1-20 OF 65
Results shown limited to content with bounding coordinates.
Richard L. Hay
Close
Save search
Follow your search
Access your saved searches in your account
Would you like to receive an alert when new items match your search?
×Close Modal
Sort by
Journal Article

Age and origin of authigenic K-feldspar in uppermost Precambrian rocks in the North American Midcontinent

Junzhe Liu, Richard L. Hay, Alan Deino, T.K. Kyser
Journal: GSA Bulletin
Published: 01 April 2003
GSA Bulletin (2003) 115 (4): 422-433.
DOI: https://doi.org/10.1130/0016-7606(2003)115<0422:AAOOAK>2.0.CO;2
FIGURES | View All (6)
PDF
Purchase
Add to Citation Manager
Book Chapter

Sedimentation Patterns in a Plio-Pleistocene Volcaniclastic Rift-Platform Basin, Olduvai Gorge, Tanzania

Robin W. Renaut, Gail M. Ashley, Gail M. Ashley, Richard L. Hay
Book: Sedimentation in Continental Rifts
Series: SEPM Special Publication
Publisher: SEPM Society for Sedimentary Geology
Published: 01 January 2002
DOI: 10.2110/pec.02.73.0107
EISBN: 9781565761957
FIGURES | View All (13)
Abstract
PDF
Purchase
Add to Citation Manager

Abstract The Plio-Pleistocene sedimentary deposits of upper Bed I and lowermost Bed II in the Olduvai basin, Tanzania, are analyzed in terms of sedimentary processes, paleoenvironments, and paleoclimate. The sedimentary basin was a shallow, closed depression (∼ 50 km wide with strata ∼ 100 m thick) located adjacent to the East African Rift between Precambrian basement rocks to the west and the large Plio-Pleistocene Ngorongoro volcanic complex to the east. Olduvai lies on the west flank of the main rift valley, and this rift platform area was subjected to crustal extension resu I ting in normal block faulting and block tilting. Through time the axial part of the sedimentary basin episodically migrated eastward toward the main rift valley. Syndepositional volcanism included basalt flows, pyroclastic air falls, ground surges, and ignimbrites from eruptive centers of the Ngorongoro volcanic complex. Hay (1976) interpreted the paleolandscape to have had a central lake basin that was filled with detrital sediment, carbonate rocks, and tephra. Detrital sediment was provided both by rivers sourced in the Ngorongoro complex and by Precambrian rocks of the Serengeti to the north and west. Recent high-resolution stratigraphic studies of paleoenvironments in a time slice (1.85-1.75 Ma) found that the sedimentary facies vary temporally and spatially because of the interplay among five independent variables affecting the sedimentary record: (1) sediment flux (pyroclastic air fall, intermittent fluvial runoff and mudflows, and eolian), (2) sediment composition (Precambrian source rocks vs. volcanic source rocks), (3) hydrology and chemistry (lake water, surface water, and groundwater), (4) soil formation, and (5) tectonics associated with rift extension. Lake cycles, ephemeral fluvial systems, soil formation on the interfluves and lake margin, well as a large groundwater-fed wetland (&gt; 3 km 2 ) are all part of the Olduvai rift-margin basin record and provide insights into the Plio-Pleistocene paleoclimate history of East Africa.

Journal Article

Origin of illite in the lower Paleozoic of the Illinois basin: Evidence for brine migrations

Georg H. Grathoff, Duane M. Moore, Richard L. Hay, Klaus Wemmer
Journal: GSA Bulletin
Published: 01 August 2001
GSA Bulletin (2001) 113 (8): 1092-1104.
DOI: https://doi.org/10.1130/0016-7606(2001)113<1092:OOIITL>2.0.CO;2
FIGURES | View All (13)
PDF
Purchase
Add to Citation Manager
Journal Article

Reply

David B. Finkelstein, Richard L. Hay, Stephen P. Altaner
Journal: GSA Bulletin
Published: 01 April 2001
GSA Bulletin (2001) 113 (4): 541-544.
DOI: https://doi.org/10.1130/0016-7606(2001)113<0541:R>2.0.CO;2
FIGURES
PDF
Purchase
Add to Citation Manager
Journal Article

