White Sands / Carlsbad Caverns Field Trip

Our field trip in spring of 1997 was to Southern New Mexico. We explored Carlsbad Caverns, the Guadalupe Mountains, White Sands, and the Chiricauhua Mountains, as well as the general geology of the region.

In addition, we got to do some excellent spelunking.

Carlsbad Caverns

Click here for our White Sands / Carlsbad Caverns field trip home page.

The Planetary Connection

As planetary scientists, we frequently ask the question on our geology field trips, 'What's the planetary connection?' We study Earth to help us put what we learn about other planets into context, and in turn use the knowledge we gain about other worlds to help us understand our own planet.

Sand

The combination of geological features we see on this trip is obviously unique to this particular area of our planet, but each of these features in turn may be in some way relevant to the study of other planets. We can see dunes on Mars and Venus, and indeed expect to find them on any planet with a solid surface and a significant atmosphere (like Titan?); they can tell us about atmospheric flow directions and surface topography. The lava flow field near Carrizozo is certainly very relevant, as we see volcanic features on many other planets. And surely there are caverns on every planetary body (save perhaps giant gaseous planets like Jupiter).

But it is also clear that many of the features seen on this trip (as on most terrestrial field studies) are associated with liquid water. As we have seen, the caverns at Carlsbad (like most caves on Earth) were formed through the dissolution of limestone, which is itself formed at the bottom of oceans and seas (the Capitan reef and Guadalupe mountains are a prime example). Hoodoos are also caused by water erosion (although the joints that initiate them are not). The Rio Grande rift is a tectonic feature (the likes of which we might find on any large planet with enough internal heat), but the river terraces we see in it are obviously the result of water flowing through it. Maar volcanoes are volcanic features, but their particular nature is determined by the presence of water. And although dunes need only a sediment supply and a flowing fluid (i.e. wind) to form, sediment is a result of erosional processes, and its supply will be much more significant if liquid water is present. (Although wind erosion may produce a reasonable supply, as on Mars and Venus; micrometeoroid erosion can produce regolith on airless bodies like the Moon, but this of course precludes the possibility of wind to produce dunes.)

So while we may see joints, faults, and tectonic rifts on other planets, as well as lava flows and other volcanic features, we do not expect to see them taken to the ends which we see here on Earth unless water is (or has been) present. To date of course we have evidence for liquid water only on Earth, although the signs are pretty clear that it existed in the past on Mars. It is thus perhaps fitting that the most relevant planetary connection for most of the features we see on this trip is with the planet we shall visit first. Hopefully it will not be too many years before geologists get a chance to explore the ancient river valleys and yet undiscovered caves of Mars.

And remember, even if we may not expect to find most of these geological features on any of the other planets of our solar system, there are of course other reasons for us to study them. As Andy Rivkin pointed out for example, the Castile evaporites are a wonderful example of a seasonal climactic record, and we may find similar analogs on other planets. So, while there may not be any interplanetary spelunkers any time soon, we can certainly become better planetary scientists by studying and understanding the geology of the world around us.