Magmatic and Metallogenic Framework of West-Central Yukon and Eastern Alaska

Allan, Murray M.; Mortensen, James K.; Hart, Craig J.R.; Bailey, Leif A.; Sánchez, Matías G.; Ciolkiewicz, Witold; McKenzie, Greg G.; Creaser, Robert A.

doi:10.5382/sp.17.04

Cited by 9 publications

(5 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A suite of extrusive rocks was emplaced ca. 72-67 Ma, including the Carmacks Group volcanic rocks (Allan et al, 2013). Both intrusive Cretaceous suites are associated with Cu-Au porphyry and related deposits that are aligned and spatially associated with the Big Creek fault (Johnston, 1999), including the Nucleus and Revenue deposits, which lie within a releasing bend between the main fault strands ( Fig.…”

Section: Big Creek Faultmentioning

confidence: 99%

“…112-105 Ma) and Casino (ca. 79-72 Ma) suites (Allan et al, 2013;Colpron et al, 2016;Friend et al, 2017;Fig. 1).…”

Section: Big Creek Faultunclassified

“…Both intrusive Cretaceous suites are associated with Cu-Au porphyry and related deposits that are aligned and spatially associated with the Big Creek fault (Johnston, 1999), including the Nucleus and Revenue deposits, which lie within a releasing bend between the main fault strands ( Fig. 1; Allan et al, 2013).…”

Section: Big Creek Faultmentioning

confidence: 99%

“…Thus, there were at least three apparent slip periods: (1) structurally controlling emplacement of the Whitehorse suite ca. 112-105 Ma, (2) slip coeval with emplacement of the Casino suite and associated mineralization during 79-72 Ma, and (3) slip after 70 Ma (Allan et al, 2013;Friend et al, 2017).…”

Section: Big Creek Faultmentioning

confidence: 99%

See 3 more Smart Citations

Syncing fault rock clocks: Direct comparison of U-Pb carbonate and K-Ar illite fault dating methods

Mottram¹,

Kellett

Barresi³

et al. 2020

Geology

View full text Add to dashboard Cite

The timing of slip on brittle faults in Earth’s upper crust is difficult to constrain, and direct radiometric dating of fault-generated materials is the most explicit approach. Here we make a direct comparison between K-Ar dating of fault gouge clay (authigenic illite) and U-Pb dating of carbonate slickenfibers and veins from the same fault. We have dated fault generated materials from the Big Creek fault, a northwest-striking, dextral strike-slip fault system in Yukon Territory, Canadian Cordillera. Both methods yielded dates at ca. 73 Ma and ca. 60–57 Ma, representing at least two periods of fault slip that form part of a complex fault and fluid-flow history. The Cretaceous result lies within previous indirect estimates for major slip on the fault. The Paleocene–Eocene result coincides with the estimated timing of slip of the nearby Tintina and Denali faults, which are crustal-scale, northwest-striking dextral faults, indicating Big Creek fault reactivation during regional faulting. The coincidence of periods of carbonate-crystallizing fracturing and fluid flow with intervals of seismic, gouge-generating slip supports the fault valve model, where fault strength is mediated by fluid pressures, and fluid emplacement requires seismic pumping in otherwise impermeable aseismic fault zones. The reproducibility of slip periods for distinct fault-generated materials using different decay systems indicates that these methods provide complimentary results and can be reliably applied to date brittle fault slip, opening new opportunities for investigating fault conditions with associated mineralizing fluid events.

show abstract

Section: Big Creek Faultmentioning

confidence: 99%

“…112-105 Ma) and Casino (ca. 79-72 Ma) suites (Allan et al, 2013;Colpron et al, 2016;Friend et al, 2017;Fig. 1).…”

Section: Big Creek Faultunclassified

Section: Big Creek Faultmentioning

confidence: 99%

Section: Big Creek Faultmentioning

confidence: 99%

See 2 more Smart Citations

Syncing fault rock clocks: Direct comparison of U-Pb carbonate and K-Ar illite fault dating methods

Mottram¹,

Kellett

Barresi³

et al. 2020

Geology

View full text Add to dashboard Cite

show abstract

“…

Introduction:The Au-mineralized Vertigo target of the JP Ross (JPR) property is located ~70 km south of Dawson City in the White Gold District, west-central Yukon-Tanana Terrane (YTT). The mid-to late-Paleozoic YTT nested arc complex endured at least ten mineralizing pulses during tectonic convergence where vein, structurally controlled, and intrusion-related gold events spanned the Mesozoic-Cenozoic [1]. Gold mineralized showings in the west-central YTT comprise a segment of the Yukon-Tintina Gold Province, which represents a range of deposit types that define a 45-m.y.-long phase of arc magmatism [2].

