John N Aleinikoff
John Aleinikoff is a Scientist Emeritus with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Filter Total Items: 109
On the origin and age of the Great Sand Dunes, Colorado On the origin and age of the Great Sand Dunes, Colorado
Over the past 100??yr, several hypotheses have been proposed for the origin and age of the Great Sand Dunes. These hypotheses differ widely in the descriptions of dune morphometry, the immediate source of eolian sand, and when sand transport occurred. The primary purpose of this paper is to evaluate these hypotheses and, where warranted, to present new ideas about the origin and age of...
Authors
R.F. Madole, J.H. Romig, J. N. Aleinikoff, D.P. VanSistine, E.Y. Yacob
Combined EPMA and SHRIMP analyses of xenotime to interpret the geochronological record Combined EPMA and SHRIMP analyses of xenotime to interpret the geochronological record
[No abstract available]
Authors
H.A. Lowers, J. N. Aleinikoff, F.K. Mazdab
Tectonic setting and metallogenesis of volcanogenic massive sulfide deposits in the Bonnifield Mining District, Northern Alaska Range: Chapter B in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Ca Tectonic setting and metallogenesis of volcanogenic massive sulfide deposits in the Bonnifield Mining District, Northern Alaska Range: Chapter B in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Ca
This paper summarizes the results of field and laboratory investigations, including whole-rock geochemistry and radiogenic isotopes, of outcrop and drill core samples from volcanogenic massive sulfide (VMS) deposits and associated metaigneous rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range (see fig. 1 of Editors’ Preface and Overview). U-Pb zircon...
Authors
Cynthia Dusel-Bacon, John N. Aleinikoff, Wayne R. Premo, Suzanne Paradis, Ilana Lohr-Schmidt
Origin of the Lyme Dome and implications for the timing of multiple Alleghanian deformational and intrusive events in southern Connecticut Origin of the Lyme Dome and implications for the timing of multiple Alleghanian deformational and intrusive events in southern Connecticut
Geologic mapping, structural analysis, and geochronology in the area of the Lyme dome, southern Connecticut provides constraints on the origin of the rocks in the core of the dome, the absolute timing of the principal deformational and thermal events attributed to Alleghanian orogenesis, and the processes that generated the dome. Detrital zircon geochronology in combination with ages on...
Authors
G. J. Walsh, J. N. Aleinikoff, R. P. Wintsch
Ages and origins of rocks of the Killingworth dome, south-central Connecticut: Implications for the tectonic evolution of southern New England Ages and origins of rocks of the Killingworth dome, south-central Connecticut: Implications for the tectonic evolution of southern New England
The Killingworth dome of south-central Connecticut occurs at the southern end of the Bronson Hill belt. It is composed of tonalitic and trondhjemitic orthogneisses (Killingworth complex) and bimodal metavolcanic rocks (Middletown complex) that display calc-alkaline affinities. Orthogneisses of the Killingworth complex (Boulder Lake gneiss, 456 ?? 6 Ma; Pond Meadow gneiss, ???460 Ma) were...
Authors
J. N. Aleinikoff, R. P. Wintsch, R.P. Tollo, D.M. Unruh, C.M. Fanning, M.D. Schmitz
SHRIMP U-Pb evidence for a Late Silurian age of metasedimentary rocks in the Merrimack and Putnam-Nashoba terranes, eastern New England SHRIMP U-Pb evidence for a Late Silurian age of metasedimentary rocks in the Merrimack and Putnam-Nashoba terranes, eastern New England
U-Pb ages of detrital, metamorphic, and magmatic zircon and metamorphic monazite and titanite provide evidence for the ages of deposition and metamorphism of metasedimentary rocks from the Merrimack and Putnam-Nashoba terranes of eastern New England. Rocks from these terranes are interpreted here as having been deposited in the middle Paleozoic above Neoproterozoic basement of the Gander...
