| Popis: |
The present paper is a result of field studies carried on in the Julian region during the summer and early fall of 1932. Considerable time was spent in plane table surveying to establish a control for aeroplane pictures used in part to map the geology and locate some of the mine openings. A portion of the Ramona and Cuyamaca sheets of the U.S.G.S. topographic atlas enlarged 5 times from a scale of 1" = 2 mi. (approximately) to a scale of 1" = 2000', was used to map certain areas, notably along the western edge of the main schist belt. The accompanying map is a compilation of data plotted on an engineer’s base map prepared by Allen and Rowe, Inc., of San Diego. The hypsography is from portions of the U.S.G.S. Ramona and Cuyamaca Quadrangles, amended by the writer, who has also revised or added certain culture date. (N.B. This is not the appended map.) |
