scholarly journals Deciphering late Quaternary land snail shell δ18O and δ13C from Franchthi Cave (Argolid, Greece)

2013 ◽  
Vol 80 (1) ◽  
pp. 66-75 ◽  
Author(s):  
André C. Colonese ◽  
Giovanni Zanchetta ◽  
Catherine Perlès ◽  
Russell N. Drysdale ◽  
Giuseppe Manganelli ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Isotope Composition ◽  
Late Quaternary ◽  
Late Glacial ◽  
Land Snail ◽  
Early Holocene ◽  
Human Occupation ◽  
Isotopic Signatures ◽  
Stable Isotopic ◽  
Oxygen Isotopic

This paper investigates the stable isotopic composition from late Pleistocene–Holocene (~ 13 to ~ 10.5 cal ka BP) shells of the land snail Helix figulina, from Franchthi Cave (Greece). It explores the palaeoclimatic and palaeoenvironmental implications of the isotope palaeoecology of archaeological shells at the time of human occupation of the cave. Modern shells from around the cave were also analysed and their isotopic signatures compared with those of the archaeological shells. The carbon isotope composition of modern shells depicts the consumption of C3 vegetation. Shell oxygen isotopic values are consistent with other Mediterranean snail shells from coastal areas. Combining empirical linear regression and an evaporative model, the δ18Os suggest that modern snails in the study area are active during periods of higher relative humidity and lower rainfall δ18O, probably at night. Late glacial and early Holocene δ18Os show lower values compared to modern ones. Early Holocene δ18Os values likely track enhanced moisture and isotopic changes in the precipitation source. By contrast, lower late glacial δ18O could reflect lower temperatures and δ18Op, compared to the present day. Shell carbon isotope values indicate the presence of C3 vegetation as main source of carbon to late glacial and early Holocene snails.

scholarly journals How dry was the Younger Dryas? Evidence from a coupled <i>δ</i><sup>2</sup>H–<i>δ</i><sup>18</sup>O biomarker paleohygrometer applied to the Gemündener Maar sediments, Western Eifel, Germany

2019 ◽  
Vol 15 (2) ◽  
pp. 713-733 ◽  
Author(s):  
Johannes Hepp ◽  
Lorenz Wüthrich ◽  
Tobias Bromm ◽  
Marcel Bliedtner ◽  
Imke Kathrin Schäfer ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Younger Dryas ◽  
Late Glacial ◽  
Climatic Conditions ◽  
Leaf Water ◽  
Early Holocene ◽  
Unexpected Finding ◽  
Temperature Dependent ◽  
The Past ◽  
Natural Climate

Abstract. Causes of the Late Glacial to Early Holocene transition phase and particularly the Younger Dryas period, i.e. the major last cold spell in central Europe during the Late Glacial, are considered to be keys for understanding rapid natural climate change in the past. The sediments from maar lakes in the Eifel, Germany, have turned out to be valuable archives for recording such paleoenvironmental changes. For this study, we investigated a Late Glacial to Early Holocene sediment core that was retrieved from the Gemündener Maar in the Western Eifel, Germany. We analysed the hydrogen (δ2H) and oxygen (δ18O) stable isotope composition of leaf-wax-derived lipid biomarkers (n-alkanes C27 and C29) and a hemicellulose-derived sugar biomarker (arabinose), respectively. Both δ2Hn-alkane and δ18Osugar are suggested to reflect mainly leaf water of vegetation growing in the catchment of the Gemündener Maar. Leaf water reflects δ2H and δ18O of precipitation (primarily temperature-dependent) modified by evapotranspirative enrichment of leaf water due to transpiration. Based on the notion that the evapotranspirative enrichment depends primarily on relative humidity (RH), we apply a previously introduced “coupled δ2Hn-alkane–δ18Osugar paleohygrometer approach” to reconstruct the deuterium excess of leaf water and in turn Late Glacial–Early Holocene RH changes from our Gemündener Maar record. Our results do not provide evidence for overall markedly dry climatic conditions having prevailed during the Younger Dryas. Rather, a two-phasing of the Younger Dryas is supported, with moderate wet conditions at the Allerød level during the first half and drier conditions during the second half of the Younger Dryas. Moreover, our results suggest that the amplitude of RH changes during the Early Holocene was more pronounced than during the Younger Dryas. This included the occurrence of a “Preboreal Humid Phase”. One possible explanation for this unexpected finding could be that solar activity is a hitherto underestimated driver of central European RH changes in the past.

