J Platt Bradbury
Biographic Data
| ID | 5641675 |
|---|---|
| NAME | J Platt Bradbury |
| GIVEN NAMES | J Platt |
| FAMILY NAME | Bradbury |
| SIGNATURE | BRADBURY J P |
| AFFILIATIONS | United States Geological Survey |
| VERIFIED | No |
| TOTAL WORKS | 15 |
| TOTAL CITATIONS | 25 |
| WORKS AS AUTHOR | 15 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 1975 |
| LATEST PUBLICATION YEAR | 2014 |
| H-INDEX | 3 |
Towards a theology of the death of the Church
The article argues that the decline of main-line churches within the Western context must be understood theologically. It offers a set of theses by which such a theology might be approached. It engages with theological themes such as providence, salvation, the theology of the cross, and ecclesiology. These themes are explored in part through a reading of key passages within the Gospel of John. It proposes that the Church might be called to a 'goo…
Philip M. Soergel, Miracles and the Protestant Imagination
A late Quaternary record of eolian silt deposition in a maar lake, St. Michael Island, western Alaska
Recent stratigraphic studies in central Alaska have yielded the unexpected finding that there is little evidence for full-glacial (late Wisconsin) loess deposition. Because the loess record of western Alaska is poorly exposed and not well known, we analyzed a core from Zagoskin Lake, a maar lake on St. Michael Island, to determine if a full-glacial eolian record could be found in that region. Particle size and geochemical data indicate that the m…
Holocene palaeoclimates of southern Patagonia
Multiproxy palaeoenvironmental and palaeolimnological analyses of two Holocene-age sediment cores from the margin of Lago Cardiel, a 76 m deep, closed-basin lake in southern Patagonia (latitude 49°S), provide information on lake-level changes that can be related to regional palaeoclimate scenarios. Sedimentol ogic (magnetic susceptibility, organic and inorganic carbon content) and environmental indicators (pollen, dia toms, ostracodes and stable …
Sources of glacial moisture in Mesoamerica
Regional aridity in North America during the middle Holocene
Increased aridity throughout the Great Plains and Rocky Mountain region during the middle Holo cene has been documented from pollen records, aeolian proxy variables in lake cores, and active sand dune migration. Varve calibration provided by a continuously varved record of the Holocene from a core from Elk Lake, northwestern Minnesota, shows that the influx of aeolian clastic material increased beginning about 8 ka and ended about 3.8 ka, with pe…
Charcoal deposition and redeposition in Elk Lake, Minnesota, USA
Sedimentary charcoal, diatom and phytolith records of the past 1500 years at Elk Lake, Minnesota, in combination with sediment trap studies and a transect of surface sediment samples, document the mechanisms by which previously deposited charcoal is redeposited and finally buried in this lake. The frequent correspon dence of high diatom concentrations and peaks of phytolith and charcoal fragments suggests that currents and turbulence related to l…
Late-Glacial to Holocene Changes in Winds, Upwelling, and Seasonal Production of the Northern California Current System
A core 120 km off the coast of southern Oregon was examined for changes in lithology, diatoms, and pollen over the past 30,000 yr. Primary production during the late Pleistocene was about half that of the Holocene. Evidence from diatoms and pollen indicates that summer upwelling was much weaker, implying an absence of strong northerly winds. Early Pliocene diatoms found throughout the late Pleistocene section were probably derived from diatomites…
Mid-Holocene Climate in Northern Minnesota
Study of Holocene ostracodes and diatoms from Elk Lake, in North-Central Minnesota, indicates that the local climate of the mid-Holocene can be subdivided into three intervals. Throughout interval 1 (ca. 7800 to 6700 yr B.P.), climate was colder and much drier than today. During intervals 2 and 3 (ca. 6700 to 4000 yr B.P.) average mean-annual air temperatures approached the modern mean (3.7°C), but warm summers persisted throughout interval 2, wh…
San Agustin Plains, New Mexico
Paleomagnetic analysis of samples from the original 600-m-long core from the San Agustin Plains, New Mexico, showed an unquestionable reversal stratigraphy dating the record back to at least 1.6 my. Analysis of pollen, ostracodes, and algae of a duplicate sample section in the vicinity of the original coring site and spanning the last 18,000 yr B.P. shows a much higher resolution than the earlier results.
