Steven M Colman
Biographic Data
| ID | 5602306 |
|---|---|
| NAME | Steven M Colman |
| GIVEN NAMES | Steven M |
| FAMILY NAME | Colman |
| SIGNATURE | COLMAN S M |
| AFFILIATIONS | United States Geological Survey |
| ORCID | 0000-0002-0564-9576 |
| VERIFIED | Yes |
| TOTAL WORKS | 13 |
| TOTAL CITATIONS | 17 |
| WORKS AS AUTHOR | 13 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 1976 |
| LATEST PUBLICATION YEAR | 2020 |
| H-INDEX | 1 |
Moraines and late-glacial stratigraphy in central Lake Superior
Seismic-reflection surveys of the Isle Royale sub-basin, central Lake Superior, reveal two large end moraines and associated glacial sediments deposited during the last cycle of the Laurentide Ice Sheet in the basin. The Isle Royale moraines directly overlie bedrock and are cored with dense, acoustically massive till intercalated down-ice with acoustically stratified outwash. Till and outwash are overlain by glacial varves, a lower red unit and a…
Sedimentary architecture of the southern basin of Lake of the Woods, Minnesota and its relation to Lake Agassiz history and Holocene environmental change
Lake of the Woods (LOTW) is a large, complex lake basin once occupied by glacial Lake Agassiz. High-resolution seismic-reflection profiles and cores in the shallow, open southern basin of LOTW reveal a sedimentary architecture comprising four lacustrine units separated by three low-stand unconformities. These units represent several phases of Lake Agassiz and its changing configuration. One unconformity marks the Moorhead low phase and another ma…
Fingerprinting of glacial silt in lake sediments yields continuous records of alpine glaciation (35–15 ka), western USA
Fingerprinting glacial silt in last glacial-age sediments from Upper Klamath Lake (UKL) and Bear Lake (BL) provides continuous radiocarbon-dated records of glaciation for the southeastern Cascade Range and northwestern Uinta Mountains, respectively. Comparing of these records to cosmogenic exposure ages from moraines suggests that variations in glacial flour largely reflect glacial extent. The two areas are at similar latitudes and yield similar …
Interplay between the Westerlies and Asian monsoon recorded in Lake Qinghai sediments since 32 ka
Two atmospheric circulation systems, the mid-latitude Westerlies and the Asian summer monsoon (ASM), play key roles in northern-hemisphere climatic changes. However, the variability of the Westerlies in Asia and their relationship to the ASM remain unclear. Here, we present the longest and highest-resolution drill core from Lake Qinghai on the northeastern Tibetan Plateau (TP), which uniquely records the variability of both the Westerlies and the…
Holocene organic carbon burial rates in the southeastern Swedish Baltic Sea
To estimate Holocene changes in organic carbon mass accumulation rates (C org MARs) in the southeastern Swedish Baltic Sea, two sediment cores were studied in combination with biogeochemical modelling. Prior to 11 300 cal. BP, C org MARs were extremely low, indicating low organic matter production on the catchment of the Baltic Ice Lake. Following a brief regression, the Ancylus Lake stage occurred between 11 100 and 9800 cal. BP. C org MARs incr…
Modeling the Radiocarbon Reservoir Effect in Lacustrine Systems
The modern water (both pre- and post-atmospheric nuclear testing) of most lakes has an anomalously old apparent radiocarbon age due to what is commonly referred to as the “reservoir effect.” In contrast to marine settings, this 14 C-offset phenomenon is primarily caused by pre-aged carbon discharged to lakes by rivers and/or groundwater. In this paper, a 2-component box model based on the principle of 14 C mass balance in lake water and in the ea…
Radiocarbon Dating, Chronologic Framework, and Changes in Accumulation Rates of Holocene Estuarine Sediments from Chesapeake Bay
Rapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelerator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different…
Evidence from Lake Baikal for Siberian Glaciation during Oxygen-Isotope Substage 5d
The paleoclimatic record from bottom sediments of Lake Baikal (eastern Siberia) reveals new evidence for an abrupt and intense glaciation during the initial part of the last interglacial period (isotope substage 5d). This glaciation lasted about 12,000 yr from 117,000 to 105,000 yr B.P. according to correlation with the SPECMAP isotope chronology. Lithological and biogeochemical evidence of glaciation from Lake Baikal agrees with evidence for the…
Radiocarbon Ages from Two Submerged Strandline Features in the Western Gulf of Maine and a Sea-Level Curve for the Northeastern Massachusetts Coastal Region
New radiocarbon dates provide ages for two submerged strandline features on the Massachusetts inner shelf. These ages provide limited control on a relative sea-level (RSL) curve for the late Wisconsinan and Holocene. The curve indicates a late Wisconsinan high stand of RSL of +33 m about 14,000 yr ago and a very short-lived relative low stand of about -43 m at about 12,000 yr ago followed by a rise to present sea level. Rapid changes of RSL aroun…
Suggested Terminology for Quaternary Dating Methods
Classification of Quaternary dating methods should be based on the level of quantitative information and the degree of confidence contained in the age estimates produced by the dating methods. We recommend the use of the terms numerical-age, calibrated-age, relative-age , and correlated-age to describe these levels. We also classify dating methods by type into sideral, isotopic, radiogenic, chemical and biological, geomorphic, and correlation met…
Glacial Sequence Near McCall, Idaho
The sequence of glacial deposits near McCall, Idaho, previously assigned to the Pinedale and Bull Lake glaciations, contains deposits of four different ages. These ages are defined by multiple relative-age criteria, including weathering rinds, soil development, surface-rock weathering, morainal morphology, and loess stratigraphy. The thickness of weathering rinds on basaltic clasts is statistically representative and reproducible and can be used …
Rock-Weathering Rates as Functions of Time
The scarcity of documented numerical relations between rock weathering and time has led to a common assumption that rates of weathering are linear. This assumption has been strengthened by studies that have calculated long-term average rates. However, little theoretical or empirical evidence exists to support linear rates for most chemical-weathering processes, with the exception of congruent dissolution processes. The few previous studies of roc…
Erosional landform map of the Redwood Creek drainage basin, Humboldt County, California, 1947-74
Landslides and actively eroding stream channels disrupt roads, damage valuable timberland, and increase stream sediment loads in northwestern California. This 1:62,500 photointerpretative map shows the distribution of ten common types of fluvial and mass-movement erosional landforms in the drainage basin of Redwood Creek in 1947 and 1974. The mapped landforms include slides, slumps, large compound earthflows, debris avalanches, unstable streamban…
Modeling the Radiocarbon Reservoir Effect in Lacustrine Systems
The modern water (both pre- and post-atmospheric nuclear testing) of most lakes has an anomalously old apparent radiocarbon age due to what is commonly referred to as the “reservoir effect.” In contrast to marine settings, this 14 C-offset phenomenon is primarily caused by pre-aged carbon discharged to lakes by rivers and/or groundwater. In this paper, a 2-component box model based on the principle of 14 C mass balance in lake water and in the ea…
Holocene organic carbon burial rates in the southeastern Swedish Baltic Sea
To estimate Holocene changes in organic carbon mass accumulation rates (C org MARs) in the southeastern Swedish Baltic Sea, two sediment cores were studied in combination with biogeochemical modelling. Prior to 11 300 cal. BP, C org MARs were extremely low, indicating low organic matter production on the catchment of the Baltic Ice Lake. Following a brief regression, the Ancylus Lake stage occurred between 11 100 and 9800 cal. BP. C org MARs incr…
Erosional landform map of the Redwood Creek drainage basin, Humboldt County, California, 1947-74
Landslides and actively eroding stream channels disrupt roads, damage valuable timberland, and increase stream sediment loads in northwestern California. This 1:62,500 photointerpretative map shows the distribution of ten common types of fluvial and mass-movement erosional landforms in the drainage basin of Redwood Creek in 1947 and 1974. The mapped landforms include slides, slumps, large compound earthflows, debris avalanches, unstable streamban…
Rock-Weathering Rates as Functions of Time
The scarcity of documented numerical relations between rock weathering and time has led to a common assumption that rates of weathering are linear. This assumption has been strengthened by studies that have calculated long-term average rates. However, little theoretical or empirical evidence exists to support linear rates for most chemical-weathering processes, with the exception of congruent dissolution processes. The few previous studies of roc…
Glacial Sequence Near McCall, Idaho
The sequence of glacial deposits near McCall, Idaho, previously assigned to the Pinedale and Bull Lake glaciations, contains deposits of four different ages. These ages are defined by multiple relative-age criteria, including weathering rinds, soil development, surface-rock weathering, morainal morphology, and loess stratigraphy. The thickness of weathering rinds on basaltic clasts is statistically representative and reproducible and can be used …
Suggested Terminology for Quaternary Dating Methods
Classification of Quaternary dating methods should be based on the level of quantitative information and the degree of confidence contained in the age estimates produced by the dating methods. We recommend the use of the terms numerical-age, calibrated-age, relative-age , and correlated-age to describe these levels. We also classify dating methods by type into sideral, isotopic, radiogenic, chemical and biological, geomorphic, and correlation met…
