Tectonic Setting of Faulted Tertiary Strata Associated with the Catalina Core Complex in Southern Arizona

Tectonic Setting of Faulted Tertiary Strata Associated with the Catalina Core Complex in Southern Arizona
Author: William R. Dickinson
Publisher: Geological Society of America
Total Pages: 130
Release: 1991
Genre: Science
ISBN: 9780813722641

Mid-Tertiary strata exposed as tilted homoclines along the flanks of the San Pedro trough and across broad uplands north of the Catalina core complex are assigned to the following formations, each of which includes informal local members and facies: (a) Mineta Formation, mid-Oligocene redbeds including both conglomeratic fluvial and finer-grained lacustrine deposits; (b) Galiuro Volcanics, including lavas and domes, air-fall and ash-flow tuffs, and intercalated volcaniclastic strata of late Oligocene to earliest Miocene age; (c) Cloudburst Formation, also of late Oligocene and earliest Miocene age but including a sedimentary upper member of conglomeratic strata as well as a volcanic lower member correlative with part of the Galiuro Volcanics; and (d) San Manuel Formation, composed of lower Miocene alluvial fan and braidplain deposits that display contrasting clast assemblages in different areas of exposure. Generally correlative Oligocene-Miocene strata exposed south of the Catalina core complex are assigned to the Pantano Formation, which contains similar lithologic components. Less-deformed Neogene strata of post-mid-Miocene basin fill are assigned to the Quiburis Formation along the San Pedro trough, but stratigraphic equivalents elsewhere lack adequate nomenclature. High benchlands mantled by paleosols mark the highest levels of Neogene aggradation. Successive stages of subsequent erosional dissection are recorded by multiple terrace levels incised into basin fill. Key exposures of syntectonic mid-Tertiary sedimentary sequences in several local subareas reveal typical structural and stratigraphic relationships. Multiple fault blocks expose pre-Tertiary bedrock overlain by tilted mid-Tertiary strata confined to intervening half-grabens. Bounding syndepositional faults dip southwest and associated homoclines dip northeast. Fanning dips and buttress unconformities reflect progressive tilt and burial of eroding fault blocks. Dips of block-bounding faults are inversely proportional to the ages of the faults. Steeper dips for younger faults suggest either progressive erosion of successive listric faults or progressive rotation of successive planar faults. Uniformly moderate to steep dihedral angles between fault surfaces and offset homoclinal bedding imply that the faults dipped more steeply near the surface when syntectonic mid-Tertiary strata were subhorizontal. Although the inference of listric faulting best links apparent strands of the Catalina detachment system, the alternate interpretation of rotational normal faulting is compatible with local structural relationships including tilt of porphyry copper orebodies. Within the San Pedro trough, multiple homo clines of mid-Tertiary strata are exposed locally in tilt-blocks exhumed by Neogene erosion from beneath nearly flat-lying basin fill of the Quiburis Formation. Faults bounding the mid-Tertiary exposures include backtilted strands of the Catalina detachment system, somewhat younger listric or rotational normal faults, and steeper basin-range normal faults that display offsets both synthetic and antithetic to the flanks of the San Petro trough. In Cienega Gap, flanking the Tucson Basin, multiple tilt-blocks of the Pantano Formation form part of the upper plate of the Catalina detachment system. Initial construction of alluvial fans by generally westward paleoflow was followed by ponding of lacustrine environments along the foot of secondary breakaway scarps that also generated massive megabreccia deposits. In summary, syntectonic Oligocene to Miocene sedimentation succeeded a prominent pulse of polymodal mid-Tertiary volcanism and was coeval with mylonitic deformation and detachment faulting along the flank of the Catalina core complex. The headwall rupture for the detachment system migrated westward from an initial position along the range front of the Galiuro Mountains. After mid-Miocene time, accumulation and subsequent dissection of essentially undeformed basin fill was accompanied by basin-range block faulting. The most challenging structural issue is whether fault strands of the Catalina detachment system are interconnected or are disconnected rotational segments.

Cordilleran Section of the Geological Society of America

Cordilleran Section of the Geological Society of America
Author: Mason L. Hill
Publisher: Geological Society of America
Total Pages: 505
Release: 2013-08-01
Genre: Science
ISBN: 0813754070

One of six volumes generated by each GSA section for the Decade of North American Geology (DNAG) project, this centennial field guide contains descriptions of 100 sites or site clusters representing outstanding geologic locations in Alaska, southern Arizona, California, Hawaii, Nevada, Oregon, Washington and British Columbia.

