Geology Class Readings Is There Earthquake Weather (Sean Greene, Bay Nature Magazine, 2013) Plate Tectonic Framework (Doris Sloan, Geology of the San Francisco Bay Region, U.C. Press, 2006) Geology – Helpful Definitions Rock Cycle (2 versions) Geologic Time Scale, standard Geologic Time Scale, clock version Geologic Map of Sonoma County Geology Activity: Field Test for Igneous Rocks Geology Activity: Rock to Rock, a fantasy journey Geology Activity: Adopt‐a‐Rock Water Cycle/Watershed Activities by Dr. Rocky Rohwedder CALNAT: California Naturalist Handbook Chapter 2 Key Concepts: By the end of this class, we hope you will be able to: Understand that geology “rocks,” not just because it is about rocks, but because it explains so much about the whole world, Name the three main types of rocks found on Earth and explain the basics of how they form by describing the rock cycle, Understand the connection between geology and groundwater (e.g. Why did the water level in Stuart Creek go up after the August 2014 earthquake?), Recognize obsidian and explain its significance for projectile points and the history of this area, Place Bouverie Preserve in a watershed and get young learners to imagine and discuss human impacts on watersheds, and Convey to 3rd and 4th graders that rocks and landforms can tell us a story about local history. For Further Study Recommended Reading Geology of the San Francisco Bay Region by Doris Sloan (U.C. Press, 2013) Roadside Geology of Northern & Central California by David Alt & Donald Hyndman (Mountain Press, 2016) Assembling California by John McPhee (Farrar, Straus and Giroux, 1994) A Land in Motion by Michael Collier (U.C. Press, 1999) Geologic Trips: San Francisco and the Bay Area by Ted Konigsmark (Geopress, 1998) Trail Tip Face Painting and Earth to Art! Materials: Small rhyolitic creek rocks of different colors and one slightly larger hard gray rock How: Wet the small, colored rocks (they will be chalky) and rub them on the larger, harder gray rock until a thin paste is formed. Dip your finger into the paste and “face paint” yourself or another student. The natural pigment can also be used for making pictures in field journals. NOTE: Make sure to Leave No Trace by rinsing and replacing rocks when finished with activity. ONLINE RESOURCES News and Information about geology and earth sciences including a broad survey of geological topics and fun facts at http://geology.com/ The U.S. Geological Survey website has educational materials for teachers and students including lessons, data, maps, and more http://education.usgs.gov Geology for Kids at http://www.kidsgeo.com/ contains child‐friendly links for information on earth sciences, volcanoes, rocks and minerals. There are similar resources for other topics including Astronomy, Biology, Botany, Chemistry, Ecology, Entomology, Herpetology, Meteorology, Ornithology, Science ‐ Science Fair/Projects, Space and World Science at http://www.kidsknowit.com/ Sonoma County virtual geology field trips with former Sonoma State University Professor Terry Wright (http://www.terrywrightgeology.com/fieldtrips.html Is There Earthquake Weather? And Was That It? by Sean Greene on October 16, 2013 A summer sunset -- having nothing at all to do with earthquakes -- from Panoramic Hill in Berkeley, just south of the epicenter of Monday's 3.2 quake. Photo: D.H. Parks I made a $100 bet on Monday that there wouldn’t be an earthquake. I was eating lunch in the courtyard at the Berkeley Graduate School of Journalism, where I am a student, and a classmate claimed, “This is earthquake weather!” I told her there’s no such thing, and the bet was on. We shook on our left hands because I was still holding a sandwich. Twelve hours later, around 1 a.m. on Tuesday, the ground shook. Not much, but enough to make me kick myself. It was a tiny magnitude 3.2, with its epicenter in Tilden Park. Does weather really cause earthquakes? Is there such thing as “earthquake weather?” Was this week earthquake weather? I called the Berkeley Seismology Lab to ask the experts. The answer from Cal seismologist Dr. Peggy Hellweg was decidedly confident. “No. The short answer is no,” she said. “No such thing as earthquake weather.” Warm fall days are what people typically think of as “earthquake weather.” But in reality, earthquakes happen all the time, “so they’re independent of weather,” Hellweg said. Before humans found out about plate tectonics, we had some interesting ways to explain earthquakes. Aristotle thought earthquakes were caused by winds trapped in underground caves. Hellweg said the Japanese believed there was a big catfish underground that caused earthquakes. In India, legend suggested the earth was sitting on the back of an elephant. When the elephant moved, there were