West Texas Fieldtrip:
Day 1 -- LPL to Kilbourne Hole

IMG00422.jpg(968216 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 08:26:26, [2268 x 1512], fl=N, f=64.0mm, exptime=0.017 s (1/60), f/3.5 Large -- Medium

The poodle Taun We watches as we pack.
IMG00425.jpg(919425 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 16:52:05, [1512 x 2268], fl=N, f=30.0mm, exptime=0.004 s (1/250), f/8.0 Large -- Medium

Gwen climbs to the rim of Kilbourne hole, a giant volcanic crater in southern New Mexico, near El Paso.
IMG00426.jpg(1096547 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 16:53:19, [2268 x 1512], fl=N, f=30.0mm, exptime=0.004 s (1/250), f/8.0 Large -- Medium

The crew looks out on the floor of Kilbourne Hole.
IMG00428.jpg(848884 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 16:54:54, [2268 x 1512], fl=N, f=70.0mm, exptime=0.002 s (1/500), f/8.0 Large -- Medium
IMG00435.jpg(1248537 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 16:57:50, [2268 x 1512], fl=N, f=30.0mm, exptime=0.008 s (1/125), f/13.0 Large -- Medium
IMG00437.jpg(944076 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:01:22, [2268 x 1512], fl=N, f=24.0mm, exptime=0.003 s (1/350), f/11.0 Large -- Medium
IMG00439.jpg(1446198 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:13:14, [2268 x 1512], fl=N, f=36.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium

The reason we came to Kilbourne Hole is that during this particular volcanic event, the lava, as it upwelled through the lower layers of the Earth, took some of those lower layers with it as the lava rushed to the surface. These blebs of foreign material that get thrown out of the volcano are called xenoliths. We were looking for them.
IMG00440.jpg(1475371 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:14:23, [2268 x 1512], fl=N, f=32.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium

To find them, we went down to a layer above the lava flows (black basaltic rock) band in the lower layers of volcanic ash (light brown stuff).
IMG00441.jpg(1916874 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:14:30, [2268 x 1512], fl=N, f=70.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium
IMG00444.jpg(1614816 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:16:19, [1512 x 2268], fl=N, f=39.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium
IMG00445.jpg(805065 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:17:57, [2268 x 1512], fl=N, f=52.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium

We found some! These greenish crystals are composed of olivene and pyroxene, the minerals that make up Earth's mantle (and the mantles of all other rocky planets, too). The mantle makes up over 80% of the Earth by volume.
IMG00446.jpg(923962 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:18:07, [2268 x 1512], fl=N, f=70.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium
IMG00448.jpg(1697459 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:19:06, [1512 x 2268], fl=N, f=34.0mm, exptime=0.004 s (1/250), f/13.0 Large -- Medium

On the ledge looking for xenoliths -- L to R Gordon Osinski (Oz), Curtis Cooper, Tamara Goldin, Dave Kring, Jani Radebaugh, John Moores, Carl Hergenrother, and Jim Richardson.
IMG00451.jpg(1180739 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:22:27, [2268 x 1512], fl=N, f=70.0mm, exptime=0.004 s (1/250), f/19.0 Large -- Medium

A great shot of a mantle xenolith.
IMG00452.jpg(1578758 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:23:41, [1512 x 2268], fl=N, f=52.0mm, exptime=0.004 s (1/250), f/19.0 Large -- Medium

Jay Melosh found a motherlode xenolith.
IMG00455.jpg(1763738 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:36:06, [2268 x 1512], fl=N, f=26.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium

Jani Radebaugh drops acid on the rock to test its composition as Oleg Abramov and Jim Richardson look on.
IMG00456.jpg(1762506 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:36:12, [2268 x 1512], fl=N, f=70.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium

It fizzed, so Jani interpreted it to be limestone.
IMG00458.jpg(1144871 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:47:39, [1512 x 2268], fl=N, f=24.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium

Later, John Moores and I found our own motherlode xenolith just peeking out from the ash. They're covered in basalt, since they erupted in lava, so they don't look different until you cut them open.
IMG00459.jpg(1171845 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:51:18, [2268 x 1512], fl=N, f=70.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium

This xenolith is probably from the lower crust.
IMG00460.jpg(2070532 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 17:51:56, [2268 x 1512], fl=N, f=70.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium
IMG00461.jpg(861734 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 18:18:20, [2268 x 1512], fl=N, f=70.0mm, exptime=0.004 s (1/250), f/11.0 Large -- Medium
IMG00462.jpg(813059 bytes) -- SIGMA-SIGMA SD9, 2004:03:31 19:06:11, [2268 x 1512], fl=N, f=24.0mm, exptime=0.006 s (1/180), f/6.7 Large -- Medium

We camped right below the rim of Kilbourne Hole on the night of day 1.