Martian linear dune gullies are landforms consisting of parallel and often sinuous channels with distinct levees and pit-shaped endings that occur in the mid-latitudes on Mars. Recent observations of ongoing activity link their formation to sliding blocks of CO2 ice in early spring. Here we combine laboratory experiments in which we release CO2-ice blocks on sandy slopes under Martian atmospheric pressure with morphometric observations of linear dune gullies on Russell crater mega dune to test this hypothesis. Our work shows that linear dune gullies are carved by burrowing blocks of CO2 ice that induce explosive ballistic sediment transport, resulting in gullies with all morphological characteristics we observe on Mars; high levees, deep channels, and extreme channel sinuosity. Our findings highlight the specific climatological, topographical, and grain size conditions under which these landforms originate, making it possible to use them as a microclimate proxy on present-day and potentially ancient Mars.