Situated just to the northeast of Dallas County is the county of Rockwall, with its capital city Rockwall, both derived from the frequent occurrence of underground rock “walls” that crop up around the area. On occasion, intrepid Texans have dug down beside a wall to see how far it goes, but they’ve never reached the bottom.
Often the walls are thin, just an inch or so thick. Others are several inches thick. When exposed, they really do look something like a manmade brick wall consisting of beveled “bricks” with mortar in between them. In recent decades, the city of Rockwall has witnessed rapid growth and the walls have been destroyed or covered, so that now none can be seen. Local folklore has arisen that a race of prehistoric giants built the walls.
Geologists have occasionally studied the walls and have each concluded that they are a natural phenomenon, much to the dismay of local romantics. In the mid-1970s, several local historians contacted the Institute for Creation Research for a creationist’s opinion. They may have thought that if anyone would acknowledge prehistoric giants, creationists would. I was a member of the geological engineering faculty of Oklahoma University at the time and was asked to investigate.
First, I reviewed all the scant scientific literature on the subject. All the geologists had concluded that the walls were sandstone dikes, cracks filled in with sand squeezed up from below like toothpaste, followed by hardening of the sand into sandstone over millions of years. Next, I collected field observations of the dikes and concluded that they had indeed come up from below and couldn’t have simply been cracks filled in from above….
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