Questions about Pedernales Falls (Canyon, Marble Falls: tree, parks, dinner)

[catholicdad]

Hello, I just got back from a (mis)adventure there. That park is rather different from nearby parks.

- Why are there so many more thorny plants? There were acacias, holly, and some kind of weird oak tree with thorny leaves. They formed walls of thorns, and I got sliced to shreds. That's in addition to the usual cacti and junipers with sharp twigs seen elsewhere.

- Why is the wind so much hotter there?

- Why is the water dark green, instead of clear like other parks?

- Some of the limestone gravel had odd shades of purple, green, and yellow. What gives them that color? (I searched online but couldn't find answers.)

Moderator cut: I don't think we need the religious comments...

[die Eichkatze]

Originally Posted by catholicdad

Hello, I just got back from a (mis)adventure there. That park is rather different from nearby parks.

- Why are there so many more thorny plants? There were acacias, holly, and some kind of weird oak tree with thorny leaves. They formed walls of thorns, and I got sliced to shreds. That's in addition to the usual cacti and junipers with sharp twigs seen elsewhere.

Welcome to the Hill Country, we have tons of thorny plants/shrubs/trees! Little to no soil, drier...ect.

- Why is the wind so much hotter there?

Drier/less humid...rocks also heat things up.

- Why is the water dark green, instead of clear like other parks?

Minerals in the water

- Some of the limestone gravel had odd shades of purple, green, and yellow. What gives them that color? (I searched online but couldn't find answers.)

Short answer...geology. The limestone rocks are different than what you see elsewhere in the area. A portion of the Llano Uplift is exposed in this area, so you are seeing what is called the Marble Falls Limestone, along with some Ellenburger as well. Without being there, I couldn't tell you for certain what each color rock was...but Marble Falls limestone is usually purple to blackish in color, Ellenburger: yellowish (maybe...) green was probably the Hammett shale. Sycamore sand is also present in this area.
http://www.geo.utexas.edu/courses/42...lls_GeoMap.pdf



Moderator cut: Edited, portions of the post you replied to were deleted

[catholicdad]

Thanks for the insights. I'll say that similarly to Balcones Canyon, a vulture followed me for a while. They seem to like single hikers.

[orngkat]

In many cultures, vultures are a sign of good things to come.

[G Grasshopper]

Vultures are a wonderful group of animals. Without them, we would be up to our hips in dead animals. They are an important part of "Nature's clean-up crew."

[cBach]

Originally Posted by catholicdad

Thanks for the insights. I'll say that similarly to Balcones Canyon, a vulture followed me for a while. They seem to like single hikers.

When they see a lone hiker in the mid-day sun they think "hot dinner on the way".

[G Grasshopper]

I forgot to mention that vultures are one of the few birds that can actually smell and they are particularly attuned to the smell chemicals when meat rots. They are often follow roads, due to road kill. But unless you smell like carrion, it is unlikely that a vulture will be interested in a hiker. Turkey vultures have better smell than black vultures, so black vultures often travel with turkey vultures, who are more adept at finding prey. Black vultures use more visual sighting of dead animals, although I understand they are not completely devoid of smelling ability, as many song birds are.