Part II
THE
FIRST 60,000,000 YEARS
By JOE N. LONG
1
The Beginning
How old are the Caverns? When did they begin to form? Are they growing larger today? What changes, if any, are now going on?
These are questions which everyone who becomes interested in the great Carlsbad Caverns wants to have answered sooner or later.
To some of these and many similar questions the answers are difficult to obtain, for when the Caverns were being created no man was around to watch the process and to report his observations first hand. As a result, we have only the word of geologists and other scientists who have specialized in the study of the earth, its formation, and the changes that have come about through the countless ages since our world began.
No one knows how old the Caverns are. All man can do is to estimate, and he bases these estimates on a study of conditions he finds within the cave itself, in the surrounding countryside, and from a general knowledge of the earth and how it has evolved.
Probably the area itself began to form about 200 million years ago, during the Permian period of geologic time.
The area at that time is supposed to have been either an inland sea or a shallow extension of the ocean. During this Permian period the earth's surface was changing. Mountains were rising and the waters were receding, thus greatly enlarging the land areas. Amphibian life was on the wane, and reptiles began to appear.
Great thicknesses of limestone deposits were made during these countless centuries, some in the form of a reef now known as the Capitan limestone. Contemporaneous rock behind the reef is called the Tansill formation. It is in these rocks that the Carlsbad Caverns are located.