earthquakes. When we talk about earthquake weather, we’ve probably already got earthquakes on our minds, Hellweg said. On Monday, there was a 7.2 quake in the Philippines. And few weeks ago, there was a 3.1 centered in Berkeley. In other words, when there’s one earthquake, people start to notice them more. “The little earthquakes that you feel are a good reminder to keep your earthquake kit ready,” Hellweg said. As we’re all busy noticing earthquakes, the Great California Shakeout, the country’s largest earthquake disaster drill, arrives on Thursday — just in time. Every year, the drill falls right in the midst of “earthquake season,” or more accurately, in October. The drill hits at 10:17 a.m. (The time always corresponds with the date.) It’s timed to remind students returning to school of proper protocol in the event of the “Big One.” This year’s Shakeout happens to coincide with the 24th anniversary of the Loma Prieta earthquake, a magnitude 6.9 also known as the World Series Earthquake. While there’s no such thing as “earthquake weather,” it’s unwise to place bets on the likelihood of a quake. Luckily my classmate forgave the debt. The Hayward Fault is fairly active and there are lots of small tremors happening all the time. That makes for some poor betting odds. Sean Greene is a graduate student at the UC Berkeley Graduate School of Journalism and a Bay Nature intern. Some Helpful Definitions BASALT is a dark, igneous rock. The Hawaiian Islands are made of basalt. The volcanoes at seafloor spreading centers erupt basalt. ________________________________________________________________ CHERT is a hard, sedimentary rock made of silica (glass). In the Bay Area, chert is colorful, and often forms layers a few inches thick. Bay Area chert is full of microscopic fossils, called radiolarians. Radiolarian chert is formed on the deep ocean floor. ________________________________________________________________ CONVECTION is a type of heat transfer where hot material rises and cooler material sinks, as in a pot of boiling water. Convection currents in the mantle move the tectonic plates. ________________________________________________________________ A CONVERGENT PLATE BOUNDARY is a boundary where two tectonic plates collide, and the Earth’s crust is folded and compressed, or CONSUMED by subduction. ________________________________________________________________ The CORE is the layer at the center of the Earth. The INNER CORE is solid and probably made of iron. The OUTER CORE is liquid and also probably made of iron. The core of the Earth is VERY HOT, around 10,000ºF! ________________________________________________________________ The CRUST is the Earth’s outer layer. It’s the familiar rock and soil we walk on, and it’s what the oceans rest upon. Ocean crust is thinner but denser (heavier) than continental crust. ________________________________________________________________ A DIVERGENT PLATE BOUNDARY is a boundary where two tectonic plates move apart, and where new crust is created. ________________________________________________________________ The FRANCISCAN FORMATION is the name applied to all of the crumpled and mashed seafloor rocks that form most of the Coast Range of California. ________________________________________________________________ GRAYWACKE SANDSTONE is a sedimentary rock made of different-colored and different-sized angular sand grains and rock pieces. Graywacke forms near subduction zones. ________________________________________________________________ The MANTLE is the middle layer of the Earth. The upper mantle is gooey, like melting plastic or silly putty. The deeper mantle is solid. ________________________________________________________________ PILLOW BASALT is lava that erupted underwater. When the HOT lava contacts COLD seawater, it hardens into blobs (or “pillows”). Most of the pillow basalt found in the Bay Area formed at a seafloor spreading center. ________________________________________________________________ RADIOLARIANS are plankton found in the ocean. They are single-celled, with beautiful skeletons made of silica. ________________________________________________________________ A SEAFLOOR SPREADING CENTER is a type of divergent plate boundary found in the ocean. New seafloor is created at seafloor spreading centers. There are about 43,000 miles of seafloor spreading centers around the world. ________________________________________________________________ SERPENTINE (Serpentinite) is a gray, green, or blue slick rock, altered by seawater. It forms in the upper mantle and squeezes into rock layers like toothpaste. Serpentine (or Serpentinite) is the state rock of California. ________________________________________________________________ SUBDUCTION is the process in which