Stable isotopic signatures of authigenic minerals in a Holocene ophiolitic debris flow, Southland, New Zealand

Clay Minerals ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 165-172 ◽  
Author(s):  
D. Craw ◽  
P. Blattner ◽  
C. A. Landis
Keyword(s):  
New Zealand ◽  
Surface Water ◽  
Debris Flow ◽  
Carbon Isotope ◽  
Climatological Data ◽  
Carbon Isotope Ratios ◽  
Isotopic Signatures ◽  
Mineral Growth ◽  
Stable Isotopic ◽  
O 24

AbstractAuthigenic chrysotile, stevensite, calcite, aragonite and pectolite have formed together in a Holocene ophiolitic debris flow in Southland, New Zealand. Mineral growth occurred about 4700-5700 years ago. The temperature of formation of these minerals is estimated from climatological data to be 5–10°C Surface water and groundwater δ180 is currently about –10‰, and was estimated to be about –9.5±1‰ during mineralization. Coexisting calcite (δ180 = +23‰) and aragonite (δl8O = +24‰) were in equilibrium with each other and with the groundwater at 5–10°C Stevensite δ180 is +14 to +16‰, chrysotile has δ180 = +5.5‰, and authigenic pectolite has δ180 near +10‰. Carbon isotope ratios for calcite and aragonite are strongly depleted (δ13C = –13 to –18) which suggests that dissolved CO2 had δ13C below -27. This isotopically light carbon probably resulted from a high organic component of carbon dissolved in the groundwater.

Late Pleistocene coastal paleogeography of the Queen Charlotte Islands, British Columbia, Canada, and its implications for terrestrial biogeography and early postglacial human occupation

2003 ◽  
Vol 40 (12) ◽  
pp. 1755-1766 ◽  
Author(s):  
Renée Hetherington ◽  
J Vaughn Barrie ◽  
Robert GB Reid ◽  
Roger MacLeod ◽  
Dan J Smith ◽  
...  
Keyword(s):  
British Columbia ◽  
Late Pleistocene ◽  
Late Quaternary ◽  
Glacial Refugia ◽  
Spatial Modelling ◽  
Early Holocene ◽  
Human Occupation ◽  
Land Bridge ◽  
Sea Levels ◽  
Queen Charlotte Islands

Molluscs, sediment lithology, and published sub-bottom profiles are used to deduce sea levels, outline the influence of glacially induced crustal displacement, and reconstruct the paleoenvironment of the northeast Pacific late Quaternary coastline. Geo-spatial modelling shows subaerially exposed land that could have been inhabited by plants and animals, and also coastally migrating early North American peoples. Ice-free terrain, present by at least 13 790 ± 150 14C years BP, a land bridge, and edible molluscs are identified. Queen Charlotte Islands (QCI) late Pleistocene coastal paleogeography may assist in explaining the biogeography of many terrestrial plant and animal species along the broader northeastern Pacific margin and provide evidence for researchers seeking late Pleistocene – early Holocene glacial refugia. Late Pleistocene – early Holocene coastlines that are not drowned and that may harbour early archaeological sites are identified along the western QCI, where migrants probably first travelled and the westernmost British Columbia mainland, where the effects of glacial ice were reduced.

Late Pleistocene and early Holocene environmental history of southwestern Washington State, U.S.A.

