Publications
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Chronology of Elk Lake sediments: Coring, sampling, and time-series construction
A 22 m series of cores from a continuously laminated sequence of postglacial sediment was recovered from 29.6 m of water from the deepest part of Elk Lake, Clearwater County, Minnesota, by piston and freeze-coring methods during the winters of 1978 and 1982. A varve time series constructed and used as a basis for subsampling the cores and samples, based on the varve chronology, allows precise dete
Authors
R.Y. Anderson, J. Platt Bradbury, Walter E. Dean, Minze Stuiver
Geochemistry of surface sediments of Minnesota lakes
Analyses of 36 trace, minor, and major elements were used to classify the sediments of 46 Minnesota lakes. Q-mode factor analyses grouped Minnesota lake sediments according to clastic-, carbonate-, organic-, and redox-related elements. Carbonate lakes occur in west-central Minnesota; their sediments have relatively high concentrations of CaCO3, Ba, and Sr. Lakes with sediments containing more than
Authors
Walter E. Dean, Eville Gorham, Dalway J. Swaine
Holocene climatic and limnologic history of the north-central United States as recorded in the varved sediments of Elk Lake, Minnesota: A synthesis
Integration of the results and interpretations of geochemical, paleoecological, and sedimentological analyses of a varved sediment record provides a detailed chronicle of limnological and climatic changes for the past 10 ka at Elk Lake, west-central Minnesota. The early Holocene record at Elk Lake was controlled by circumstances of glacial history (e.g., basin morphometry and surrounding till lith
Authors
J. Platt Bradbury, Walter E. Dean, R.Y. Anderson
Elk Lake in perspective
Elk Lake is located in the forested region of north-central Minnesota at the headwaters of the Mississippi River and occupies one of countless basins left behind as the last great Pleistocene ice sheet retreated northward into Canada. In this respect it resembles many other moderately deep, dimictic, hard-water lakes in the north-central United States, the sediments of which contain a history of p
Authors
R.Y. Anderson, Walter E. Dean, J. Platt Bradbury
Climatic and limnologic setting of Elk Lake
Elk Lake is located on the Itasca moraine near the source of the Mississippi River in northwestern Minnesota. The basin is in calcareous glacial drift, and the lake water is a dilute solution of calcium and magnesium bicarbonate. Low-magnesian calcite formed by precipitation from the lake water has been a major component of the sediment throughout the lake’s history. The sediment also is laminated
Authors
R.O. Megard, J. Platt Bradbury, Walter E. Dean
Environment of deposition of CaCO3 in Elk Lake, Minnesota
Elk Lake is near the present forest-prairie border in northwestern Minnesota, and is also located on the boundary between hard-water lakes that are typical of once-glaciated parts of the north-central United States and more saline prairie lakes of western Minnesota and the Dakotas. The sediments of the prairie lakes just west of Elk Lake are unusual in that they commonly contain high-Mg calcite an
Authors
Walter E. Dean, R.O. Megard
Physical properties, mineralogy, and geochemistry of Holocene varved sediments from Elk Lake, Minnesota
Elk Lake in northwestern Minnesota is situated close to a climatically sensitive ecotone, the forest-prairie border, that migrated back and forth over the drainage basin of the lake during the Holocene. The entire postglacial (Holocene) sediment record in the deepest part of Elk Lake is composed of annual layers (varves) that record the seasonal pulses of many sediment components, and, most import
Authors
Walter E. Dean
Sulfidization and magnetization above hydrocarbon reservoirs
Post-depositional iron-sulfide (Fe-S) minerals that are related to hydrocarbon seepage have changed the original magnetizations at Cement oil field (Anadarko basin, Oklahoma), at Simpson oil field (North Slope basin, Alaska), and above deep Cretaceous oil and gas reservoirs, south Texas coastal plain. At Cement, ferrimagnetic pyrrhotite (Fe7S8) formed with pyrite and marcasite in Permian red beds.
Authors
Richard L. Reynolds, Martin B. Goldhaber, Michele L. Tuttle
The potential response of eolian sands to greenhouse warming and precipitation reduction on the Great Plains of the U.S.A.
Sand dunes and sand sheets are extensive on the semi-arid GreatPlains but are at present stabilized by a sparse vegetation cover. Use of a dune mobility index, which incorporates wind strength and the ratio of mean annual precipitation to potential evapotranspiration, shows that under predicted greenhouse climate effects of increased temperature and reduced precipitation, sand dunes and sand sheet
Authors
D.R. Muhs, P.B. Maat
Strontium isotope characterization of the Ash Meadows ground-water system, southern Nevada, USA
No abstract available.
Authors
Zell E. Peterman, John S. Stuckless, Shannon A. Mahan, Brian D. Marshall, E. D. Gutentag, J. S. Downey
Isotopic studies of fracture coatings at Yucca Mountain, Nevada, USA
No abstract available.
Authors
Brian D. Marshall, J. F. Whelan, Zell E. Peterman, Kiyoto Futa, Shannon A. Mahan, John S. Stuckless
U-Th-Pb, Rb-Sr, and Sm-Nd isotopic systematics of lunar troctolitic cumulate 76535: Implications on the age and origin of this early lunar, deep-seated cumulate
No abstract available.
Authors
Wayne R. Premo, M. Tatsumoto