Field Guide to Plutons, Volcanoes, Faults, Reefs, Dinosaurs, and Possible Glaciation in Selected Areas of Arizona, California, and Nevada (GSA Field Guide 11)

270 Pages·2008·32.06 MB·English

by  Ernest M. Duebendorfer, Eugene Irwin Smith

..T HE GEOLOGICAL SOCIETY
• OF AMERICA®
Field Guide 11
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edited by Ernest M. Duebendorter and Eugene I. Smith
Field Guide to Plutons, Volcanoes, Faults, Reefs, Dinosaurs,
and Possible Glaciation in Selected Areas of Arizona,
California, and Nevada
edited by
Ernest M. Duebendorfer
Northern Arizona University
Geology Department
Frier Hall
Knoles Drive
Flagstaff, Arizona 86011-4099
USA
Eugene I. Smith
Department of Geoscience
University of Nevada, Las Vegas
4505 S. Maryland Parkway
Las Vegas, Nevada 89154-4010
USA
Field Guide 11
3300 Penrose Place, P.O. Box 9140 Boulder, Colorado 80301-9140 USA
2008
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Published by The Geological Society of America, Inc.
3300 Penrose Place, P.O. Box 9140, Boulder, Colorado 80301-9140, USA
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Printed in U.S.A.
Library of Congress Cataloging-in-Publication Data
Field guide to plutons, volcanoes, faults, reefs, dinosaurs, and possible glaciation in selectedareas of
Arizona, California, and Nevada / edited by Ernest M. Duebendorfer, Eugene I. Smith.
p. cm. -- (Field guide ; 11)
Includes bibliographical references.
ISBN: 978-0-8137-0011-3 (pbk.)
1. Geology--Arizona. 2. Geology--California. 3. Geology--Nevada. I. Duebendorfer, Ernest M.
II. Smith, Eugene I. (Eugene Irwin), 1944-
QE85.F54 2008
557.9--dc22
2008006898
Cover: Spectacular geology in the Lake Mead area just west of Las Vegas. The River Mountains
volcanic section (foreground in Nevada) and the Wilson Ridge pluton (on the skyline to the east in
Arizona) represent a linked volcanic-plutonic system separated by the Saddle Island detachment fault.
The mesa is Fortification Hill capped by 5.8 m.y. old basalt. Photo by Eugene Smith, May 2006.
10 9 8 7 6 5 4 3 2 1
ii
Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
1. The mid-Miocene Wilson Ridge pluton and River Mountains volcanic section,
Lake Mead area of Nevada and Arizona: Linking a volcanic and plutonic section . . . . . . . . . . . . 1
Denise Honn and Eugene I. Smith
2. Late Paleozoic deformation in central and southern Nevada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Pat Cashman, Jim Trexler, Walt Snyder, Vladimir Davydov, and Wanda Taylor
3. Active tectonics of the eastern California shear zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Kurt L. Frankel, Allen F. Glazner, Eric Kirby, Francis C. Monastero, Michael D. Strane,
Michael E. Oskin, Jeffrey R. Unruh, J. Douglas Walker, Sridhar Anandakrishnan,
John M. Bartley, Drew S. Coleman, James F. Dolan, Robert C. Finkel, Dave Greene,
Andrew Kylander-Clark, Shasta Marrero, Lewis A. Owen, and Fred Phillips
4. Ediacaran and early Cambrian reefs of Esmeralda County, Nevada: Non-congruent
communities within congruent ecosystems across the Neoproterozoic-Paleozoic boundary . . . . 83
Stephen M. Rowland, Lynn K. Oliver, and Melissa Hicks
5. Magmatism and tectonics in a tilted crustal section through a continental arc,
eastern Transverse Ranges and southern Mojave Desert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Andrew P. Barth, J. Lawford Anderson, Carl E. Jacobson, Scott R. Paterson, and Joseph L. Wooden
6. Cenozoic evolution of the abrupt Colorado Plateau–Basin and Range boundary,
northwest Arizona: A tale of three basins, immense lacustrine-evaporite deposits,
and the nascent Colorado River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
James E. Faulds, Keith A. Howard, and Ernest M. Duebendorfer
7. Interpretation of Pleistocene glaciation in the Spring Mountains of Nevada: Pros and Cons . . . 153
Jerry Osborn, Matthew Lachniet, and Marvin (Nick) Saines
8. Quaternary volcanism in the San Francisco Volcanic Field: Recent basaltic eruptions
that profoundly impacted the northern Arizona landscape and disrupted the lives of
nearby residents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
S.L. Hanson, W. Duffield, and J. Plescia
9. The Spirit Mountain batholith and Secret Pass Canyon volcanic center:
A cross-sectional view of the magmatic architecture of the uppermost crust
of an extensional terrain, Colorado River, Nevada-Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Nicholas P. Lang, B.J. Walker, Lily L. Claiborne, Calvin F. Miller, Richard W. Hazlett,
and Matthew T. Heizler
iii
iv Contents
10. Devonian carbonate platform of eastern Nevada: Facies, surfaces, cycles,
sequences, reefs, and catastrophic Alamo Impact Breccia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
John E. Warme, Jared R. Morrow, and Charles A. Sandberg
11. Dinosaurs and dunes! Sedimentology and paleontology of the Mesozoic in
the Valley of Fire State Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Joshua W. Bonde, David J. Varricchio, Frankie D. Jackson, David B. Loope,
and Aubrey M. Shirk
Preface
Welcome to Las Vegas! This guidebook has been prepared in conjunction with the 2008 combined Cor-
dilleran and Rocky Mountain Sections meeting of the Geological Society of America. This volume contains
background information and road logs for eleven fi eld trips in Nevada, Arizona, and California.
