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Recognizing and Characterizing Thrust Faults and Earthquakes in the Himalaya

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Recognizing and Characterizing Thrust Faults and Earthquakes in the Himalaya 2464-6 Earthquake Tectonics and Hazards on the Continents 17 - 28 June 2013 Recognizing and characterizing thrust faults and earthquakes in the Himalaya S. G. Wesnousky Univ. of Nevada USA Extension and Transtension in the Basin and Range and the Walker Lane Trieste 2013 Wesnousky Just how ‘rigid is the Does ‘CNSB’ continue interior of the Great Basin? northward beyond what we see Historically? Is Spatial and Temporal clustering of earthquakes unique to CNSB? Are the patterns of contemporary seismicity and strain accumulation reflected in record of fault displacements during latest Quaternary Where and how is strain accumulation accommodated in Walker Lane? What characteristics are shared (or not) in manner crustal strain is accommodated in Walker Lane and San Andreas Fault Systems? Qfi Qbf(l) Qfy 39º30' faceted rangefront Generalized regional Quternary stratigraphy Qfy Br Edwards QTp Br Br Br Qfi 7º42'30" Creek Qfo Br 11 Br Br Qfo Br Qfi Valley Qfy Qfi Qfi Qfy Qfy Qfi Qfy Qfi Qfi Qfi playette Qfi Qbf(l) Qfi Qfy Qfi Qbb Br ? Qbb (shorelines) Qfy Qfy Qfy ? v-bar Qfi Qfy Qfy Qbf (playa) Qfy Hd (dunes) Br ? Qfo Qbf (playa) Qfy ? Qfi 39º27'30" stream deposits Qfi ? 117º45' Qfy Trench Edwards Qfi/Qfo? ? Figure 3. Qfy Qfi Qfo Creek S.H. ~6 m Qfi ? Qfo Koehler, 2009, Fig 8A Qfo ? Qfy Desatoya Range Qfo North 0 1 2km Scale ~60 cm thick Figure 5. stage II carbonate soil 6 5 7 4 West side Desatoya Range, Edwards Creek trench log ? 3 6 K 1 4 2 5 ??? Depth (m) 3 1 1 0 2 02468101214161820 22 24 2628 30 Distance (m) Figure 6. time Scarps degrade as function of time Wallace (1977) time time If scarp age = 5500 years, then κ is about 1.2 View northwest across Shawave Mountains Lake Range West-tilted fault block - ridgelines exceed 2100 m with adjacent flats ~1200 mSelenite Range Nightingale Range Humoldts A horst 4600 and ~1900 years ~2900m elevation ~1300 m adjacent basins ago Greater uplift and dissection of older alluvial surface Post-Lahontan fault scarp (~2m) Lahontan highstand shoreline I-80 to Reno ImlayImlay Sonoma Range Bacon Canyon Trench Site Scarp formed 20ka… Sonoma Range East-tilted fault block ~1300 m vertical relief Highest ridges ~2700 m Shoshone Range - Lewis Canyon Mt Lewis ~2800 m adjacent valley fill ~1400 m Progressive offset of fan surfaces - most recent displacement ~3300 years ago Proceeded by another ~40,000 years ago… Horizontal Extension Across Interior of Basin and Range Just how ‘rigid is the Does ‘CNSB’ continue interior of the Great Basin? northward beyond what we see Historically? Is Spatial and Temporal clustering of earthquakes unique to CNSB? Are the patterns of contemporary seismicity and strain accumulation reflected in record of fault displacements during latest Quaternary Where and how is strain accumulation accommodated in Walker Lane? What characteristics are shared (or not) in manner crustal strain is accommodated in Walker Lane and San Andreas Fault Systems? W E S ~200KM T E R N S A G N R A E N A D T 38°N R E B A A 122° S S 4 F 0° A I N Mohawk Valley 36°N U L T SY ~20-30 km ST EM S ~50 mm/yr Honey Lake PACIFIC i PLATE 114°W e 120°W Warm Springs 39° r r a Pyramid Lake 21° 1 1. Tahoe 1 Olinghouse 2. Carson Carson L. 2 38° 3 Wabuska L. 3. Smith 4 4. Mason 5 Agai Pai Indian Head 5. Antelope 6 Gumdrop 6. Bridgeport 7 >34 km 7. Walker Lake Petrified 120° Rattlesnake Springs 37° Teels Marsh Benton Candelaria Springs 117° Coaldale N Fish Lake e Valley - v White ~>50 km Mtn 36 a ° Furnace d Creek - a 119° Owens Stateline Valley Sierran Rangefront 35° Saline- Death Hunter Mountain- Valley ° 8 1 1 Panamint View North along Owens Valley Fault Sierra Nevada Shephard Creek - Sierra Rangefront Partitioning of Oblique Slip between strike-slip and dip slip... View South along Furnace Creek Strike-Slip toward Death Valley W E S ~200KM T E R N S A G N R A E N A D T 38°N R E B A A 122° S S 4 F 0° A I N Mohawk Valley 36°N U L T SY ~20-30 km ST EM S ~50 mm/yr Honey Lake PACIFIC i PLATE 114°W e 120°W Warm Springs 39° r r a Pyramid Lake 21° 1 1. Tahoe 1 Olinghouse 2. Carson Carson L. 2 38° 3 Wabuska L. 3. Smith 4 4. Mason 