alluvial fans
... that "toe-trimmed" alluvial fans on Mars provide evidence of ancient Martian river systems?
... that "toe-trimmed" <b id="mwBK4"><a href="./Alluvial_fan" id="mwBK8" rel="mw:WikiLink" title="Alluvial fan">alluvial fans</a></b> on Mars provide evidence of ancient Martian river systems?