1984 ◽  
Vol 21 (6) ◽  
pp. 619-629 ◽  
Author(s):  
Cathy W. Barnosky
Keyword(s):  
Environmental History ◽  
Late Quaternary ◽  
Late Glacial ◽  
Cascade Range ◽  
Early Holocene ◽  
Olympic Mountains ◽  
Tundra Vegetation ◽  
Plant Remains ◽  
History Of ◽  
Glacial Time

A comparison of pollen records and associated plant remains from sites along a major precipitation gradient in southwestern Washington enables reconstruction of the late Quaternary environment during glacial and early Holocene time. During the Evans Creek Stade (25 000 – 17 000 years BP) little moisture reached lowlands east of the Olympic Mountains and as a result both the Puget Trough and the Columbia Basin featured a cold dry climate and parkland–tundra vegetation In glacial time, greatest aridity seems to have occurred between 19 000 and 17 000 years BP. After 17 000 years BP the development of mesophytic subalpine parkland suggests that maritime conditions extended farther east into the Puget Trough, and the Cascade Range became an important precipitation divide. Conditions warmer and (or) drier than today developed throughout western Washington between 10 000 and 8000–6000 years BP. Vegetation on opposite sides of the Cascade Range became dissimilar as early as 17 000 years BP, but this trend was accentuated in late glacial and early Holocene time.

Ice Complex formation on Bol'shoy Lyakhovsky Island (New Siberian Archipelago, East Siberian Arctic) since about 200 ka

2019 ◽  
Vol 92 (2) ◽  
pp. 530-548 ◽  
Author(s):  
Sebastian Wetterich ◽  
Natalia Rudaya ◽  
Vladislav Kuznetsov ◽  
Fedor Maksimov ◽  
Thomas Opel ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Late Quaternary ◽  
Late Glacial ◽  
Interglacial Period ◽  
Last Interglacial ◽  
Oxygen Isotope Stage ◽  
Mis 3 ◽  
Transport Patterns ◽  
Mis 5 ◽  
Ice Complex

AbstractLate Quaternary landscapes of unglaciated Beringia were largely shaped by ice-wedge polygon tundra. Ice Complex (IC) strata preserve such ancient polygon formations. Here we report on the Yukagir IC from Bol'shoy Lyakhovsky Island in northeastern Siberia and suggest that new radioisotope disequilibria (230Th/U) dates of the Yukagir IC peat confirm its formation during the Marine Oxygen Isotope Stage (MIS) 7a–c interglacial period. The preservation of the ice-rich Yukagir IC proves its resilience to last interglacial and late glacial–Holocene warming. This study compares the Yukagir IC to IC strata of MIS 5, MIS 3, and MIS 2 ages exposed on Bol'shoy Lyakhovsky Island. Besides high intrasedimental ice content and syngenetic ice wedges intersecting silts, sandy silts, the Yukagir IC is characterized by high organic matter (OM) accumulation and low OM decomposition of a distinctive Drepanocladus moss-peat. The Yukagir IC pollen data reveal grass-shrub-moss tundra indicating rather wet summer conditions similar to modern ones. The stable isotope composition of Yukagir IC wedge ice is similar to those of the MIS 5 and MIS 3 ICs pointing to similar atmospheric moisture generation and transport patterns in winter. IC data from glacial and interglacial periods provide insights into permafrost and climate dynamics since about 200 ka.

Late Quaternary vegetational history of the Howard Pass Area, northwestern Alaska

1999 ◽  
Vol 77 (4) ◽  
pp. 570-581 ◽  
Author(s):  
W Wyatt Oswald ◽  
Linda B Brubaker ◽  
Patricia M Anderson
Keyword(s):  
Late Quaternary ◽  
Local Variation ◽  
Late Glacial ◽  
Early Holocene ◽  
Pollen Accumulation Rates ◽  
Rubus Chamaemorus ◽  
History Of Vegetation ◽  
History Of ◽  
Western Arctic ◽  
Northern Alaska

