olivine-rich
anorthosite, or a pyroxene-depleted relative of
gabbro. However, unlike gabbro, no troctolite corresponds in composition to a partial melt of peridotite. Thus, troctolite is necessarily a
cumulate of crystals that have fractionated from melt.[1]
^Paces, James B.; Miller, James D. (1993). "Precise U-Pb ages of Duluth Complex and related mafic intrusions, northeastern Minnesota: Geochronological insights to physical, petrogenetic, paleomagnetic, and tectonomagmatic processes associated with the 1.1 Ga Midcontinent Rift System". Journal of Geophysical Research: Solid Earth. 98 (B8): 13997–14013.
Bibcode:
1993JGR....9813997P.
doi:
10.1029/93JB01159.
ISSN0148-0227.