MILJÖARKEOLOGISKA LABORATORIET

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1 MILJÖARKEOLOGISKA LABORATORIET RAPPORT nr Pollen analysis of samples from the defensive ditch (vollgrav) at Site FO4 Klypen-Øst, Follobanen, Oslo Philip Buckland and Jan-Erik Wallin INSTITUTIONEN FÖR IDÈ- OCH SAMHÄLLSSTUDIER

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3 Pollen analysis of samples from the defensive ditch (vollgrav) at Site FO4 Klypen-Øst, Follobanen, Oslo Philip Buckland 1 and Jan-Erik Wallin 2 1 The Environmental Archaeology Lab, Umeå University, Sweden 2 Pollenlaboratoriet i Umeå AB, Sweden Background Nine samples were submitted for pollen analyses from three profiles from the "Vollgrav" defensive ditch feature, at the Follobanen FO4 Klypen-Øst excavation in Oslo. These samples were investigated with respect to their pollen contents and, in a separate investigation, soil micromorphology. The micromorphological methods and results are described in detail in a separate report from Richard Macphail (2016). Where relevant, these findings are commented on with respect to the other analysis results below. Methods Sampling Sampling was undertaken by archaeological staff in connection with the excavation process. Pollen analyses Samples were treated according the standard methodology for pollen preparation as described by Moore et al The concentrated pollen was placed on a slide and coloured with saffron-dyed glycerine. Pollen taxa were identified under microscope using the keys of Beug (1961) and Moore et al. (1991), counted, and summarised as standard pollen percentage diagrams for this report. Carbon particles (>25 µm) were also counted and included in two of the pollen diagrams. When analysing pollen from soil samples, there is a risk of the overrepresentation of taxa producing thick-walled pollen grains (e.g. flowers of the Compositae family); the thicker walls reducing their susceptibility to decay with respect to other taxa. A number of thickwalled taxa were found at relatively high abundance in this project (e.g. flowers in the Compositae, Chenopodioideae and Vicia families). However, due to the high abundance of pollen of other species, the results are considered reliable. Pollen interpretation Percentage pollen diagrams are used to illustrate the relative proportion of different pollen taxa in each sample. Pollen taxa are not always equivalent to a specific species or family of plants. They may sometimes represent a group of plants with indistinguishable fossil pollen, and thus a lower taxonomic resolution than may often be obtained from plant macrofossil analyses. The taxonomic resolution used in this report allows for the identification of groups representing different landscape communities of archaeological interest (see Table 2). 3

4 Results The pollen diagrams presented here (Figure 3-4) show the depth of the sample and sample number on the y-axis, and relative proportion of each pollen taxa on the x-axis. It is praxis in palynology to use a filled curve to join the percentage values for each sample, the black area showing actual percentages and the lighter shaded area showing values x10. Whilst the filled curve is useful for providing an impression of changes over time, it can be misleading where samples do not come from a profile representing continuous deposition. The deposits described in this report appear to be a mixture of short continuous deposition and sporadic depositional events. Three series of three samples were submitted for pollen screening and subsequent pollen analysis ( Table 1). These samples were interpreted by archaeologists as representing primary and secondary fills in three composite cut depressions, in addition to natural sediments into which these features were cut (Figure 1). Figure 1. Profile drawing of the defensive ditch (vollgrav) profile showing the location of pollen samples (circled dots, see Table 1) and micromorphology samples (squares, see separate report from Richard Macphail and notes below). The pollen profiles, from left to right, are referred as profiles öst, mitt and väst in this report. Depths given in the pollen diagrams are taken from this figure. Table 1. Pollen sample series' from the defensive ditch. Pollen profile öst Pollen profile mitt Pollen profile väst (secondary fill) (primary fill) (underlying sediment)

