4. What rock underlies Point San Quentin: melange, rhyolite, sandstone, serpentinite?
5. What gave its name to Black Diamond Mines: coal, metallurgical sand, shellmound lime, smoky quartz?
6. What makes up the bubbles in our region's hot springs: carbon dioxide, hydrogen sulfide, methane, water vapor?
7. What mineral was mined at New Almaden before the Gold Rush: alabaster, bitumen, cinnabar, orpiment?
8. What resource was used by the native tribes near St. Helena: coal, obsidian, potsherds, steam?
9. What stones whose history involved outer space occur in Sonoma County soils?
10. What rock class is the Great Valley Sequence: igneous, metamorphic, plutonic, sedimentary?
11. What part of California releases the most seismic energy: Bay Area, Central, Northwest, Southern?
12. Where is the Bay Area's most recent volcanism: Clear Lake, Loma Prieta, Mount Diablo, Sutter Buttes?
13. What gemstone is sometimes found at Rodeo Beach: aquamarine, carnelian, moonstone, peridot?
14. What city straddles the Rodgers Creek fault: Colma, Morgan Hill, Santa Rosa, Vacaville?
15. What is the Bluerock district of Antioch named for: blue clay, blue ground, blueschist, celestite?
16. How much damage did the Japanese tsunami of March 2011 cause California: none, $15 million, $100 million, $1 billion?
17. What resource originates in the Monterey Shale: aggregate, ball clay, petroleum, shale?
18. Which South Bay mountain is higher: Fremont Peak, Loma Prieta, Mount Hamilton, Pinnacles?
19. Which North Bay mountain is higher: Geyser Peak, Mount Konocti, Mount St. Helena, Mount Vaca?
20. What rock type underlies Twin Peaks: basalt, chert, granite, sandstone?
Added on December 31:
All right, keyboards down! Following are the answers. Most of them are found in posts I made during the year, and I've linked the answers to those posts. Another helpful post for some of the questions is the list of geologic maps I posted last year. And the US Geological Survey has an easy page for learning about Bay Area earthquake faults and watching their current activity.
1. Calaveras fault
2. Atmospheric rivers
3. San Jose
4. Melange
5. Coal
6. Carbon dioxide
7. Cinnabar
8. Obsidian
9. Tektites
10. Sedimentary
11. Northwest
12. Clear Lake
13. Carnelian
14. Santa Rosa
15. Blue clay
16. $100 million
17. Petroleum
18. Mount Hamilton
19. Mount St. Helena
20. Chert
Hope you enjoyed the quiz. Same time next year!