troctolite
/ˈtrɒktə(ʊ)lʌɪt
/noun [mass noun] Geology
Gabbro made up mainly of olivine and calcic plagioclase, often having a spotted appearance likened to a trout’s back.There is some grain size reduction of the troctolite adjacent to the anorthosite, indicating a chilling effect....
- Metasomatic anorthosite formed by replacement of layered gabbroic troctolite in the Skaergaard intrusion is shown here.
- Similar advantages in melt behaviour are also achieved by using troctolite as the iron and magnesium source rather than traditional materials.
Origin
Late 19th century: from German Troklotit, from Greek trōktēs, a marine fish (taken to be ‘trout’).