Southern Nevada and adjoining areas contain a rich geologic history spanning the interval from the
Paleoproterozoic to the present. Las Vegas lies at or near several critical geological junctures and localities
including the structural boundary between the Colorado Plateau and Basin and Range, the physiographic
boundary between the Great Basin and the southern Basin and Range, the eastern margin of the Sevier fold-
and-thrust belt, the tectonically active Death Valley area, tilted and faulted volcanic-plutonic systems expos-
ing the upper part of the crust, and the enigmatic “amagmatic zone.”
Field trips in this volume span the geologic record from the Ediacaran (late Neoproterozoic) to the Holo-
cene. Steve Rowland, Lynn Oliver, and Melissa Hicks will lead participants to three of the best examples of
Ediacaran and Early Cambrian reefs in North America (Chapter 4). A trip led by John Warme, Jared Morrow,
and Charles Sandberg (Chapter 10) examines the long-lived Devonian shallow-water carbonate platform and
features a visit to the spectacular Alamo Impact Breccia. Middle Mississippian to late Permian tectonism as
recorded by regional unconformities, folding, thrusting, and the stratigraphic record is the focus of a trip led
by Pat Cashman, Jim Trexler, Walt Snyder, Vladimir Davydov, and Wanda Taylor (Chapter 2).
Andy Barth, Lawford Anderson, Carl Jacobson, Scott Paterson, and Joe Wooden bring us into the Meso-
zoic with an overview of the tectonic evolution of a tilted section through the upper and middle crust of the
Cretaceous Cordilleran arc (Chapter 5). Cretaceous sedimentary rocks deposited in the foredeep of the Sevier
fold-and-thrust belt and their dinosaur fossils are the topic of a trip led by Joshua Bonde, David Varricchio,
Frankie Jackson, David Loope, and Aubrey Shirk (Chapter 11).
The Cenozoic is well represented by six different trips. Nick Lang, B.J. Walker, Lily Claiborne, Calvin
F. Miller, Rick Hazlett, and Matt Heizler (Chapter 9) examine spectacular cross-section view of the Miocene
Spirit Mountain batholith and a coeval, and possibly related, eruptive center (Secret Pass) in the Colorado
River extensional corridor. Another volcano-plutonic complex, the River Mountains–Wilson Ridge igneous
system, which was dismembered by the Saddle Island detachment fault is the destination of a trip led by
Denise Honn and Gene Smith (Chapter 1). Jim Faulds, Keith Howard, and Ernie Duebendorfer examine
synextensional basins that constrain the timing of the structural demarcation between the Colorado Plateau
and the Basin and Range (Chapter 6). Jerry Osborn, Matthew Lachniet, and Nick Saines weigh the evidence
for and against Pleistocene glaciation in the Spring Mountains of southern Nevada in Chapter 7. The cultural
effects of some of the youngest volcanism in the continental United States outside the Cascades is the focus
of a trip by Sarah Hanson, Wendell Duffi eld, and Jeffrey Plescia (Chapter 8) to the San Francisco volcanic
fi eld near Flagstaff, Arizona. Finally, Kurt Frankel and a cast of thousands bring us up to date with a look at
the active tectonics of the eastern California shear zone with discussions regarding signifi cant discrepancies
between long-term slip rates and the current rate of strain accumulation along active faults (Chapter 3).