Occurrence of Zeolites in Sedimentary Rocks: An Overview

Richard L. Hay, Richard A. Sheppard
Published: 01 January 2001
Reviews in Mineralogy and Geochemistry (2001) 45 (1): 217-234.
DOI: https://doi.org/10.2138/rmg.2001.45.6
FIGURES
PDF
Purchase
Add to Citation Manager
Journal Article

Formation of Zeolites in Open Hydrologic Systems

Richard A. Sheppard, Richard L. Hay
Published: 01 January 2001
Reviews in Mineralogy and Geochemistry (2001) 45 (1): 261-275.
DOI: https://doi.org/10.2138/rmg.2001.45.8
FIGURES | View All (5)
PDF
Purchase
Add to Citation Manager
Book Chapter

Overview: Ancient Lake Creede

Philip M. Bethke, Philip M. Bethke, Richard L. Hay, Richard L. Hay
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Hydrologic budget of the late Oligocene Lake Creede and the evolution of the upper Rio Grande drainage system

Philip M. Bethke, Paul B. Barton, Richard L. Hay, Thomas A. Steven, Daniel O. Hayba
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Intracaldera volcanism and sedimentation- Creede Caldera, Colorado

Philip M. Bethke, Grant Heiken, Richard L. Hay, Donathan Krier, Tamsin McCormick, M. G. Snow
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Stratigraphy, correlation, depositional setting, and geophysical characteristics of the Oligocene Snowshoe Mountain Tuff and Creede Formation in two cored boreholes

Philip M. Bethke, Daniel Larsen, Richard L. Hay, Philip H. Nelson
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Sedimentary petrology and authigenic mineral distributions in the Oligocene Creede Formation, Colorado, United States

Philip M. Bethke, Daniel Larsen, Richard L. Hay, Laura J. Crossey
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Alteration history of volcaniclastic sediments in the upper Oligocene Creede Formation, southwestern Colorado

Philip M. Bethke, David B. Finkelstein, Richard L. Hay, Stephen P. Altaner, Richard L. Hay
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Stable isotope evolution and paleolimnology of ancient Lake Creede

Philip M. Bethke, Robert O. Rye, Richard L. Hay, Philip M. Bethke, David B. Finkelstein
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Isotopic studies of authigenic sulfides, silicates, and carbonates, and calcite and pyrite veinlets in the Creede Formation, San Juan Mountains, Southwest Colorado

Philip M. Bethke, Philip M. Bethke, Richard L. Hay, Robert O. Rye, David B. Finkelstein
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Sulfur, carbon, and oxygen isotope geochemistry of pyrite and calcite from veins and sediments sampled by borehole CCM-2, Creede Caldera, Colorado

Philip M. Bethke, Robert P. Ilchik, Richard L. Hay, Douglas Rumble, Jr
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Evolution of the Creede Caldera and its relation to mineralization in the Creede mining district, Colorado

Philip M. Bethke, Paul B. Barton, Richard L. Hay, Robert O. Rye, Philip M. Bethke
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Duration of sedimentation of Creede Formation from 40 Ar/ 39 Ar ages

Philip M. Bethke, Marvin A. Lanphere, Richard L. Hay
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Recognition of primary and diagenetic magnetizations to determine the magnetic polarity record and timing of deposition of the moat-fill rocks of the Oligocene Creede Caldera, Colorado

Philip M. Bethke, Richard L. Reynolds, Richard L. Hay, Joseph G. Rosenbaum, Donald S. Sweetkind, Marvin A. Lanphere, Andrew P. Roberts, Kenneth L. Verosub
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Central San Juan caldera cluster: regional volcanic framework

Philip M. Bethke, Peter W. Lipman, Richard L. Hay
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.

Book Chapter

Neogene geomorphic and climatic evolution of the central San Juan Mountains, Colorado: K/Ar age and stable isotope data on supergene alunite and jarosite from the Creede mining district

Philip M. Bethke, Robert O. Rye, Richard L. Hay, Philip M. Bethke, Marvin A. Lanphere, Thomas A. Steven
Abstract
PDF
Purchase
Add to Citation Manager

Full article available in PDF version.