The Cordova daily times., 1917-12-15
BERKELEY HILLS WAS ONCE 4
 VOLCANO
(By Associated Press)

BERKELEY, Cal, Dec. 14.-That a l: volcano once burst out in the Der kelley hills, has now been proved by the University of California.
 This volcano spilled molten rock : all the way from Berkeley to a point : five miles south of Hayward. Later long succession of earthquakes took :l place, caused by shiftings of vast blocks in the earths crust. Thus great rifts and faults were torn in l this lava bed. Then the water of storms and springs percolated !: through these earthquake Assures m the rocks, and deposited a great var
 iety of minerals. Such was the ori-
 gin of Oakland's unusual mining in- T dustry-the mining of pyrite at Le-
 ona, as a material from which to make
 sulphuric acid. These stirring events
 in the past geological history of the
 Berkeley hills are told in a paper by
 Clifton w. Clark on "The Geology and
 Ore Deposits of the Leona Rhyolit."
 just issued in the University of Cali
 fornia Publication in Geology.
 C1arl rniY1tc mt hot hnn
 in the earth's crust have slipped re- l peatedly along the Hayward fault, a
 line of cleavage between blocks of
 the earth's surface. running from
 Berkeley southeast along the base of the steep slopes of the Berkeley
 hills from the neighborhood of the
 Greek theatre on the university cam
 pus at Berkeley on to Hamilton gulch,
 at the head of Dwight way. in Der
 kelley, where the extruded rhyoIite- 1 the volcanic rock-first shows, on
 past the Berkeley institution for the 1 deaf and the blind and the Claremont
 hotel, on through a rift valley from | Temescaf lake to a point southeast of Leona heights then southerly;
 further on, up Arroyo Viejo creek, c. Talbot ranch, connecting with the l oblique fault west of Lake Chabot, I and on through several saddles and breaks in the western slope of the
 hills to the town of Hayward Slip
 pings of the earth's crust along this
 fault line still occur from time to
 time. The rainwater and spring Wa ters of countless centuries, percoIat- ing downward through the old lava
 deposit, through fractures caused by slippings on the earthquake fault,
 carried pyrite downwards, and caused
 the deposit of considerable accumula- l tions of this pyrite. For number of
 years mining has gone on and is con-
 tinuing of such deposits of pyrite,
 near Leona heights, east of Oakland. 1 The ore is found in a fracture zone in the rhyolite-the volcano. rock | which is joined and faulted so that considerable quantities of gouge and small displacements may be seen
 nearly everywhere in the mine, with
 abundant evidence of much intense
 fracturing that originally caused the
 localization of the ore body Associat-
 ed with the pyrite are a number of
 other minerals, including ehalcopy
 rite, copper, melanterite, pisanite, | chalcocite, bornite and sphalerite.
 None of these minerals in the Leona
 rhyolite except the pyrite is of any
 present economic importance.
 The lOueSt TOChS III CIilS feSiOu Ol } the Berkeley hills, according to Clark, are sandstones, basalts, and other rocks of the Franciscan group" Above these Franciscan" deposits are several hundred feet of the Lower Cretaceous or Knoxville formation, originally laid down far beneath the I sea, and then the Chico Cretaceous,
 which represents submarine deposit of thousands of feet in depth of sand
 stones and shales. A vast period of stime then passed during which the hills were raised above the sea and
 then most of these once submarine | donooifS Waahad away hy 0ruDtiOn