Paleoecological Studies at Lake Patzcuaro on the West-Central Mexican Plateau and at Chalco in the Basin of Mexico
A 1520-cm sediment core from Lake Patzcuaro, Michoacan, Mexico, is 44,000 yr old at the base. All parts of the core have abundant pollen of Pinus (pine), Alnus (alder), and Quercus (oak) with frequent Abies (fir). The interval dated from 44,000 to 11,000 yr ago has a homogeneous flora characterized by abundant Juniperus (juniper) pollen and frequent Artemisia (sagebrush). It is believed to represent an appreciably drier and colder climate than at…
Limnology of the Klutlan Moraines, Yukon Territory, Canada
Lakes of the Klutlan moraines originate by down-melting of stagnant ice under a mantle of rock debris and vegetation ranging from scattered herbs and shrubs on the younger moraines to multiple-generation closed spruce forest on the oldest moraines, which are 600–1200 yr old. Lakes on the youngest moraines are temporary, turbid with glacial silt, and marked by unstable ice-cored slopes. On older moraines most lakes have clear water and stable slop…
Paleolimnology of Two Lakes in the Klutlan Glacier Region, Yukon Territory, Canada
Lakes developed on progressively younger end moraines of the Klutlan Glacier were initially assumed to have originated shortly after moraine emplacement and to have persisted to the present. Limnological differences between lakes on old vs young moraines were thought to result from limnological maturation within the lakes and ponds themselves and in response to the development of soils and vegetation on moraine surfaces. This study represents a p…
L'union des géographes socialistes (L'UGS/USG)
Diatom Stratigraphy and Human Settlement in Minnesota
Holocene palaeoclimates of southern Patagonia
Multiproxy palaeoenvironmental and palaeolimnological analyses of two Holocene-age sediment cores from the margin of Lago Cardiel, a 76 m deep, closed-basin lake in southern Patagonia (latitude 49°S), provide information on lake-level changes that can be related to regional palaeoclimate scenarios. Sedimentol ogic (magnetic susceptibility, organic and inorganic carbon content) and environmental indicators (pollen, dia toms, ostracodes and stable …
Charcoal deposition and redeposition in Elk Lake, Minnesota, USA
Sedimentary charcoal, diatom and phytolith records of the past 1500 years at Elk Lake, Minnesota, in combination with sediment trap studies and a transect of surface sediment samples, document the mechanisms by which previously deposited charcoal is redeposited and finally buried in this lake. The frequent correspon dence of high diatom concentrations and peaks of phytolith and charcoal fragments suggests that currents and turbulence related to l…
Regional aridity in North America during the middle Holocene
Increased aridity throughout the Great Plains and Rocky Mountain region during the middle Holo cene has been documented from pollen records, aeolian proxy variables in lake cores, and active sand dune migration. Varve calibration provided by a continuously varved record of the Holocene from a core from Elk Lake, northwestern Minnesota, shows that the influx of aeolian clastic material increased beginning about 8 ka and ended about 3.8 ka, with pe…
Diatom Stratigraphy and Human Settlement in Minnesota
L'union des géographes socialistes (L'UGS/USG)
Limnology of the Klutlan Moraines, Yukon Territory, Canada
Lakes of the Klutlan moraines originate by down-melting of stagnant ice under a mantle of rock debris and vegetation ranging from scattered herbs and shrubs on the younger moraines to multiple-generation closed spruce forest on the oldest moraines, which are 600–1200 yr old. Lakes on the youngest moraines are temporary, turbid with glacial silt, and marked by unstable ice-cored slopes. On older moraines most lakes have clear water and stable slop…
Paleolimnology of Two Lakes in the Klutlan Glacier Region, Yukon Territory, Canada
Lakes developed on progressively younger end moraines of the Klutlan Glacier were initially assumed to have originated shortly after moraine emplacement and to have persisted to the present. Limnological differences between lakes on old vs young moraines were thought to result from limnological maturation within the lakes and ponds themselves and in response to the development of soils and vegetation on moraine surfaces. This study represents a p…
Paleoecological Studies at Lake Patzcuaro on the West-Central Mexican Plateau and at Chalco in the Basin of Mexico
A 1520-cm sediment core from Lake Patzcuaro, Michoacan, Mexico, is 44,000 yr old at the base. All parts of the core have abundant pollen of Pinus (pine), Alnus (alder), and Quercus (oak) with frequent Abies (fir). The interval dated from 44,000 to 11,000 yr ago has a homogeneous flora characterized by abundant Juniperus (juniper) pollen and frequent Artemisia (sagebrush). It is believed to represent an appreciably drier and colder climate than at…
San Agustin Plains, New Mexico
Paleomagnetic analysis of samples from the original 600-m-long core from the San Agustin Plains, New Mexico, showed an unquestionable reversal stratigraphy dating the record back to at least 1.6 my. Analysis of pollen, ostracodes, and algae of a duplicate sample section in the vicinity of the original coring site and spanning the last 18,000 yr B.P. shows a much higher resolution than the earlier results.
