The unraveling of some Texas Hill Country mysteries started, when I began searching the Internet for clarification on two similar, but different trees referred to as Live Oaks.
One of the trees has a single trunk.
The other has multiple trunks. The leaves appear to be the same. It turns out that the single trunk tree is indeed called a Live Oak, but the tree with multiple trunks is referred to as a Texas Live Oak. The Texas Live Oak is said to grow only to the north and west of the Balcones Escarpment. Hmm? Balcones; I've seen that word around here. I better research what the Balcones Escarpment is, and so the story begins.
The Balcone Escarpment is a cliff face created along the Balcone Fault, when over millions of years the area east of the fault slid 700 feet lower than the western side of the fault. This fault runs parallel to Hwy 35 through the center of Austin. To the west of the fault is a large area known formally as Edward's Plateau, but more affectionately as Texas Hill Country. The area to the east of the escarpment is referred to as a coastal plain. Hmm? Why would it be called a coastal plain when we are so far from the coast? Maybe researching that topic, would answer the question of why I'm finding seashells in the desert.
Here are some I've collected in the R.V. park. As I'm sure you've already guessed, the ocean at one time covered this part of the Earth. These shells are kept safe buried in the soil until, through erosion, they eventually make their way to the surface. Trying to accept the age of these shells is more than I can wrap my mind around!
The ocean shoreline of prehistoric times is said to have risen and fallen many times. The hills have rippled terraces suggesting multiple shorelines. I wouldn't typically be so interested in an area's geology, but Texas Hill Country so blatantly displays the time period that created it. I've got a lead on dinosaur tracks and some rare prehistoric trees in the area. I look forward to finding them. More on that to come.