rocks has been determined at 650 sites in the. San Francisco .... At the 535 sample sites of maï¬c vents and lava ï¬ows ..... agreed best either with ï¬eld relations or with a ..... 5 N87°W : 5° 2.9 1 0.3 San Frana'seo volmnic ï¬eld (this paper).
