Radiocarbon dating suitability of aquatic plant macrofossils

2014 ◽  
Vol 52 (4) ◽  
pp. 435-443 ◽  
Author(s):  
James Marty ◽  
Amy Myrbo
Keyword(s):  
Radiocarbon Dating ◽  
Aquatic Plant ◽  
Plant Macrofossils

scholarly journals Stepped-Combustion 14C Dating of Sediment: A Comparison with Established Techniques

Radiocarbon ◽  
2001 ◽  
Vol 43 (2A) ◽  
pp. 255-261 ◽  
Author(s):  
J McGeehin ◽  
G S Burr ◽  
A J T Jull ◽  
D Reines ◽  
J Gosse ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Clay Minerals ◽  
Radiocarbon Dating ◽  
Age Determination ◽  
Clay Content ◽  
Plant Macrofossils ◽  
Bulk Sediment ◽  
14C Dating ◽  
Organic Carbon Fractions ◽  
Sediment Age

Radiocarbon dating of bulk sediment has long been used as a method of last resort when reliable wood, charcoal, or plant macrofossils are not available for analysis. Accurate dating of sediment is complicated by the presence of multiple organic carbon fractions, each with a potentially different 14C activity. Additionally, the presence of carbon bound by clay minerals can significantly reduce the accuracy of a sediment age determination, with the oldest 14C ages seen in samples with the highest clay content (Scharpenseel and Becker-Heidmann 1992).

Refining chronologies by dating pollen concentrates – new approach of separating pollen using flow cytometry

2020 ◽  
Author(s):  
Christoph Steinhoff ◽  
Nadine Pickarski ◽  
Thomas Litt
Keyword(s):  
Flow Cytometry ◽  
Radiocarbon Dating ◽  
Sediment Cores ◽  
Pollen Grains ◽  
Plant Macrofossils ◽  
Small Samples ◽  
Large Lakes ◽  
Promising Alternative ◽  
Ams Radiocarbon Dating ◽  
Short Period

<p>Radiocarbon dating of terrestrial plant-remains is a traditional method for precise age estimations of lake sediments. The absence of sufficient large plant macrofossils required for AMS dating in continental records, especially large lakes, demands for a satisfactory alternative, such as carbon-containing microfossils. Due to their ubiquitous presence in sedimentary archives pollen grains may be considered for dating. Nevertheless, the isolation and enrichment of pollen without a significant carbon contamination is still challenging. Even though commonly applied separation techniques can be used to remove the predominant portions of foreign particles, the undesirable transfer of these particles into the pollen concentrate cannot be excluded, yet. However, flow cytometry, as a highly promising alternative, offers the possibility to sort huge quantities of particles in a short period of time and to generate pure pollen concentrates from heterogeneous samples suitable for AMS radiocarbon dating.</p><p>In this study we present the approach to sort limnic sediment samples using flow cytometry. We are able to unequivocally identify pollen populations in the heterogeneous composition of the sediments and isolate them. The sediments analyzed were taken from the continental record of Lake Van (Eastern Anatolia). Annually laminated layers from the Holocene section of the sediment cores allow a precise temporal classification and validation of generated radiocarbon ages derived from fossil pollen. Although it is now possible to produce pollen concentrates without the contamination of foreign particles, the isolation of a sufficient quantity of pollen grains to generate reliable radiocarbon ages is still difficult. An increase pollen yield is required. Due to the limitation of the initial material, it is therefore especially necessary to improve the efficiency during the cytometric analysis.</p><p>Our results show the importance to steadily optimize the processing steps during chemical pretreatment, cytometric analysis as well as the radiocarbon dating itself. This facilitates the handling of the ultra-small samples and ensures precise age estimations of the pollen concentrates. Furthermore improving the laboratory routine for the enrichment of pollen will allow the analysis of vast amounts of samples in a short period of time. In consequence, dating pollen concentrates generated by flow cytometry can be used as a robust contribution and independent time control for existing chronologies in continental climate records.</p>

scholarly journals Protocol Development for Purification and Characterization of Sub-Fossil Insect Chitin for Stable Isotopic Analysis and Radiocarbon Dating

Radiocarbon ◽  
2001 ◽  
Vol 43 (2A) ◽  
pp. 199-208 ◽  
Author(s):  
G W L Hodgins ◽  
J L Thorpe ◽  
G R Coope ◽  
R E M Hedges
Keyword(s):  
Radiocarbon Dating ◽  
Terrestrial Ecosystems ◽  
Strong Acid ◽  
Plant Macrofossils ◽  
Base Hydrolysis ◽  
Proteinase K ◽  
Alternative Methods ◽  
Enzyme Treatment ◽  
Fossil Insect ◽  
Hydrolysis Reactions

