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Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225, 1–888–ASK–USGS Digital files available at http://dx.doi.org/10.3133/pp1812 Suggested citation: Hildreth, Wes, and Fierstein, Judy, 2016, Eruptive history of Mammoth Mountain and its mafic periphery: U.S. Geological Survey Professional Paper 1812, 128 p., 2 plates, scale 1:24,000, http://dx.doi.org/10.3133/pp1812. ISSN 1044-9612 (print) ISSN 2330-7102 (online) http://dx.doi.org/10.3133/pp1812 Eruptive History of Mammoth Mountain and its Mafic Periphery, California By Wes Hildreth and Judy Fierstein 2016 U.S. Department of the Interior U.S. Geological Survey Professional Paper 1812 Plate 2 of 2 Pamphlet accompanies map LIST OF MAP UNITS [Uniform black stipple indicates units partly or wholly pyroclastic. See Description of Map Units (in pamphlet) for complete unit descriptions] SURFICIAL DEPOSITS Phreatic ejecta (late Holocene) Pumice deposits (late Holocene) Rock glacier deposits (Holocene) Spring deposits (Holocene and late Pleistocene) Alluvium, undivided (Holocene and late Pleistocene) Alluvial fan deposits (Holocene and late Pleistocene) Older alluvium (late and middle Pleistocene) Precaldera alluvium (early Pleistocene) Rockfall avalanche deposits (Holocene and late Pleistocene) Surficial deposits, undivided (Holocene and late Pleistocene) Explosion breccia deposit of Bailey (late Pleistocene) Diamict of lower Mammoth Creek (late Pleistocene) Sandstone of Long Valley Lake (middle Pleistocene) Siltstone of Long Valley Lake (middle Pleistocene) GLACIAL DEPOSITS Till of Cold Water Canyon (late Pleistocene) Till of Dry Creek (late Pleistocene) Till derived from Lakes Basin (late Pleistocene) Till derived from Mammoth Mountain (late Pleistocene) Undivided glacial deposits (late and middle Pleistocene) Casa Diablo Till (latest middle Pleistocene) Sherwin Till (late early Pleistocene) QUATERNARY VOLCANIC ROCKS SAN JOAQUIN Trachyandesite of Cone 2962 (late Pleistocene) Trachyandesite of Pumice Butte (middle Pleistocene) Trachybasalt west of Deer Creek (middle Pleistocene) Basalt of Red Cones (Holocene) Trachydacite of Rainbow Falls (late Pleistocene) Basaltic trachyandesite of Devils Postpile (late Pleistocene) Basaltic trachyandesite of upper Soda Springs (late Pleistocene) MAMMOTH MOUNTAIN Trachyandesite of Mammoth Pass (late Pleistocene) Trachydacite of Bottomless Pit (late Pleistocene) Trachydacite of lower Dragons Back (late Pleistocene) Trachydacite of upper Dragons Back (late Pleistocene) Trachydacite of Face Lift (late Pleistocene) Trachydacite of Gold Rush Express (late Pleistocene) Trachydacite of Lincoln Peak (late Pleistocene) Trachydacite of Main Lodge Coulee (late Pleistocene) Trachydacite of McCoy Station (late Pleistocene) Trachydacite north of Horseshoe Lake (late Pleistocene) Trachydacite of North Knob (late Pleistocene) Trachydacite of Old Mammoth (late Pleistocene) Trachydacite of upper Reds Creek (late Pleistocene) Trachydacite of South Summit Dome (late Pleistocene) Trachydacite of Skyline Dome (late Pleistocene) Trachydacite of Mammoth Mountain summit (late Pleistocene) Trachydacite of Twin Lakes outlet (late Pleistocene) Trachydacite of White Bark Ridge (late Pleistocene) Trachydacite of Dome 2861 (late Pleistocene) Trachydacite of Dome 2781 (late Pleistocene) Alkalic rhyodacite of Canyon Express (late Pleistocene) Alkalic rhyodacite pumice fall of Highway 203 (late Pleistocene) Alkalic rhyodacite of Mammoth Mountain fumarole (late Pleistocene) Alkalic rhyodacite of Reds Creek (late Pleistocene) Alkalic rhyodacite of Quicksilver ski run (late Pleistocene) Alkalic rhyodacite of Solitude ski run (late Pleistocene) SOUTH