C143385 34 10 10 3b 9d 30 9e / 9et 50 25 0 Hoult L. 8 R 40 12 oa 10 LOCATION C143387 d 9di 45 12a 4a Kh 64.5±1.8 G 10 55 80 60 12b C143721 G 12b 33 2e 24 10 E Kenney Dam Vanderhoof 12 E 80 10 Road 8 12 4a "500" K 80 12 80 24 A 40 73 km 22 65 L 56 60 C203463 "R 1 9c ed" R 0 12 60 3at oa 0 0 d 76 km 9e 0 12 E 0 0 25 3at G 12b 15 1 65 12a Hoult L. 12b B 12 GEOLOGICAL SURVEY BRANCH 20 C203461 10 B 12 60 E 25 12b N 40 12b 10 12 F/6 F/7 N A U 12 32 12a 3at E 010 12b T T 66 E B GEOSCIENCE MAP 1997-2 C 18 62 A 9c S 30 60 i km L 9e / 9et g o Res H 3a K 2 W 12 12a ak ervoir 6 25 30 20 ech 11 U 30 E 30 60 N A 12b 60 3b Z N K 32 12a O 9e 30 36 3a K 67 C203462 Yellow Moose 45 . 99 km 12 12 Mt. Swannell . R 9d Lake 12b BEDROCK AND SURFICIAL GEOLOGY F . S 3b 12b 12b A a F 3as 12a W ots 45 12 B O - e N s 3b 12 Fawnie Nose Fawnie sku Tatelkuz 56 n I lu 67 12b E Dome K 10 12a d Mtn. 52 12a OF THE SOUTHERN NECHAKO PLATEAU, O.F. 1993-14 O.F. 1995-17 3a 3b 3as 143388 50 4b 9et 12 142 km 4a 87 RA 5 63 F/3 F/2 66 3a 13 12 50 Kuyakuz d 12b R NG oa L C143392 C r " A CENTRAL BRITISH COLUMBIA U t Mtn. Kb 49.2±1 K 41 r e 74 Cow L. P u e u E 43 p l 10? 50 d S e la B R " O a E a 5 NTIAK k E M o us - A Mt. Davidson r ( N E C H A K O 51 sk N e 12b R 75 lu v K i 44 52 1 G R 48 87 2 R 12a r) H E 0 E wate C S E R d 12b 50 34 0 NTS 93F/ 2, 3, 6, & 7 ck A V e 45 Tsacha (Bla E O I R 12a 66 80 12 Moose L. Road R ) R 4a Mtn. est 14 12b W 10 63 32 43 33 LS C H U 12 NAG HIL E U 61 70 74 12b LICO 19 F 50 By L.J. Diakow and V.M. Levson 39 12a O.F. 1994-2 O.F. 1995-16 10 2a? 12 G 12b 38 C056986 9e J C143722 12b 12b C177438 1 20 80 Scale 1:100 000 2 3a 52 H 60 54°30' 2 10 12 12 12 10 60 2e? ° ° Houston 12b 35 4a 35 0 2 4 6 8 10 8 9e J 4b 2a? 72 C177439 2 35 12b 4b 1 53 12 12b 41 15 Burns N 7 JAVA 50 12b 25 Lake C143390 30 30 Kilometres C203465 E Vanderhoof 12 70 40 38 4a F C177440 C C 50 1400 Prince LT 46 12 C203466 3as AU 7 H F 16 E C177437 H George D 47 Ah152±2 Z 60 A 5 3a KU KU 4b A 10 AL 12b C143713 2e P T 4b Z 12a NA 40 4a 70 20 C143715 K 4b 35 LEGEND L 93 F 10 60 12a C177435 21 C177436 A O 3a 78 C203467 20 C143391 12a 1 VOLCANIC AND SEDIMENTARY ROCKS 10 20 12a 2 4a 10 0 65 r C143712 0 2e T e 5 12a 60 20 ter iv G C143720 12 E wa R 10 LATE QUATERNARY LOWER AND MIDDLE JURASSIC (continued) ack 12b 30 4b Bl Fluvial/glaciofluvial sand and gravel, lacustrine/glaciolacustrine sediments, and A 42 G HAZELTON GROUP (continued) 12b 4b C Tweedsmuir B 42 8 12b 12 organic deposits: geochemical signature generally regional and difficult to trace to U h 001 NAGLICO FORMATION 12a B J source; includes floodplain, terrace, delta, alluvial fan, outwash, esker, kame, peat Quesnel 3a e 12a 60 52 35 d E bog, swamp and marsh deposits. Note: See 1:50 000 scale Open File maps for Provincial a Limestone: white and grey; recrystallized; fossiliferous; 3 metre thick exposure Mt. 12b 68 k 3al F 60 12b 9e u internal subdivisions of this unit. R Swannell 17 z 12a 3a along the van Tine road. A 12 P S 00 C143716 12a Park L E 10 B 12 Morainal diamicton: dominantly basal tills; some glacially-derived debris flow Sandstone, siltstone, mudstone and subordinate granule-pebble conglomerate as A R C 12 deposits; geochemical signature generally local and traceable; diamicton massive 3as B T a 4b 71 recessive intervals between Unit 3a flows: green, angular feldspar and volcanic Anahim E 12 004 or crudely stratified, dense, unsorted to very poorly sorted; matrix sandy to silty A p B 12b 060 lithic clasts are the major detrital components, the clasts are generally off white and Lake U o clay; clasts up to boulder size; flutings and crag-and-tail features common; deposits 23 