Terrestrial analogs and thermal models for Martian flood lavas

The recent flood lavas on Mars appear to have a characteristic "platy-ridge d" surface morphology different from that inferred for most terrestrial con tinental flood basalt flows. The closest analog we have found is a portion of the 1783-1784 Laki lava flow in Iceland that has a surface that was brok en up and transported on top of moving lava during major surges in the erup tion rate. We suggest that a similar process formed the Martian flood lat a surfaces and attempt to place constraints on the eruption parameters using thermal modeling. Our conclusions from this modeling are (1) in order to p roduce flows >1000 km long with flow thicknesses of a few tens of meters, t he thermophysical properties of the lava should be similar to fluid basalt, and (2) the average eruption rates were probably of the order is, with the flood-like surges having flow rates of the order of 10(5) - 10(6) m(3)/s. We also suggest that these high eruption rates should have formed huge volu mes of pyroclastic deposits which may be preserved in the Medusae Fossae Fo rmation, the radar "stealth" region, or even the polar layered terrains.