1. Northern Sacramento Valley Geologic Cross-Sections & Sand- Provenance Analysis Geology and Groundwater Conference Kelly Staton November 4, 2009

2. Study Area

3. Geologic Map of the Northern Sacramento Valley with Cross-section Locations A A’ B B’ C’ D’ D D C E E’E’

4. Geologic Cross-Sections

6. Project Time-Line & Background 2000 - Begin drawing cross-sections based on DOGGR geophysical logs & previous literature 2000 - Collect lithology samples & geophysical logs from 2009 DWR oversight of over 50 test-holes drilled in the northern Sacramento Valley. 2006 - Start cross-section revisions using bore hole data 2007 - Perform sand provenance analysis; digitize and finalize geologic map 2008 - Finalize cross-sections and write report 2009 - Review and publish cross-sections, geologic map, and report

7. What We Used to Create the Cross- Sections Observation Well Drilling: Lithology Logs 3627 cutting samples from 38 test holes (approximately 36,270 feet of drilled hole sampled every ten feet) Geophysical Log Resistivity Signature 38 electrical resistivity logs Sand Sample Analysis 56 sand samples from 14 test holes and 5 surface exposure sites

8. What We Used to Create the Cross- Sections Division of Oil, Gas, & Geothermal Resources : Geophysical Log Resistivity Signature 126 electrical resistivity logs used on the cross-sections Reviewed over 500 e-logs Lithology Logs Reviewed over 500 lithology logs (not necessarily for the same gas wells as the e-logs)

9. What We Used to Create the Cross- Sections References/previous literature Major references for contacts Redwine, 1972 Helley and Harwood, 1985, 1987

10. Observation Monitoring Grid Prior to 2000 About 20 Sites (64 wells) Tehama Fm and Tuscan Fm Subsurface and Surface Exposures Tehama Formation Tuscan Formation

11. Observation Monitoring Grid 2000 to 2009 About 40 Sites (161 wells) Tehama Fm and Tuscan Fm Subsurface and Surface Exposures Tehama Formation Tuscan Formation

12. Observation Monitoring Grid Current About 60 Sites 225 wells Tehama Fm and Tuscan Fm Subsurface and Surface Exposures Tehama Formation Tuscan Formation

13. Cutting Samples

14. Observation Well Log Showing: Lithology Logs Well Construction Geophysical Log

15. 10 X Vertical Exaggeration

16. Geologic Contacts

17. Sand Provenance Analysis Raymond Ingersoll, UCLA, and Martin Steinpress, Brown & Caldwell 56 sand samples from 14 test holes and 5 surface exposure sites 300 grain-count per sand sample Statistical analysis; % lithic grains Full report in Appendix B

18. Cross-Section and Sand Sample Location Map

19. Trilinear Diagram Lithic Volcanic, Metamorphic, and Sedimentary Percentages

20. Major Constituents

21. Sand Sample Analysis “Sand Pies” Ls - Lithic Sedimentary Lm - Lithic Metamorphic Lv - Lithic Volcanic

22. Sand Sample Analysis Photomicrographs

23. Tehama Formation Metamorphic & Sedimentary

24. Tuscan Formation Volcanics

25. Intermixing of Formations Lithic Metamorphic Lithic Sedimentary Lithic Volcanic

27. Geologic Report

28. Table of Contents

29. Figure 3 Geochronology of the Northern Sacramento Valley

30. Appendix A Northern Sacramento Valley Sand Provenance Study Ray Ingersoll, UCLA Martin Steinpress, Brown & Caldwell

31. Appendix B Observation Well Logs Showing Lithology Logs, Geophysical Logs, and Well Construction DWR, Northern Region Geologists and Engineers

32. Next Steps Base of Fresh Water Report Hydrogeology - Texture Analysis Water Quality Analysis and Report