With fi eld trips ranging from old to the present, the middle crust to the surface, from tectonics to paleon-
tology, and from volcanism to glaciation, this volume offers something for everyone.
Ernest M. Duebendorfer
Eugene I. Smith
v
Map of the Nevada, California, Arizona, and Utah areas visited in these fi eld trips showing locations of trips by number.
The Geological Society of America
Field Guide 11
2008
The mid-Miocene Wilson Ridge pluton and River Mountains
volcanic section, Lake Mead area of Nevada and Arizona:
Linking a volcanic and plutonic section
Denise Honn*
Eugene I. Smith*
Department of Geoscience, University of Nevada, Las Vegas, Nevada 89154-4010, USA
ABSTRACT
This fi eld trip will visit the River Mountains volcanic section (12.17 ± 0.02 to
13.45 ± 0.02 Ma) and Wilson Ridge pluton (13.10 ± 0.11 Ma) in southern Nevada and
northwestern Arizona. Although this volcanic-plutonic system was disrupted by the
Saddle Island detachment fault during Miocene crustal extension, there are convinc-
ing lithological, mineralogical, geochemical and geochronological indicators that sug-
gest a cogenetic relationship. The trip consists of 17 stops that emphasize evidence
that links the volcanic and plutonic sections. In addition we will visit the Saddle Island
detachment fault at its type locality on Saddle Island.
Keywords: plutonic rocks, volcanoes, Lake Mead, petrology, geochronology.
INTRODUCTION The River Mountains volcanic section–Wilson Ridge plu-
ton igneous system crops out at the northern end of the Colo-
The study of an igneous system is limited by exposure and rado River extensional corridor, a north-south trending area of
preservation of the rock record. In most cases, only a portion southern Nevada, western Arizona and eastern California that
of the system is exposed (i.e., volcanic or plutonic) and there- underwent up to 100% extension between ca. 23 and 12 Ma.
fore only part of the magmatic history can be studied. Based In the northern part of the corridor, volcanic rocks of Tertiary
on work done over the past 20 years, we interpret the River age lie on Precambrian crystalline rocks and locally a thin con-
Mountains volcanic section of southern Nevada and the Wilson glomerate containing sedimentary and crystalline clasts. Paleo-
Ridge Pluton in northwestern Arizona as volcanic and plutonic zoic and Mesozoic sedimentary sections are missing and were
segments of the same igneous system (Fig. 1). The connection probably stripped from a rising structural arch (the Kingman
between the River Mountains volcanic section and the Wilson Arch) during late-Cretaceous, early Tertiary time (Faulds et al.,
Ridge pluton is based on structure, lithology, mineralogy, geo- 2001). The arch plunges gently to the north (~15°) and termi-
chemistry, and geochronology. This fi eld trip will visit both the nates against the Lake Mead fault system just north of Lake
River Mountains and Wilson Ridge and will emphasize links Mead. In the Colorado River extensional corridor, magmatism
between the volcanic and plutonic sections. migrated to the north, pre-dating crustal extension by about
1 m.y. (Faulds et al., 2001).
*
2 Honn and Smith
Hoover
Dam
Fortification
Ridge
WilsonRidge
M-PC
M-PC
Twrc
Twrc
Arch
Mountain
Detrital Wash
Saddle
Island
Tid
Tmf
Mz-P
QTs
Tpm
Canyon
Gilbert
o o o o
114 50' 114 45' 114 40' 114 35'
Tcf Tcf Mz-P Thc Thc Thc
QTs
QTs QTs
Tbw
Tcf QTs
Tgp QTs Tgp Tgp
Tgp Thc QTs
o Tgp Tcf Twrh
36 10' o
Twrh QTs 36 10'
Tgp
Tgp Tgp Tcf Tcf Thc Tbr Tgp
Tbr QTs
QTs
Tgp QTs Tgp Twrh M-PC Boulder
Tcf Wash
Twrh Twrc
Tgp
Tgp QTs Lake
QTs
Tgp QTs Mead
Twrh
o
114 50'
Tgp Twrc
QTs
QTs Tpb QTs 0 1 Km Tgp
Tpb Tpd
Tpd 0 1 Mi M-PC
N Twrh Tgp
Tpd
Tpb Twrm Tgp QTs
36o 05' Tpb o
Tpd M-PC Lake Mead Tmf Tmf 36 05'
QTs Tpb Twrh
Tpd QTs
Qts
Tvu
Tpd Twrc
Tpd Tmf
Tpd
Tmf
Tpd QTs
QTs
Tpd K-Tpp
Tmf
Tmf
Qts
Twrm
Tsv Promontory
Tpb
Point Thd Tvu QTs Tmf
Tsv Twrc
Tmf
Tpd
Tid
QTs QTs Tvu Qts
QTs K-Tpp
Tpd QTs Tsv M-PC Tid Tmf
Trs Tpm Tvu Twrc
Thd
QTs QTs
Tbc Tpm
Tbv Boulder City
35o 00' Tmf o
36 00'
o o o o o
114 50' 114 50' 114 45' 114 40' 114 35'
Figure 1. Geologic map of Lake Mead region. Adapted from Smith et al. (1990).
