Blue Ridge Ophiolite

The Blue Ridge Ophiolite occurs frequently throughout the Appalachian Mountains. There are many pods located in the western parts of North Carolina such as the Newdale, Daybook, and Buck Creek Dunite. Some of these also pods extend into Tennessee and South Carolina. == Mineralogy ==

The Blue Ridge Ophiolite can be broken up into two categories: altered and unaltered. Unaltered ultramafic The majority of the Blue Ridge Ophiolite has minimal altered composition of dunite. Unaltered samples of the Blue Ridge Ophiolite are green or brown. Samples tend to have a grainy texture like sugar, with conchoidal fracture. In thin section the most abundant and easiest to identify mineral is olivine, about 60% to 80% of the thin section. Minerals that appear in these rocks along with olivine are chlorite, talc, phlogopite, tremolite, and hornblende. When minerals like olivine are introduced to water they break down to form talc, and then through further alterations phlogopite can form. Through reworking, the minerals can form phyllite and other metamorphic textures. Altered samples of the Blue Ridge Ophiolite are green, with white and black crystals that are visible. In thin section some samples have no olivine such as the sample form Todd, North Carolina. Altered minerals that can be seen in thin section are chlorite and chromite.. Sample taken by Loren Raymond.|left|200x200px == Formation ==

Evidence points to the protolith being from a mid-ocean ridge mafic rock around the time of the Taconic orogeny. These were dated using rhenium–osmium dating to determine the age. The use of examination of chromite in rock samples show deformation as far back as the early to middle Ordovician period. Middle Ordovician deformation caused other metamorphic suites in the Appalachian Mountains and buried and altered ophiolite pods throughout the region. == References ==