U.S. Department of the Interior Scientific Investigations Map 2922 Pamphlet accompanies map U.S. Geological Survey
115 114o 34o o 0' CORRELATION OF MAP UNITS
Qw Qr Qp Qs QaR Contact Holocene QaL QUATERNARY Contact—Approximately located Qpv Qbm Qbmg Qbms QaI QaG 60 Pleistocene QTmm QTmw QTe QTes Fault—Showing dip where known. Bar and ball on downthrown side. Arrows show apparent sense of lateral displacement. Dotted where concealed CENOZOIC QTaF Pliocene Thrust fault—Teeth on upthrown side Tbs Tbl
TaE TERTIARY Miocene Low-angle detachment fault—Hachures on upper plate. Dotted where concealed
Tbx Tsb Tfbx Ti Tv Oligocene(?) Anticline—Trace of axial surface
Kgp Syncline—Trace of axial surface
Kml Overturned syncline—Trace of axial surface
Kmk 45 Strike and dip of beds Kmj
Kmi Strike and dip of foliation or cleavage CRETACEOUS Kmh 35 Inclined Kmg KJa Vertical Kmf 15 20 Strike and dip of inclined foliation and plunge of lineation Kme MESOZOIC
35 Kmd Strike and dip of inclined foliation and horizontal lineation Kmc 35 Strike and dip of beds and intersecting foliation KJmb CRETACEOUS 25 OR JURASSIC KJma 40 Strike and dip of beds and intersecting foliation of equal strike and
75 opposing dip Jv Jp Jpgd Jpgb JURASSIC Edge of alluvial terrace—Hachures point downslope from surface of terrace J^u J^s ^qm TRIASSIC Crest of sand dune
^d TRIASSIC(?)
P*s PERMIAN AND GEOMORPHIC SURFACE PENNSYLVANIAN MAP UNIT ESTIMATED AGE (KA) EPOCH |s P_s PALEOZOIC OF BULL (1991) MISSISSIPPIAN M_s TO CAMBRIAN Qw Q4b 0
QTaF Q1 >1200 PLEISTOCENE HOLOCENE Correlation of units QTa2, Qa3–Qa6, and Qw with alluvial geomorphic surfaces of Bull (1991) STONE, 1990; HARDING AND LIST OF MAP UNITS PELKA, 1973 [See pamphlet for Description of Map Units] THIS REPORT CONEY, 1985 McCoy Mountains Conglomerate Mbr. McCoy Mountains Formation (Cretaceous and Jurassic?) Member L Formation, (structurally Qw Alluvium of modern washes (Holocene) undifferentiated repeated) Kml Member K Unit 14 Qr Alluvium of the modern Colorado River flood plain (Holocene) Member L (Cretaceous) Member J Unit 13 Kmk Member K (Cretaceous) Qp Playa lake deposits (Holocene) Member I Unit 12 Siltstone Member H Unit 11 member Kmj Member J (Cretaceous) Qs Eolian sand (Holocene)—Brown lines mark dune crests Member G Unit 10 Unit 9 Alluvial-fan and alluvial-valley deposits (Holocene to Miocene) Kmi Member I (Cretaceous) Unit 8 Sandstone Kmh QaR Unit 6 (Holocene) Member H (Cretaceous) Member F Unit 7 member Unit 6 Conglomerate Kmg Member G (Cretaceous) QaL Unit 5 (Holocene) Unit 5 member Kmf Member F (Cretaceous) Mudstone QaI Unit 4 (Holocene and Pleistocene) Member E Unit 4 MCCOY MOUNTAINS FORMATION MOUNTAINS MCCOY member Member E (Cretaceous) QaG Unit 3 (Holocene and Pleistocene) Kme Member D Unit 3 Basal sandstone Member C Unit 2 member 2 Kmd Member D (Cretaceous) QTaF Unit 2 (Pleistocene to Miocene) Member B Basal sandstone Unit 1 member 1 Kmc Member C (Cretaceous) Member A TaE Unit 1 (Miocene) Correlation of members A–L of the McCoy Mountains Formation Alluvial deposits of the ancestral Colorado River (Pleistocene and KJmb Member B (Cretaceous or Jurassic) with units of Pelka (1973) and Harding and Coney (1985) Pliocene) KJma Member A (Cretaceous or Jurassic) Qpv Alluvial deposits of Palo Verde Mesa (Pleistocene) 115o00' 114o30' J^u Volcanic and sedimentary rocks, undivided (Jurassic and Triassic) 34o00' 7 Qbm Alluvial deposits east of the Big Maria Mountains (Pleistocene) 6 Jv Volcanic rocks (Jurassic) Qbmg Gravel-dominated deposits 6 Jp Plutonic rocks (Jurassic) Qbms Sand-dominated deposits Jpgd Foliated granodiorite and diorite 1 2 QTmm Alluvial deposits of the Mule Mountains (Pleistocene or Pliocene) Jpgb Hornblende gabbro QTmw Alluvial deposits of the McCoy Wash area (Pleistocene and/or Pliocene) J^s Sedimentary rocks (Jurassic and Triassic) QTe Alluvial deposits of the Ehrenberg area (Pleistocene and/or Pliocene) 3 ^qm Quartz monzonite and monzodiorite (Triassic) QTes Sand-dominated deposits ^d Diorite and gabbro (Triassic?) 7 Bouse Formation (Pliocene and/or Miocene) |s Sedimentary rocks, undivided (Paleozoic) Tbs Fine-grained clastic sedimentary rocks P_s Sedimentary rocks (Permian to Cambrian) Tbl Limestone P*s 5 Sedimentary rocks (Permian and Pennsylvanian) 4 Tbx Sedimentary breccia (Miocene and Oligocene?) 33o30' M_s Sedimentary rocks (Mississippian to Cambrian) 0 10 20 KM Tsb Slide blocks (Miocene and Oligocene?) NO C Manuscript approved for publication April 6, 2006 5000 0 5000 10000 15000 20000 25000 FEET A L Note: 1. A preliminary map of this area was presented by Stone (1990). ETIC IF N ORN TRUE NORTH 2. See accompanying pamphlet for reference information. AG IA M CONTOUR INTERVAL 50 METERS ARIZONA APPROXIMATE MEAN DECLINATION, 2006 AREA OF MAP Any use of trade, firm, or product names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. This map was printed on an electronic plotter directly from digital files. Dimensional Geologic Map of the West Half of the Blythe 30' by 60' Quadrangle, Riverside County, California, and La Paz County, Arizona calibration may vary between electronic plotters and between X and Y directions on the same plotter, and paper may change size due to atmospheric conditions; Compiled by therefore, scale and proportions may not be true on plots of this map. For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Paul Stone Center, Denver, CO 80225, 1-888-ASK-USGS Digital files available on World Wide Web at http://pubs.usgs.gov/sim/2006/2922/ 2006