Reliable radiocarbon dating depends upon well-defined samples. We have been investigating whether or not reliable 14C dates can be obtained directly from sub-fossil insect cuticle or biochemical fractions derived from it. Initial carbon and nitrogen stable isotope measurements on sub-fossil insect chitin from species with known feeding behaviors found within a single site (St Bees, Cumbria) clustered in a manner reminiscent of trophic level effects seen in terrestrial ecosystems. Although this finding implied some chemical stability, the measurement of CN ratios from the same samples indicated compositional variability. In addition, 14C dates obtained from these same samples were different from dates obtained from plant macrofossils found at the same depth. We have experimented with protocols designed to biochemically reduce chitin to its principle carbohydrate component glucosamine with the aim of using this compound to generate reliable 14C dates. Solvent extractions of sub-fossil chitin were carried out to remove both endogenous and exogenous lipid-soluble materials. Base hydrolysis reactions designed to extract polypeptides retained surprisingly high levels of contaminating amino acids. Proteinase K enzyme treatment had little affect on the level of amino acid contamination. Strong acid hydrolysis reactions designed to depolymerize chitin to glucosamine yielded only 5% glucosamine. Clearly alternative methods of chitin depolymerization must be identified before the purification and 14C dating of glucosamine from sub-fossil chitin becomes practical.

scholarly journals Disturbances in the primary stratigraphy of lake sediments on the Murmansk coast (Russia): their identification and relationship with catastrophic events

Baltica ◽  
2019 ◽  
Vol 32 (2) ◽  
pp. 156-169
Author(s):  
Svetlana Nikolaeva ◽  
Dmitriy Tolstobrov ◽  
Alena Tolstobrova
Keyword(s):  
Lake Sediments ◽  
Radiocarbon Dating ◽  
Barents Sea ◽  
Plant Macrofossils ◽  
Analysis Data ◽  
Diatom Analysis ◽  
Catastrophic Events ◽  
Coastal Lake ◽  
Diatom Flora ◽  
The Barents Sea

The results of lithological, diatom analysis and radiocarbon dating of bottom sediments of small coastal lake basins along the Murmansk coast of the Barents Sea (the Kola Region, Russia) are presented. Sedimentary successions of two lakes reveal the presence of distinctive deposits, very different from the sediment above and below. These deposits are represented by erosional unconformity beds, gyttja and sand mixed with plant macrofossils, and characterized by changes in diatom flora and sand in a matrix of organic material. The sediments were deposited due to different catastrophic events: paleo-tsunami and paleo-earthquakes. According to radiocarbon analysis data, a tsunami occurred between 10,400–8200 cal yr BP and a paleo-earthquake occurred between 8200–7200 cal yr BP. We discuss various causes and mechanisms for the formation of disturbances in lake sediments, including the Storrega tsunami and paleo-earthquakes, which during and after deglaciation were strong and frequent.

scholarly journals Carbon Isotope Variations and Chronology of the Last Glacial-Interglacial Transition (14–9 ka BP)

Radiocarbon ◽  
1997 ◽  
Vol 40 (2) ◽  
pp. 873-881 ◽  
Author(s):  
Chris S. M. Turney ◽  
Doug D. Harkness ◽  
J. John Lowe
Keyword(s):  
Radiocarbon Dating ◽  
Plant Macrofossils ◽  
Data Sets ◽  
Site Specific ◽  
Terrestrial Plant ◽  
Last Glacial ◽  
Sedimentary Sequences ◽  
The United Kingdom ◽  
Organic Sediment ◽  
The Last Glacial

We present δ13C data from both bulk organic sediment samples and terrestrial plant macrofossils from five high-resolution sedimentary sequences from the United Kingdom from which extensive multiproxy data sets have been obtained. These span the last glacial-interglacial transition. Chronological control has been provided by radiocarbon dating and/or tephrochronology. The results demonstrate that significant shifts in bulk organic δ13C can be identified at key climatic transitions in most of the sites. The data are affected by site-specific influences that restrict their use as chronological markers. However, terrestrial plant macrofossil records are more consistent and reveal shifts that appear to be synchronous and which therefore offer a basis for interregional correlation as well as significant paleoenvironmental information.

scholarly journals Interdisciplinary studies of spring mire deposits from Radzików (South Podlasie Lowland, East Poland) and their significance for palaeoenvironmental reconstructions