Radiocarbon Ages from Two Submerged Strandline Features in the Western Gulf of Maine and a Sea-Level Curve for the Northeastern Massachusetts Coastal Region
New radiocarbon dates provide ages for two submerged strandline features on the Massachusetts inner shelf. These ages provide limited control on a relative sea-level (RSL) curve for the late Wisconsinan and Holocene. The curve indicates a late Wisconsinan high stand of RSL of +33 m about 14,000 yr ago and a very short-lived relative low stand of about -43 m at about 12,000 yr ago followed by a rise to present sea level. Rapid changes of RSL aroun…
Evidence from Lake Baikal for Siberian Glaciation during Oxygen-Isotope Substage 5d
The paleoclimatic record from bottom sediments of Lake Baikal (eastern Siberia) reveals new evidence for an abrupt and intense glaciation during the initial part of the last interglacial period (isotope substage 5d). This glaciation lasted about 12,000 yr from 117,000 to 105,000 yr B.P. according to correlation with the SPECMAP isotope chronology. Lithological and biogeochemical evidence of glaciation from Lake Baikal agrees with evidence for the…
Radiocarbon Dating, Chronologic Framework, and Changes in Accumulation Rates of Holocene Estuarine Sediments from Chesapeake Bay
Rapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelerator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different…
Holocene organic carbon burial rates in the southeastern Swedish Baltic Sea
To estimate Holocene changes in organic carbon mass accumulation rates (C org MARs) in the southeastern Swedish Baltic Sea, two sediment cores were studied in combination with biogeochemical modelling. Prior to 11 300 cal. BP, C org MARs were extremely low, indicating low organic matter production on the catchment of the Baltic Ice Lake. Following a brief regression, the Ancylus Lake stage occurred between 11 100 and 9800 cal. BP. C org MARs incr…
Modeling the Radiocarbon Reservoir Effect in Lacustrine Systems
The modern water (both pre- and post-atmospheric nuclear testing) of most lakes has an anomalously old apparent radiocarbon age due to what is commonly referred to as the “reservoir effect.” In contrast to marine settings, this 14 C-offset phenomenon is primarily caused by pre-aged carbon discharged to lakes by rivers and/or groundwater. In this paper, a 2-component box model based on the principle of 14 C mass balance in lake water and in the ea…
Fingerprinting of glacial silt in lake sediments yields continuous records of alpine glaciation (35–15 ka), western USA
Fingerprinting glacial silt in last glacial-age sediments from Upper Klamath Lake (UKL) and Bear Lake (BL) provides continuous radiocarbon-dated records of glaciation for the southeastern Cascade Range and northwestern Uinta Mountains, respectively. Comparing of these records to cosmogenic exposure ages from moraines suggests that variations in glacial flour largely reflect glacial extent. The two areas are at similar latitudes and yield similar …
Interplay between the Westerlies and Asian monsoon recorded in Lake Qinghai sediments since 32 ka
Two atmospheric circulation systems, the mid-latitude Westerlies and the Asian summer monsoon (ASM), play key roles in northern-hemisphere climatic changes. However, the variability of the Westerlies in Asia and their relationship to the ASM remain unclear. Here, we present the longest and highest-resolution drill core from Lake Qinghai on the northeastern Tibetan Plateau (TP), which uniquely records the variability of both the Westerlies and the…
Sedimentary architecture of the southern basin of Lake of the Woods, Minnesota and its relation to Lake Agassiz history and Holocene environmental change
Lake of the Woods (LOTW) is a large, complex lake basin once occupied by glacial Lake Agassiz. High-resolution seismic-reflection profiles and cores in the shallow, open southern basin of LOTW reveal a sedimentary architecture comprising four lacustrine units separated by three low-stand unconformities. These units represent several phases of Lake Agassiz and its changing configuration. One unconformity marks the Moorhead low phase and another ma…
Moraines and late-glacial stratigraphy in central Lake Superior
Seismic-reflection surveys of the Isle Royale sub-basin, central Lake Superior, reveal two large end moraines and associated glacial sediments deposited during the last cycle of the Laurentide Ice Sheet in the basin. The Isle Royale moraines directly overlie bedrock and are cored with dense, acoustically massive till intercalated down-ice with acoustically stratified outwash. Till and outwash are overlain by glacial varves, a lower red unit and a…
Geology and Paleoclimatology Research (12 works) · Geology (10 works) · Paleontology (9 works) · Geography (6 works) · Geomorphology (6 works) · Glacial period (6 works) · Oceanography (6 works) · Geological formations and processes (5 works) · Holocene (5 works) · Physical geography (5 works)