General geology of the central Alaska Range between the Nenana River and Mount Deborah

Sherwood, Kirk W.; Craddock, Campbell

doi:10.14509/32

Cited by 12 publications

(28 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unit well exposed north of Denali fault, particularly in B-l to B-6 and C-2 to C-4 quadrangles. On strike to the west in the Healy quadrangle, metasedimentary rocks correlated with the fine-grained metasedimentary rocks (j°S) of the Jarvis Creek Glacier subterrane contain Devonian to Mississippian conodonts (Sherwood and Craddock, 1979;Csejtey and others, 1992). U-Pb isotopic analysis of clastic zircons in quartzites in unit (jcs) indicates the protolith was derived in part from an Early Proterozoic source rock with radiometric sample ages of 2.0 to 2.3 Ga (Table 2 of Nokleberg and others (1992), localities 22, 23) (Aleinikoff and Nokleberg, 1985a;Aleinikoff and others, 1987).…”

Section: Jcsmentioning

confidence: 86%

“…Unit occurs in west-central part of quadrangle, south of Denali fault in small roof pendants in the East Susitna batholith. Lithologically similar rocks on strike in Healy quadrangle to west contain Pennsylvanian to Triassic conodonts (Sherwood and Craddock, 1979;Csejtey and others, 1992), and fragments of bivalves of Late Triassic age (Jones and others, 1987). Correlated with Nenana terrane of Jones and others (1987).…”

Section: East Susitna Batholith and Schist Quartztie And Amphffioltmentioning

confidence: 99%

See 1 more Smart Citation

Preliminary geologic map of the Mount Hayes quadrangle, eastern Alaska Range, Alaska

Nokleberg¹,

Aleinikoff²,

Lange³

et al. 1992

Open-File Report

View full text Add to dashboard Cite

show abstract

Section: Jcsmentioning

confidence: 86%

Section: East Susitna Batholith and Schist Quartztie And Amphffioltmentioning

confidence: 99%

Preliminary geologic map of the Mount Hayes quadrangle, eastern Alaska Range, Alaska

Nokleberg¹,

Aleinikoff²,

Lange³

et al. 1992

Open-File Report

View full text Add to dashboard Cite

show abstract

“…Compositional layering in marbles defined by calcite alternating with quartz-rich, and/or chlorite-rich layers. (Sherwood and Craddock, 1979;Csejtey and others, 1992). U-Pb isotopic analysis of clastic zircons in quartzites in unit jcs indicates the protolith was derived in part from an early Proterozoic source rock with radiometric sample ages of 2.0 to 2.3 Ga (table 2 of Nokleberg and others [1992a], localities 22, 23) (Aleinikoff and Nokleberg, 1985;Aleinikoff and others, 1987).…”

Section: Macomb Subterrane -South Of Tanana River Fault and North Of mentioning

confidence: 95%

“…The protolith of the terrane is interpreted as chiefly continental rise or slope sedimentary rock and associated submarine con tinental margin arc rock that were intruded by gabbro (Nokleberg and others, 1983;Nokleberg and Richter, 2007 (Sherwood and Craddock, 1979).…”

Section: Pingston Terrane -South Of Hines Creek Fault and North Of Nementioning

confidence: 99%

“…Unit occurs in fault-bounded wedges, and is intruded by gabbro of Mount Moffit (pimg) and by smaller bodies, dikes, and sills of granite and gabbro. (Sherwood and Craddock, 1979). A U-Pb zircon age from a metarhyodacite layer in the terrane is 375 ± 8 Ma (Aleinikoff and Nokleberg, 1983;Nokleberg and others, 1992a).…”

Section: Pingston Terrane -South Of Hines Creek Fault and North Of Nementioning

confidence: 99%

See 1 more Smart Citation

Geologic maps of the eastern Alaska Range, Alaska (44 quadrangles, 1:63,360 scale), with descriptions and interpretations of map units

