Late Quaternary Eolian Deposition in Central Italy

2000 ◽  
Vol 54 (2) ◽  
pp. 246-252 ◽  
Author(s):  
Biancamaria Narcisi
Keyword(s):  
North Africa ◽  
Late Holocene ◽  
Late Quaternary ◽  
Ice Core ◽  
Central Italy ◽  
Last Interglacial ◽  
Central Mediterranean ◽  
Volcanic Lakes ◽  
Dust Loading ◽  
The Antarctic

Records of eolian quartz from two continuous sediment sequences drilled in Lagaccione and Lago di Vico volcanic lakes in central Italy contribute to the knowledge of eolian deposition in the central Mediterranean during the last 100,000 years. The chronology is based on 14C and 40Ar/39Ar dating and tephra analysis. Pollen data provide the paleoenvironmental framework and enable correlation between the cores. Eolian inputs were high during the steppe phases corresponding to oxygen isotope stages 4 and 2. Low inputs correspond to the forest phases of the last interglacial and the middle Holocene. Eolian inputs have increased in the late Holocene. Patterns of eolian deposition in central Italy resemble the Antarctic dust record from the Vostok ice core. The Italian patterns may also correspond with hydrological changes registered in North Africa. The main source of dust loading over the Mediterranean now, North Africa, may have played an important role in dust supply throughout the last climatic cycle.

A continuous stable isotope record from the penultimate glacial maximum to the Last Interglacial (159–121 ka) from Tana Che Urla Cave (Apuan Alps, central Italy)

2014 ◽  
Vol 82 (2) ◽  
pp. 450-461 ◽  
Author(s):  
Eleonora Regattieri ◽  
Giovanni Zanchetta ◽  
Russell N. Drysdale ◽  
Ilaria Isola ◽  
John C. Hellstrom ◽  
...  
Keyword(s):  
Regional Scale ◽  
Central Italy ◽  
Global Scale ◽  
Interglacial Period ◽  
Last Interglacial ◽  
Central Mediterranean ◽  
Oxygen Isotope Stage ◽  
Last Interglacial Period ◽  
Glacial Stage ◽  
Isotope Record

AbstractRelatively few radiometrically dated records are available for the central Mediterranean spanning the marine oxygen isotope stage 6–5 (MIS 6–5) transition and the first part of the Last Interglacial. Two flowstone cores from Tana che Urla Cave (TCU, central Italy), constrained by 19 U/Th ages, preserve an interval of continuous speleothem deposition between ca. 159 and 121 ka. A multiproxy record (δ18O, δ13C, growth rate and petrographic changes) obtained from this flowstone preserves significant regional-scale hydrological changes through the glacial/interglacial transition and multi-centennial variability (interpreted as alternations between wetter and drier periods) within both glacial and interglacial stages. The glacial stage shows a wetter period between ca. 154 and 152 ka, while the early to middle Last Interglacial period shows several drying events at ca. 129, 126 and 122 ka, which can be placed in the wider context of climatic instability emerging from North Atlantic marine and NW European terrestrial records. The TCU record also provides important insights into the evolution of local environmental conditions (i.e. soil development) in response to regional and global-scale climate events.

Late Quaternary glaciation and deglaciation of the Bunger Hills, Antarctica

1992 ◽  
Vol 4 (4) ◽  
pp. 435-446 ◽  
Author(s):  
Donald A. Adamson ◽  
Eric A. Colhoun
Keyword(s):  
Late Holocene ◽  
Late Quaternary ◽  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
Quaternary Glaciation ◽  
Last Glaciation ◽  
Coastal Inlets ◽  
The Antarctic ◽  
Raised Beaches ◽  
Middle And Late Holocene

The Bunger Hills were covered by the Antarctic Ice Sheet during the last glaciation. During deglaciation the ice sheet margin collapsed into the marine inlets and the sea entered the oasis before 7.7 ka BP. Raised beaches occur widely below 8.5 m and indicate uplift at 1.4 m ka−1 during the middle and late Holocene. After the coastal inlets were formed, the Edisto Ice Tongue and Apfels Glacier still impinged on land margins in the west of the oasis. Two sets of marginal moraines were formed; the Older Edisto Moraines after 6.2 ka BP and the Younger Edisto Moraines during the last few centuries. The margins of the Antarctic Ice Sheet and Apfels Glacier in the south have maintained their present positions since at least 5.6 ka BP and probably 10 ka BP.

scholarly journals A brief history of ice core science over the last 50 yr

2013 ◽  
Vol 9 (4) ◽  
pp. 3711-3767 ◽  
Author(s):  
J. Jouzel
Keyword(s):  
Environmental Changes ◽  
Ice Core ◽  
Ice Cores ◽  
Future Research ◽  
Interglacial Period ◽  
Last Interglacial ◽  
Last Interglacial Period ◽  
History Of ◽  
Scientific Results ◽  
The Antarctic

Abstract. For about 50 yr, ice cores have provided a wealth of information about past climatic and environmental changes. Ice cores from Greenland, Antarctica and other glaciers, now emcompass a variety of timescales. However, the longer time scales (e.g. at least back to the Last Glacial period) are covered by deep ice cores the number of which is still very limited, seven from Greenland, with only one providing an undisturbed record of a part of the Last Interglacial Period, and a dozen from Antarctica with the longest record covering the last 800 000 yr. This article aims to summarize this successful adventure initiated by a few pioneers and their teams and to review key scientific results in focusing on climate (in particular water isotopes) and climate related (e.g. greenhouse gases) reconstructions. Future research is well taken into account by the four projects defined by IPICS. However it remains a challenge to get an intact record of the Last Interglacial in Greenland and to extend the Antarctic record through the mid-Pleistocene transition, if possible back to 1.5 Myr.

