Author: George E. GehrelsPublisher:
ISBN:
Category : Arizona
Languages : en
Pages : 218
Book Description
Geologic Excursions Through the Sonoran Desert Region, Arizona and Sonora
Author: George E. GehrelsPublisher:
ISBN:
Category : Arizona
Languages : en
Pages : 218
Book Description
The Mojave-Sonora Megashear Hypothesis
Author: Thomas Howard AndersonPublisher: Geological Society of America
ISBN: 0813723930
Category : Science
Languages : en
Pages : 726
Book Description
Studies on the Mesozoic of Sonora and adjacent areas
Author: César Jacques-AyalaPublisher: Geological Society of America
ISBN: 0813723019
Category : Science
Languages : en
Pages : 204
Book Description
Geologic Excursions in Southwestern North America
Author: Philip A. PearthreePublisher: Geological Society of America
ISBN: 0813700558
Category : Science
Languages : en
Pages :
Book Description
A Natural History of the Sonoran Desert
Author: Steven J. PhillipsPublisher: Univ of California Press
ISBN: 9780520219809
Category : History
Languages : en
Pages : 676
Book Description
"A Natural History of the Sonoran Desert provides the most complete collection of Sonoran Desert natural history information ever compiled and is a perfect introduction to this biologically rich desert of North America."--BOOK JACKET.
A Guide to the Geology of Organ Pipe Cactus National Monument and the Pinacate Biosphere Reserve
Author: John V. BezyPublisher: Arizona Geological Survey
ISBN: 9781892001115
Category : Geology
Languages : en
Pages : 74
Book Description
Southern Arizona and northern Sonora provide one of the most beautiful and dangerous landscape in the desert southwest. As described in this colorful and well-illustrated text, Organ Pipe Cactus National Monument is full of splendid geologic features. Along Ajo Mountain Drive volcanic rocks rise high above alluvial fans that display excellent examples of desert pavement and desert varnish. Join Bezy, Gutmann and Haxel as they explore the volcanic terrain of the Pinacate Biosphere Reserve. As one of the youngest volcanic fields in western North America, the Pinacate¿s are home to hundreds of cinder cones, the Sierra Pinacate shield volcano, maar craters and tuff rings. The presence of black basalt lava flows evokes an otherworldly moonscape. The enumerated index map will assist the first time visitor in tracking down the most representative vent types.
Tectonic Setting of Faulted Tertiary Strata Associated with the Catalina Core Complex in Southern Arizona
Author: William R. DickinsonPublisher: Geological Society of America
ISBN: 9780813722641
Category : Science
Languages : en
Pages : 130
Book Description
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.
Publications of the Geological Survey
Author: Geological Survey (U.S.)Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 876
Book Description
Accommodation zones and transfer zones; the regional segmentation of the Basin and Range Province
Author: James E. FauldsPublisher: Geological Society of America
ISBN: 081372323X
Category : Science
Languages : en
Pages : 247
Book Description
This volume focuses on the geometry, kinematic development, and origin of regional segmentation structures within the basin and range province of Western North America. Contributions range from analysis of individiual structures to broad regional syntheses, including a map of basin and range structures and tilt domains. Several papers discuss the implications of regional segmentation structures in assessing seismic hazards, hydrocarbon and mineral resources, and ground-water supplies.
New Publications of the U.S. Geological Survey
Author: Geological Survey (U.S.)Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 68
Book Description