Joints

• Joints -- outcrop showing four sets of joints
• Joints -- outcrops showing 3 sets of orthogonal joints
• Joints -- two sets of joints in ultramafic rocks  

Normal, Thrust and Reverse Faults

• Cross-section of normal faults -- vertical roadcut exposing layers offset by two normal faults
• Scarp of normal fault -- created in 1969 Montana earthquake
• Aerial view of normal fault scarp -- fault offsets glacial moraines at mouth of McGee Cr
• Normal fault scarp -- ground photo of normal fault offsetting McGee Cr. glacial moraines by 75 ft
• Normal fault scarp -- aerial view of scarps on E side of Klamath Lake
• Normal fault scarp -- closer view of Klamath Lake scarp showing fresher surface
• Normal fault scarp -- close up of fresh portion of Klamath Lake scarp
• Normal fault scarp -- E side of Sierra Nevada
• Graben -- valley formed by downdrop along two normal faults that face each other. This one is quite young.
• Eroded normal fault scarp -- inactive scarp has been cut by streams to form triangular facets
• Eroded normal fault scarp -- inactive scarp has been cut by streams to form facets
• Thrust fault -- Dacite thrust over younger pyroclastic deposits; exposed in roadcut in Lake Co. CA

Strike-Slip Faults -- Physical evidence for inferring fault location and activity

• Offset sidewalk -- evidence for creep along San Andreas Fault in Hollister, CA
• Offset wall -- evidence for creep along San Andreas Fault in Hollister, CA
• Offset gullies -- evidence for movement along San Andreas Fault, Carrizo Plains
• Offset ridges -- evidence for movement along San Jacinto Fault near Hemet, CA
• Sag ponds and pinch-up ridges -- these mark the trace of the San Andreas Fault as it crosses the Carrizo Plains
• Sag pond -- small pond formed along trace of San Andreas fault -- suggests fault is active because such ponds typically are filled within a few thousand years if not rejuvenated by continued fault movement
• Line of sag ponds -- this line of ponds north of San Jose marks the trace of the San Andreas Fault
• Fault gouge -- brecciated (sheared and broken ) granite along the trace of the San Andreas. This material is weak and easily eroded.
• Linear fault valley -- the valley of the Garcia River in Mendocino Co. follows the weaker sheared rocks along the trace of the San Andreas Fault.
• Fault zones near San Francisco -- map showing the major branches of the San Andreas Fault south and east of San Francisco
• Linear fault valley -- the trace of the San Andreas on the San Francisco Peninsula is marked by a prominent linear valley eroded in the weaker sheared rocks along the fault.
• Linear fault valley -- aerial view NW along the San Andreas fault on the San Francisco Peninsula
• Linear fault valley -- another aerial view NW along the San Andreas on the San Francisco Peninsula
• A geological nightmare, or how to do everything wrong -- trace of San Andreas near Mussel Rocks south of San Francisco. Development is built directly across fault zone, partially on fill, partially on weak unconsolidated rocks near steep, landslide-prone cliff.
• Hayward Fault -- air photo showing trace of Hayward Fault through Berkeley
• Offset fence -- fence near Olema offset 2.5 m by 1906 earthquake on San Andreas
• Groundwater effects -- in this area near Palmdale, the San Andreas acts as a barrier to groundwater flow, causing a difference in vegetation density across the fault. The fault can easily be mapped on this basis.

Folds

• Flat lying sediments -- Grand Mesa, CO. Resistant layers form cliffs.
• Aerial view of flat-lying sediments -- note that their outcrop pattern looks like contours
• Cuesta scarp -- eroded edge of a seies of beds tilted to the right
• Anticline -- moderately eroded surface of Sheep Mtn. anticline
• Anticline -- cross-section of Sheep Mtn. anticline where river has cut it
• Plunging anticline -- deeply eroded portion of Sheep Mtn. anticline; anticline plunges to the right
• Syncline -- cross-section exposed in mountain in Alaska
• Eroded syncline and anticline -- note that the center of the syncline forms the crest of a ridge
• Structural basin 

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