nodules from Udachnaya-East pipe, Yakutia, Russia

• Main Authors: Victor V. Sharygin, Vadim S. Kamenetsky, Maya B. Kamenetsky, Er V
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: nodules; Yakutia
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.619.8076; http://www.cosis.net/abstracts/9IKC/00060/9IKC-A-00060-1.pdf

Abundant chloride-bearing nodules have been recently described in the diamondiferous Udachnaya-East pipe in Yakutia (Kamenetsky et al., 2006; 2007a). They occur in the deep levels of the pipe (> 350 m) in exceptionally fresh kimberlites (Marshintsev et al., 1976). The lack of secondary, alteration-related minerals in these Udachnaya-East kimberlites (UEK) is associated with an essentially carbonate-chloride groundmass and the presence of chloride-bearing nodules (Kamenetsky et al., 2004, 2006, 2007a; Sharygin et al., 2007b). The shapes and sizes of chloride-bearing nodules and segregations are variable, from spherical and round to angular and from 0.5 to 30 cm in diameter, rarely up to 1 m. The contacts of the nodules with the host kimberlite are sharp (< 1 mm), without evidence of thermometamorphic effects. In some cases, the contact zone is composed of a breccia-like aggregate of olivine, calcite, Na-Ca carbonates, sodalite, phlogopite–tetraferriphlogopite, humite– clinohumite, perovskite, apatite, Fe-Ti oxides, djerfisherite and alkali sulfates set in a matrix of chlorides (Kamenetsky et al., 2006, 2007a).