Thermophysical properties of Alaskan loess: An analog material for the Martian polar layered terrain?

The Martian surface has several regions where thermal inertia measurements indicate a porous ice-free insulating surface, yet are mechanically compete nt enough to sustain substantial slopes. In support of the interpretation o f those regions within the Martian polar layered terrain, we report measure ments of thermal conductivity for loess from the field and in the USA CRREL Permafrost Tunnel. Permafrost Tunnel loess is a desiccated material that c an form vertical walls, but is of low density (800-1000 kg/m(3)), modest sh ear strength (4 kPa), and has a low thermal conductivity (0.1 W/m-K at 1 ba r). These properties are similar to the inferred properties of the Martian polar layered terrain. The Birch Kill field sample has a density of 1160 kg /m(3) and a conductivity of 0.15 W/m-K. The Chena Spur Road sample has a de nsity of 1360 kg/m(3) and a conductivity of 0.7 W/m-K. The relatively high conductivity for the Chena Spur Road is due to the cementation of soil grai n contacts, its higher density, coarser grain size, and higher quartz grain content.