Characterization and Reconstruction of Multiple Copper-Bearing Hydrothermal Systems in the Tea Cup Porphyry System, Pinal County, Arizona

Nickerson, Phillip A.; Barton, Mark D.; Seedorff, Eric

doi:10.5382/sp.15.1.17

Cited by 12 publications

(24 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Eventually, Wilkins and Heidrick (1995) suggested that all porphyry deposits in the Basin and Range province should be assumed to be faulted and tilted until proven otherwise. During the past decade, the importance of tilting of orebodies across the Basin and Range province has continued to be emphasized (e.g., Seedorff et al, 2005a, p. 276-277;Maher, 2008;Stavast et al, 2008;Nickerson et al, 2010) and is again demonstrated here.…”

Section: Exploration Targetssupporting

confidence: 55%

“…Benefits of this superposition arise when products of one of the geologic processes can be used to help constrain aspects of the other process. For example, predictable patterns in hydrothermal alteration zoning can be used as geologic markers that may better constrain structural reconstructions (e.g., Nickerson et al, 2010), and, in turn, aid in better discriminating between different styles of extension. Conversely, ore-forming processes can be better constrained where deep levels of ore-forming systems are exhumed and can be examined at the surface (Proffett, 1979;Carten, 1986;Dilles and Einaudi, 1992;Seedorff et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dismembered Porphyry Systems near Wickenburg, Arizona: District-Scale Reconstruction with an Arc-Scale Context

Nickerson¹,

Seedorff²

2016

Economic Geology

Self Cite

View full text Add to dashboard Cite

This study combines results from reconnaissance-scale mapping of hydrothermal alteration, rock types, and structures to provide a district-scale cross section and associated palinspastic reconstruction of an area with two previously undescribed Laramide (~70 Ma) porphyry systems at Sheep Mountain and Copper Basin (Crown King). Extension at the district scale is placed in an arc-scale context using an original compilation of strike and dip measurements on Tertiary rocks to reconstruct the Laramide porphyry belt prior to extension. The study area contains five sequential, partially superimposed sets of normal faults that are nearly planar where exposed. Dips of all normal faults initiated at 60° to 70° and rotated during slip to angles as gentle as 20°. A palinspastic reconstruction reveals that two, spatially distinct hydrothermal systems overlie different cupolas of a Late Cretaceous pluton. Hydrothermal alteration is zoned from greisen to potassic to transitional greisenpotassic assemblages from deep to shallow structural levels. The reconstruction is used to identify two covered exploration targets. The prospects may be porphyry molybdenum systems of the quartz monzonitic-granitic porphyry Mo-Cu subclass, joining others in an arc that is best known for porphyry copper deposits. The Laramide porphyry belt prior to extension displays a variably well-defined axis, ~100 km wide, with gaps and clusters of deposits along its 700-km strike length. The majority of deposits lie along the axis, but others lie in fore-or rear-arc positions. The interpreted preextensional geometry of the Laramide porphyry belt resembles other porphyry belts and the distribution of active volcanoes at convergent margins.

show abstract

Section: Exploration Targetssupporting

confidence: 55%

Section: Introductionmentioning

confidence: 99%

Dismembered Porphyry Systems near Wickenburg, Arizona: District-Scale Reconstruction with an Arc-Scale Context

Nickerson¹,

Seedorff²

2016

Economic Geology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Both high‐angle reverse faults and low‐angle thrusts have been interpreted in areas affected by significant Cenozoic extension and in areas affected only by minor extension (Figure ). Basement‐cored uplifts bounded by moderate‐angle reverse faults have been documented in the central Tortilla Mountains (Favorito & Seedorff, ; Nickerson et al, ), in a large area centered on the Mustang Mountains (Davis, ), and in the Chiricahua Mountains and surrounding ranges (Lawton, ; Lawton & Olmstead, ). The Salt River area is characterized by monoclines, associated high‐angle reverse faults, and extensive northeast Laramide tilting related to regional uplift (Davis et al, ; Granger & Raup, ; Krantz, ; Sandberg & Butler, ).…”

Section: Discussionmentioning

confidence: 99%

“…Restored fault orientations without kinematic indicators, such as fault‐related folds and slickenlines, may not be sufficient to determine the transport direction of faults. This lack of data is common in southeastern Arizona because faults commonly are poorly exposed, and fault‐related folding may not be apparent if only basement rocks are exposed (e.g., Nickerson et al, ). In southeastern Arizona, Laramide reverse faults and ductile fabrics, regardless of shortening style, are largely interpreted to have either east or northeast transport directions (e.g., Bykerk‐Kauffman & Janecke, ; Richard & Spencer, ; Waldrip, ).…”

Section: Discussionmentioning

confidence: 99%

“…The Galiuro Mountains are located within the Basin and Range province of southeastern Arizona. Even though the San Pedro Valley and Tortilla Mountains, located immediately west of the Galiuro Mountains, have been highly extended and tilted by middle to late Cenozoic extension (Barton et al, ; Dickinson, ; Favorito & Seedorff, ; Maher, ; Nickerson et al, ), the Galiuro Mountains are cut by only a few normal faults and are only mildly extended (Creasey et al, ; Dickinson, ). Nearby towns include Mammoth and Dudleyville, and nearby Laramide porphyry copper deposits include Copper Creek, San Manuel‐Kalamazoo, Chilito, and Christmas (Leveille & Stegen, ), each of which is no farther than 15 km from boundaries of the study area.…”

