Fridrich, C.J., 1986, The Grizzley Peak cauldron, <strong>Colorado</strong> - Structure and petrology <strong>of</strong> a deeply dissected resurgent ash-flow caldera: Stanford, Calif., Stanford University, Ph.D. <strong>the</strong>sis, 201 p. Fridrich, C.J., and Mahood, G.A., 1984, Reverse zoning in <strong>the</strong> resurgent intrusions <strong>of</strong> <strong>the</strong> Grizzley Peak cauldron, Sawatch Range, <strong>Colorado</strong>: <strong>Geologic</strong>al Society <strong>of</strong> America Bulletin, v. 95, p. 779-787. Fridrich, C.J., DeWitt, E., Bryant, B., Richard, S., and Smith, R.P., 1998, <strong>Geologic</strong> map <strong>of</strong> <strong>the</strong> Collegiate Peaks Wilderness Area and <strong>the</strong> Grizzley Peak caldera, Sawatch Range, central <strong>Colorado</strong>: U.S. <strong>Geologic</strong>al Survey Miscellaneous Investigations Series I-2565, scale 1:50,000. Gibbs, A.D., 1984, Structural evolution <strong>of</strong> extensional basin margins: Journal <strong>of</strong> <strong>the</strong> <strong>Geologic</strong>al Society <strong>of</strong> London, v.141, p. 609-620. Guilinger, J.R., and Keller, J.W., 2002, Directory <strong>of</strong> active permitted mines and mine permits in <strong>Colorado</strong> – 2002: <strong>Colorado</strong> <strong>Geologic</strong>al Survey Information Series 68, 40 p., map 1:500,000. Hayden, F.V., 1869, Preliminary field report [Third] Annual report <strong>of</strong> <strong>the</strong> United States <strong>Geologic</strong>al and Geographical Survey <strong>of</strong> <strong>the</strong> territories, <strong>Colorado</strong> and New Mexico: Washington, U.S. Govt. Printing Office, 155 p. Heimann, A., Spry, P.G., and Teale, G.S., 2005, Zincian spinel associated with metamorphosed Proterozoic base-metal sulfide occurrences, <strong>Colorado</strong>; A reevaluation <strong>of</strong> gahnite composition as a guide in exploration: Canadian Mineralogist, v. 43, p. 601-622. Heinrich, E.W., 1981, Precambrian tungsten and copper-zinc skarn deposits <strong>of</strong> southcentral <strong>Colorado</strong>: <strong>Colorado</strong> <strong>Geologic</strong>al Survey Resource Series 21, 115 p. Hubbard, M.S., Oviatt, C.G., Kelley, S., Perkins, M.E., Hodges, K.V., and Robbins, R., 2001, Oligocene-Miocene basin formation and modification in <strong>the</strong> nor<strong>the</strong>rn Rio Grande rift; Constraints from 40 Ar/ 39 Ar, fission track and tephrochronology [abstr.]: <strong>Geologic</strong>al Society <strong>of</strong> America Abstracts With Programs, v. 33, no.6, p. A-257. Humphreys, W.J., 1914 through 1924, Seismological reports for October 1914 to June 1924: U.S. Wea<strong>the</strong>r Bureau, Monthly Wea<strong>the</strong>r Review, Section V-Seismology. 208
Hutchinson, R.M., and Hedge, C.E., 1967, Precambrian basement rocks <strong>of</strong> <strong>the</strong> central <strong>Colorado</strong> Front Range and its 700-million-year history: <strong>Geologic</strong>al Society America, Rocky Mountain Section, Annual Meeting, 20 th , Golden, <strong>Colorado</strong>, Guidebook No. 1, 51 p. IUGS Classification: International Union <strong>of</strong> <strong>Geologic</strong>al Sciences Subcommission <strong>of</strong> Systematics <strong>of</strong> Igneous Rocks: See Streckeisen (1973, 1976 and 1979). Ingram, R.L., 1989, Grain-size scales, in Dutro, J.T., Jr., Dietrich, R.V., and Foose, R.M., compilers, AGI data sheets—for geology in <strong>the</strong> field, laboratory, and <strong>of</strong>fice (3 rd ed.): Alexandria, Va., American <strong>Geologic</strong>al Institute, sheet 29.1. International Commission on Stratigraphy, 2005, International stratigraphic chart: downloaded January 2006 from <strong>the</strong> International Commission on Stratigraphy website, www.stratigraphy.org/chus.pdf. Keller, J.W., McCalpin, J.P., and Lowry, B.W., 2004 <strong>Geologic</strong> map <strong>of</strong> <strong>the</strong> Buena Vista East