Lava coil explained

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]

Notes and References

1. https://books.google.com/books?id=4holAQAAIAAJ&q=lava+coils%22&pg=SL2-PA148 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. Ryan. A. J.. Christensen, P. R. . Coils and Polygonal Crust in the Athabasca Valles Region, Mars, as Evidence for a Volcanic History. Science. 26 April 2012. 336. 6080. 449–452. 10.1126/science.1219437. 22539716. 2012Sci...336..449R. 39352082.