Section: Geologic Settingmentioning

confidence: 99%

See 1 more Smart Citation

Discovery of Major Basement‐Cored Uplifts in the Northern Galiuro Mountains, Southeastern Arizona: Implications for Regional Laramide Deformation Style and Structural Evolution

Favorito

Seedorff

2018

Tectonics

Self Cite

View full text Add to dashboard Cite

The Laramide orogeny is poorly understood in southeastern Arizona, largely because of complex structural overprinting by mid-Cenozoic extension that occurred over large areas. This study integrates new geological mapping with previous work, combined with structural reconstructions and forward modeling, to determine the primary structural style, timing, evolution, and kinematics of Laramide shortening in the northern Galiuro Mountains. Cenozoic normal faulting in the study area is minor and has only resulted in up to 13°of eastward tilting, as indicated by the gentle dips of synextensional strata. Detailed mapping has revealed newly identified reverse fault systems measuring at least 50 km in combined strike length. Each major fault strikes north-northwest, dips moderately to the west, places older rocks on younger, and has related fault-propagation folds. Once restored to their original orientation, reverse faults range in dip from 38°to 47°. These moderate dips of faults combined with related folds, the significant degree of basement involvement, and cover sequence lacking obvious penetrative deformation indicate that these faults are thick-skinned, basement-cored uplifts. Forward modeling and Cenozoic erosion surfaces suggest regionally extensive Laramide-age tilting to the west-southwest and gentle folding, possibly caused by a regional-scale reverse fault underlying the study area. These results are consistent with the interpretation that Laramide shortening in southeastern Arizona was primarily characterized by thick-skinned tectonics. Kinematic indicators, folded basement rocks, north-northwest strikes of reverse faults, and lack of evidence for basin inversion suggest that preexisting basement faults and fabrics had little or no effect on the subsequent structural evolution.Plain Language Summary The Late Cretaceous to early Eocene Laramide orogeny was a period of crustal shortening in the North American Cordillera that involved two different styles of reverse faulting. One style involves low-angle thrusts that typically slip parallel to bedding planes in layered rocks, whereas the other style involves faults that cut across bedding at moderate angles and continue downward through underlying crystalline basement rock. In southeastern Arizona, the style of Laramide shortening is debated and not well understood, in part because most of the region has undergone subsequent Cenozoic extension that has significantly rotated, dismembered, and buried most faults formed during Laramide crustal shortening. This study examines a newly discovered set of Laramide reverse faults that extend for more than 50 km along strike and that have only been affected by minor extension. Results from field mapping and structural modeling indicate that these faults are basement-involved, moderate-angle reverse faults. Because the upper crustal architecture across the region is largely consistent, the region as a whole may be characterized by moderate-angle reverse faults. Thus, nearby Laramide faults that have been previously interpr...

show abstract

Oligocene‐Miocene Exhumation of the Pinaleño Metamorphic Core Complex, Southeastern Arizona: Support for Magmatism and Plate Margin Reorganization as Controls on Regional Exhumation Trends

Chapman,

Scoggin,

Jepson

et al. 2024

Tectonics

View full text Add to dashboard Cite

The Pinaleño Mountains of southeastern Arizona is the eastern‐most metamorphic core complex in the southern U.S. and northern Mexican Cordillera. This study investigates the thermal history and exhumation record of the Pinaleño core complex using mica 40Ar/39Ar, apatite and zircon (U‐Th)/He, and apatite fission‐track thermochronometers. The Pinaleño Mountains experienced two periods of rapid cooling during the Cenozoic. The first period, from ca. 27 to 21 Ma, records tectonic exhumation related to the development of the core complex and extensional shear zone. This period was followed by a relatively quiescent interval from 21 to 13.5 Ma that records little to no exhumation. The second period of rapid cooling, from 13.5 to 11 Ma, records tectonic exhumation related to high‐angle normal faulting, characteristic of the Basin and Range province. The exhumation timing of the Pinaleño core complex matches previously recognized spatiotemporal trends in the southern Basin and Range province and indicates that core complex exhumation in this region started in southeastern Arizona (ca. 32–33°N) and migrated both northward and southward. These trends correlate well with the latitude and timing of subduction of the Pacific‐Farallon spreading ridge and the migration of the Mendocino (northward) and Rivera (southward) triple junctions. Spatiotemporal core complex exhumation trends also correlate well with regional magmatism associated with the mid‐Cenozoic flare‐up, including syn‐extensional intrusive rocks found in the footwalls of core complexes.

show abstract

Characterization and Reconstruction of Multiple Copper-Bearing Hydrothermal Systems in the Tea Cup Porphyry System, Pinal County, Arizona

Cited by 12 publications

References 27 publications

Dismembered Porphyry Systems near Wickenburg, Arizona: District-Scale Reconstruction with an Arc-Scale Context

Dismembered Porphyry Systems near Wickenburg, Arizona: District-Scale Reconstruction with an Arc-Scale Context

Discovery of Major Basement‐Cored Uplifts in the Northern Galiuro Mountains, Southeastern Arizona: Implications for Regional Laramide Deformation Style and Structural Evolution

Oligocene‐Miocene Exhumation of the Pinaleño Metamorphic Core Complex, Southeastern Arizona: Support for Magmatism and Plate Margin Reorganization as Controls on Regional Exhumation Trends

Contact Info

Product

Resources

About