Sierra Nevada and Klamaths (and Peninsular Range) Study Guide
modern topography: related to basin and range; bedrock related to Mesozoic subduction, breakup of Pangaea, N. America moves west, subduction zone, granitic batholith, roof pendants, foothills terranes,
Accreted terranes: boundaries = faults = sutures; ophiolites, ultra-mafic rocks, Moho, mafic intrusives, sheeted dikes, pillow basalts, ooze and chert; serpentine
Nevadan Subduction Zone (210 my; 120-80 my peak), granitic batholith, volcanics largely eroded (except Minerets caldera), metamorphic roof pendants and inclusions, younger to the east (angle of subduction)
Gold: lode deposits, hydrothermal quartz veins (Mother Lode = Melones Fault), submarine volcanic minerals remobilized by Nevadan magmatism, placer deposits, modern stream gravels, panning; ancient river gravels, hydraulic mining
Describe the main groups of rocks found in the Sierra Nevada.
Describe the evolution of the western margin of North America in the Paleozoic and Mesozoic.
What is an accreted terrane? How do they form? Where are they found in California? What are the boundaries between terranes like?
How did the rocks of the Sierra Nevada form? How are they related to plate tectonics?
How did the gold in California form? Where is it most commonly found? Explain the difference between lode deposits and placer deposits. Describe how placer deposits are mined.
What is an ophiolite? Describe the sequence of rocks typically found in an ophiolite.
Explain why the Sierra Nevada appears as a large, solid red mass on the geologic map of California. Describe the tectonic setting in which these rocks formed. How has the area changed since these rocks formed? How did the modern landscape form?
Describe the rocks represented by the blue and green stripes of rocks in the western foothills of the Sierra. How did they get there? What are the thin strips of purple that are mixed in with them? How did the purple get there?