The Balcones Fault Zone runs through the south central part of Texas. Running directly through Austin, most of this area is considered to be subtropical humid to sub-humid. The landscape was created somewhere between 27 million and 12 million years ago by tectonic processes, including the extension of the continental crust, causing the many faults in the area. It is a grouping of many normal fault along a fairly large area.
1000 years from now
Since there is little to no seismic activity in the area anymore, I think the Balcones Fault Zone will become shaped by the weathering, erosion and deposition of new sediment. As we have seen this year, the area has become susceptible to long droughts, decreasing the growth of vegetation, and making it more prone to weathering and erosion. As these processes continue, the escarpment will be begin to change.
Actually, it is possible the only reason the escarpment in the Balcones Fault Zone is still so prominent is due to the differential erosion of the rocks.The more resilient rocks resist the weathering processes.
10,000 years from now
The composition of the rocks, mostly limestone, lend themselves to physical and chemical weathering, and erosion. But the different types of limestone are susceptible to different degrees. As differential erosion occurs, the side that once appeared to be up thrown might be eroded to become even with the lower side. Each layer of rock has a different ability to withstand weathering processes. While on side begins to erode faster than the other, a new layer of rock is exposed and might be of a"harder" composition. The steep cliffs of the fault also increase the ability of water to weather and erode the rocks. Slowly, the fault will be weathered and eroded away, and the escarpment will no longer be as obvious as it was once.
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| Possible changes in the fault |
1,000,000 years from now
Eventually, the surface representation of the Balcones Fault will disappear. The escarpment will no longer be distinguishable from the surrounding landscape. It might also be important to point out that many of the faults have become parts of rivers or lakes. As the water weathers and erodes the susceptible limestone, chances of mass wasting from undercutting increase and more quickly change the landscape.
In conclusion
The Balcones Fault Zone was created in an instant (in geologic time). As the landscape of this area is left to the processes of erosion and weathering, the evidence of this massive seismic event will slowly fade away. Perhaps, in the future, another tectonic process will once again reshape the landscape of this area. When the escarpment and rolling hills caused by the Balcones Fault Zone are merely historical data in a geology book (if life on Earth still exists), there maybe another event that becomes part of geographical research.
Sources
http://www.lib.utexas.edu/geo/ggtc/ch3.html
http://www.utexas.edu/depts/grg/kimmel/GRG301K/grg301kkoppen.html
http://www.tshaonline.org
http://water.usgs.gov/ogw/karst/aquifers/edwards/index
