Buck Creek ultramafic body, NC - chloritization in dunite

Click on the image to enlarge.           Photo © Daniel R. Snyder

Advanced stage of chloritization in dunite, Buck Creek ultramafic body, Blue Ridge Mountains, Clay County, western North Carolina. Pratt and Lewis (1905)* described the chloritization of the Buck Creek dunite thus: "In some cases the olivine alters extensively to chlorite, which penetrates the grains generally along cleavage cracks first, though frequently in diagonal directions, in long slender laths, sometimes passing uninterruptedly through two or three grains." XPL. Imaged area 1.3 mm x 2 mm.

Thanks to Dr. Brannon Andersen of Furman University for giving me detailed instructions on reaching this exposure.

*Joseph Hyde Pratt and Joseph Volney Lewis, Corundum and the Peridotites of North Carolina.

Buck Creek ultramafic body - unaltered dunite grading into chloritized dunite

Click on image to enlarge.          Photo © Daniel R. Snyder

Portion of a thin section showing unaltered dunite (left) grading to heavily chloritized dunite (right). Buck Creek ultramafic body, Blue Ridge Mountains, Clay County, western North Carolina. Macrophoto, XPL. Imaged area 10 mm x 20 mm.

Buck Creek dunite - serpentinized and chloritized

Click on image to enlarge. See image below for enlargement of outlined area.

Polished slab of partially serpentinized and chloritized dunite. Buck Creek ultramafic body, Blue Ridge Mountains, Clay County, western North Carolina. Optical scan at 1524 pixels/cm (600 dpi). Original width 3400 pixels, reduced by Blogger to 1600 pixels at maximum magnification. Slab dimensions 8 cm x 14.5 cm. Below is a higher-resolution image (6096 pixels/cm.) of the 3.5-cm-by-3.5-cm area outlined in the larger image.

Click on image enlarge. Click again to get really close up.