True marble for buildings and statues has been the epitome of class for many centuries for its beauty and workability. Behind any piece of marble is a long story and hard times, because noble marble started out as common limestone or dolomite. Marble is one example of a metamorphic rock; that is, a rock that has been altered from its original form by heat and pressure. Generally, the formation of marble is by the movement of liquid rock, magma, into the immediate vicinity of the deeply buried sedimentary rock. The nearby heat, ranging from a bit over 900 degree to around 1500 degrees, changes the physical makeup of the carbonate rock. Depending on the original characteristics of the limestone, the pressure, and the heat, marble may end up to be the sculpture's dream or just another rock.
Marble occurs in various places in the Chihuahuan Desert, but perhaps
the most accessible to most people in the northern reaches is the Castner Marble,
exposed in cuts along Trans-Mountain Road in El Paso's Franklin Mountains. Alas,
not a commercial treasure trove!
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.