Late Quaternary distal tephra-fall deposits in lacustrine sediments, Kenai Peninsula, Alaska

AbstractTephra-fall deposits from Cook Inlet volcanoes were detected in sediment cores from Tustumena and Paradox Lakes, Kenai Peninsula, Alaska, using magnetic susceptibility and petrography. The ages of tephra layers were estimated using 21 14C ages on macrofossils. Tephras layers are typically fine, gray ash, 1–5 mm thick, and composed of varying proportions of glass shards, pumice, and glass-coated phenocrysts. Of the two lakes, Paradox Lake contained a higher frequency of tephra (0.8 tephra/100 yr; 109 over the 13,200-yr record). The unusually large number of tephra in this lake relative to others previously studied in the area is attributed to the lake's physiography, sedimentology, and limnology. The frequency of ash fall was not constant through the Holocene. In Paradox Lake, tephra layers are absent between ca. 800–2200, 3800–4800, and 9000–10,300 cal yr BP, despite continuously layered lacustrine sediment. In contrast, between 5000 and 9000 cal yr BP, an average of 1.7 tephra layers are present per 100 yr. The peak period of tephra fall (7000–9000 cal yr BP; 2.6 tephra/100 yr) in Paradox Lake is consistent with the increase in volcanism between 7000 and 9000 yr ago recorded in the Greenland ice cores.

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Influences of forested and grassland vegetation on late Quaternary ecosystem development as recorded in lacustrine sediments

Quaternary Research ◽

10.1017/qua.2018.148 ◽

2019 ◽

Vol 92 (1) ◽

pp. 201-215 ◽

Cited By ~ 1

Author(s):

Kendra K. McLauchlan ◽

Ioan Lascu ◽

Emily Mellicant ◽

Robert J. Scharping ◽

Joseph J. Williams

Keyword(s):

Chemical Weathering ◽

Forest Type ◽

Late Quaternary ◽

Sediment Cores ◽

Lacustrine Sediments ◽

Parent Material ◽

Elemental Abundance ◽

Sediment Delivery ◽

Sedimentary Sequences ◽

Northern United States

AbstractGeosphere-biosphere interactions are ubiquitous features of the Earth surface, yet the development of interactions between newly exposed lithologic surfaces and colonizing plants during primary succession after glaciation are lacking temporal detail. To assess the nature, rate, and magnitude of vegetation influence on parent material and sediment delivery, we analyzed ecosystem and geochemical proxies from lacustrine sediment cores at a grassland site and a forested site in the northern United States. Over time, terrigenous inputs declined at both sites, with increasing amounts of organic inputs toward present. The similarities between sites were striking given that the grassland sequence began in the Early Holocene, and the forested sequence began after the last glacial maximum. Multiple mechanisms of chemical weathering, hydrologic transport, and changes in source material potentially contribute to this pattern. Although there were strong links between vegetation composition and nitrogen cycling at each site, it appears that changes in forest type, or from oak woodland to grassland, did not exert a large influence on elemental (K, Ti, Si, Ca, Fe, Mn, and S) abundance in the sedimentary sequences. Rather, other factors in the catchment-lake system determined the temporal sequence of elemental abundance.

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Tephra Layers in a Sediment Core from Lake Hestvatn, Southern Iceland: Implications for Evaluating Sedimentation Processes and Environmental Impacts on a Lacustrine System Caused by Tephra Fall Deposits in the Surrounding Watershed

Volcaniclastic Sedimentation in Lacustrine Settings ◽

10.1002/9781444304251.ch11 ◽

2009 ◽

pp. 223-246 ◽

Cited By ~ 3

Author(s):

J. Hardardttir ◽

. Geirsdttir ◽

T. Thrdarson

Keyword(s):

Environmental Impacts ◽

Sediment Core ◽

Tephra Fall ◽

Tephra Layers ◽

Sedimentation Processes ◽

Fall Deposits

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Independent verification of age tie points and planktic reservoir ages deduced for two marine sediment records at the Chilean continental margin by 14C plateau tuning

10.5194/egusphere-egu2020-5683 ◽

2020 ◽

Author(s):

Kevin Küssner ◽

Michael Sarnthein ◽

Frank Lamy ◽

Elisabeth Michel ◽

Gesine Mollenhauer ◽

...