Palynological records from Tukuto and Etivlik Lakes contribute to an improved understanding of the late Quaternary history of vegetation in the Howard Pass area of northern Alaska. During the Itkillik II glaciation (24-14 ka BP), the vegetation of the western Arctic Foothills was sparse, xeric tundra, as evidenced by taxa indicative of dry, rocky substrates (e.g., Selaginella rupestris (L.) Spring, Chenopodiaceae, and Encalypta cf. rhaptocarpa) and very low pollen accumulation rates in this interval of the 30-ka-old Tukuto Lake record. Mesic tundra dominated by non-Sphagnum (Bryidae) mosses, Cyperaceae, and Salix species expanded near Tukuto Lake during the late-glacial period, followed by the establishment of Sphagnum moss and increased shrub cover at ca. 10 ka BP. Landscapes around both lakes supported stands of Populus cf. balsamifera during the early Holocene, and Alnus crispa expanded in the Howard Pass area during the middle Holocene. Local variation in plant communities is illustrated by the comparison of the Tukuto and Etivlik pollen records. During the early Holocene, Populus cf. balsamifera was more common near Etivlik Lake than Tukuto Lake, and Juniperus cf. communis was present only in the vicinity of Etivlik Lake. Throughout the middle to late Holocene, Sphagnum, mesic tundra shrubs (Betula nana L., Salix, and Ericaceae species), and minor herbaceous taxa (e.g., Rubus chamaemorus L., Thalictrum, and Caryophyllaceae) were more prevalent at Tukuto Lake than at Etivlik Lake. These differences are likely related to the influence of local landform and soil characteristics near the two sites.Key words: Alaska, Arctic Foothills, Brooks Range, pollen analysis, Quaternary.

scholarly journals How dry was the Younger Dryas? Evidence from a coupled δ<sup>2</sup>H-δ<sup>18</sup>O biomarker paleohygrometer, applied to the Lake Gemündener Maar sediments, Western Eifel, Germany

2018 ◽  
Author(s):  
Johannes Hepp ◽  
Lorenz Wüthrich ◽  
Tobias Bromm ◽  
Marcel Bliedtner ◽  
Imke Kathrin Schäfer ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Younger Dryas ◽  
Vegetation Period ◽  
Late Glacial ◽  
Climatic Conditions ◽  
Leaf Water ◽  
Early Holocene ◽  
Air Humidity ◽  
Relative Air Humidity ◽  
Natural Climate

Abstract. The Late Glacial to Early Holocene transition phase and particularly the Younger Dryas period, i.e. the major last cold spell in Central Europe during the Late Glacial, are considered crucial for understanding rapid natural climate change in the past. The sediments from Maar lakes in the Eifel, Germany, have turned out to be valuable archives for recording such paleoenvironmental changes. For this study, we investigated a Late Glacial to Early Holocene sediment core that was retrieved from Lake Gemündener Maar in the Western Eifel, Germany. We analysed the hydrogen (δ2H) and oxygen (δ18O) stable isotope composition of leaf wax-derived lipid biomarkers (n-alkanes C27 and C29) and hemicellulose-derived sugar biomarkers (arabinose), respectively. Both δ2H and δ18O are suggested to reflect mainly leaf water of vegetation growing in the catchment of the Gemündener Maar. This enables the coupling of the results via a δ2H-δ18O biomarker paleohygrometer approach and allows calculating past relative air humidity values, which is the major advantage of the applied approach. Fundamental was the finding that the isotopic enrichment of leaf water due to evapotranspiration depends mainly on relative humidity. We hence use the coupled δ2H-δ18O biomarker approach to reconstruct the deuterium-excess of leaf water and in turn relative air humidity values corresponding to the vegetation period and daytime (RHdv). Most importantly, the results of the coupled δ2H-δ18O biomarker paleohygrometer approach (i) support a two-phasing of the Younger Dryas, i.e. a relative wet phase (on Allerød level) followed by a drier Younger Dryas ending, (ii) do not corroborate overall drier climatic conditions characterising the Younger Dryas or a two-phasing with regard to a first dry and cold Younger Dryas phase followed by a warmer period along with increasing precipitation amounts, and (iii) suggest that the amplitude of RHdv changes during the Early Holocene was more pronounced compared to the Younger Dryas. One possible driver for the unexpected Lake Gemündener Maar RHdv variations could be the solar activity.

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