quadrangle, <strong>Chaffee</strong> <strong>County</strong>, <strong>Colorado</strong>: <strong>Colorado</strong> <strong>Geologic</strong>al Survey Open- File Report 04-4, scale 1:24,000, 1 CD-ROM. Kirkham, R.M., and Rogers, W.P., 1981, Earthquake potential in <strong>Colorado</strong>: <strong>Colorado</strong> <strong>Geologic</strong>al Survey Bulletin 43, 171 p. Kirkham, R.M., and Rogers, W.P., 2000, <strong>Colorado</strong> earthquake information, 1867-1996: <strong>Colorado</strong> <strong>Geologic</strong>al Survey Bulletin 52, CD-ROM. Kluth, C.F., and Coney, P.J., 1981, Plate tectonics <strong>of</strong> <strong>the</strong> Ancestral Rocky Mountains: Geology, v. 9, p. 10-15. Knepper, D.H., 1974, Tectonic analysis <strong>of</strong> <strong>the</strong> Rio Grande rift zone, central <strong>Colorado</strong>: Golden, Colo., <strong>Colorado</strong> School <strong>of</strong> Mines, Ph.D. <strong>the</strong>sis (T-1593), 237 p. Knepper, D.H., 1976, Late Cenozoic structure <strong>of</strong> <strong>the</strong> Rio Grande rift zone, central <strong>Colorado</strong>, in Epis, R.C. and Weimer, R.J., eds., Studies in <strong>Colorado</strong> field geology: Pr<strong>of</strong>essional Contributions <strong>of</strong> <strong>the</strong> <strong>Colorado</strong> School <strong>of</strong> Mines, no. 8, p.421-430. Knight, D.C., 1981, Stratigraphy and mineralogy <strong>of</strong> a zinc-rich sillimanite gneiss near <strong>Maysville</strong>, <strong>Chaffee</strong> <strong>County</strong>, <strong>Colorado</strong>: Winnipeg, Manitoba, University <strong>of</strong> Manitoba, M.Sc. <strong>the</strong>sis, 94 p. Kou<strong>the</strong>r, M.J.H., 1969, Geology and mineralization <strong>of</strong> <strong>the</strong> northwest part <strong>of</strong> <strong>the</strong> Bonanza quadrangle, <strong>Chaffee</strong> and Saguache Counties, <strong>Colorado</strong>: Golden, Colo., <strong>Colorado</strong> 209
- Page 1 and 2:
OPEN-FILE REPORT 06-10 Geologic Map
- Page 3 and 4:
TABLE OF CONTENTS Introduction…
- Page 5 and 6:
mylonitic, augen textures………
- Page 7 and 8:
INTRODUCTION LOCATION AND ACCESS Th
- Page 9 and 10:
SAWATCH RANGE RIFT-SHOULDER UPLIFT
- Page 11 and 12:
of the South Arkansas River (subseq
- Page 13 and 14:
EXPLANATION Rio Grande Rift Neogene
- Page 15 and 16:
in descriptions of the geologic uni
- Page 17 and 18:
During the Early and Middle Paleozo
- Page 19 and 20:
Mountains, and White River uplifts
- Page 21 and 22:
field are the largest remnants of t
- Page 23 and 24:
Figure 5. Detailed geologic-structu
- Page 25 and 26:
with the Colorado mineral belt (Boo
- Page 27 and 28:
Shannon, 2005). Widmann and others
- Page 29 and 30:
the Upper Arkansas graben (fig. 5)
- Page 31 and 32:
15-minute quadrangle, which is adja
- Page 33 and 34:
etween the northern and southern se
- Page 35 and 36:
on U.S. Forest Service color aerial
- Page 37 and 38:
We use fractional map units on the
- Page 39 and 40:
Qpt Pinedale till, undivided (late
- Page 41 and 42:
weathered, but Mount Princeton quar
- Page 43 and 44:
stratified, matrix-supported, bould
- Page 45 and 46:
as rockfalls, rock avalanches, rock
- Page 47 and 48:
stream-channel deposits of all pere
- Page 49 and 50:
Figure 10. View west up South Arkan
- Page 51 and 52:
Figure 11. View west up South Arkan
- Page 53 and 54:
valley near the eastern map boundar
- Page 55 and 56:
lithologies are variable and depend
- Page 57 and 58:
Arkansas River in parts of Redman C
- Page 59 and 60:
angular to subangular. Deposits gen
- Page 61 and 62:
elations, age constraints from foss
- Page 63 and 64:
elated to the inferred Squaw Creek
- Page 65 and 66:
Figure 14. Crude bedding in coarse
- Page 67 and 68:
microcline, and muscovite. The latt
- Page 69 and 70:
Volcanic Ash Figure 17. View of eas
- Page 71 and 72:
Figure 18. Close-up view of intense
- Page 73 and 74:
The western zone of brecciated Pale
- Page 75 and 76:
Tr Rhyolite dikes (early to late Ol
- Page 77 and 78:
as the overall N47°E trend of the