Quantification of excess 231Pa in late Quaternary igneous baddeleyite

2020 ◽  
Vol 105 (12) ◽  
pp. 1830-1840 ◽  
Author(s):  
Yi Sun ◽  
Axel K. Schmitt ◽  
Lucia Pappalardo ◽  
Massimo Russo
Keyword(s):  
Late Quaternary ◽  
Central Italy ◽  
Direct Analysis ◽  
Weight Percent ◽  
Volcanic Field ◽  
Distribution Coefficients ◽  
Secular Equilibrium ◽  
Melt Distribution ◽  
D Values ◽  
Significant Figures

Abstract Initial excess protactinium (231Pa) is a frequently suspected source of discordance in baddeleyite (ZrO2) geochronology, which limits accurate U/Pb dating, but such excesses have never been directly demonstrated. In this study, Pa incorporation in late Holocene baddeleyite from Somma-Vesuvius (Campanian Volcanic Province, central Italy) and Laacher See (East Eifel Volcanic Field, western Germany) was quantified by U-Th-Pa measurements using a large-geometry ion microprobe. Baddeleyite crystals isolated from subvolcanic syenites have average U concentrations of ~200 ppm and are largely stoichiometric with minor abundances of Nb, Hf, Ti, and Fe up to a few weight percent. Measured (231Pa)/(235U) activity ratios are significantly above the secular equilibrium value of unity and range from 3.4(8) to 14.9(2.6) in Vesuvius baddeleyite and from 3.6(9) to 8.9(1.4) in Laacher See baddeleyite (values within parentheses represent uncertainties in the last significant figures reported as 1σ throughout the text). Crystallization ages of 5.12(56) ka (Vesuvius; MSWD = 0.96, n = 12) and 15.6(2.0) ka (Laacher See; MSWD = 0.91, n = 10) were obtained from (230Th)/(238U) disequilibria for the same crystals, which are close to the respective eruption ages. Applying a corresponding age correction indicates average initial (231Pa)/(235U)0 of 8.8(1.0) (Vesuvius) and 7.9(5) (Laacher See). For reasonable melt activities, model baddeleyite-melt distribution coefficients of DPa/DU = 5.8(2) and 4.1(2) are obtained for Vesuvius and Laacher See, respectively. Speciation-dependent (Pa4+ vs. Pa5+) partitioning coefficients (D values) from crystal lattice strain models for tetra- and pentavalent proxy ions significantly exceed DPa/DU inferred from direct analysis of 231Pa for Pa5+. This is consistent with predominantly reduced Pa4+ in the melt, for which D values similar to U4+ are expected. Contrary to common assumptions, baddeleyite-crystallizing melts from Vesuvius and Laacher See appear to be dominated by Pa4+ rather than Pa5+. An initial disequilibrium correction for baddeleyite geochronology using DPa/DU = 5 ± 1 is recommended for oxidized phonolitic melt compositions.

Brokering Trade in the Central Mediterranean

2017 ◽  
Author(s):  
Corey Tazzara
Keyword(s):  
Central Italy ◽  
Competitive Response ◽  
Central Mediterranean ◽  
Commercial Development ◽  
International Commerce ◽  
Exchange Networks ◽  
North Central ◽  
Autonomous Region ◽  
Global Commerce ◽  
Quantitative Examination

Chapter 6 offers a quantitative examination of the commercial development of Livorno, showing how it plugged local and regional exchange networks into the currents of global commerce. Livorno was at the epicenter of the reorganization of maritime trade in the Tyrrhenian and throughout the Mediterranean. Despite dense connections between north-central Italy and the free port, however, international commerce did not substantially affect productive relations in the hinterland. North-central Italy remained an autonomous region; rather than a colonial outpost subservient to northern capitalism, Livorno was a large marketplace connecting otherwise distinct economies. The Tuscan city’s success in organizing trade eventually provoked a competitive response by neighboring ports.

scholarly journals Late Quaternary Landscape Dynamics at the La Spezia Gulf (NW Italy): A Multi-Proxy Approach Reveals Environmental Variability within a Rocky Embayment

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 427
Author(s):  
Veronica Rossi ◽  
Alessandro Amorosi ◽  
Marco Marchesini ◽  
Silvia Marvelli ◽  
Andrea Cocchianella ◽  
...  
Keyword(s):  
Sea Level ◽  
Environmental Variability ◽  
Late Quaternary ◽  
Landscape Dynamics ◽  
Last Interglacial ◽  
Core Depth ◽  
Coastal Bay ◽  
Nw Italy ◽  
Global Sea Level ◽  
Geomorphological Features

