Lava coil  From Wikipedia, the free encyclopedia Jump to:
navigation, search  A lava coil is a spiral or scroll-shaped
lava formation occurring when relatively low viscosity lava such
as Pahoehoe solidifies along a slow-moving shear zone in the
flow. The shear produces a Kelvin–Helmholtz instability that
forms spiral-shaped patterns. Depending on the side of the flow
the spiral is clockwise or anti-clockwise. They have been
observed on flows near Kilauea on Hawai'i,[1] in Kenya[2] and
possibly on Mars.[3]     1. ^ " Dallas Peck, Lava coils of some
recent historic flows, Hawaii. Geological Survey Research,
B148-B151 1966   2. ^ Temperley BN (1966) Vortex exudation coils
on a recent basaltic lava in Kenya. Overseas Geol Mineral.
Resour. 10:42--46   3. ^ a b Ryan, A. J.; Christensen, P. R. (26
April 2012). "Coils and Polygonal Crust in the Athabasca Valles
Region, Mars, as Evidence for a Volcanic History". Science 336
(6080): 449–452. doi:10.1126/science.1219437.