MOAT AND LAKES BASIN Trachyandesite of McLeod Lake (late Pleistocene) Trachyandesite of Shady Rest Campground (middle Pleistocene) Basalt of Casa Diablo Hot Springs (late Pleistocene) Basalt east of Dry Creek (late Pleistocene) Basalt of Fish Hatchery (late Pleistocene) Basalt of Horseshoe Lake (late Pleistocene) Basalt of Mammoth Crest (late Pleistocene) Trachybasalt of Sherwin Creek Road (middle Pleistocene) Basalt of Sawmill Cutoff (middle Pleistocene) Trachybasalt of Shady Rest (late Pleistocene) Basaltic trachyandesite of Canyon Lodge (middle Pleistocene) Basaltic trachyandesite of Knolls Vista (middle Pleistocene) Basaltic trachyandesite of lower Laurel Creek (middle Pleistocene) Basaltic trachyandesite of Mammoth Creek (middle Pleistocene) Basaltic trachyandesite of Sawmill Cutoff (middle Pleistocene) WEST MOAT Trachyandesite of Inyo Craters (late middle Pleistocene) Trachybasalt of Arcularius Ranch (late Pleistocene) Trachybasalt south of Crater Flat (middle Pleistocene) Trachybasalt northeast of Minaret Summit (late Pleistocene) Trachydacite of Dry Creek (late Pleistocene) Trachydacites of northwest moat (late Pleistocene) Basaltic trachyandesite south of Crestview (late Pleistocene) Basaltic trachyandesite of Deer Mountain (late or middle Pleistocene) Basaltic trachyandesite northeast of Deadman Pass (late Pleistocene) Mafic pyroclastic deposit of Inyo Craters (Holocene or late Pleistocene) Basaltic trachyandesite northwest of Dry Creek (late Pleistocene) Basaltic trachyandesite of Owens River Road (late Pleistocene) Basaltic trachyandesite scoria southeast of Dry Creek (late Pleistocene) Basaltic andesite of Scenic Loop Road junction (late or middle Pleistocene) LONG VALLEY AND INYO CHAIN Bishop Tuff (middle Pleistocene) Rhyolite of Cratered Dome (Holocene) Rhyolite of caldera wall (Holocene) Rhyolite of Dry Creek Dome (late Pleistocene) Rhyolite of Deer Mountain (late Pleistocene) Early rhyolite of Bailey (middle Pleistocene) Lookout Mountain subunit Tuff of Little Antelope Valley subunit Pumice Cone 2368 subunit Tuff east of Casa Diablo subunit Rhyolite of Hot Creek flow (middle Pleistocene) Rhyolite and rhyodacite of Inyo chain (1350 C.E.) Rhyolite of Mammoth Knolls (late Pleistocene) Rhyolite of north-central chain (middle Pleistocene) Rhyolite of North Deadman Creek Dome (Holocene) Rhyolite of West Moat Coulee (middle Pleistocene) TERTIARY VOLCANIC ROCKS SAN JOAQUIN AND SIERRA NEVADA Trachyandesite of Crater Creek (Pliocene) Trachyandesite of San Joaquin River (Miocene) Trachybasalt south of Lost Dog Lake (Pliocene) Trachybasalt east of Pond Lily Lake (Pliocene) Basalt of The Buttresses (Pliocene) Basaltic trachyandesite west of Cabin Lake (Pliocene?) Basaltic trachyandesite south of Upper Crater Meadow (Pliocene) Basaltic trachyandesite west of Crater Creek (Pliocene) Basaltic trachyandesite of Emerald Lake (Pliocene?) Basaltic trachyandesite south of Deer Creek (Pliocene?) Basaltic trachyandesite west of Castle Lake (Pliocene?) LAKES BASIN Trachybasalt of Mammoth Mine (Pliocene) Basalt of Red Mountain (Pliocene) Basaltic trachyandesite of Mammoth Crest (Pliocene) WEST WALL Trachydacite pyroclastic-density-current deposit of Deadman Pass (Pliocene) Trachybasalt of Deadman Pass (Pliocene) Trachydacite of Dome 3321 (Pliocene) Trachydacite block-and-ash-flow deposits of San Joaquin Ridge (Pliocene) Trachydacite complex of upper Deadman Creek (Pliocene) Trachydacite of White Wing Mountain (Pliocene) Trachydacite of Dome 2965 (Pliocene) Basaltic trachyandesite of White Wing Mountain (Pliocene?) NORTH WALL Trachyandesite east of Crestview (Pliocene) Trachyandesite north of White Wing Camp (Pliocene) Basalt east of Big Springs (Miocene) Trachybasalt and basaltic trachyandesite of Cone 8478 (Pliocene) Trachydacite of Dome 7835 (Pliocene) Trachydacite of Dome 8325 (Pliocene) Basaltic trachyandesite of Crestview (Pliocene) Basaltic trachyandesite west and east of Obsidian flow (Pliocene) Rhyolite tuff of Alpers Canyon (Miocene) SOUTH WALL Trachydacite of Laurel Mountain (Pliocene) PRE-CENOZOIC BASEMENT ROCKS [Listed in order of increasing age] Mono Creek Granite (Late Cretaceous) Round Valley Peak Granodiorite (Late Cretaceous) Granite of June Lake (Late Cretaceous) Granite of Big Springs (Jurassic?) Granodiorite northeast of Minaret Summit (Mesozoic) Metavolcanic rocks of Ritter Range pendant (Mesozoic) Metasedimentary rocks of Mount Morrison pendant (Paleozoic) EXPLANATION OF MAP SYMBOLS Contact—Long-dashed where approximately located; short-dashed where inferred; dotted where concealed; dash-dot line for internal contact within unit Fault—Bar and ball on downthrown side; dashed where approximately located; dotted where concealed Volcanic craters and partial crater rims—Hachures point inward Volcanic fissure vent Surficial rift or fissure on lava flow (not a vent) Lava flow direction Moraine crests Strike and dip of ejecta, stacks of thin lava flows, and sandstone Inclined Vertical Horizontal Volcanic vent (other than craters and fissures) Rootless volcanic vent (other than craters and fissures) 25 pe p rg sd al fan oal pal av s eb lmd ss st gcc gdc glb gmm gud gcd gst a62 apb bdc brc drf mdp mss amp dbp ddl ddu dfl dgr dlp dml dms dnh dnk dom drc dsd dsk dsu dtl dwr d61 d81 rce rfp rmf rrc rsq rss aml asr bcd bed bfh bhl bmc bsc bsm bsr mcl mkv mlc mmc msc aic bar bar' bcf bmn bmn' ddc dnw mcv mdm mdn mdn' mic mnd mor msd msj rbt rcd rcw rdc rdm rer rlm rtav r68 rtcd rhc rhc' ric rmk rnc rnd rwm Tacc Tasj Tbld Tbpl Tbtb Taec Tmcl Trac Tmcm Tmcw Tmel Tmsd Tmwc Tbmm Tbrm Tmcr Tdpd Tbdp Tdsd Tdsj Tdud Tdww Td65 Tmww Taww Tbbs Tb84 Td78 Td83 Tmcv Tmwo Tdlm Kmo Krv Krv' Kjl Jbs gd mv ms 11.7 ka 126 ka 788 ka 5.3 Ma 2.58 Ma 65.5 Ma 251 Ma Tacc Tasj Tbld Tbpl Tbtb Tmcm Tmcl Tmcw Tmel Tmsd Tmwc Tdpd Tdsd Tdsj Tbdp Tdud Td65 Tdww Tmww bcd bed bfh bhl bmc bsc bsm bsr mcl mkv mlc mmc msc aml asr bcf bmn ddc dnw mcv mdn mdn' mdm mic mor mnd msj msd aic bar bar' dbp ddl ddu dfl dgr dms dlp dml dnk dom drc dsd dnh dsk dtl dsu d61 dwr d81 rce rfp rmf rrc rsq rss amp rbt rcd rcw rdm rdc rlm rtav r68 rtcd rer rhc rhc' ric rmk rnd rnc rwm bdc brc drf mdp mss a62 apb sd pe p rg rg' oal pal fan al av lmd ss st s eb gcc gdc glb gmm gud gst Tmcr Tbmm Tbrm Taec Taww Tb84 Tbbs Td78 Td83 Tmwo Trac Tmcv Tdlm Jbs Kmo Krv Krv' Kjl ms mv gd gcd Middle Pleistocene Early Pleistocene Pliocene Miocene MESOZOIC CENOZOIC PALEOZOIC Late Pleistocene Holocene (1350 C.E.) CORRELATION OF MAP UNITS [Extended boxes indicate known age ranges for long-lived units. See Description of Map Units (in pamphlet) for specific unit age assignments] SURFICIAL DEPOSITS AGE GLACIAL DEPOSITS QUATERNARY VOLCANIC ROCKS SAN JOAQUIN AND SIERRA NEVADA WEST CALDERA WALL SOUTH MOAT AND LAKES BASIN WEST MOAT MAMMOTH MOUNTAIN LONG VALLEY AND INYO SUITES SAN JOAQUIN LAKES BASIN NORTH CALDERA WALL SOUTH CALDERA WALL PRE-CENOZOIC BASEMENT ROCKS TERTIARY VOLCANIC ROCKS Basaltic scoria cone 5 km south-southwest of Mammoth Mountain summit. The cone is 120 m high and 500 m wide and has a twin cone just south of it (see fig. 10). Named Red Cones, the pair erupted concurrently about 8,000 years ago, representing the most recent magmatic eruption of the entire Mammoth system. Both cones are breached to the west, where they jointly formed an agglutinate fan, which fed a lava field that extends 2.5 km southwest. See unit brc in Description of Map Units.