Authors
R. P. Wintsch, J. N. Aleinikoff, G. J. Walsh, Wallace A. Bothner, A. M. Hussey, C.M. Fanning
Science and Products
Filter Total Items: 109
On the origin and age of the Great Sand Dunes, Colorado On the origin and age of the Great Sand Dunes, Colorado
Over the past 100??yr, several hypotheses have been proposed for the origin and age of the Great Sand Dunes. These hypotheses differ widely in the descriptions of dune morphometry, the immediate source of eolian sand, and when sand transport occurred. The primary purpose of this paper is to evaluate these hypotheses and, where warranted, to present new ideas about the origin and age of...
Authors
R.F. Madole, J.H. Romig, J. N. Aleinikoff, D.P. VanSistine, E.Y. Yacob
Combined EPMA and SHRIMP analyses of xenotime to interpret the geochronological record Combined EPMA and SHRIMP analyses of xenotime to interpret the geochronological record
[No abstract available]
Authors
H.A. Lowers, J. N. Aleinikoff, F.K. Mazdab
Tectonic setting and metallogenesis of volcanogenic massive sulfide deposits in the Bonnifield Mining District, Northern Alaska Range: Chapter B in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Ca Tectonic setting and metallogenesis of volcanogenic massive sulfide deposits in the Bonnifield Mining District, Northern Alaska Range: Chapter B in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Ca
This paper summarizes the results of field and laboratory investigations, including whole-rock geochemistry and radiogenic isotopes, of outcrop and drill core samples from volcanogenic massive sulfide (VMS) deposits and associated metaigneous rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range (see fig. 1 of Editors’ Preface and Overview). U-Pb zircon...
Authors
Cynthia Dusel-Bacon, John N. Aleinikoff, Wayne R. Premo, Suzanne Paradis, Ilana Lohr-Schmidt
Origin of the Lyme Dome and implications for the timing of multiple Alleghanian deformational and intrusive events in southern Connecticut Origin of the Lyme Dome and implications for the timing of multiple Alleghanian deformational and intrusive events in southern Connecticut
Geologic mapping, structural analysis, and geochronology in the area of the Lyme dome, southern Connecticut provides constraints on the origin of the rocks in the core of the dome, the absolute timing of the principal deformational and thermal events attributed to Alleghanian orogenesis, and the processes that generated the dome. Detrital zircon geochronology in combination with ages on...
Authors
G. J. Walsh, J. N. Aleinikoff, R. P. Wintsch
Ages and origins of rocks of the Killingworth dome, south-central Connecticut: Implications for the tectonic evolution of southern New England Ages and origins of rocks of the Killingworth dome, south-central Connecticut: Implications for the tectonic evolution of southern New England
The Killingworth dome of south-central Connecticut occurs at the southern end of the Bronson Hill belt. It is composed of tonalitic and trondhjemitic orthogneisses (Killingworth complex) and bimodal metavolcanic rocks (Middletown complex) that display calc-alkaline affinities. Orthogneisses of the Killingworth complex (Boulder Lake gneiss, 456 ?? 6 Ma; Pond Meadow gneiss, ???460 Ma) were...
Authors
J. N. Aleinikoff, R. P. Wintsch, R.P. Tollo, D.M. Unruh, C.M. Fanning, M.D. Schmitz
SHRIMP U-Pb evidence for a Late Silurian age of metasedimentary rocks in the Merrimack and Putnam-Nashoba terranes, eastern New England SHRIMP U-Pb evidence for a Late Silurian age of metasedimentary rocks in the Merrimack and Putnam-Nashoba terranes, eastern New England
U-Pb ages of detrital, metamorphic, and magmatic zircon and metamorphic monazite and titanite provide evidence for the ages of deposition and metamorphism of metasedimentary rocks from the Merrimack and Putnam-Nashoba terranes of eastern New England. Rocks from these terranes are interpreted here as having been deposited in the middle Paleozoic above Neoproterozoic basement of the Gander...
Authors
R. P. Wintsch, J. N. Aleinikoff, G. J. Walsh, Wallace A. Bothner, A. M. Hussey, C.M. Fanning