load stockpiled material into overhead hoppers    and    trucks. The    production    of    any    pit    material that requires crushing and screening depends    on    the    capacity    of    the    processing equipment    used. QUARRY OPERATIONS Quarrying involves not only extraction of material (rock) but also crushing and screening that makes the rock suitable for use as construction material. Quarry   Terminology Figure     5-10     shows     the     names     of various quarry features. Overburden is the waste material that often overlies pit or quarry sites. Deposits within the    waste    materials    are    called    spoil    and must be removed before excavation of the construction materials lying below. Overburden refers to loose material but locally it may include solid rock lying above the desired material. Burden is the construction material    on    the    face    of    a    quarry.    The floor    of    the    quarry    is    the    inside    bottom surface     that     marks     the     lower     limit     of excavation. Often quarries contain one or    more    working    floors    at    various    levels above     the     final     quarry     floor.     A     quarry wall    is    a    more    or    less    vertical    surface that marks the lateral limit of excavation.    The    face    of    a    quarry    is    a rock surface (usually vertical) from which    rock    is    to    be    excavated.    The    top of    the    face    is    called    the    crest,    and    the bottom    is    called    the    toe.    A    bench    is    a steplike mass of rock behind a face and    below    a    working    floor,    Notice    that each    bench    has    a    face,    toe,    and    crest. Quarry Development The layout of a quarry should provide     a     gravity     flow     of     material     from the    face    to    the    crusher,    from    the    crusher to    the    storage    bin,    and    from    the    bin    to the     hauling     equipment,     as     illustrated     in figure    5-11.    A    quarry    laid    out    in    this manner   assures   that   a   maximum   quantity   of rock   can   be   processed   with   a   minimum   of labor    and    equipment.    In    quarries    laid    out on the gravity-flow principle, the drainage problem is practically eliminated. Military quarries are generally of the open-face type with the vertical surface   of      the      rock      exposed.      Depending Figure 5-12.-Determining the direction of the quarry face. upon   local   conditions,   they   may   be   developed by   the   single-   or   multiple-bench   method. Where    the    rock    face    is    not    exposed, core    samples    should    be    taken    in    a    grid pattern    so    rock    formations    can    be    plotted, and   the   lay   of   the   strata,   the   quality   and quantity     of     the     deposit,     and     depth     of overburden     can     be     determined.     Should     a rock formation be jointed or stratified, the    layout    of    the    quarry    is    determined    by the strike (direction) of the formation; that    is,    the    face    of    the    quarry    must    be directed at right angles to the strike (fig. 5-12). This ensures a vertical or near     vertical     face     with     less     chance     of undercutting the face and creating a dangerous     overhang. 5-13