Ocean Drilling Program Leg 183 (Kerguelen Plateau) produced some of the most systematic and detailed descriptions of lava flows ever compiled. A wide variety of lava types in various states of preservation were recovered. An initial attempt to make the identification of mafic lava flow types more systematic using only macroscopic observations made on the drill core is presented here. This technique successfully categorizes pahoehoe, aa, slab pahoehoe, and rubbly pahoehoe flows and provides an estimate of the certainty of each categorization. However, the technique needs to be improved in the future by increasing the list of diagnostic characteristics for slab and rubbly pahoehoe. Because of poor recovery and/or extreme alteration and weathering of the units, 12 of the 42 units (29%) could not be classified. Of the remaining 30 units, 7% were classified as slab pahoehoe, 13% as aa, 27% as pahoehoe, and 53% as rubbly pahoehoe. Pahoehoe and rubbly pahoehoe flows were found in Holes 1136A, 1137A, 1138A, and 1139A, whereas aa and slab pahoehoe flows were confined to the latter two holes.
1Keszthelyi, L., 2002. Classification of the mafic lava flows from ODP Leg 183. In Frey, F.A., Coffin, M.F., Wallace, P.J., and Quilty, P.G. (Eds.), Proc. ODP, Sci. Results, 183 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/183_SR/012/012.htm>. [Cited YYYY-MM-DD]
2Lunar and Planetary Laboratory, University of Arizona, Tucson AZ 85721-0092, USA. lpk@pirl.lpl.arizona.edu
Initial receipt: 20 February 2002
Acceptance: 26 February 2002
Web publication: 17 June 2002
Ms 183SR-012