Episodic deposition of Illinois Valley Peoria silt in association with Lake Michigan Lobe fluctuations during the last glacial maximum

2017 ◽  
Vol 89 (3) ◽  
pp. 739-755 ◽  
Author(s):  
Thomas A. Nash ◽  
Jessica L. Conroy ◽  
David A. Grimley ◽  
William R. Guenthner ◽  
Ben Brandon Curry
Keyword(s):  
Last Glacial Maximum ◽  
Lake Michigan ◽  
Climatic Factors ◽  
The United States ◽  
Glacial Maximum ◽  
Sediment Supply ◽  
Illinois River ◽  
Last Glacial ◽  
Age Model ◽  
Lake Michigan Lobe

AbstractThe chronology and cause of millennial depositional oscillations within last glacial loess of the Central Lowlands of the United States are uncertain. Here, we present a new age model that indicates the Peoria Silt along the Illinois River Valley accumulated episodically from ~28,500 to 16,000 cal yr BP, as the Lake Michigan Lobe margin fluctuated within northeastern Illinois. The age model indicates accelerated loess deposition coincident with regional glacial advances during the local last glacial maximum. A weakly developed paleosol, the Jules Geosol, represents a period of significantly slower deposition, from 23,700 to 22,000 cal yr BP. A gastropod assemblage-based reconstruction of mean July temperature shows temperatures 6–10°C cooler than modern during Peoria Silt deposition. Stable oxygen and carbon isotope values (δ18O and δ13C) of gastropod carbonate do not vary significantly across the pedostratigraphic boundary of the Jules Geosol, suggesting slower loess accumulation was a result of reduced glacial sediment supply rather than direct climatic factors. However, a decrease in δ18O values occurred between 26,000 and 24,000 cal yr BP, synchronous with the Lake Michigan Lobe’s southernmost advance. This δ18O decrease suggests a coupling of regional summer hydroclimate and ice lobe position during the late glacial period.

scholarly journals An Intertropical Convergence Zone shift controlled the terrestrial material supply on the Ninetyeast Ridge

2021 ◽  
Author(s):  
Xudong Xu ◽  
Jianguo Liu ◽  
Yun Huang ◽  
Lanlan Zhang ◽  
Liang Yi ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Last Glacial Maximum ◽  
Intertropical Convergence Zone ◽  
Glacial Maximum ◽  
Sediment Supply ◽  
Convergence Zone ◽  
Ninetyeast Ridge ◽  
Last Glacial ◽  
The North ◽  
Terrestrial Material

Abstract. Among various climate drivers, direct evidence for the Intertropical Convergence Zone (ITCZ) control of sediment supply on the millennium scale is lacking, and the changes in ITCZ migration demonstrated in paleoclimate records need to be better investigated. Here, we use clay minerals and Sr-Nd isotopes obtained from a gravity core on the Ninetyeast Ridge to track the corresponding source variations and analyze the relationship between terrestrial material supplementation and climatic changes. On the glacial-interglacial scale, chemical weathering weakened during the North Atlantic cold climate periods, and falling sea level hindered the transport of smectite into the study area due to the exposure of islands. However, the influence of the South Asian monsoon on the sediment supply was not obvious on the millennium scale. We suggest that the north-south migration of the ITCZ controlled the rainfall in Myanmar and further directly determined the supply of clay minerals on the millennium scale because the transport of smectite was highly connected with ITCZ location. Furthermore, the regional shift of the ITCZ induced an abnormal increase in the smectite percentage during the late Last Glacial Maximum (LGM) in our records. The smectite percentage in the studied core is similar to distinct ITCZ records in different time periods, revealing that regional changes in the ITCZ were significantly obvious, and that the ITCZ is not a simple N-S displacement and closer connections occurred between the Northern-Southern Hemispheres in the eastern Indian Ocean during the late Last Glacial Maximum (LGM).

From source to sink: Glacially eroded, Late Devonian algal “cysts” (Tasmanites) delivered to the Gulf of Mexico during the Last Glacial Maximum

2020 ◽  
Author(s):  
Barry Kohl ◽  
B. Brandon Curry ◽  
Merrell Miller
Keyword(s):  
Gulf Of Mexico ◽  
Last Glacial Maximum ◽  
Lake Michigan ◽  
Clay Fraction ◽  
Black Shales ◽  
Glacial Maximum ◽  
Long Distance ◽  
Radiocarbon Dates ◽  
Last Glacial ◽  
Source To Sink

The source of reworked Devonian algal “cysts” in last glacial maximum (LGM) sediment in the Gulf of Mexico is traced to their host black shales, which ring the southwestern Great Lakes. The source-to-sink pathway includes intermediate storage in fine-grained LGM glacial lacustrine sediment and till. The “cysts” are pelagic chlorophyllous algae (Tasmanites and Leiosphaeridia), collectively referred to herein as tasmanitids. Radiocarbon dates of syndepositional Gulf of Mexico foraminifera, derived from accelerator mass spectrometry, bracket the Gulf of Mexico sediment age with common tasmanitids from 28.5 ± 0.6−17.8 ± 0.2 cal kyr B.P. Approximately 1400 km north of the Gulf of Mexico, tasmanitids are abundant in Upper Devonian black shales (New Albany, Antrim, and Ohio Shales) that ring the Michigan, Illinois, and Appalachian intracratonic basins. Tasmanitids were eroded from bedrock and incorporated in glacial sediment dating from ca. 28.0−17.6 cal kyr B.P. by the Lake Michigan, and Huron-Erie lobes of the Laurentide Ice Sheet. The physical characteristics of tasmanitids are ideal for long-distance transport as suspended sediment (density: 1.1−1.3 g/cc, size ranging from 63 µm to 300 µm), and these sand-sized tasmanitids traveled with the silt-clay fraction. Thus, the source-to-sink journey of tasmanitids was initiated by subglacial erosion by water or friction, sequestering in till or glaciolacustrine sediment, re-entrainment and suspension in meltwater, and final delivery in meltwater plumes to the Gulf of Mexico. River routes included the Mississippi, Illinois, Ohio, Wabash, Kaskaskia, and many of their tributaries. Reworked Devonian tasmanitids are a previously unrecognized link between their occurrence in deep-water deposits of the Gulf of Mexico and the late Wisconsin glacial history of the Upper Mississippi Valley. We propose that tracking occurrences of tasmanitid concentrations from the source area to sink, along with adjunct proxies such as clay minerals, will facilitate a more refined analysis of the timing and duration of megafloods. This study also demonstrates that isotopically dead carbon, from reworked Devonian tasmanitid “cysts,” can contaminate radiocarbon dating of LGM bulk sediment samples toward older ages.

Freshwater control of ice-rafted debris in the last glacial period at Mono Lake, California, USA

2011 ◽  
Vol 76 (2) ◽  
pp. 264-271 ◽  
Author(s):  
Susan R. H. Zimmerman ◽  
Crystal Pearl ◽  
Sidney R. Hemming ◽  
Kathryn Tamulonis ◽  
N. Gary Hemming ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Warm Season ◽  
Glacial Maximum ◽  
Sediment Supply ◽  
Mono Lake ◽  
Last Glacial ◽  
Type Section ◽  
High Lake Level ◽  
The Last Glacial Maximum ◽  
The Last Glacial

AbstractThe type section silts of the late Pleistocene Wilson Creek Formation at Mono Lake contain outsized clasts, dominantly well-rounded pebbles and cobbles of Sierran lithologies. Lithic grains > 425 μm show a similar pattern of variability as the > 10 mm clasts visible in the type section, with decreasing absolute abundance in southern and eastern outcrops. The largest concentrations of ice-rafted debris (IRD) occur at 67–57 ka and 46–32 ka, with strong millennial-scale variability, while little IRD is found during the last glacial maximum and deglaciation.Stratigraphic evidence for high lake level during high IRD intervals, and a lack of geomorphic evidence for coincidence of lake and glaciers, strongly suggests that rafting was by shore ice rather than icebergs. Correspondence of carbonate flux and IRD implies that both were mainly controlled by freshwater input, rather than disparate non-climatic controls. Conversely, the lack of IRD during the last glacial maximum and deglacial highstands may relate to secondary controls such as perennial ice cover or sediment supply. High IRD at Mono Lake corresponds to low glacial flour flux in Owens Lake, both correlative to high warm-season insolation. High-resolution, extra-basinal correlation of the millennial peaks awaits greatly improved age models for both records.

scholarly journals Changes in detrital sediment supply to the central Yellow Sea since the Last Glacial Maximum

2020 ◽  
Author(s):  
Hyo Jin Koo ◽  
Hyen Goo Cho
Keyword(s):  
Last Glacial Maximum ◽  
Yellow Sea ◽  
Clay Mineralogy ◽  
Glacial Maximum ◽  
Sediment Supply ◽  
Last Glacial ◽  
Sea Mud ◽  
Detrital Sediment ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract. The sediment supply to the central Yellow Sea since the Last Glacial Maximum was uncovered through clay mineralogy and geochemical analysis of core 11YS-PCL14 in the Central Yellow Sea mud (CYSM). The core can be divided into four units: Unit 4 (700–520 cm; 15.5–14.8 ka), Unit 3 (520–280 cm; 14.8–12.1 ka), Unit 2 (280–130 cm; 12.1–8.8 ka), and Unit 1 (130–0 cm;

scholarly journals A late Quaternary paleoenvironmental record in sand dunes of the northern Atacama Desert, Chile

2018 ◽  
Vol 90 (1) ◽  
pp. 127-138 ◽  
Author(s):  
Kari M. Finstad ◽  
Marco Pfeiffer ◽  
Gavin McNicol ◽  
Michael Tuite ◽  
Kenneth Williford ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Late Quaternary ◽  
Sand Dunes ◽  
Atacama Desert ◽  
Glacial Maximum ◽  
Sediment Supply ◽  
Steady Increase ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

AbstractThis paper reports a previously unidentified paleoenvironmental record found in sand dunes of the Atacama Desert, Chile. Long-term aeolian deflation by prevailing onshore winds has resulted in the deposition of sand on the irregular surface of a Miocene-aged anhydrite outcrop. Two deposits ~25 km apart, along the prevailing wind trajectory, were hand excavated then analyzed for vertical (and temporal) changes in physical and chemical composition. Radiocarbon ages of organic matter embedded within the deposits show that rapid accumulation of sediment began at the last glacial maximum and slowed considerably after the Pacific Ocean attained its present post-glacial level. Over this time period, grain sizes are seen to increase while accumulation rates simultaneously decrease, suggesting greater wind speeds and/or a change or decrease in sediment supply. Changes in δ34S values of sulfate in the sediment beginning ~10 ka indicate an increase in marine sources. Similarly, δ2H values from palmitic acid show a steady increase at ~10 ka, likely resulting from aridification of the region during the Holocene. Due to the extreme aridity in the region, these sand dunes retain a well-preserved chemical record that reflects changes in elevation and coastal proximity after the last glacial maximum.

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