The Gulf of La Spezia (GLS) in Northwest Italy is a rocky embayment with low fluvial influence facing the Mediterranean Sea. Past landscape dynamics were investigated through a multi-proxy, facies-based analysis down to a core depth of 30 m. The integration of quantitative ostracod, foraminifera, and pollen analyses, supported by radiocarbon ages, proved to be a powerful tool to unravel the late Quaternary palaeoenvironmental evolution and its forcing factors. The complex interplay between relative sea-level (RSL), climatic changes, and geomorphological features of the embayment drove four main evolution phases. A barrier–lagoon system developed in response to the rising RSL of the Late Pleistocene (likely the Last Interglacial). The establishment of glacial conditions then promoted the development of an alluvial environment, with generalised erosion of the underlying succession and subsequent accumulation of fluvial strata. The Holocene transgression (dated ca. 9000 cal year BP) caused GLS inundation and the formation of a low-confined lagoon basin, which rapidly turned into a coastal bay from ca. 8000 cal year BP onwards. This latter environmental change occurred in response to the last Holocene stage of global sea-level acceleration, which submerged a morphological relief currently forming a drowned barrier-island complex in the embayment.

Chemical Composition of Ice Containing Tephra Layers in the Byrd Station Ice Core, Antarctica

1988 ◽  
Vol 30 (3) ◽  
pp. 315-330 ◽  
Author(s):  
Julie M. Palais ◽  
Philip R. Kyle
Keyword(s):  
Chemical Composition ◽  
Silicate Glass ◽  
Residence Time ◽  
Volcanic Ash ◽  
Global Climate ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
Tephra Layers ◽  
The Antarctic ◽  
Hydrolysis Of

The chemical composition of ice containing tephra (volcanic ash) layers in 22 sections of the Byrd Station ice core was examined to determine if the volcanic eruptions affected the chemical composition of the atmosphere and precipitation in the vicinity of Byrd Station. The liquid conductivity, acidity, sulfate, nitrate, aluminum, and sodium concentrations of ice samples deposited before, during, and after the deposition of the tephra layers were analyzed. Ice samples that contain tephra layers have, on average, about two times more sulfate and three to four times more aluminum than nonvolcanic ice samples. The acidity of ice samples associated with tephra layers is lowered by hydrolysis of silicate glass and minerals. Average nitrate, sodium, and conductivity are the same in all samples. Because much of the sulfur and chlorine originally associated with these eruptions may have been scavenged by ash particles, the atmospheric residence time of these volatiles would have been minimized. Therefore the eruptions probably had only a small effect on the composition of the Antarctic atmosphere and a negligible effect on local or global climate.

Climate related variations in atmospheric nitrous oxide concentration during the Mid- to Late Holocene

2021 ◽  
Author(s):  
Syed Azharuddin ◽  
Jinho Ahn ◽  
Yeongjun Ryu ◽  
Ed Brook
Keyword(s):  
Nitrous Oxide ◽  
Late Holocene ◽  
Ice Core ◽  
Progressive Increase ◽  
La Niña ◽  
La Nina ◽  
National University ◽  
Seoul National University ◽  
Sudden Decrease ◽  
Nitrous Oxide Concentration

<p>Nitrous oxide (N<sub>2</sub>O) is an important greenhouse gas with sources that respond to the biogeochemical processes on land and ocean. The major sources of atmospheric N<sub>2</sub>O are nitrification and denitrification occurring in terrestrial soils and the ocean. Here we present a new high-resolution atmospheric N<sub>2</sub>O record obtained from South Pole Ice (SPICE) core site covering the Mid- to Late Holocene (since ~5.5 ka). The N<sub>2</sub>O analysis was performed in a specialised wet extraction facility installed at Seoul National University that used small ice samples (<20 g) to yield a high precision (average standard deviation of ~1ppb) record. The new N<sub>2</sub>O data agree well with existing records on the millennial scale and reveal new details on the multi-centennial scale. Our results show a progressive increase in atmospheric N<sub>2</sub>O during 5.5 to 3.2 ka which correlates well with the increase of marine denitrification around the Arabian Sea (AS) and Peru-Chile Margin (PCM) as well as Indian monsoon precipitation around the same period. A local minimum in N<sub>2</sub>O is observed around 2.8 ka, possibly related to a sudden decrease in Western Tropical South (WTS) Pacific sea surface temperature and increased La-Nina like conditions which may have supressed denitrification along PCM. These conditions may have further influenced the monsoons and reduced denitrification in land soils. Our record also shows a local N<sub>2</sub>O maximum around 2.2 ka which may correspond to relaxed La-Nina like conditions around WTS Pacific. Subsequently, the N<sub>2</sub>O further dropped to attain a pronounced minimum around 1.4 ka. Similar N<sub>2</sub>O minima are also observed in Styx (Antarctica) and  NEEM (Greenland) ice core records, demonstrating the robustness of the signals.</p>

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