USGS: Professional Paper 1812

U.S. Department of the Interior Professional Paper 1812 U.S. Geological Survey Plate 2 of 2 Pamphlet accompanies map

CORRELATION OF MAP UNITS LIST OF MAP UNITS mdn' mdn Basaltic trachyandesite northeast of Deadman Pass (late Pleistocene) [Extended boxes indicate known age ranges for long-lived units. See Description of Map Units (in pamphlet) for specific unit age assignments] [Uniform black stipple indicates units partly or wholly pyroclastic. See Description of Map Units mic Mafic pyroclastic deposit of Inyo Craters (Holocene or late Pleistocene) (in pamphlet) for complete unit descriptions] mnd Basaltic trachyandesite northwest of Dry Creek (late Pleistocene) AGE SURFICIAL DEPOSITS GLACIAL DEPOSITS QUATERNARY VOLCANIC ROCKS SURFICIAL DEPOSITS mor pe Phreatic ejecta (late Holocene) Basaltic trachyandesite of Owens River Road (late Pleistocene) SAN JOAQUIN MAMMOTH MOUNTAIN SOUTH MOAT AND LAKES BASIN WEST MOAT LONG VALLEY AND INYO SUITES p Pumice deposits (late Holocene) msd Basaltic trachyandesite scoria southeast of Dry Creek (late Pleistocene)

rg Rock glacier deposits (Holocene) msj Basaltic andesite of Scenic Loop Road junction (late or middle Pleistocene) pe ric (1350 C.E.) sd Spring deposits (Holocene and late Pleistocene) LONG VALLEY AND INYO CHAIN p rcd rcw Holocene rbt Bishop Tuff (middle Pleistocene) rg al Alluvium, undivided (Holocene and late Pleistocene) rg' rcd rnd Rhyolite of Cratered Dome (Holocene) al sd fan Alluvial fan deposits (Holocene and late Pleistocene) brc rcw Rhyolite of caldera wall (Holocene) oal 11.7 ka mic Older alluvium (late and middle Pleistocene) rdc Rhyolite of Dry Creek Dome (late Pleistocene) pal Precaldera alluvium (early Pleistocene) mdn' mdn rdm Rhyolite of Deer Mountain (late Pleistocene) av Rockfall avalanche deposits (Holocene and late Pleistocene) rer Early rhyolite of Bailey (middle Pleistocene) s Surficial deposits, undivided (Holocene and late Pleistocene) rlm Lookout Mountain subunit gcc gdc glb gmm eb Explosion breccia deposit of Bailey (late Pleistocene) rtav Tuff of Little Antelope Valley subunit dnw lmd Diamict of lower Mammoth Creek (late Pleistocene) r68 bhl Pumice Cone 2368 subunit mcv ss Sandstone of Long Valley Lake (middle Pleistocene) rtcd Tuff east of Casa Diablo subunit st Siltstone of Long Valley Lake (middle Pleistocene) rhc' rhc Rhyolite of Hot Creek flow (middle Pleistocene) GLACIAL DEPOSITS ric Rhyolite and rhyodacite of Inyo chain (1350 C.E.) rss gcc Till of Cold Water Canyon (late Pleistocene) rmk Rhyolite of Mammoth Knolls (late Pleistocene) gdc Till of Dry Creek (late Pleistocene) rnc Rhyolite of north-central chain (middle Pleistocene) dlp glb Till derived from Lakes Basin (late Pleistocene) rnd Rhyolite of North Deadman Creek Dome (Holocene) ddu dgr gmm Till derived from Mammoth Mountain (late Pleistocene) rwm Rhyolite of West Moat Coulee (middle Pleistocene) gud Undivided glacial deposits (late and middle Pleistocene) ddl av gcd Casa Diablo Till (latest middle Pleistocene) TERTIARY VOLCANIC ROCKS dbp gst Sherwin Till (late early Pleistocene) SAN JOAQUIN AND SIERRA NEVADA rsq Tacc Trachyandesite of Crater Creek (Pliocene) QUATERNARY VOLCANIC ROCKS rmf dsu Tasj Trachyandesite of San Joaquin River (Miocene) SAN JOAQUIN dfl drc Tbld Trachybasalt south of Lost Dog Lake (Pliocene) a62 Trachyandesite of Cone 2962 (late Pleistocene) dnk Tbpl Trachybasalt east of Pond Lily Lake (Pliocene) apb Trachyandesite of Pumice Butte (middle Pleistocene) dnh mor msd Tbtb Basalt of The Buttresses (Pliocene) bdc dms Trachybasalt west of Deer Creek (middle Pleistocene) mnd Tmcl Basaltic trachyandesite west of Cabin Lake (Pliocene?) brc Basalt of Red Cones (Holocene) fan s dml Late Tmcm Basaltic trachyandesite south of Upper Crater Meadow (Pliocene) Pleistocene drf Trachydacite of Rainbow Falls (late Pleistocene) Tmcw Basaltic trachyandesite west of Crater Creek (Pliocene) oal dsk mdp Basaltic trachyandesite of Devils Postpile (late Pleistocene) Tmel Basaltic trachyandesite of Emerald Lake (Pliocene?) dwr dom mss Basaltic trachyandesite of upper Soda Springs (late Pleistocene) gud Tmsd Basaltic trachyandesite south of Deer Creek (Pliocene?) lmd eb MAMMOTH MOUNTAIN dtl amp Trachyandesite of Mammoth Pass (late Pleistocene) Tmwc Basaltic trachyandesite west of Castle Lake (Pliocene?)

