Southern New Mexico

Spring, 2001
May 12-14

This fieldtrip took us into New Mexico to study Kilbourne Hole (a volcanic maar crater), White Sands and assorted rocketry connections, and the Carrizozo lava flow. As usual, Jay Melosh was the trip leader.

Jason and Ross took pictures on our trip to Southern New Mexico.

Day 1

Andreas started the trip by telling us about the Cross Hill landslide. This is a "long runout" landslide that travelled a greater horizontal distance than simple theory predicts based on its vertical drop. Jay was enthusiastic about acoustic fluidization. Being beside the train tracks, we collected flattened coins and left some unflattened ones for future visitors.

Terry then talked about the lifeways of the peoples of the San Pedro river valley. This is an important archaeological site for understanding the history of the Southwest.

The always-popular subject of spheroidal weathering was reviewed by Ross. The route of I-10 passes through some spectacular examples of this around Texas Canyon. Alas, we did not stop at the nearby "Thing."

Paul gave two brief talks on palaeoshorelines (terrestrial and martian) from Willcox Playa (once Lake Cochise) and Animas Lake. The humping cattle were a very popular distraction.

The University Motor Pool, in its infinite wisdom, had sent us out on dodgy Firestone tyres long after their propensity to fail on SUVs (such as those we were using) was well-known. Luckily, Fred stopped his vehicle to inspect its strange handling before the tyre exploded. Jason entertained us during the tyre-changing by demonstrating a sub-orbital potato cannon.

Day 2

After camping near Kilbourne Hole, Jani described this maar crater. In this kind of crater, hot magma wells upwards into the saturated water table and generates large amounts of pressurized, superheated steam that explodes in all directions. This example was caused by magma from great depth within the Earth and some mantle rock fragments (xenoliths) are scattered around the site. There were some snakes as well, which Fred just loved. He still hasn't forgiven Jonathan for presenting him with a shed snakeskin.

Gwen found an inspiring overlook to tell us about the early days of rocketry and the White Sands Missile Range (which inspired the successful potato cannon seen above). New Mexico has quite a history of things that go boom and Jason discussed the Manhatten Project and the Trinity Test Site, which, unfortunately, we were not able to visit.

We stopped at the "Heart of the Dunes" vista in the White Sands National Monument. These white dunes are very different from those we're used to seeing on fieldtrips into Mexico and California. White Sands contains small, soft particles of gypsum (hydrated calcium sulphate) instead of the large, rough quartz crystals of our usual dunes. Fred compared these dunes to martian dunes. Then we all played in the sand!

Day 3

We camped on the Carrizozo flow in the rain, then started the day with a walk around the basaltic flow and a speech from Windy. This flow was Laz's thesis topic, so she was quite the expert.

Jim took us to the ghost town of White Oak and its laccolith. Continuing the volcanic theme, Joe described the Socorro Magma Body that seethes beneath this placid-looking Rio Grande town.

We stopped for lunch at the Very Large Array. You'd think astronomers would be better at coming up with names from things than this, but no. Jonathan talked about this array of 25m radio telescopes and its connections to SETI and Jodie Foster's Contact. This project was completed ahead of schedule and under budget. Tourists in the visitors' centre seemed to enjoy Jonathan's talk.

We mined our way home. Abby talked about uranium mining in New Mexico, Dave talked about the Morenci copper mine in Arizona, and Ingrid talked about how hydrothermal activity emplaces ore bodies.

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Last Updated: 02 May 2003