The quicksilver resources of California . the wave-like form of ore deposits, from the factthat parallel zones of ore deposition are found, and finally fromthe character of the vein filling, which shows repeated fissuringand refilling, resulting in a ribbon formation in the seams, theconclusion must be drawn that this fracturing was persistentduring a long period of time. The ore deposits are limited on their hanging-wall side by the alta, anGionfpZv^^^ impermeable stra-tum through whichno water circula-tion could foot-wall sideis persistently ser-pentine, hence itmust be concludedtha
The quicksilver resources of California . the wave-like form of ore deposits, from the factthat parallel zones of ore deposition are found, and finally fromthe character of the vein filling, which shows repeated fissuringand refilling, resulting in a ribbon formation in the seams, theconclusion must be drawn that this fracturing was persistentduring a long period of time. The ore deposits are limited on their hanging-wall side by the alta, anGionfpZv^^^ impermeable stra-tum through whichno water circula-tion could foot-wall sideis persistently ser-pentine, hence itmust be concludedthat in this minethe serpentine is associated with the cause of fracturing of theother rock strata, and this would lead to the conclusion thathere the serpentine must be considered as an alteration prod-uct of intrusive peridotites, not as an alteration of strata ofthe Franciscan series. This conclusion finds confirmation bya section of the country from Mine Hill toward the Washing-ton shaft. [See Fig. 58.] The fracturing has taken place on. Fig. 59. Section over Santa Rita West, Giant Powderslopes, New Almaden. SANTA CLARA COUNTY. 179 both sides of the serpentine, which apparently can not be con-sidered otherwise than as an intrusive body having uplifted therocks of the Franciscan series. The ore bodies form principallj^ in those parts of the zoneswhere the dip of the alta is very flat, as indicated in Fig. 59—an ideal section over two connected stopes, which have bothproduced considerable amounts of ore. The contact of the
Size: 1973px × 1266px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectminesandmineralresou
