Now, in the cave, a team of scientists and explorers is
conducting research and working on a documentary. Stein-Erik
Lauritzen, a professor of geology at the University of Bergen in
Norway, is retrieving samples for uranium-thorium dating. His
preliminary research suggests the largest of the crystals are
about 600,000 years old. Penelope Boston, an associate professor
of cave and karst science at New Mexico Tech, searches for
microbes that might live among the crystals. In some of them,
tiny bubbles of suspended fluid—the kind García studied—sparkle
in our lights. They are little time capsules: Italian scientists
led by Anna Maria Mercuri extracted pollen that may have been
trapped within these inclusions. The grains appear to be 30,000
years old and suggest that this part of Mexico was once covered
not by desert but by forest. One long, slender beam bears a deep
scar from where someone tried to cut through it. I imagine a
miner dripping and alone in the smothering silence, his weak
headlamp bouncing with eac