Geologic map of central (interior) Alaska

Wilson, Frederic H.; Dover, J.H.; Bradley, Dwight C.; Weber, Florence R.; Bundtzen, Thomas K.; Haeussler, Peter J.

doi:10.3133/ofr98133a

Cited by 27 publications

(28 citation statements)

References 21 publications

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“…Halites and anhydrites, although not specified in a general geological description of the national park (Wilson et al, 1998), could be found within the late Triassic calcareous sedimentary rocks of the valley sides.…”

mentioning

confidence: 89%

“…The upstream catchment is ,115 km 2 with elevations ranging from 1835 m to the south, to 1197 m in the valley bottom. The underlying geology comprises calcareous and siliceous strata, and along the valley sides are Triassic calcareous sedimentary and submarine basalt, and Paleocene volcanic units (Wilson et al, 1998). The sedimentary units in the valley bottom are inferred to comprise basal glacial till, overlain by fluvial-glacial outwash deposits, and colluvium along the valley side (products of extensive paraglacial weathering; Ballantyne and Benn, 1994).…”

Section: Field Sitementioning

confidence: 99%

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Water Flow Dynamics of Groundwater-Fed Streams and Their Ecological Significance in a Glacierized Catchment

Crossman

Bradley

Boomer

et al. 2011

Arctic, Antarctic, and Alpine Research

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mentioning

confidence: 89%

Section: Field Sitementioning

confidence: 99%

Water Flow Dynamics of Groundwater-Fed Streams and Their Ecological Significance in a Glacierized Catchment

Crossman

Bradley

Boomer

et al. 2011

Arctic, Antarctic, and Alpine Research

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“…Figure 1, and the rock types follow the legend in Figure 2. The geologic maps are modified from Csejtey et al [1978], Winkler et al [1981], Winkler [1992], Wilson et al [1998], and the reference given in Figure 2. modern arc [Calvert et al, 2008].…”

Section: Felsic Magmatism In Intraoceanic Arcsmentioning

confidence: 99%

Intermediate to felsic middle crust in the accreted Talkeetna arc, the Alaska Peninsula and Kodiak Island, Alaska: An analogue for low‐velocity middle crust in modern arcs

et al. 2010

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Seismic profiles of several modern arcs have identified thick, low‐velocity midcrustal layers (Vp = 6.0–6.5 km/s) that are interpreted to represent intermediate to felsic plutonic crust. The presence of this silicic crust is surprising given the mafic composition of most primitive mantle melts and could have important implications for the chemical evolution and bulk composition of arcs. However, direct studies of the middle crust are limited by the restricted plutonic exposures in modern arcs. The accreted Talkeetna arc, south central Alaska, exposes a faulted crustal section from residual subarc mantle to subaerial volcanic rocks of a Jurassic intraoceanic arc and is an ideal place to study the intrusive middle crust. Previous research on the arc, which has provided insight into a range of arc processes, has principally focused on western exposures of the arc in the Chugach Mountains. We present new U‐Pb zircon dates, radiogenic isotope data, and whole‐rock geochemical analyses that provide the first high‐precision data on large intermediate to felsic plutonic exposures on Kodiak Island and the Alaska Peninsula. A single chemical abrasion–thermal ionization mass spectrometry analysis from the Afognak pluton yielded an age of 212.87 ± 0.19 Ma, indicating that the plutonic exposures on Kodiak Island represent the earliest preserved record of Talkeetna arc magmatism. Nine new dates from the extensive Jurassic batholith on the Alaska Peninsula range from 183.5 to 164.1 Ma and require a northward shift in the Talkeetna arc magmatic axis following initial emplacement of the Kodiak plutons, paralleling the development of arc magmatism in the Chugach and Talkeetna mountains. Radiogenic isotope data from the Alaska Peninsula and the Kodiak archipelago range from ɛNd(t) = 5.2 to 9.0 and 87Sr/86Srint = 0.703515 to 0.703947 and are similar to age‐corrected data from modern intraoceanic arcs, suggesting that the evolved Alaska Peninsula plutons formed by extensive differentiation of arc basalts with little or no involvement of preexisting crustal material. The whole‐rock geochemical data and calculated seismic velocities suggest that the Alaska Peninsula represents an analogue for the low‐velocity middle crust observed in modern arcs. The continuous temporal record and extensive exposure of intermediate to felsic plutonic rocks in the Talkeetna arc indicate that evolved magmas are generated by repetitive or steady state processes and play a fundamental role in the growth and evolution of intraoceanic arcs.

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“…4), the Nixon Fork subterrane consists of Cambrian through Devonian carbonate rocks and limited exposures of Neoproterozoic(?) strata similar to those at Lone Mountain (Wilson et al, 1998;LePain et al, 2000). To the northeast, in the Medfra quadrangle (Fig.…”

Section: Stratigraphy and Lithologiesmentioning

confidence: 83%

Neoproterozoic–early Paleozoic provenance evolution of sedimentary rocks in and adjacent to the Farewell terrane (interior Alaska)

et al. 2018

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Geologic map of central (interior) Alaska

Cited by 27 publications

References 21 publications

Water Flow Dynamics of Groundwater-Fed Streams and Their Ecological Significance in a Glacierized Catchment

Water Flow Dynamics of Groundwater-Fed Streams and Their Ecological Significance in a Glacierized Catchment

Intermediate to felsic middle crust in the accreted Talkeetna arc, the Alaska Peninsula and Kodiak Island, Alaska: An analogue for low‐velocity middle crust in modern arcs

Neoproterozoic–early Paleozoic provenance evolution of sedimentary rocks in and adjacent to the Farewell terrane (interior Alaska)

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