…”

mentioning

confidence: 99%

Combined Geochemical and Mineralogical Investigation of Gold Mineralized Quartz Veins at the Vertigo Target, White Gold District, Yukon, Canada

Alexander

Loon²,

Banerjee

2021

Microsc Microanal

View full text Add to dashboard Cite

Tectonic Underplating and Dismemberment of the Maclaren‐Kluane Schist Records Late Cretaceous Terrane Accretion Polarity and ~480 km of Post‐52 Ma Dextral Displacement on the Denali Fault

2021

View full text Add to dashboard Cite

Terrane accretion introduces irregular geometry and allochthonous material to obliquely convergent margins, which create opportunities to quantify strike-slip displacement along otherwise margin-parallel fault systems. We present new bedrock geologic mapping and U-Pb and 40 Ar/ 39 Ar geochronology from the Alaska Range suture zone in the eastern Alaska Range, which confirm a longhypothesized correlation between the Maclaren Glacier metamorphic belt (Alaska, USA) and the Kluane metamorphic assemblage (Yukon Territory, Canada) across the right-lateral Denali fault. The new data inform a palinspastic reconstruction showing that the dissected metamorphic belts and associated plutons record ~480 km of dextral displacement along the Denali fault since ca. 52 Ma. Before strike-slip separation, the Maclaren-Kluane schist formed by west-vergent forearc underplating in the waning stage of the ca. 100-90 Ma arc built upon the Yukon-Tanana terrane. The prograde structural and metamorphic evolution of the Maclaren-Kluane schist records the final collision of the Wrangellia composite terrane at ca. 75-65 Ma along a set of east-dipping thrust shear zones, which we infer to record the polarity of the Late Cretaceous plate boundary between the composite terrane and North America. Paleogene extension partially exhumed the schists to the upper crust and may be a consequence of regionally distributed strike-slip faulting at that time. Localization of the modern Denali fault after ca. 52 Ma dismembered the schists and four neighboring belts of plutonic, metasedimentary, and volcanic rocks. The transition to Yakutat oblique flat slab subduction at ca. 30-25 Ma marks the onset of transpressional deformation in the Denali fault system, which reactivated Late Cretaceous collisional structures bounding the Maclaren schist. Neogene reactivation of the Totschunda fault reduced strike-slip motion on the Denali fault east of the Denali-Totschunda intersection and continues to transfer residual plate boundary slip onto the Denali fault west of the intersection. Key outcomes of our synthesis include: (a) Much of the ~480 km of displacement on the Denali fault accumulated after strike-slip on the neighboring Tintina and Border Ranges fault systems had largely shut down; (b) The modern Denali fault system should not be grouped with strike-slip faults credited with large-scale margin-parallel transport of Cordilleran terranes in the Cretaceous. Instead, a poorly understood proto-Denali fault system may be a candidate for large-scale Cretaceous translation; and (c) the longevity (≥33 Myr) of the highly localized Denali fault master strand (≤1 km wide) implies that it occupies a major mechanical boundary that penetrates the lithosphere.Plain Language Summary Many of the rocks that make up present-day western Canada and southern Alaska did not form as part of North America. Instead, most formed as coherent island chains (called terranes), collided with North America, and then slid northward along fault systems to their present location. The timing of...

show abstract

Magmatic and Metallogenic Framework of West-Central Yukon and Eastern Alaska

Cited by 9 publications

References 37 publications

Syncing fault rock clocks: Direct comparison of U-Pb carbonate and K-Ar illite fault dating methods

Syncing fault rock clocks: Direct comparison of U-Pb carbonate and K-Ar illite fault dating methods

Combined Geochemical and Mineralogical Investigation of Gold Mineralized Quartz Veins at the Vertigo Target, White Gold District, Yukon, Canada

Tectonic Underplating and Dismemberment of the Maclaren‐Kluane Schist Records Late Cretaceous Terrane Accretion Polarity and ~480 km of Post‐52 Ma Dextral Displacement on the Denali Fault

Contact Info

Product

Resources

About