Keyword(s):

Continental Margin ◽

Marine Sediment ◽

Sediment Cores ◽

Ice Cores ◽

Time Interval ◽

Stratigraphic Correlation ◽

Short Term ◽

Planktic Foraminifera ◽

Last Glacial ◽

Tephra Layers

On the basis of 14C plateau tuning we established a robust centennial-scale age control for last glacial-to-deglacial sediment sections in two marine sediment cores MD07-3088 and PS97-137 from the upper Chilean continental margin to facilitate a precise stratigraphic correlation between short-term changes in South Pacific oceanography and global paleoclimate signals recorded in ice cores from Antarctica and elsewhere (K&#252;ssner et al., in prep.). Age tie points and reservoir ages were derived from tuning a suite of planktic 14C plateaus to a suite of pertinent atmospheric 14C plateaus defined at Lake Suigetsu (Sarnthein et al., 2015). Off central Chile four tephra layers in Core MD07-3088 provide independent proof both for the age assignment and for short-term changes in planktic reservoir age we deduced by means of 14C plateau tuning. Reservoir ages derived from 14C plateau tuning at 11&#8211;16.5 cal. ka closely match, one-by-one, four reservoir ages that have been deduced from the difference between the 14C ages of planktic foraminifera associated with the tephra layers in marine sediments and the atmospheric 14C ages of plants associated with paired tephras analyzed nearby on land (Siani et al. 2013). &#8211; In Core PS97-137, near to the southern tip of Chile, sediments of the Last Glacial Maximum show a section with distinct lamination of 5-7 layers / cm depth, associated with atmospheric 14C Plateau 6a by plateau tuning. A rough count of the layers in the 160 cm long sediment section of the planktic 14C Plateau 6a gives a number that comes extremely close to the ~900 year-long time span of the atmospheric 14C Plateau 6a, thus provides independent proof for both the accuracy of the time interval assigned to correlated atmospheric &#8216;Plateau 6a&#8217; and the approach of plateau tuning in general.&#160;K&#252;ssner et al., Paleoceanography, in prep.,Sarnthein et al., Radiocarbon, 2015, 57 (1), 129&#8211;151.Siani et al., 2013, Nature comm., 4, 2758.

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Volcanism and climate change as drivers in Holocene depositional dynamic of Laguna del Maule (Andes of central Chile – 36° S)

10.5194/cp-2019-147 ◽

2020 ◽

Author(s):

Matías Frugone-Álvarez ◽

Claudio Latorre ◽

Fernando Barreiro-Lostres ◽

Santiago Giralt ◽

Ana Moreno ◽

...

Keyword(s):

Late Quaternary ◽

Sediment Cores ◽

Sedimentary Facies ◽

High Elevation ◽

Early Holocene ◽

Lake Levels ◽

Lake Productivity ◽

Central Chile ◽

Age Model ◽

Tephra Layers

Abstract. Late Quaternary volcanic basins are active landscapes from which detailed archives of past climate, seismic and volcanic activity can be obtained. A multidisciplinary study performed on a transect of sediment cores was used to reconstruct the depositional evolution of the high-elevation Laguna del Maule (LdM) (36° S, 2180 m asl, Chilean Andes). The recovered 5 m composite sediment sequence includes two thick turbidite units (LT1 and LT2) and numerous tephra layers (23 ash and 6 lapilli). We produced an age model is based on nine new 14C AMS date, existing 210Pb and 137Cs data and the Quizapú ash horizon (CE 1932). According to this age model, early Holocene were followed by a phase of increased productivity during the mid Holocene and higher lake levels after 4.0 ka BP. Major hydroclimate transitions occurred at ca. 0.5, 4.0, 8.0 and 11 ka BP. Decreased summer insolation and winter precipitation due to a southward shift in the Southern Westerly Winds and a strengthened Pacific Subtropical High could explain early Holocene lower lake levels. Increased biological productivity during the mid-Holocene (~ 8.0 to 6.0 ka) is coeval with a warm-dry phase described for much of southern South America. Periods of higher lake productivity are synchronous to higher frequency of volcanic events. During the late Holocene, the tephra layers shows compositional changes suggesting a transition from silica-rich to silica-poor magmas at around 4.0 cal ka BP. This transition was synchronous with increased variability of sedimentary facies and geochemical proxies, indicating higher lake levels and increased moisture at LdM after 4.0 cal ka BP, most likely caused by the inception of current ENSO/PDO-like dynamics in central Chile.

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Volcanism and climate change as drivers in Holocene depositional dynamic of Laguna del Maule (Andes of central Chile – 36° S)

Climate of the Past ◽

10.5194/cp-16-1097-2020 ◽

2020 ◽

Vol 16 (4) ◽

pp. 1097-1125

Author(s):

Matías Frugone-Álvarez ◽

Claudio Latorre ◽

Fernando Barreiro-Lostres ◽

Santiago Giralt ◽

Ana Moreno ◽

...

Keyword(s):

Southern Oscillation ◽

Late Quaternary ◽

Sediment Cores ◽

High Elevation ◽

Early Holocene ◽

Lake Levels ◽

Lake Productivity ◽

Central Chile ◽

Age Model ◽

Tephra Layers

Abstract. Late Quaternary volcanic basins are active landscapes from which detailed archives of past climate and seismic and volcanic activity can be obtained. A multidisciplinary study performed on a transect of sediment cores was used to reconstruct the depositional evolution of the high-elevation Laguna del Maule (LdM) (36∘ S, 2180 m a.s.l., Chilean Andes). The recovered 5 m composite sediment sequence includes two thick turbidite units (LT1 and LT2) and numerous tephra layers (23 ash and 6 lapilli). We produced an age model based on nine new 14C AMS dates, existing 210Pb and 137Cs data, and the Quizapú ash horizon (1932 CE). According to this age model, the relatively drier Early Holocene was followed by a phase of increased productivity during the mid-Holocene and higher lake levels after 4.0 ka cal BP. Major hydroclimate transitions occurred at ca. 11, 8.0, 4.0 and 0.5 ka cal BP. Decreased summer insolation and winter precipitation due to a southward shift in the southern westerly winds and a strengthened Pacific Subtropical High could explain Early Holocene lower lake levels. Increased biological productivity during the mid-Holocene (∼8.0 to 6.0 ka cal BP) is coeval with a warm–dry phase described for much of southern South America. Periods of higher lake productivity are synchronous to a higher frequency of volcanic events. During the Late Holocene, the tephra layers show compositional changes suggesting a transition from silica-rich to silica-poor magmas at around 4.0 ka cal BP. This transition was synchronous with increased variability of sedimentary facies and geochemical proxies, indicating higher lake levels and increased moisture at LdM after 4.0 ka cal BP, most likely caused by the inception of current El Niño–Southern Oscillation and Pacific Decadal Oscillation (ENSO–PDO) dynamics in central Chile.

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Electron Microprobe Correlation of Tephra Layers from Eastern Mediterranean Abyssal Sediments and the Island of Santorini

Quaternary Research ◽

10.1016/0033-5894(80)90026-5 ◽

1980 ◽

Vol 13 (2) ◽

pp. 160-171 ◽

Cited By ~ 100

Author(s):

Alan N. Federman ◽

Steven N. Carey

Keyword(s):

Major Element ◽

Late Quaternary ◽

Eastern Mediterranean ◽

Explosive Eruptions ◽

Volcanic Complex ◽

Quaternary Sediments ◽

Additional Layer ◽

Oxygen Isotope Stratigraphy ◽

Tephra Layers ◽

Isotope Stratigraphy

AbstractFive widespread tephra layers are found in late Quaternary sediments (0–130,000 yr B.P.) of the Eastern Mediterranean Sea. These layers have been correlated among abyssal cores and to their respective terrestrial sources by electron-probe microanalysis of glass and pumice shards. Major element variations are sufficient to discriminate unambiguously between the five major layers. Oxygen isotope stratigraphy in one of the cores studied was used to data four of the five layers. Two of the widespread layers are derived from explosive eruptions of the Santorini volcanic complex: the Minoan Ash (3370 yr B.P.) and the Acrotiri Ignimbrite (18,000 yr B.P.). An additional layer, found in one core only, is most likely correlated to the Middle Pumice Series of Santorini (approximately 100,000 yr B.P.). Two layers are correlated to deposits on the islands of Yali and Kos and date to 31,000 and 120,000 yr B.P., respectively. One layer originated from the Neapolitan area of Italy 38,000 yr B.P.

