1. Introduction to Groundwater, Karst and the Edwards Aquifer Water color by Kathy Rottier

3. Groundwater Zones

4. Alternate image of groundwater zones

5. Porosity

6. Permeability

7. Types of groundwater flow

8. Aquifer Recharge and Discharge

9. Groundwater flow timescales

10. Artesian groundwater systems

11. Water: the great dissolver and precipitator Dissolves:Precipitates: Limestone, gypsum, salt (makes caves and landscapes these rocks) Cave deposits (stalactites, travertine, etc) Cements that hold sedimentary rocks together (calcareous, siliceous, and ferruginous) Few minerals from sandstones, shales, and igneous and metamorphic rocks (does not make caves in these rocks) Spring and geyser deposits Concretions and geodes

12. Limestone Dissolution H 2 O + CO 2 = H 2 CO 3 water + carbon dioxide = carbonic acid H 2 CO3 + CaCO 3 = Ca ++ + 2 HCO 3 - carbonic acid + calcium carbonate (limestone) = calcium ions + bicarbonate ions

13. Karst Development: Initial Stage

14. Karst Development: Intermediate Stage

15. Karst Development: Late Stage

16. Karst Terrain Mike Warton

17. Geologic History of the Edwards Aquifer

21. Uplifting and Earthquakes

22. The Edwards Aquifer

23. Barton Springs Segment (map view)

25. Barton Springs Segment (cross-section view)

29. Inner Space Caverns Photos by Marsha Willis

30. Longhorn Caverns ’Photos by Larry Jayroe

31. Photo Credit: City of Austin <http://www.ci.austin.tx.us/watershed/images/ bartonaerial.jpg>,accessed September 22, 2008

32. Barton Springs Pool

35. Example Hydrograph

36. Discharge at Barton Springs January 1980 – September 2008 Source: USGS,accessed September 19, 2008

37. Source: http://media.point2.com/p2a/htmltext/d51f/3a57/e5a5/4d13a91f bcd071034cf8/original.jpg, accessed September 22, 2008 The End