rce rfp dbp Trachydacite of Bottomless Pit (late Pleistocene) LAKES BASIN Tbmm Trachybasalt of Mammoth Mine (Pliocene) ddl Trachydacite of lower Dragons Back (late Pleistocene) dsd d61 Tbrm Basalt of Red Mountain (Pliocene) mdp ddu Trachydacite of upper Dragons Back (late Pleistocene) rrc Tmcr Basaltic trachyandesite of Mammoth Crest (Pliocene) dfl Trachydacite of Face Lift (late Pleistocene) amp bar' bar WEST WALL dgr Trachydacite of Gold Rush Express (late Pleistocene) Tdpd bmn Trachydacite pyroclastic-density-current deposit of Deadman Pass (Pliocene) dlp Trachydacite of Lincoln Peak (late Pleistocene) Tbdp aml Trachybasalt of Deadman Pass (Pliocene) dml Trachydacite of Main Lodge Coulee (late Pleistocene) Tdsd Trachydacite of Dome 3321 (Pliocene) bsr dms Trachydacite of McCoy Station (late Pleistocene) drf Tdsj Trachydacite block-and-ash-flow deposits of San Joaquin Ridge (Pliocene) bfh bmc ddc dnh Trachydacite north of Horseshoe Lake (late Pleistocene) rdm Tdud Trachydacite complex of upper Deadman Creek (Pliocene) dnk d81 Trachydacite of North Knob (late Pleistocene) Tdww rdc Trachydacite of White Wing Mountain (Pliocene) dom Trachydacite of Old Mammoth (late Pleistocene) Td65 Trachydacite of Dome 2965 (Pliocene) rmk drc Trachydacite of upper Reds Creek (late Pleistocene) Tmww Basaltic trachyandesite of White Wing Mountain (Pliocene?) dsd Trachydacite of South Summit Dome (late Pleistocene) NORTH WALL dsk Trachydacite of Skyline Dome (late Pleistocene) Taec Trachyandesite east of Crestview (Pliocene) a62 dsu Trachydacite of Mammoth Mountain summit (late Pleistocene) Taww Trachyandesite north of White Wing Camp (Pliocene) mss dtl Trachydacite of Twin Lakes outlet (late Pleistocene) Tbbs Basalt east of Big Springs (Miocene) bed bcd CENOZOIC dwr Trachydacite of White Bark Ridge (late Pleistocene) 126 ka msj mdm Tb84 Trachybasalt and basaltic trachyandesite of Cone 8478 (Pliocene) d61 Trachydacite of Dome 2861 (late Pleistocene) Td78 Trachydacite of Dome 7835 (Pliocene) mlc aic d81 Trachydacite of Dome 2781 (late Pleistocene) Td83 Trachydacite of Dome 8325 (Pliocene) rce Alkalic rhyodacite of Canyon Express (late Pleistocene) gcd apb Tmcv Basaltic trachyandesite of Crestview (Pliocene) rfp Alkalic rhyodacite pumice fall of Highway 203 (late Pleistocene) rwm Tmwo Basaltic trachyandesite west and east of Obsidian flow (Pliocene) msc rmf Alkalic rhyodacite of Mammoth Mountain fumarole (late Pleistocene) Trac Rhyolite tuff of Alpers Canyon (Miocene) bdc rrc Alkalic rhyodacite of Reds Creek (late Pleistocene) mkv mmc SOUTH WALL rsq Alkalic rhyodacite of Quicksilver ski run (late Pleistocene) Tdlm Trachydacite of Laurel Mountain (Pliocene) bsm bcf rss Alkalic rhyodacite of Solitude ski run (late Pleistocene) PRE-CENOZOIC BASEMENT ROCKS bsc SOUTH MOAT AND LAKES BASIN [Listed in order of increasing age] mcl aml Trachyandesite of McLeod Lake (late Pleistocene) Kmo Mono Creek Granite (Late Cretaceous)

asr asr Trachyandesite of Shady Rest Campground (middle Pleistocene) Krv' Krv Round Valley Peak Granodiorite (Late Cretaceous) bcd Basalt of Casa Diablo Hot Springs (late Pleistocene) Kjl Granite of June Lake (Late Cretaceous)