Nokleberg¹,

Aleinikoff²,

Bond³

et al. 2015

View full text Add to dashboard Cite

Limestone to marble composed of calcite with minor quartz, plagioclase, and sericite. Local skarn, devel oped in lenses up to 1 m thick along diabase-marble contact, composed of fine-to medium-grained schis tose calcite and minor epidote, hornblende, wollastonite, garnet, and clinopyroxene. Volcanic sandstone composed of fine-grained, rounded to subangular clasts of twinned and zoned plagio clase and minor quartz in matrix predominantly of chlorite. Authigenic analcite replaces and cements clasts in some calcareous sandstone. Calcareous volcanic graywacke composed of abundant twinned and zoned plagioclase clasts up to 1.5 mm long in a fine-grained, sparsely fossiliferous matrix of calcite and minor epidote and white mica. Presence of graded bedding, poor sorting, and slump structures indicates sedimentary and volcaniclastic strata depos ited from turbidity currents in a low-energy environment below wave base located near active volcanic vents (Bond, 1973, 1976). Andesite has intergranular to ophitic porphyritic texture. Composed of twinned and zoned plagioclase phenocrysts locally resorbed and sparse glomerocrysts up to 3.5 mm long and local hornblende phenocrysts up to 2 mm long, in a fine-grained to felty groundmass of plagioclase, quartz, and white mica. Locally amygdules filled with clinozoisite and chlorite. Andesite tuff composed of angular to subangular plagioclase fragments in matrix predominantly of clay minerals, opaque minerals, and locally abundant calcite. Hornblende(?) completely replaced by chlorite. Diabase composed of fine-grained plagioclase and clinopyroxene and minor opaque minerals, chlorite, and epidote. Relict minerals are plagioclase and sparse hornblende, quartz, clinopyroxene, and opaque minerals. Metamorphic minerals are chlorite, epidote, calcite, and white mica. Dacitic to rhyodacitic ash to lapilli tuffs, green to gray, mainly broken plagioclase, quartz, K-feldspar, and lithic fragments in matrix of very-fine-grained aggregate of quartz, feldspar, chlorite and local leucoxene. Plagioclase commonly twinned. Pumice fragments preserved as irregular platelets and disks of chlorite with porous or tubular texture. Lithic fragments angular; composed of a variety of volcanic rocks exhibiting por phyritic, trachytic, pilotaxitic, glassy, microvesicular, and scoriaceous textures. Locally stratified due to var iation in grain size, color, and grading. Local normal and double grading. A 200-m-thick, unstratified lapilli tuff in northwest Mount Hayes A-3 Quadrangle exhibits distinctive large aerial extent, lack of K-feldspar, and coarse pumice fragments ranging from less than 1 cm to nearly 1 m long (Bond, 1976). Green to grayish green debris-flow deposits composed of poorly sorted angular fragments, from 5 to 20 cm across and locally imbricate, in a matrix of sand, silt, and mud. Angular fragments composed of volcanic rock fragments, plagioclase, quartz, and fossil debris. Matrix mainly microcrystalline quartz, fine chlorite, and/or sericite, and leucoxene. Individual beds range in thickness fro...

show abstract

Terrestrial isotopic evidence for a Middle-Maastrichtian warming event from the lower Cantwell Formation, Alaska

Salazar-Jaramillo

Fowell

McCarthy

et al. 2016

Palaeogeography, Palaeoclimatology, Palaeoecology

View full text Add to dashboard Cite

General geology of the central Alaska Range between the Nenana River and Mount Deborah

Cited by 12 publications

References 0 publications

Preliminary geologic map of the Mount Hayes quadrangle, eastern Alaska Range, Alaska

Preliminary geologic map of the Mount Hayes quadrangle, eastern Alaska Range, Alaska

Geologic maps of the eastern Alaska Range, Alaska (44 quadrangles, 1:63,360 scale), with descriptions and interpretations of map units

Terrestrial isotopic evidence for a Middle-Maastrichtian warming event from the lower Cantwell Formation, Alaska

Contact Info

Product

Resources

About