Drift Patterns Watercolor on archival paper, 6" x 6" $125.00 + $6.00 shipping in US. SOLD I was fascinated by these elegant drift patterns along a raised roadway. It took awhile for me to figure out how the strange combination of black and white formed. Here's what I think happened: Large snowdrifts occured earlier in the winter. Later, when most of the snow had melted and the upper layers of plowed fields dried out, winds blew dark topsoil across the drifts, turning them black. Then later storms drifted more snow in, covering the dirt. Now, as warmer weather arrives, the topmost layer of snow is melting back, revealing the dark wet soil beneath. I think I deserve an "A" for my geology lesson.