Middle bed Basalt east of Dry Creek (late Pleistocene) Jbs Granite of Big Springs (Jurassic?) Pleistocene bfh Basalt of Fish Hatchery (late Pleistocene) gd Granodiorite northeast of Minaret Summit (Mesozoic) rhc rhc' bhl Basalt of Horseshoe Lake (late Pleistocene) mv Metavolcanic rocks of Ritter Range pendant (Mesozoic) st ss bmc Basalt of Mammoth Crest (late Pleistocene) ms Metasedimentary rocks of Mount Morrison pendant (Paleozoic) bsc Trachybasalt of Sherwin Creek Road (middle Pleistocene) rnc bsm Basalt of Sawmill Cutoff (middle Pleistocene) EXPLANATION OF MAP SYMBOLS Contact—Long-dashed where approximately located; short-dashed where bsr Trachybasalt of Shady Rest (late Pleistocene) inferred; dotted where concealed; dash-dot line for internal contact within mcl Basaltic trachyandesite of Canyon Lodge (middle Pleistocene) unit Fault—Bar and ball on downthrown side; dashed where approximately located; rlm mkv Basaltic trachyandesite of Knolls Vista (middle Pleistocene) dotted where concealed

mlc Volcanic craters and partial crater rims—Hachures point inward rtav Basaltic trachyandesite of lower Laurel Creek (middle Pleistocene) rer mmc Volcanic fissure vent r68 Basaltic trachyandesite of Mammoth Creek (middle Pleistocene) msc Basaltic trachyandesite of Sawmill Cutoff (middle Pleistocene) Surficial rift or fissure on lava flow (not a vent) rtcd WEST MOAT Lava flow direction rbt aic Trachyandesite of Inyo Craters (late middle Pleistocene) 788 ka Moraine crests bar' bar Trachybasalt of Arcularius Ranch (late Pleistocene) Strike and dip of ejecta, stacks of thin lava flows, and sandstone 25 TERTIARY VOLCANIC ROCKS bcf Trachybasalt south of Crater Flat (middle Pleistocene) Inclined Early pal gst Pleistocene bmn' bmn Trachybasalt northeast of Minaret Summit (late Pleistocene) Vertical

SAN JOAQUIN AND SIERRA NEVADA LAKES BASIN WEST CALDERA WALL NORTH CALDERA WALL SOUTH CALDERA WALL ddc Trachydacite of Dry Creek (late Pleistocene) Horizontal

dnw Trachydacites of northwest moat (late Pleistocene) Volcanic vent (other than craters and fissures) 2.58 Ma Tbld Tdww Td65 Tmcv mcv Basaltic trachyandesite south of Crestview (late Pleistocene) Rootless volcanic vent (other than craters and fissures) Tbpl Tmcr Tdud mdm Basaltic trachyandesite of Deer Mountain (late or middle Pleistocene) Tmsd Tbmm Tbrm Tdsj Tdsd Tmcl Tmcm Taww Tb84 Tdpd Pliocene Tmel Tmcw Tbtb Tmww Tmwo Taec

Tmwc Td83 Td78 Tbdp Tdlm Tacc 5.3 Ma

Tasj

Trac Miocene Tbbs

PRE-CENOZOIC BASEMENT ROCKS

65.5 Ma

Kmo Kjl Krv' Krv

gd Jbs MESOZOIC

251 Ma

PALEOZOIC

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.

Eruptive History of Mammoth Mountain and its Mafic Periphery, California 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, By Denver, CO 80225, 1–888–ASK–USGS Digital files available at http://dx.doi.org/10.3133/pp1812 Wes Hildreth and Judy Fierstein ISSN 1044-9612 (print) Suggested citation: Hildreth, Wes, and Fierstein, Judy, 2016, Eruptive history of Mammoth ISSN 2330-7102 (online) Mountain and its mafic periphery: U.S. Geological Survey Professional Paper 1812, 128 p., 2016 http://dx.doi.org/10.3133/pp1812 2 plates, scale 1:24,000, http://dx.doi.org/10.3133/pp1812. U.S. Department of the Interior Professional Paper 1812 U.S. Geological Survey Plate 2 of 2 Pamphlet accompanies map