- Page 79 and 80:
One age determination on the rhyoli
- Page 81 and 82:
northwest-trending fault. Thus, fie
- Page 83 and 84:
on the North Fork leucogranite intr
- Page 85 and 86:
A small 400 by 400 foot body of Nor
- Page 87 and 88:
N12°E, 62°NW (about 6,000 ft sout
- Page 89 and 90:
The age of the quartz latite porphy
- Page 91 and 92:
Tma Mount Aetna quartz monzonite po
- Page 93 and 94:
of the Maysville quadrangle and the
- Page 95 and 96:
Mount Aetna ring dikes (Tma), one i
- Page 97 and 98:
the margins of the pluton, includin
- Page 99 and 100:
Shannon (1988). The average of seve
- Page 101 and 102:
indicating a granite b composition
- Page 103 and 104:
analysis by Crawford (1913), two an
- Page 105 and 106:
locally tanish to pinkish gray. It
- Page 107 and 108:
quadrangle (tables 1 and 3) were fr
- Page 109 and 110:
slices of Paleozoic sedimentary roc
- Page 111 and 112:
south-southwest of Maysville is a 9
- Page 113 and 114:
There is one additional Paleozoic s
- Page 115 and 116:
near the southwest margin of the qu
- Page 117 and 118:
eastern contact of the diorite intr
- Page 119 and 120:
endoskarn zones. The two widely sep
- Page 121 and 122:
Xhig) along the southeastern contac
- Page 123 and 124:
Xgd Granodiorite (Early Proterozoic
- Page 125 and 126:
Hybrid granodiorite is locally deve
- Page 127 and 128:
Xcs Calc-silicate gneiss (Early Pro
- Page 129 and 130:
Many of the calc-silicate gneiss zo
- Page 131 and 132:
typically expressed by intermittent
- Page 133 and 134:
The field relations and characteris
- Page 135 and 136:
the north side of all three segment
- Page 137 and 138:
eplaced by muscovite. The western m
- Page 139 and 140:
sillimanite-quartz-muscovite that a
- Page 141 and 142:
sillimanite gneiss (Xmsg) and the m
- Page 143 and 144:
Figure 35. Outcrop of Proterozoic h
- Page 145 and 146:
samples) indicates they are compose
- Page 147 and 148:
Xal Lineated amphibolite (Early Pro
- Page 149 and 150:
of the Proterozoic metamorphic rock
- Page 151 and 152:
that the present structural configu
- Page 153 and 154:
elated to rotation of domain blocks
- Page 155 and 156:
sometimes terminate at a cross stru
- Page 157 and 158: limestone that is exposed in a wind
- Page 159 and 160: quadrangle are intimately associate
- Page 161 and 162: of the quadrangle. The north-northw
- Page 163 and 164: quartz monzonite ring dikes (Tma).
- Page 165 and 166: that truncates the Upper Arkansas g
- Page 167 and 168: as at the mouth of Squaw Creek. How
- Page 169 and 170: adjacent to the southwestern edge o
- Page 171 and 172: graben and the Upper Arkansas Valle
- Page 173 and 174: GEOLOGIC HAZARDS Potential geologic
- Page 175 and 176: In addition, older landslides may h
- Page 177 and 178: sparse vegetation. One such area is
- Page 179 and 180: Table 7. Historical (pre-instrument
- Page 181 and 182: 4262272N. ECONOMIC GEOLOGY Currentl
- Page 183 and 184: A number of the larger pegmatite bo
- Page 185 and 186: River placers near Buena Vista (Van
- Page 187 and 188: The small mines and prospects along
- Page 189 and 190: elatively recent (post-1970) explor
- Page 191 and 192: contact of two Quaternary gravels (
- Page 193 and 194: quadrangle. The first area is a clu
- Page 195 and 196: y Sharp (1976) to be a fault slice
- Page 197 and 198: quadrant of the Maysville quadrangl
- Page 199 and 200: the large Paleozoic rock outlier) i
- Page 201 and 202: WATER RESOURCES Water resources on
- Page 203 and 204: water near Maysville is being produ
- Page 205 and 206: to Rudy C. Epis: Colorado School of
- Page 207: University, M.Sc. thesis, 50 p. Din
- Page 211 and 212: Litsey, L.R., 1958, Stratigraphy an
- Page 213 and 214: County, Colorado, in Berg, R.R., an
- Page 215 and 216: Stark, J.T., and Barnes, F.F., 1935
- Page 217 and 218: Tweto, O., 1987, Rock units of the
- Page 219 and 220: quadrangle, Colorado: U.S. Geologic
- Page 221 and 222: 94A 391996 4263422 Prospect YXp;Xbf
- Page 223 and 224: 336A 396189 4274961 Prospect Xgdf B
- Page 225: 854 391849 4268852 42 Adit; Geochem