<http://webisa.webdatacommons.org/prov/479555410>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/318570420> .
<http://webisa.webdatacommons.org/318570420>	<http://www.w3.org/ns/prov#value>	"As the calcium carbonate deposit hardens it forms layers, and, with time, erosion can leave hollow spaces in the earth where animals, such as the desert tortoise, can escape from the heat of the Sonoran Desert." .
<http://webisa.webdatacommons.org/318570420>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<nps.gov> .
<http://webisa.webdatacommons.org/318570420>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .