1. Weathering, Erosion, Deposition: Effects on the Texas Ecoregion Environents

2. In the natural world, enviroments are characterized by:
Types of soil
Precipitation
Temperature
Land features
Vegetation
Animal wildlife

3. We have:
Analyzed the characteristics of the ecoregions of Texas
Investigated processes that change the surface of the Earth
Explored how the process of weathering, erosion, and deposition have affected the environments in Texas ecoregion.

4. Edwards Plateau / Llano Uplift
Enchanted Rock
Located in Central Texas
What’s happening?
Exfoliation – mechanical weathering has caused the rock to “peel” in sheets. This was caused by contracting and expanding during heating and cooling in the temperature
Mechanical or chemical weathering? What station?
The weathering of sedimentary rock has exposed the granite dome underneath
Other types of mechanical weathering present – plant roots

5. Edwards Plateau Georgetown- Inner Space Cavern
Rainwater mixes with carbon dioxide in the atmosphere and soils to form carbonic acid (H2CO3), which acts to dissolve away limestone.
Georgetown-
Inner Space Cavern

6. High Plains
Palo Duro Canyon was formed by water erosion by a fork in Red River that continues to become deeper
One of the windiest regions in the US
Low vegetation, so high wind erosion
Which station activity most closely models the formation of Palo Duro Canyon?

7. Trans Pecos / Chihuanhuan Desert
Big Bend– erosion from water
flow from the
Red River
Big Bend–
Ancient swamp,
current desert
Davis Mountains –
formed from volcanic activity
Guadalupe Mountains –
formed by fossilized coral reef

8. Trans Pecos / Chihuanhuan Desert
Big Bend - the warm red and brown colors of igneous rocks show oxidation, oxygen reacting with iron forming rust
Big Bend– limestone cliff eroded by carbonic acid
Water droplets capture
carbon dioxide to form carbonic acid
Which station models this erosion of the limestone cliffs?

9. Piney Woods
Due to ample precipitation and abundant vegetation that holds the soil in place, there is very little erosion
Thick vegetation near rivers inhibits river erosion.
Which station activity most closely models seasonal flooding?

10. Gulf Coast Plains and Marshes
Wave action, a cause of weathering, erosion
and deposition, is constant along the Texas
Coastline.
Sediments are weathered and eroded along
beaches and carried out into the ocean to
form sand bars and islands
Galveston Beach
Mustang Island was
formed by erosion and
deposition
Sand dunes in
Padre Island

11. Gulf Coast Plains and Marshes
When rivers, like the Brazos enter the Gulf of Mexico
sediment being carried by the river stop moving and get deposit causing a delta.

12. Before Katrina
After Katrina

13. Which station activity most closely models the effects of a hurricane on the Gulf Coast? Justify your answer.
After Katrina