V. THE GOLD BLUFFS (continued)
E. GEOLOGISTS REPLACE the PROMOTERS and ADVENTURERS
Efforts were now concentrated on discovering more efficient ways to exploit the gold found in the bluffs. A. W. Chase observed in a paper read before the California Academy of Science on January 5, 1874, that the gold came from the bluffs. After "caves" the gold obtained on the beaches was much coarser in character, and moreover it was only "after a continued succession of swells that cut the beach at an angle that the rich sands . . . [were] found." When the surf bore in head on, it merely loaded the beach with gravel. Finally, anyone who witnessed the power of the surf had to respect its immense grinding force. All that he had observed had satisfied him that "the gold follows the first two or three lines of breakers, and will never be found in paying quantities beyond." 
Some "experts", however, still contended, despite the failure of the Gold Bluffs Submarine Mining Co., and Buhme & Duff, that the beach gold came from the ocean floor, but most agreed with Professor Chase that the grains of gold came from the bluffs fronting on the ocean. These people had observed every winter that after the summer's heat had parched and cracked the earth, the heavy autumn and winter rains caused huge sections of earth and gravel to cave in and split off the perpendicular face of the bluffs. Falling into the ocean, these giant clods were ground to pieces, and cradled by the swirling motion of the waves. The gravel was carried out to sea, and the black sand which contained the gold, being heavier, was deposited in streaks along the shore. After the tide had ebbed, the black sand was collected and washed in ordinary and patented toms.
Persons familiar with the area always watched for a panning surf, one bearing in from the southwest, which struck the beach diagonally, washing away the gravel and leaving the black sand. If the surf struck the beach head-on, it merely piled up a gravel deposit several feet deep. 
Considerable attention was now focused on working out more effective methods of separating the gold from the sand with various machinery, and by chlorination and boiling. But in the end the companies working the bluffs always returned to sluicing. Only a moiety of gold was obtained by this process but it yielded a small profit. The auriferous sands also contained some platinum. 
Last Updated: 15-Jan-2004