2012 ◽  
Vol 39 (1) ◽  
pp. 10-29 ◽  
Author(s):  
Radosław Dobrowolski ◽  
Irena Pidek ◽  
Witold Alexandrowicz ◽  
Stanisław Hałas ◽  
Anna Pazdur ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Environmental Changes ◽  
Younger Dryas ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Interdisciplinary Studies ◽  
Carbon Stable Isotopes ◽  
Calcareous Tufa ◽  
Palaeoenvironmental Reconstructions ◽  
Late Glacial And Holocene

Abstract The paper presents the results of interdisciplinary (multiproxy) palaeoenvironmental studies of peat — calcareous tufa depositional sequences of spring mire from Radzików site (east Poland). Analyses of three biotic proxies (plant macrofossils, pollen, molluscs) were supplemented with sedimentological, geochemical, oxygen and carbon stable isotopes analyses and radiocarbon dating and used for reconstruction of environmental changes in Late Glacial and Holocene. The obtained results enable us to (1) reconstruct main phases of mire development and (2) determine environmental factors influencing changes of water supply. The object started to develop in Allerød. The Late Glacial and Early Holocene deposit sequence is relatively thick (about 1.0 m), with good palaeoecological record. The boundary between Younger Dryas and Preboreal is especially well confirmed by palynological and malacological analyses as well as radiocarbon dating. The Mesoholocene deposits are considerably worse preserved. Mire development was evaluated in terms of general mire ecology.

scholarly journals 14C Dating of Plant Macrofossils in Lake Sediment

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 411-416 ◽  
Author(s):  
Michael Andree ◽  
Hans Oeschger ◽  
Ulrich Siegenthaler ◽  
Trudi Riesen ◽  
Markus Moell ◽  
...  
Keyword(s):  
Aquatic Plant ◽  
Hard Water ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Water Effect ◽  
Terrestrial Plants ◽  
14C Dating ◽  
Pollen Zone ◽  
Swiss Plateau ◽  
Terrestrial Material

Macrofossils of terrestrial plants have been picked from a sediment core taken in Lake Lobsigen, a small lake on the Western Swiss Plateau. The sediments were previously analyzed for pollen composition, plant and animal macrofossils, and stable isotopes. Plant macrofossils were selected near pollen zone boundaries in Late Glacial and early Postglacial sediment for 14C dating by AMS. In the same lake carbonate and gyttja (aquatic plant) samples were dated by decay counting. The dates on terrestrial material are generally younger than those on carbonate and gyttja, ie, material reflecting the 14C/C ratio of dissolved bicarbonate in lake water. This is probably due to a contribution of dissolved limestone carbonate and thus a somewhat reduced 14C/C ratio in the lake's water (hard water effect).

Lake nutrient variability inferred from elemental (C, N, S) and isotopic (δ13C, δ15N) analyses of aquatic plant macrofossils

2010 ◽  
Vol 29 (17-18) ◽  
pp. 2161-2172 ◽  
Author(s):  
Ulrike Herzschuh ◽  
Steffen Mischke ◽  
Hanno Meyer ◽  
Birgit Plessen ◽  
Chengjun Zhang
Keyword(s):  
Aquatic Plant ◽  
Plant Macrofossils ◽  
Nutrient Variability

Anomalous Radiocarbon Ages from a Holocene Detrital Organic Lens in Alaska and their Implications for Radiocarbon Dating and Paleoenvironmental Reconstructions in the Arctic

1988 ◽  
Vol 29 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Robert E. Nelson ◽  
L. David Carter ◽  
Stephen W. Robinson
Keyword(s):  
Coastal Plain ◽  
Radiocarbon Dating ◽  
Plant Macrofossils ◽  
The Arctic ◽  
Size Fractions ◽  
Radiocarbon Age ◽  
Organic Debris ◽  
Arctic Coastal Plain ◽  
Alaskan Arctic ◽  
Age Determinations

Eleven radiocarbon age determinations clearly show that a lens of Holocene fluvial organic debris on the Alaskan Arctic Coastal Plain contains mostly pre-Holocene organic material. Radio-carbon ages of identified plant macrofossils indicate the material was deposited about 9000 to 9500 yr B.P. Radiocarbon analyses of bulk samples from this deposit, however, range from 13,300 to 30,300 yr B.P. Most of the old organic matter seems to be in the smaller size fractions in the deposit, particularly in the fraction between 0.25 and 0.5 mm, but all size fractions are contaminated. Particular caution must be exercised in submitting bulk samples for radiocarbon dating from areas where conditions favor redeposition of isotopically “dead” carbon.

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