Mid-Holocene Climate in Northern Minnesota
Study of Holocene ostracodes and diatoms from Elk Lake, in North-Central Minnesota, indicates that the local climate of the mid-Holocene can be subdivided into three intervals. Throughout interval 1 (ca. 7800 to 6700 yr B.P.), climate was colder and much drier than today. During intervals 2 and 3 (ca. 6700 to 4000 yr B.P.) average mean-annual air temperatures approached the modern mean (3.7°C), but warm summers persisted throughout interval 2, wh…
Late-Glacial to Holocene Changes in Winds, Upwelling, and Seasonal Production of the Northern California Current System
A core 120 km off the coast of southern Oregon was examined for changes in lithology, diatoms, and pollen over the past 30,000 yr. Primary production during the late Pleistocene was about half that of the Holocene. Evidence from diatoms and pollen indicates that summer upwelling was much weaker, implying an absence of strong northerly winds. Early Pliocene diatoms found throughout the late Pleistocene section were probably derived from diatomites…
Regional aridity in North America during the middle Holocene
Increased aridity throughout the Great Plains and Rocky Mountain region during the middle Holo cene has been documented from pollen records, aeolian proxy variables in lake cores, and active sand dune migration. Varve calibration provided by a continuously varved record of the Holocene from a core from Elk Lake, northwestern Minnesota, shows that the influx of aeolian clastic material increased beginning about 8 ka and ended about 3.8 ka, with pe…
Charcoal deposition and redeposition in Elk Lake, Minnesota, USA
Sedimentary charcoal, diatom and phytolith records of the past 1500 years at Elk Lake, Minnesota, in combination with sediment trap studies and a transect of surface sediment samples, document the mechanisms by which previously deposited charcoal is redeposited and finally buried in this lake. The frequent correspon dence of high diatom concentrations and peaks of phytolith and charcoal fragments suggests that currents and turbulence related to l…
Sources of glacial moisture in Mesoamerica
A late Quaternary record of eolian silt deposition in a maar lake, St. Michael Island, western Alaska
Recent stratigraphic studies in central Alaska have yielded the unexpected finding that there is little evidence for full-glacial (late Wisconsin) loess deposition. Because the loess record of western Alaska is poorly exposed and not well known, we analyzed a core from Zagoskin Lake, a maar lake on St. Michael Island, to determine if a full-glacial eolian record could be found in that region. Particle size and geochemical data indicate that the m…
Holocene palaeoclimates of southern Patagonia
Multiproxy palaeoenvironmental and palaeolimnological analyses of two Holocene-age sediment cores from the margin of Lago Cardiel, a 76 m deep, closed-basin lake in southern Patagonia (latitude 49°S), provide information on lake-level changes that can be related to regional palaeoclimate scenarios. Sedimentol ogic (magnetic susceptibility, organic and inorganic carbon content) and environmental indicators (pollen, dia toms, ostracodes and stable …
Philip M. Soergel, Miracles and the Protestant Imagination
Towards a theology of the death of the Church
The article argues that the decline of main-line churches within the Western context must be understood theologically. It offers a set of theses by which such a theology might be approached. It engages with theological themes such as providence, salvation, the theology of the cross, and ecclesiology. These themes are explored in part through a reading of key passages within the Gospel of John. It proposes that the Church might be called to a 'goo…
Geology and Paleoclimatology Research (10 works) · Geography (8 works) · Geology (8 works) · Holocene (7 works) · Physical geography (7 works) · Paleontology (6 works) · Climatology (5 works) · Geology (5 works) · Oceanography (5 works) · Oceanography (5 works)