5 Table 2. Pollen taxa found in this investigation and their general environmental/cultural indications. English name Deciduous woodland Coniferous woodland Meadowland /grassland Cultivated /arable land Swedish (Norwegian) & Scientific name (Lövskog) (Barrskog) (Ängsmark) (Åkermark) Alder X Al (Or) Alnus Birch X Björk Betula Pine X Tall (Furu) Pinus Spruce X Gran Picea Lime X Lind Tilia Elm X Alm Ulmus Oak X Ek (Eik) Quercus Hazel/Bog myrtle X Hassel/Pors Corylus type type Heather X Ljung (Lyng) Calluna Goat Willow/ Sälg/vide (Vier) Salix Willow Juniper X En (Einer) Juniperus Grass X Gräs (Gras) Poaceae Asters X Korgblommiga växter (rörf.), (Turf) Asteraceae undiff. Cichoriaceae X Korgblommiga växter (Tungf.) (Tistel, Lövetann) Cichoriaceae Buttercups X Smörblommor (Soleie) Ranunculus type Rose family Rosväxter (Mure) Rosaceae undiff. Mugwort X Gråbo (Burot) Artemisia vulgaris type Målla (Meldestokk) Chenopodiaceae Chenopodioideae X (goosefoots) Pink family X X Nejlikväxter (Smelle, tjärnblom) Caryophyllaceae Spurrey X Spärgel (Bendel) Spergula Nettles X Nässla (Nesle) Urtica Bedstraw Måra (Maure) Galium Hops/cannabis X Humle/Hampa Cannabis type type Sorrels X Syror (Syre) Rumex Willowherb X Mjölkört (Geitrams) Epilobium Rattle X Skallra (Engkall) Rhinanthus type Tufted vetch type X Vicker (Vikke) Vicia cracca type Barley X Korn (Bygg-typ) Hordeum type Wheat/oats X Vete/Havre typ (Hvete-typ) Triticum Rye X Råg (Rug) Secale Sedges X Starr (Storr) Cyperaceae Meadowsweet Älgört (Mjödurt) Filipendula Cow wheat X Kovall (Marimjelle) Melampyrum Cow parsley X Käx (Kjeks) Apiaceae Spores Sporer Lycopodium Lummer (Kråkefot) Lycopodium Ferns Ormbunkar (Telg) Polypodiaceae Lesser clubmoss Dvärglummer (Dvergjamne) Selaginella 5

6 Interpretation Carbon particles Carbon particles are present at low concentrations in the basal samples of profiles mitt and öst. The proportion increases up the profile and shows a dramatic increase in the upper sample of profile mitt (13886), suggesting an increase in human activity close to the ditch at the time of deposition. Woodland vegetation All three profiles display a similar picture of woodland vegetation. The proportions of coniferous woodland (pine) represented by the pollen are larger in the basal samples, decreasing and being replaced by alder and birch in the upper samples of each profile. Profile väst (13448, and 13446) Figure 2 Profile väst lacks spruce pollen in its basal sample (13446), suggesting a date for its accumulation of earlier than ca. AD The upper samples contain only one grain of spruce pollen each, which could quite possibly be derived from long-distance transportation. It is therefore also possible that these samples also date to before ca. AD On the basis of the pollen evidence, it is therefore possible that the entire feature of profile väst is older than the other profiles and older than AD On this basis it is also possible that sample predates the basal sediments represented in samples and 13883, which contain small amounts of spruce pollen. However, posthole construction/formation processes are complex, and these sediments could quite easily represent the use of older deposits to fill around a post dug into natural sediments. These results should therefore be interpreted with care and reference to a stratigraphic analysis of the deposits. The proportion of pollen indicating cultivated land is low throughout this profile, with only a few grains from barley and rye present. Meadow/grassland plants, or indicators of disturbance, are more frequent. The pollen assemblage suggests that meadowland was present at the site and that it became more prominent up the profile, although the reduction in pine in the upper sample is less significant than in the other profiles. Profile mitt (13886, and 13883) Figure 3 The basal sample (13883) shows only a very weak indication of cultivated crops (one barley pollen grain), and thus a weak signal from arable lands. The micromorphology results also suggest that the sediment may not be entirely of natural origin, and that human activity may have been present on the site even if the farming activities only appear as a background in the pollen record. This could perhaps suggest construction of the ditch prior to the establishment of a settlement on the site. The indications of cultivated land in the rest of the profile are, however clearly stronger than in profile väst. The relative amount of pollen indicating a cultivated landscape increases with time, and both wheat and rye were most likely cultivated near to the site from sample onwards. Pine trees dominate the initial arboreal signal, followed by alder and birch. Later layers show a decreasing proportion of coniferous woodland and increasing proportion of deciduous trees, especially birch. The proportion of carbon particles increases significantly up the profile, and may indicate extensive clearance burning in sample This activity is most likely after 6

