Recent and Planned Developments of the Program OxCal

Ramsey, Christopher Bronk; Lee, Sharen

doi:10.1017/s0033822200057878

Cited by 1,095 publications

(270 citation statements)

References 14 publications

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“…The radiocarbon dates are reported in calendar years before present (cal yrs BP; Stuiver and Polach, 1977). The age model of the core was built with the OxCal v4.2 program based on the radiocarbon-dated mollusc shells and a depositional model (P_sequence, k = 0.5; Ramsey, 2008;Ramsey and Lee, 2013). Also, the base of the adjacent multicore dated with 210 Pb was used in the model.…”

Section: Bayesian Modelling Of 14 C Ages For the Chronologymentioning

confidence: 99%

Sources and characteristics of terrestrial carbon in Holocene-scale sediments of the East Siberian Sea

et al. 2017

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Abstract. Thawing of permafrost carbon (PF-C) due to climate warming can remobilise considerable amounts of terrestrial carbon from its long-term storage to the marine environment. PF-C can be then be buried in sediments or remineralised to CO 2 with implications for the carbon-climate feedback. Studying historical sediment records during past natural climate changes can help us to understand the response of permafrost to current climate warming. In this study, two sediment cores collected from the East Siberian Sea were used to study terrestrial organic carbon sources, composition and degradation during the past ∼ 9500 cal yrs BP. CuO-derived lignin and cutin products (i.e., compounds solely biosynthesised in terrestrial plants) combined with δ 13 C suggest that there was a higher input of terrestrial organic carbon to the East Siberian Sea between ∼ 9500 and 8200 cal yrs BP than in all later periods. This high input was likely caused by marine transgression and permafrost destabilisation in the early Holocene climatic optimum. Based on source apportionment modelling using dual-carbon isotope ( 14 C, δ 13 C) data, coastal erosion releasing old Pleistocene permafrost carbon was identified as a significant source of organic matter translocated to the East Siberian Sea during the Holocene.

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Section: Bayesian Modelling Of 14 C Ages For the Chronologymentioning

confidence: 99%

Sources and characteristics of terrestrial carbon in Holocene-scale sediments of the East Siberian Sea

et al. 2017

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“…Collagen from these and other associated materials, such as charcoal, have since been radiocarbon dated. The most recent direct date comes from [75] (10 960 + 80 radiocarbon years BP) and is recalibrated here using the most recent international calibration curve, IntCal13 [76,77], equivalent to 13 020-12 700 cal yrs BP (2s range). Archaeological material is widespread and abundant on the Northern Channel Islands, including evidence early in the record from Daisy Cave and Cardwell Bluffs on San Miguel Island and sites 512 and 706 from the northwest side of Santa Rosa Island (shown in figure 1) [78][79][80][81][82].…”

Section: The Northern California Channel Islandsmentioning

confidence: 99%

“…All ages have been calibrated with IntCal13 (age ranges in purple, green or dark grey) or Marine13 with a local marine reservoir correction applied (samples in blue) where appropriate [76]. Archaeological sites Daisy Cave, 512 W, SRI-706, SMI-679SE and SMI-678 are presented within sequence models [77]. Also shown in red is the estimate of the first human appearance date on Santa Rosae.…”

Section: (C) Wider Significancementioning

confidence: 99%

Fire history on the California Channel Islands spanning human arrival in the Americas

Hardiman

Scott

Pinter

et al. 2016

Phil. Trans. R. Soc. B

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One contribution of 24 to a discussion meeting issue 'The interaction of fire and mankind'. Recent studies have suggested that the first arrival of humans in the Americas during the end of the last Ice Age is associated with marked anthropogenic influences on landscape; in particular, with the use of fire which, would have given even small populations the ability to have broad impacts on the landscape. Understanding the impact of these early people is complicated by the dramatic changes in climate occurring with the shift from glacial to interglacial conditions. Despite these difficulties, we here attempt to test the extent of anthropogenic influence using the California Channel Islands as a smaller, landscape-scale test bed. These islands are famous for the discovery of the 'Arlington Springs Man', which are some of the earliest human remains in the Americas. A unifying sedimentary charcoal record is presented from Arlington Canyon, Santa Rosa Island, based on over 20 detailed sedimentary sections from eight key localities. Radiocarbon dating was based on thin, fragile, long fragments of charcoal in order to avoid the 'inbuilt' age problem. Radiocarbon dating of 49 such fragments has allowed inferences regarding the fire and landscape history of the Canyon ca 19-11 ka BP. A significant period of charcoal deposition is identified approximately 14-12.5 ka BP and bears remarkable closeness to an estimated age range of the first human arrival on the islands.This article is part of the themed issue 'The interaction of fire and mankind'.

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“…The whole data set consists of several thousand samples with several million pollen grains counted. The Oxcal time models are based on more than 200 radiocarbon dates (Ramsey and Lee 2013). The pollen type nomenclature follows Beug (2004).…”

Section: Methodsmentioning

confidence: 99%

Evidence for rare crop weeds of the Caucalidion group in Southwestern Germany since the Bronze Age: palaeoecological implications

Rösch

2017

Veget Hist Archaeobot

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The crop weed communities of dry calcareous soils are today very rare and endangered. In the first half of the 20th century this group was already in an advanced stage of disappearance, caused by the intensification of agriculture since the 19th century. Therefore, botanists only found these plants in a few regions with calcareous soils, obviously reflecting the geological conditions. But many archaeobotanical finds are in places where this species was never observed as a living plant and edaphic conditions seem to exclude it. In the western Lake Constance region floristic observations are lacking. Of Orlaya grandiflora, there is now proof from several pollen diagrams that this species did occur regularly and with high frequency in this region from the Late Bronze Age to the 19th century ad. Several other species of the Caucalidion are also reflected in the pollen record, but are less frequent, reflecting the ecological conditions triggered by agriculture; due to soil erosion, topsoils were thin, especially on slopes, with low water capacity, and low yields. The weeds with spiny fruits were distributed over long distances by migrating domestic animals. Pollen grains in high-resolution pollen profiles from the northern Black Forest and Allgäu, where these plants were not to be expected and were never observed, indicate a ubiquitous distribution of the Caucalidion between Late Bronze Age and early Modern Ages in Central Europe and adjacent regions, reflecting the tenuous situation of long-term extensive ard agriculture in hilly landscapes. More and better pollen diagrams and macrofossil studies would bring better evidence.

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Recent and Planned Developments of the Program OxCal

Cited by 1,095 publications

References 14 publications

Sources and characteristics of terrestrial carbon in Holocene-scale sediments of the East Siberian Sea

Sources and characteristics of terrestrial carbon in Holocene-scale sediments of the East Siberian Sea

Fire history on the California Channel Islands spanning human arrival in the Americas

Evidence for rare crop weeds of the Caucalidion group in Southwestern Germany since the Bronze Age: palaeoecological implications

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