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The volcanological significance of deep-sea ash layers associated with ignimbrites

Geological Magazine ◽

10.1017/s0016756800028533 ◽

1980 ◽

Vol 117 (5) ◽

pp. 425-436 ◽

Cited By ~ 66

Author(s):

R. S. J. Sparks ◽

T. C. Huang

Keyword(s):

Deep Sea ◽

Eastern Mediterranean ◽

Eruption Column ◽

Size Distributions ◽

Ash Fall ◽

Column Collapse ◽

Median Diameter ◽

Grain Size Distributions ◽

Bimodal Grain Size ◽

Fall Deposits

SummaryMany volcanic ash layers preserved in deep-sea sediments are the products of large magnitude ignimbrite eruptions. The characteristics of such co-ignimbrite ash-fall deposits are illustrated by two layers from the Eastern Mediterranean: the Minoan ash, Santorini, and the Campanian ash, Italy. These layers are divisible into a coarse lower unit and a fine upper unit in proximal cores. Both layers also show striking bimodal grain size distributions in more distal cores. The coarser mode decreases in median diameter with distance from source whereas the finer mode shows no lateral variation. These features are interpreted in terms of a model for ignimbrite formation by eruption column collapse. Comparable volumes of ignimbrite and associated air-fall ejecta are produced.

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Correlated Millennial-Scale Changes in Surface Hydrography and Terrigenous Sediment Yield Inferred from Last-Glacial Marine Deposits off Northeastern Brazil

Quaternary Research ◽

10.1006/qres.1998.1992 ◽

1998 ◽

Vol 50 (2) ◽

pp. 157-166 ◽

Cited By ~ 226

Author(s):

Helge W. Arz ◽

Jürgen Pätzold ◽

Gerold Wefer

Keyword(s):

North Atlantic ◽

Isotope Composition ◽

Sediment Cores ◽

Ice Cores ◽

Northeastern Brazil ◽

Salt Flux ◽

Terrigenous Sediment ◽

The North ◽

North Brazil ◽

The North Atlantic

The stable isotope composition of planktonic foraminifera correlates with evidence for pulses of terrigenous sediment in a sediment core from the upper continental slope off northeastern Brazil. Stable oxygen isotope records of the planktonic foraminiferal species Globigerinoides sacculiferand Globigerinoides ruber(pink) reveal sub-Milankovitch changes in sea-surface hydrography during the last 85,000 yr. Warming of the surface water coincided with terrigenous sedimentation pulses that are inferred from high XRF intensities of Ti and Fe, and which suggest humid conditions in northeast Brazil. These tropical signals correlate with climatic oscillations recorded in Greenland ice cores (Dansgaard-Oeschger cycles) and in sediment cores from the North Atlantic (Heinrich events). Trade winds may have caused changes in the North Brazil Current that altered heat and salt flux into the North Atlantic, thus affecting the growth and decay of the large glacial ice sheets.

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Late Quaternary paleoenvironment of the Ross Sea continental shelf, Antarctica

Annals of Glaciology ◽

10.3189/1998aog27-1-275-280 ◽

1998 ◽

Vol 27 ◽

pp. 275-280 ◽

Cited By ~ 4

Author(s):

Akira Nishimura ◽

Toru Nakasone ◽

Chikara Hiramatsu ◽

Manabu Tanahashi

Keyword(s):

Organic Carbon ◽

Marine Environment ◽

Environmental Changes ◽

Ross Sea ◽

Late Quaternary ◽

Sedimentary Environment ◽

Sediment Cores ◽

Ice Sheet ◽

Ice Shelf ◽

Accelerator Mass Spectrometer

Based on sedimenlological and micropaleontological work on three sediment cores collected at about 167° Ε in the western Ross Sea, Antarctica, and accelerator mass spectrometer l4C ages of organic carbon, we have reconstructed environmental changes in the area during the late Quaternary. Since 38 ka BP at latest, this area was a marine environment with low productivity. A grounded ice sheet advanced and loaded the sediments before about 30-25 ka BP. After 25 ka BP, the southernmost site (76°46'S) was covered by floating ice (shelf ice), preventing deposition of coarse terrigenous materials and maintaining a supply of diatom tests and organic carbon until 20 ka BP. The northernmost site (74°33'S) was in a marine environment with a moderate productivity influenced by shelf ice/ice sheet after about 20 ka BP. Since about 10 ka BP, a sedimentary environment similar to the present-day one has prevailed over this area.

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