The terminology of karst is intricate, reflecting the great variety of forms produced by the interaction of water and lime rocks. Where a flat limerock surface is attacked by water, solution grooves may form along bedding planes or fractures (joints). The surfaces between the grooves are clints, and the grooves are grikes (or grykes). Generally a clint-and-grike karrenfeld is a fairly regular grid. At Columbia the surface is much more irregular, with wider grooves, and is better classified as a crevice karst.
In any event, this wide, rugged hard-rock surface acted for millions of years as the riffles in the bed of an enormous sluicebox. Large deposits of gold-bearing gravel traveled over the Columbia area and heavy nuggets were left behind, in seemingly every hollow. The first miners pulled fist-sized nuggets from the ground here starting in 1850, and thousands of gold-seekers followed. Columbia had the richest gold placers ever discovered. Some $500 million worth of gold (at today's prices) was dug out by hand in less than 20 years. For a time it was the second-largest city in California. Now all that's left is a state historic park, a marble quarry north of town, and the ancient karrenfeld.