“Regardless of what you call it, ancient gully, valley, gulch, ravine, you can come up with a thousand names, the question is – how did it form?” Golombek reiterated. “ That is our objective. What matters is whether we can determine if this feature was water-carved, and if it was, determine if it was prominently liquid water, like a stream or lake coming over the edge. Or, was it a mudflow, hyper-concentrated liquid slush with sediment? Or was it a dry avalanche? We can test these hypotheses,” he said.