Gneiss Domes in Orogeny

Gneiss Domes in Orogeny
Author: Donna Whitney
Publisher: Geological Society of America
Total Pages: 404
Release: 2004-01-01
Genre: Science
ISBN: 0813723809

Volcaniclastic Sedimentation in Lacustrine Settings

Volcaniclastic Sedimentation in Lacustrine Settings
Author: James D. L. White
Publisher: John Wiley & Sons
Total Pages: 320
Release: 2009-03-05
Genre: Science
ISBN: 1444304267

This volume presents a unique compendium of papers assessing theeffects of volcanism on lakes, as recorded by the volcaniclasticsediments deposited within them. The unifying theme is that theeffects of volcanism on lacustrine sedimentation are diverse anddistinctive, and that volcaniclastic lacustrine sediments hold thekey to understanding a range of processes and events that cannot bereadily addressed by the study of any non-volcanic lakes. Thirteen papers, with authors from nine countries, examine bothmodern and ancient eruption-affected lacustrine deposits. Volcaniceruptions affect lakes and their deposits in many ways, and thesepapers evaluate processes and products of volcanic eruptions withinlakes, of tectonically impounded lakes strongly influenced byvolcanism, of eruption-impounded lakes and of general factorscontrolling sedimentation of vitric ash and pumice.Tephrastratigraphic studies also take advantage of the exceptionalpreservation of thin laminae in quiet lakes to precisely dateepisodes in the evolution of long-lived lakes and their catchmentareas, and to understand how volcanism affects normal lacustrineprocesses. The volume as a whole is an unparalleled source of informationon all aspects of the physical sedimentary results of volcanism inlacustrine settings, and serves as a complement to other studiesconcerned primarily with thermal and geochemical characteristics oflakes within volcanic craters. If you are a member of the International Association ofSedimentologists, for purchasing details, please see:http://www.iasnet.org/publications/details.asp?code=SP30

Jurassic Magmatism and Tectonics of the North American Cordillera

Jurassic Magmatism and Tectonics of the North American Cordillera
Author: David M. Miller
Publisher: Geological Society of America
Total Pages: 434
Release: 1995
Genre: Science
ISBN: 0813722993

Demonstrating the multidisciplinary approach currently used to understand Jurassic magmatism and tectonics in western North America, 19 papers report a wealth of new data in the fields of structural geology, igneous petrology and isotope geochemistry, geochronology, sedimentology, and volcanology. T

Structural Geology and Geomechanics

Structural Geology and Geomechanics
Author: Zheng Yadong
Publisher: CRC Press
Total Pages: 322
Release: 2018-03-29
Genre: Science
ISBN: 1351413112

The 30th International Geological Congress was held in Beijing, China in August 1997. Leading scientists convened to present their findings and views to the international geological research community. Volume 14 of 26 focuses on structural geology and geomechanics. All articles in the proceedings have been refereed and keynote papers have been included in Volume 1. These proceedings aim to present a view of contemporary geology and should be of interest to researchers in the geological sciences.

Crustal Cross Sections from the Western North American Cordillera and Elsewhere

Crustal Cross Sections from the Western North American Cordillera and Elsewhere
Author: Robert Bruce Miller
Publisher: Geological Society of America
Total Pages: 324
Release: 2009
Genre: Science
ISBN: 0813724562

"Exposed crustal cross sections provide a unique direct view of continental crust, and are a major source of insights into variations in lithologic and geochemical composition, structural style, metamorphism, plutonism, and rheology with progressive depth through the crust. This volume provides a synthesis of crustal cross sections with a special emphasis on Phanerozoic sections from the western North American Cordillera, supplemented by articles on lower- and mid-crustal sections through Proterozoic crust in North America and Australia, and the classic crustal section of Fiordland, New Zealand. Many of the papers describe multidisciplinary research on crustal sections and include data from various combinations of structural analysis, geochemistry, geothermobarometry, geochronology, geophysics, and other disciplines. The volume also discusses common problems for the interpretation of crustal cross sections, including how sections that expose deep-crustal rocks are eventually exhumed, and leading to the conclusion that there is no simple 'standard model' for continental crust. This volume will be useful to those interested in structural geology, tectonics, geodynamics, regional geology, petrology, geochemistry/isotope geology, and geophysics."--Pub. desc.

Geologic Excursions in Southwestern North America

Geologic Excursions in Southwestern North America
Author: Philip A. Pearthree
Publisher: Geological Society of America
Total Pages: 562
Release: 2019-09-23
Genre: Science
ISBN: 0813700558

"Over the course of his 43-year career, James C. Knox conducted seminal research on the geomorphology of the Driftless Area of southwestern Wisconsin. His research covered wide-ranging topics such as long-term land-scape evolution in the Driftless Area; responses of floods to climate change since the last glaciation; processes and timing of floodplain sediment deposition on both small streams and on the Mississippi River; impacts of European settlement on the landscape; and responses of stream systems to land-use changes. This volume pre-sents the state of knowledge of the physical geography and geology of this unglaciated region in the otherwise-glaciated Midwest with contributions written by Knox prior to his passing in 2012 and by numerous of his for-mer colleagues and graduate students"--