composed of aphanitic rhyolite; rare conglomerate composed of clasts up to 30 cm o 55 41 B 59 CH PLUTON thin (<1 m thick) on steep upper slopes and thicker on lower slopes. r s 12a F that are derived locally from Units 2c and 3a. Abundant bivalves and rare Bella e 12b v e 022 A 31 44 Williams i U ammonites. Coola L Resedimented glacial debris: sandy diamicton, gravel and sand; dominantly glacial Lake R 12 57 T 12a 29 12b debris flow deposits with interbedded and/or overlying sands and gravels; common 52° 0 Mainly lapilli tuff and lesser breccia dominated by fragments of Unit 3a. 0 B B 36 3at 0 30 along meltwater channels and within areas of hummocky topography. 1 CAPOOSE 85 25 12a B 021 12b 28 Lapilli tuff, ash tuff and crystal-ash tuff, rare accretionary lapilli tuff: maroon and 9e BATHOLITH 40 C 12a 3b 1 r Thin till and colluvial deposits: unsorted or very poorly sorted diamicton with light green; minute (generally 1.5 mm) broken quartz grains are diagnostic but ke 2 e Kb 48.8±1.3 12b Approximate mean magnetic declination (1986) for centre of map is 25°48' or 459 mils decreasing 14.4' per year. B La Tutlai 0 12a e abundant angular clasts of local bedrock; occurs mainly as veneers less than B Mtn. 50 12b 0 k Kh 51.8±1.8 scarce (1-2%); faint to distinctly layered fine grained interbeds, local internal Universal Transverse Mercator Grid Zone 10 B 23 26 Uz 51.8±1 1200 12b 1 metre thick over bedrock in upland areas; locally includes thicker colluvial fan grading; similar bedded tuffs recur upsection in Unit 5 in the northern Fawnie 33 se 12 5 H and talus deposits at the base of steep slopes. oo 3a 35 12a Range. 31 C ap 45 r e C 60 e B d 12 k 12 a 3a Dacitic porphyry flows: maroon, local faint flow laminae. B B 12b 12 o 82 12b 4a 3c 4b R NEOGENE - MIOCENE TO PLIOCENE 30 ce 1400 Servi 2e 70 CHILCOTIN GROUP ENTIAKO FORMATION (EARLY TOARCIAN TO AALENIAN (?)) 12a 12 12b 12b 28 12a 60 12b 4b st 5 2e 30 45 Olivine basalt lava flows: weather brown, crudely layered and columnar jointed, 75 3a ore 11 Rhyolitic lapilli tuff and rare accretionary lapilli tuff: light pink or off white, 1 F 4a 50 0 039 massive to vesicular, typically aphanitic or olivine phyric. 2a 0 12 1 67 63 12b characterized by up to 5% angular quartz, and potassium-bearing lithic fragments. 0 70 4 12 57 76 0 Symbols 0 4a 5 a 73 Exposed best in the vicinity of Kuyakuz Mountain. Kb 67.1±2.3 E ts 78 Rare friable black mudstone and sandstone; may contain plant debris. Stratigraphic contact (approximate) . 50 91762 5 o 4a 45 84 44 66 11a E -O T 50 C143383 s B 30 u 3a Sandstone and siltstone composed mainly of angular plagioclase and subordinate Intrusive contact (approximate) . B k 33 A 2as 12b s 12a 28 12 Uz ~70 u T 12a quartz grains: gradational above and laterally with tuffs of Unit 2a. High angle fault (assumed) . C203475 l o K PALEOGENE - UPPER EOCENE k E 80 12b Thrust fault (assumed) . Uz 71.9+2/-0.2 80 040 a 54 L 5 12 i 12b ENDAKO GROUP Waterlain mafic ash and lapilli tuff: well bedded, dominated by finely vesicular and t 12a 12 K Bedding, flow layering . 9et 4b 2b n Uz 142±0.6 3b E Basaltic andesite and andesitic lava flows: weather buff grey-green, fresh surface amygdaloidal basaltic lapilli. Locally underlies units 2a and 2as at Kuyakuz Foliation . 12 U 10 E 12 65 12b Uz 157.6+5.2/0.3 12b 12b Z lustrous black, aphanitic to sparsely porphyritic, contain plagioclase and Mountain. Fossil locality [macrofossil (F), palynology (Fp); GSC location number] . F C143834 8 65 2c 34 5? 4a 40 16 microscopic augite and hypersthene, rarely amygdaloidal with scarce amygdules Age determination site [method Ar-Ar (A), K-Ar (K), U-Pb (U); age in m.y.