PDS_VERSION_ID        = PDS3
RECORD_TYPE           = STREAM

OBJECT                = TEXT
  PUBLICATION_DATE    = 2009-11-15
  NOTE                = "Sample context description"
END_OBJECT            = TEXT
END

Layered tuff sequence with distinct layers, differing in composition, sorting
and amount of lamination. From the top to the bottom, the first layer is
fairly fine, well-sorted ash, followed by a massive (about 9 cm),
poorly-sorted, matrix-supported layer containing accretionary lapilli of
varying sizes (largest just under 1 cm). This layer is followed by a thin
(less than 1 cm), clast-supported layer that is entirely composed of
accretionary lapilli of uniform size and shape. The next layer is about 1.5cm
thick and is composed of angular clasts varying in color from white to black
and on the order of 2-3 mm in diameter. The following layer is 2 cm thick and
is a finely-laminated ash with alternating layers of light and dark ash. This
is followed by a layer much like the preceding layer of angular clasts, but is
slightly thinner than the first layer. This layer directly overlays a layer
that is composed of fine ash that appears to be similar to the
finely-laminated ash layer above, except it contains more large clasts than
the other layer. It is also thicker (more than 4 cm). The bottom two layers of
this sequence are more cohesive and are cross-cut by a reddish layer of
variable thickness (from 2 mm to 2 cm) that is a palagonitized fluid escape
pipe (3680). The reddish escape pipe is more resistant to erosion than the
tuff. Finer grains of ash are removed and coarser grains are left behind
immediately surrounding the escape pipe.