U.S. DEPARTMENT OF THE INTERIOR MISCELLANEOUS FIELD STUDIES MAP MF–2413 U.S. GEOLOGICAL SURVEY Jhii SHEET 1 OF 2 Version 1.0 Mlri hMap Pamphlet accompanies map Jhip 159˚36´ 157˚12´ 68˚45´ 30´ Ktfm 30´ 68˚45´ Kop JMmi Koi 30´ 158˚00´ LIST OF MAP UNITS Koi SURFICIAL MATERIALS (QUATERNARY) Qs ? ? JMmi Qs Jdo Ktfm c Qs Qa Main stream alluvium Qs Ktfm Qs Qs Surficial deposits, undivided JMmi Jhii Ktfm Jhip Jhii Jdo Jdo Qg Glacial deposits, undivided Kop Dlk Mlri ? Qs FOREDEEP DEPOSITS OF THE Jhe COLVILLE BASIN Qs KJo Jhii Ktfm (LOWER CRETACEOUS) KMn JMmi Qa Qs ? Mlri Qa h Qa Ktfm Torok Shale and Fortress Mountain Formation, undivided J ip Jdo hMap Jhen KJo Ktfm Jdo (Albian and Aptian) Koi Kop Ktfm Jdo ENDICOTT SEQUENCE hMn Koi KJo Ktfm (LOWER CRETACEOUS TO DEVONIAN) Koi Koi KMp KDe Rocks of the Endicott sequence, undivided (Lower Jhii Jdo Cretaceous (Neocomian) to Devonian) Qs Jdo Mlri KJo Okpikruak Formation (Lower Cretaceous (Valanginian) to Jhip Qs KJo Qs KMi Upper Jurassic (Kimmeridgian)) Qa hMn Qs Qs KMi c h Etivluk Group (Middle Jurassic to Pennsylvanian) Kon JMmi Jdo JMmi J e Koi Jhii Qa Qs KJo Jdo Otuk Formation (Middle Jurassic to Triassic) hMap Jdo Mlri h Jhii JMmi h h Phs Jhip J ii J ii J ii Siksikpuk Formation (Permian to Pennsylvanian) Jhe Koi Jhen KMi Qs Qs JMmi Lisburne Group (Pennsylvanian and Mississippian) ? Mkn Mkn Kon ? Mlri hMkv Volcaniclastic rocks (Pennsylvanian? and Qs ? Qs Kop Mississippian?) h h Koi Qs J en h J en KMn Jhip J ii JMmi hMk Kuna Formation (Lower Pennsylvanian and Mlri KMn KMp Jhii ? hMn Qs Jhe Kon JMmi ? Mlri Mississippian) JMmi JMmi h h KMi Jhii Mlb h Mn Mn Qs Jhip Bupto facies (Upper and Lower Mississippian) J ii Koi Jhip Kon ? KMp hMap Jhen Kop Mlr Rough Mountain Creek unit of Dumoulin and Harris, Jhen Qs Qs KJo 1997 (Lower Mississippian) ? hMap Endicott Group (Lower Mississippian and Upper PlPs Qa Mlri Devonian) Qs ? Kop Jhii KMi b Mkn Jhii Key Creek facies Qa KMi Jhii Mlri Kayak Shale (Lower Mississippian) Kon ? Jhii Mk Qs Jdo KJo KJo Jhii Jhe b Mlb h Mkl Limestone unit of Kayak Shale (lower Lower J ip Jhip b h b Mississippian) KMp J ip ? Mu c Qs Koi Kon hMap Mik Isikut unit of Mull and Werdon (1994) and Kayak Mlb Jdo Koi Dl Shale, undivided (lower Lower Mississippian) Qs KJo JMmi Koi Mikv ? Volcanic-rich part of Isikut unit of Mull and Jhii Jhe Jdo ? Werden (1994) and Kayak(?) Shale, undivided (lower Qs Koi JMmi h Jhii Jdo J e Jhii Lower Mississippian) Phs Jhe Mlri MDkn Kanayut Conglomerate and Noatak Sandstone, Jdo Kok Mki JMmi Mlri hMk Qs Jhii undivided (Lower Mississippian? and Upper Devonian) Kop Koi hMkv Kanayut Conglomerate (Lower Mississippian? and h KJo Mlri MDk Mlri J ip h Qa Jhe J ii Mlri Upper Devonian) Mko Qs Mu Phs Dn Noatak Sandstone (Upper Devonian) Mlri h Mu J ip Qs hMap hMap Mko Dlk Koi Aniuk River facies b Dl Jhip JMmi Mi Isikut unit of Mull and Werdon (1994) (Lower Dlk JMmi Dl Phs Ktfm KJo hMk Dl Mississippian) Jdo Jhe h h KJo JMmi Kanayut Conglomerate (Lower Mississippian? and J e J e h MDka Jdo Jdo J ii Upper Devonian) hMkv Mlri Qs Mlri Kop Dl h Noatak Sandstone (Upper Devonian) Ktfm JMmi Qs J ii Jhip Kop Dna Mlr Jhip Qs Qs Jhii Mk h PICNIC CREEK SEQUENCE hMk Map Mki h h hMk J ii (LOWER CRETACEOUS TO MISSISSIPPIAN ) Mk Mki Qs Ktfm KJo Mk hMap Mlri KMp Rocks of the Picnic Creek sequence, undivided (Lower Koi Koi Koi ? hMk Qs Jhip Cretaceous (Neocomian) to Mississippian) Mlr KMp KJo Kop Kop Kop Okpikruak Formation (Lower Cretaceous (Valanginian)) ? KMi Dlk h Mlri KJo P s Qa Mlri Jhii Mlb Kop Jhip Imnaitchiak Chert of Etivluk Group (Jurassic to Jhip Jhe ? hMap Qs JMmi Jhip ? JMmi Pennsylvanian) Jhe KJo Koi JMmi Mk hMkv KMp 30´ hMap Akmalik Chert of Lisburne Group (Pennsylvanian and Jhip JMmi Mississippian) Dl h Jhip Koi Qs J ip Qs Jhe KELLY RIVER SEQUENCE Qs h KJo KJo Mlr Dlk J ip (CRETACEOUS TO DEVONIAN) JMmi Jhii Koi Mlri Kok Okpikruak Formation (Lower Cretaceous (Valanginian Mlri JDbc Jdo Mlri h Jhe and Berriasian)) Jhii Jhip Map Jhe Kop Lisburne Group (Mississippian) Kop Dl Phs Qs h JDbc KJo Map JlPip h h J ip Mko Kogruk Formation Jhe J ip h Koi Jhii Koi J e Qs Dlk Mki Kop Mu Utukok Formation Mlri KJo Mko h Mlri J ip Mlr KJmv Dlk Limestone (Devonian) Kop JMmi KJo KJmv IPNAVIK RIVER SEQUENCE hMap Mko MDk (CRETACEOUS TO MISSISSIPPIAN) Kop Mik ? Jhii Kop Jhip KMi Rocks of the Ipnavik River sequence, undivided KJo Mko JDbc (Cretaceous to Mississippian) Qa Qs Jdo JMmi h Koi Okpikruak Formation (Lower Cretaceous (Valanginian Qs Mn Jdo Qs Kop and Berriasian)) KMi Jhip Dl hMap Kot Tuff (Cretaceous) Mlri Mafic sills and dikes (Jurassic? to Mississippian?) h JMmi Mlri J ip Qs c Qs JDbc Qa JMmi h Mk Jhii Imnaitchiak Chert of Etivluk Group (Jurassic to Jhip Qs J e Mkl Kop hMk KDe Pennsylvanian) Qs Dl hMk h Kop J e Jhip ? Jhii PDlc Mlri Rim Butte unit of Lisburne Group of Dumoulin and Kop Jhip Jsd PDlc others (1993) (Mississippian) Dl KMp KDe Mi Mki Kayak Shale of Endicott Group (Lower Mississippian) Jsf Mi Qs Mi Mik PDlc Jsb SEQUENCE AFFINITY UNCERTAIN Qs Mlr Mk Mik Dl Dl Dl Limestone (Devonian) JDbc Mi Qs Mk Mk hMk NUKA RIDGE SEQUENCE Qs Mi Mik Jsb Mi Mik (CRETACEOUS TO MISSISSIPPIAN) Jslg Qs Jhip Qs Mi Mlri ? Jhe hMk Dl Jsd MDk Mi KMn Rocks of the Nuka Ridge sequence, undivided Qa hMap Mi Mi (Cretaceous to Mississippian) MDkn Qs Jsf Mi Mi Jhii Jhip Mi MDk ? Jhe Kon Okpikruak Formation (Lower Cretaceous (Valanginian)) Phs Mk Koi JDbc Mi Jhen d Etivluk Group (Middle Jurassic to Pennsylvanian) J o Dn Kop KMp Dn MDk Mi hMn Nuka Formation (Pennsylvanian and Mississippian) Qs ? Dn Jhe Mkn Kayak Shale of Endicott Group (Lower Mississippian) Jsg KJo hMk Qs Mk KJo Dn COPTER PEAK SEQUENCE Dn Qs Dn D Dn KMi Qg (CRETACEOUS? TO DEVONIAN) U MDk Jdo Qs d Dn Jslg J o d Dn KJmv Volcaniclastic rocks of Memorial Creek (Cretaceous? and Kot J o MDk Dl JMmi Mlr c Mik Jurassic?) JMmi hMk MDk Qa Qa JDbc Basalt (Jurassic? to Devonian?) Jdo Mk KJo MDkn Dn Dn Kot Jhe Qg Mi Dn MDk PDlc Limestone (Permian and Devonian) Jsdh MDk Dn Dn Dn Qs Mikv Mu Mlri Qs Mik Dna Dna MISHEGUK SEQUENCE h Mikv J e d Dna (MIDDLE? JURASSIC) Mko Koi Qa J o Mk Dna Qa Jhii Jsf Mk Mk Dn Jsu Igneous complex of Siniktanneyak Mountain, undivided JMmi hMk ? Mi (Middle? Jurassic) Jslg ? KJo MDka Mi Jhe Jhii Mik c Mi Jsb Basalt Jdo Mi Dna Kop MDk Mikv Mikv Mi Jsf Felsic intrusive rocks Dn ? Jsu Dn Qs Koi Mi Jsd Diabase Qa Mi KMp Dn Mi Mi Jsg Massive gabbro Jsu MDka MDka Dl Qs ? Dn hMk Mlri Mi Mi Mi Jslg Layered gabbro Phs Jhii ? Qa MDka Mik MDka Jsdh ? ? Qs Dna Dunite and harzburgite Mlri ? ? Mi MDka Qs Mi Dlk Mlr ? Mi Mi Qs Mi Qs Mi Dlk Mki Mu Mi ? Mi Mi Mi Jdo Contact—Dashed where approximately located h hMk Mi Mi Qs J e MDkn Mi Mi KJo Jhii h Qs Trace of bedding—Interpreted from aerial photographs P s KMi Jsu Mi Mi Qa Mi Koi Qs Mi Mi 68˚15´ 68˚15´ Mi MDka MDka 159˚36´ 30´ 157˚12´ High-angle fault of unknown type or having 30´ Dna 159˚00´ 30´ 158˚00´ predominantly vertical movement—Bar and ball on Mu h h Jhe Jsu Dna P s J e downthrown side, where relative displacement known; Base from U.S. Geological Survey SCALE 1:100 000 Geology mapped 1950-94 (see details in accompanying Dlk Mko dashed where approximately located, dotted where Misheguk Mountain 1:63,360, B-1, 1990 (provisional); C-1, 1984 1 012 3 4 567891110 12 KILOMETERS pamphlet) concealed under surficial cover Howard Pass 1:63,360, B-3, B-4, B-5, C-3, C-4, C-5, 1984 Digital database by James H. Dover and Nora Shew D Sinistral strike-slip fault—Fault having predominantly left- Projection and 5,000-meter grid 1 0 1 2 345 678 9 10 MILES Map editing and digital cartography by Diane E. Lane U Universal Transverse Mercator, zone 4 Graphics by Gayle Dumonceaux lateral movement; arrows show sense of relative 20,000-foot grid ticks based on Alaska system, zone 6 Manuscript approved for publication November 18, 2002 displacement. Dotted where concealed under surficial 1927 North American Datum CONTOUR INTERVAL 20 METERS cover. Where known locally, subordinate vertical (CONTOUR INTERVAL IN MISHEGUK MOUNTAIN B-1 IS 100 FEET) component of movement indicated by U, upthrown side, NATIONAL GEODETIC VERTICAL DATUM OF 1929 and D, down-thrown side. Mapped only along the 1984 MAGNETIC DECLINATION AT CENTER OF QUADRANGLES ALONG Makpik fault segment of the Makpik-Bupto fault zone SOUTH EDGE OF MAP AREA VARIES FROM 22½˚ TO 23˚ EAST Late Cretaceous or younger thrust fault—Sawteeth on upper plate; dashed where approximately located, dotted where concealed under surficial cover. Thrust faults that involve the Albian-Aptian (upper Lower Cretaceous) GEOLOGY Torok Shale and Fortress Mountain Formation, and (or) that displace and therefore post-date major thrust- bounded sequences, along with their internal and CORRELATION OF MAP UNITS sequence-bounding sole thrusts Early Cretaceous or older thrust fault—Sawteeth on upper Qa plate; dashed where approximately located, dotted where concealed under surficial cover.