There is little difference between a patch of soil poking through CO2 ice and being blown by the wind, and a geyser. If CO2 was erupting upwards then I wonder why CO2 ice manages to be stay all around it, and apparently is not sublimated by the heat of the geyser. What is the source of the geyser heat, to make this CO2 gas appear under pressure? There is little room for sunlight to penetrate to throw what must be a geyser 10s of meters into the air. Anyway how can one tell the difference between soil blown across the ground and a geyser going into the air? I would think a geyser would have a gap or a smaller dark area between the exit point and the end of the fan or dark streak where the geyser hots the ground again. If blown by the wind then it should be more continuous, which it is.
If it is a liquid flow then how could all the streaks point in the same direction and be of approximately the same size, when the topography is almost random? The force of gravity would cause any liquid to run down the slopes making the pattern uneven. The force of gravity would also cause any vents for geysers to open other than straight up, because material would press on one side of the vent more than the other on a slope and thus also cause the geysers to spray out in random directions. The only think which is constant in one direction and need not follow gravity is wind streaks.