7 the "short break in activities/waterlaid sedimentation" indicated in the soil micromorphology for the upper part of micromorphology sample Profile öst (14755, and 14753) Figure 4 This profile demonstrates the highest proportion of cultivated/arable lands, with barley and wheat/oats present at high percentages. Barley and wheat/oats pollen is present in the basal sample (14753), indicating an anthropogenic landscape around this sediment. The proportion of cereal pollen increases considerably in the upper sample and cultivated land was most likely present at the site throughout the profile. Soil micromorphology notes Micromorphology samples and overlap the pollen analysis above and suggest that the cut for layer was made through the water table, and the latter sediments, containing pollen sample 13885, were deposited in standing water. The possible presence of tree buds in the 'natural' sediment (SA11) suggests that trees indicated in the pollen evidence (sample 13883) are either growing close to the ditch, or that there is periodic flooding leading to the deposition of these macrofossil traces against a background of more distant trees. The presence of woody fragments and leaves in finer layers above (14779) suggest that either the woody vegetation remains growing close-by on site, or that material from construction is finding its way into these sediments. The layer appears also to have been deposited into standing water after a period of erosion (of layer 14779) which followed a period of stability and initial soil formation. According to the micromorphology the depositional environment later becomes dryer, but no pollen samples were taken in these layers. References Beug, H.J. (1961) Leifaden der Pollenbestimmung fur Mitteleuropa und angrenzende Gebiete. Lief pp. Stuttgart. Macphail (2016) Follobaneprosjektet: Follobanen FO4 Klypen-Øst soil micromorphology (including SEM/EDS). Report for NiKU, Norsk institutt for kulturminneforskning. nstitute of Archaeology, University College London (UCL) Moore, P.D., Webb, J.A. & Collinson, M.E. (1991) Pollen analysis. Oxford. 7

8 Appendices Figure 2. Pollen percentage diagram from profile väst samples 13446, and Note that the samples do not represent continuous sedimentation within the profile, but three distinct depositional phases. (Sample depths have been read from photographs provided on submission of samples). 8

9 RUMEX ACETOSA/ACETOSELLA SPERGULA TYPE URTICA TYPE VICIA CRACCA TYPE SUMMA STÖRNINGS INDIKERANDE VÄXTER HORDEUM TYPE TRITICUM SUMMA ODLADE VÄXTER CYPERACEAE APIACEAE FILIPENDULA MELAMPYRUM RANUNCULUS TYPE ROSACEAE UNDIFF. LYCOPODIUM ANNOTINUM POLYPODIACEAE TYPE PROV NR Analys Jan-Erik Wallin Pollenlaboratoriet i Umeå AB jan CICHORIACEAE EPILOBIUM TYPE GALIUM TYPE ARTEMISIA VULGARIS TYPE ASTERACEAE UNDIFF. CANNABIS TYPE CARYOPHYLLACEAE CHENOPODIACEAE ULMUS CORYLUS TYPE SALIX CALLUNA POACEAE FAGUS QUERCUS TILIA PINUS PICEA BETULA FOLLOBANEN F04, KLYPEN ÖST VALLGRAV, POLLENPROFIL MITT ALNUS KOLPARTIKLAR >25 mikrometer DEPTH (cm) Figure 3. Pollen percentage diagram from profile mitt samples 13883, & Note that the samples do not represent continuous sedimentation within the profile, but three distinct depositional phases. (Sample depths have been read from photographs provided on submission of samples)

10 VICIA CRACCA TYPE SUMMA STÖRNINGS INDIKERANDE VÄXTER HORDEUM TYPE TRITICUM SUMMA ODLADE VÄXTER CYPERACEAE APIACEAE FILIPENDULA MELAMPYRUM RANUNCULUS TYPE ROSACEAE UNDIFF. LYCOPODIUM ANNOTINUM POLYPODIACEAE TYPE PROV NR RUMEX ACETOSA/ACETOSELLA SPERGULA TYPE CENTAUREA TYPE URTICA TYPE POACEAE ARTEMISIA VULGARIS TYPE ASTERACEAE UNDIFF. CAMPANULA TYPE CANNABIS TYPE CARYOPHYLLACEAE CHENOPODIACEAE CICHORIACEAE PLANTAGO MEDIA / MAJOR JUNIPERUS TYPE SALIX CALLUNA FRAXINUS QUERCUS TILIA ULMUS CORYLUS TYPE PINUS Analys Jan-Erik Wallin Pollenlaboratoriet i Umeå AB jan PICEA FOLLOBANEN F04, KLYPEN ÖST VALLGRAV. POLLENPROFIL ÖST KOLPARTIKLAR >25 mikrometer ALNUS BETULA DEPTH (cm) Figure 4. Pollen percentage diagram from profile öst samples 14753, and Note that the samples do not represent continuous sedimentation within the profile, but three distinct depositional phases. (Sample depths have been read from photographs provided on submission of samples)

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12 MAL Miljöarkeologiska laboratoriet Umeå Universitet UMEÅ Jan-Erik Wallin Pollenlaboratoriet i Umeå AB Sågställarvägen 2A Umeå pollenlaboratoriet@ume.se