84 A Bibliography of the Geology, etc., of California. 



performed in his Majesty's ship Blossom, under the com- 

 mand of Capt. F. W. Beechey. London, 1831. 2 vols. 



In the volume on the zoology of Captain Beechey's voyage (Lon- 

 don, 1839, 4to), by Prof. Buckland, there are several references to the 

 geology of the vicinity of San Francisco, prepared from the notes 

 and collections of Lieutenant Belcher. 



A map of the headland, embracing San P'rancisco Bay, accom- 

 panies this report. This is colored around the shores so as to indi- 

 cate the several formations; serpentine, sandstone, and jasper rock 

 are represented. Lieutenant Belcher collected specimens of serpen- 

 tine on the M'est side of Angel Island. The occurrence of jasper rock 

 is also noted. 



The author, on page 174, gives the following account of the geology 

 of California, which was the first ever published ; it is given in full,, 

 on account of its value : 



GEOLOGY, BAY OF SAN FRANCISCO. 



"The specimens collected in and near the Bay of San Francisco- 

 consist of many varieties of common serpentine, bronzite, and asbes- 

 tos ; clay-slate and mica slate, chlorite slate, horn-stone, brown, green, 

 and red jasper, and rolled blocks of glassy actynolite ; grey sandstone, 

 and imperfect wood-coal. The country near the port of fsan Fran- 

 cisco is comjjosed chietly of sandstone, jasper, and serpentine. Wood- 

 coal is found in slight seams on the north side of the entrance of the 

 bay, and native salt near Santa Clara. Many of the summits of the 

 hills are comjjosed of jasper, forming enlongated ridges, of which 

 the general direction is north and south. This jasper is succeeded by 

 sandstone, of a loose texture, not effervescing with acids, and dis- 

 posed in every angle of stratitication, occasionally it is hard and of 

 a blue cast ; it is frequently interrupted by abrupt masses of lami- 

 nated jasper in wavy stratification. The appearance of the jasper, 

 at its contact with the sandstone, is often very remarkable. The 

 jasper appears not to have acted on or displaced the sandstone ; its 

 exterior, for eighteen inches or two feet, is usually rugged, and mixed 

 with carbonate of lime, quartz, and indurated clay ; its interior, 

 however, presents a very beautiful wavy disposition of the component 

 laminae, a remarkable example of which occurs at the >seedle Rock, 

 nearly opposite the fort. A view of it is engraved at PI. Ill, Geology. 

 It resembles an immense mass of sheets of paper, or bands of list, 

 crumpled and contorted by lateral pressure. This contortion only 

 occurs in the red jasper, the j^ellow being seldom (if at all) stratified, 

 but generally separated by cracks into rhomboidal pieces. A mass 

 of at least one hundred feet in thickness is beautifully stratified in 

 short, wavy lines, opposite the fort near Punta Diavolo, and rests on 

 sandstone. 



"Between Punta Boneta and Punta Diavolo the sandstone is of a 

 bluish-grey colour, containing particles of coal. 



"The Island of Los Angelos is of very confused formation. Its 

 eastern side is sandstone, with occasional jasper rocks; its western 

 side exhibits sandstone, conglomerate, clay-slate, and serpentine ; its 

 south side, bluish earth, (apparently decomposed serpentine), and 

 jasper beds containing red siliceous nodules, and much iron pyrites. 