5 Agai Pai Indian Head 5. Antelope 6 Gumdrop 6. Bridgeport 7 >34 km 7. Walker Lake Petrified 120° Rattlesnake Springs 37° Teels Marsh Benton Candelaria Springs 117° Coaldale N Fish Lake e Valley - v White ~>50 km Mtn 36 a ° Furnace d Creek - a 119° Owens Stateline Valley Sierran Rangefront 35° Saline- Death Hunter Mountain- Valley ° 8 1 1 Panamint View westward next slide 35cm contour interval View eastward Diatomaceous Beds of Stewart (84) Lower Tuffs of Badlands at Willow Wash ~2.6-2.8 m.y. View southeastward W E S ~200KM T E R N S A G N R A E N A D T 38°N R E B A A 122° S S 4 F 0° A I N Mohawk Valley 36°N U L T SY ~20-30 km ST EM S ~50 mm/yr Honey Lake PACIFIC i PLATE 114°W e 120°W Warm Springs 39° r r a Pyramid Lake 21° 1 1. Tahoe 1 Olinghouse 2. Carson Carson L. 2 38° 3 Wabuska L. 3. Smith 4 4. Mason 5 Agai Pai Indian Head 5. Antelope 6 Gumdrop 6. Bridgeport 7 >34 km 7. Walker Lake Petrified 120° Rattlesnake Springs 37° Teels Marsh Benton Candelaria Springs 117° Coaldale N Fish Lake e Valley - v White ~>50 km Mtn 36 a ° Furnace d Creek - a 119° Owens Stateline Valley Sierran Rangefront 35° Saline- Death Hunter Mountain- Valley ° 8 1 1 Panamint 50cm contour interval 1 meter contour interval View northward Clan Alpines Stillwater Range Fairview Peak Monty Cristos Mystery Ridge Gabbs Valley Petrified Springs Fault W E S ~200KM T E R N S A G N R A E N A D T 38°N R E B A A 122° S S 4 F 0° A I N Mohawk Valley 36°N U L T SY ~20-30 km ST EM S ~50 mm/yr Honey Lake PACIFIC i PLATE 114°W e 120°W Warm Springs 39° r r a Pyramid Lake 21° 1 1. Tahoe 1 Olinghouse 2. Carson Carson L. 2 38° 3 Wabuska L. 3. Smith 4 4. Mason 5 Agai Pai Indian Head 5. Antelope 6 Gumdrop 6. Bridgeport 7 >34 km 7. Walker Lake Petrified 120° Rattlesnake Springs 37° Teels Marsh Benton Candelaria Springs 117° Coaldale N Fish Lake e Valley - v White ~>50 km Mtn 36 a ° Furnace d Creek - a 119° Owens Stateline Valley Sierran Rangefront 35° Saline- Death Hunter Mountain- Valley ° 8 1 1 Panamint ~5 mm/yr 5 mm/yr oblique view 20-30 km >32 km 5 mm/yr oblique view 20-30 km >32 km W E S ~200KM T E R N S A G N R A E N A D T 38°N R E B A 122° 40 S A S F A I ° N Mohawk Valley 36°N U basins L T S YS The modes ~20-30 km T EM S ~50 mm/yr Honey Lake PACIFIC i PLATE 114°W e 120°W of deformation r Warm Springs 39 ° r a Pyramid Lake are 121° 1. Tahoe 1 Olinghouse 2. Carson Carson L. Basins 2 many 38° 3 Wabuska L. 3. Smith 4 4. Mason 5 Agai Pai Indian Head 5. Antelope and complex 6 Gumdrop 6. Bridgeport 7 >34 km 7. Walker Lake Petrified 120° Rattlesnake Springs 37° Teels Marsh Benton Candelaria Springs 117° somewhat Coaldale N Fish Lake more so e Valley - v White ~>50 km Mtn 36 a than ° Furnace d Creek - a the 119° Owens Stateline Valley San Andreas... Sierran Rangefront 35° Saline- Death Hunter Mountain- Valley ° 18 1 Panamint Walker Lane fault system San Andreas fault system Greater cumulative slip and a component of compression along the San Andreas system leads to a simpler pattern of active faulting than observed along the transtensional Walker Lane system 5mm/yr Transverse Range , California Thrusting in A Strike-Slip Environment Trieste 2013 Wesnousky with thanks to James Dolan who provided the majority of the following slides and did much of the work described. Thrust faulting tends to occur where the San Andreas is not aligned with the Pacific-North American plate motion vector. GPS Site Velocity Vectors for Southern California courtesy James Dolan The San Andreas fault in Southern California NIF courtesy James Dolan Major faults of the Los Angeles region Dolan et al. (1995) courtesy James Dolan courtesy James Dolan courtesy James Dolan Cucamonga Fault (Strand C) courtesy James Dolan Colluvial Wedge Cucamonga MRE Cucamonga Fault Fault (Strand C) (Strand C) courtesy James Dolan James Mori courtesy James Dolan The Puente Hills ThrustBlind fault Thrust(PHT) Faults are Common in southern California, but how do we determine ages and displacements Cut-away in past view eqs of on Geometry of PHT these and overlying faults? fold The PHT is a “blind” thrust fault (does not extend all the way up to the Earth’s surface) courtesy James Dolan courtesy James Dolan courtesy James Dolan courtesy James Dolan - work of Shaw and students Major faults of the Los Angeles region Dolan et al.
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