Tpb
Tpd
Tpd
Mid-Miocene Wilson Ridge pluton and River Mountains volcanic section 3
Quaternary Qts - Tertiary and younger sediments
Faults - dotted where concealed
Tmf - Fortification Hill basalt or inferred ball on downthrown side
Tcf - Callville Mesa volcanic rocks Contacts
Thc - Hamblin-Cleopatra volcanic rocks Dikes
Tgp - Unassigned volcanic rocks
Tvu - upper Hoover Dam volcanic rocks
Powerline road volcanic rocks
Tpd - dacite
Tpd - basalt and andesite
Tbc - Boulder City Pluton Wilson Ridge Pluton
Tbv - Bootleg Wash volcanic rocks Twrh - hypabyssal phase
Twrm - medium grained phase
Twrc - coarse grained phase
Thd - Tuff of Hoover Dam and Dam Conglomerate Twrg - red feldspar granite phase
Tbw - Boulder Wash volcanic rocks Tid - diorite phase
Tbr - Breccia
River Mountains Stratovolcano
Trs - quartz monzonite stock
Tpm - Patsy Mine volcanic rocks
Tsv - andeste and dacite
K-Tpp - Paint Pots intrusive rocks
Mesozoic
Mz-p - Pennsylvanian through Mesozic rocks
Paleozoic
M-Pc - Precambrian through Mississippian rocks
Precambrian
Figure 1 (continued).
RIVER MOUNTAINS VOLCANIC SECTION fractures and coatings on rocks of the quartz monzonite
stock and surrounding altered volcanic rocks. M agnesio-
The River Mountains volcanic section (12.17 ± 0.02 to riebeckite is also found in fractures and thin veins in
40 39
13.45 ± 0.02 Ma, Ar/ Ar whole-rock and mineral dates; Faulds various phases of the Wilson Ridge pluton and within the
et al., 1999) composed of mainly dacite, andesite, basalt and rhy- Colorado River extensional corridor appears to be unique
olite is locally intruded by hypabyssal dacite plugs and a quartz to this volcanic-plutonic system.
monzonite stock. Smith (1982; 1984) suggested that the River 2. The Bootleg Wash section just north Boulder City, Nevada,
Mountains are composed of at least four volcanoes that were composed from base to top of a section of andesite fl ows,
juxtaposed by mid-Tertiary strike-slip faulting related to the left- volcaniclastic breccia, and fl ow-banded dacite fl ows.
l ateral Lake Mead fault system: 3. The Red Mountain section formed by highly altered
1. The River Mountains stratovolcano and related satellitic andesite and dacite fl ows, volcaniclastic rocks, and local
dacite, rhyolite and basalt volcanoes. The stratovolcano granitic intrusions. On Red Mountain, andesite fl ows
is cored by the River Mountains quartz monzonite stock, and breccia are interleaved along numerous low-angle
which is surrounded by a zone of altered volcanic rocks faults. The Red Mountain section is separated from the
cut by numerous dikes. The stock contains many xeno- River Mountains stratovolcano by a northwest-striking
liths of basalt and dolomite. Dikes of porphyritic dacite fault (probably strike slip) and may represent highly
radiate from the plug. The stock is chemically equivalent altered volcanic and plutonic rocks related to the Boul-
to rocks of the Wilson Ridge pluton and may represent der City pluton (14.17 ± 0.6 Ma; NAVDAT (http://navdat.
the detached apex of one of the Wilson Ridge intrusions. kgs.ku.edu/); 13.8 Ma K/Ar age reported by Anderson
Rocks above the intrusion are altered and mineralized et al., 1972).
andesite and plutonic rock cut by numerous dacite dikes 4. The Casino dacite just east of Railroad Pass is character-
that emanate from the River Mountains stock. The blue ized by andesite and dacite fl ows and a thin moderately
sodium amphibole, magnesio-riebeckite, occurs along welded ash-fl ow tuff.
Tertiary