Nanna Noe-Nygaard

Butchering and marrow fracturing as a taphonomic factor in archaeological deposits

A major aim of the analysis of faunal remains from archaeological sites is the reconstruction of the palaeoecology of early man. Since taphonomic work must precede palaeoecological work, theories concerning the palaeoecology of early man would benefit from firmly based taphonomic studies of the archaeological deposits. One of the numerous taphonomic factors to be considered is the bone fragmentation produced by early man. The degree of bone fragmentation in a deposit uninfluenced by human factors is an expression of the resistance of the various bones to mechanical and chemical decomposition before and during burial. Thus, the degree of fragmentation where human factors are predominant should provide an illustration of man as a taphonomic factor. In both cases the degree of fragmentation may be used as an indicator of the degree of taphonomic overprint. Examination of bone material from four West European Mesolithic sites (all bog deposits), Star Carr 7200 ± 120 B.C., Kongemosen 6600 ± 100 B.C., Praestelyngen 3200 ± 100 B.C., and Muldbjerg I 2900 ± 80 B.C., reveals differences in marrow fracturing techniques. Furthermore, the different techniques result in different numbers of fragments for the same type of bone. Comparison of faunas from different sites based on the number of bone fragments must therefore be preceded by analysis of the marrow fracturing techniques used at the various sites. The number of fragments per estimated minimum number of individuals should indicate the degree of taphonomic loss. The various types of marrow fracturing found seem to belong to cultures at different levels of technical development. Thus, it may be possible within a limited area such as northern Europe to establish a chronology using marrow fracturing type as one of the ecostratigraphic tools.

Mesolithic hunting in Denmark illustrated by bone injuries caused by human weapons

Abstract Animal skeletons from eight Danish Mesolithic settlements and 14 isolated bog finds have been investigated for injuries caused by hunters. The injuries comprise arrow-pierced limb bones, ribs and vertebrae together with healed and unhealed injuries found on shoulder blades. Special attention has been drawn to the skull lesions on Sus scrofa L. Some pathological features in the shoulder blades of the same animal are also discussed for comparison. The sizes and shapes of the injuries in some cases give an indication of the types of weapons that have been used. The proportion of unhealed to healed fractures seems to change during time. This feature may be related to the change to an increasingly stationary mode of life of the hunters.

New osteological and C-isotope evidence on mesolithic dogs: Companions to hunters and fishers at Star Carr, Seamer Carr and Kongemose

The skulls and bones of domestic dog (Canis familiaris) and wolf (Canis lupus) from the Mesolithic site of Star Carr, Yorkshire, England are reviewed in the context of the new find of the cervical vertebrae of a dog from the nearby site of Seamer Carr. Examination of the stable carbon isotope ratio of these vertebrae has revealed that the dogs diet must have consisted mainly of marine food. This surprising result compares closely with the stable carbon isotope ratio for dog bone from the Early Atlantic site of Kongemose in Sjaelland, Denmark. If the domestic dogs were feeding predominantly on the scraps left by coastal people then they must have been living on the sea shore and it can be assumed that they died while on hunting trips inland. This in turn implies that Seamer Carr and Kongemose were temporary hunting camps of Mesolithic people who lived for the greater part of the year on the sea shore. This hypothesis is supported by a review of the butchery and age at death of the animal remains from the three sites.

Bivalve mass mortality caused by toxic dinoflagellate blooms in a Berriasian-Valanginian lagoon, Bornholm, Denmark

Thin lagoon-margin clay beds of the Berriasian-Valanginian Jydegdrd Formation contain monospecific assemblages of the bivalve Neomiodon angulata and the gastropod Viviparus cariniferus and polyspecific assemblages of Viviparus and juvenile bivalves. The three assemblage types were all formed by mass mortality. The N. angulata assemblage resulted from seasonal toxic dinoflagellate blooms, the V. cariniferus assemblage from desiccation of shallow ponds, and the polyspecific assemblage from storm washover. Paleoecologic, sedimentologic, and stable-isotope data show that the shallow bay or lagoonal waters fluctuated between almost fresh and brackish. Rapid changes in temperature and especially salinity can therefore be invoked to explain the mass mortality events. There is no direct evidence for hypersaline conditions. The beds with the Neomiodon angulata assemblages contain a highly unusual dinoflagellate flora consisting of only two species, one of which, Sentusidinium pelionense, constitutes over 99% of the assemblage. This suggests the occurrence of repeated virtually monospecific blooms of S. pelionense in the shallow, brackish water. Toxins formed during the bloom probably caused seasonal mass mortality of the opportunistic, salinity-tolerant Neomiodon faunas. The Viviparus cariniferus assemblages were probably killed during progressive desiccation of shallow lagoon-margin ponds. The polyspecific gastropod-bivalve assemblages were formed by washover during storms. All three types of assemblages were thus caused by mass mortality. The first two monospecific assemblages are non-transported census populations, while the third was formed by transport.

Hummocky cross-stratification from the Lower Jurassic Hasle Formation of Bornholm, Denmark

Abstract The exposed part of the Lower Pliensbachian Hasle Formation is composed of coarse siltstone and fine-grained sandstone and is hummocky cross-stratified throughout. The stratification can be described as amalgamated H and/or HF divisions. The Dott-Bourgeois ideal sequence for hummocky cross-stratification is slightly modified so that the basal pebbly lag is extended to include the graded and laminated pebbly portion at the base of the H division. The suggestion to include a parallel-laminated P division below the H division is not followed. The hummocks of the Hasle Formation are mainly of erosional nature but hummocks representing growing bed forms have been observed. The formation was deposited in an open marine shelf 1–2 km from the fault controlled coast lines. The hummocky cross-stratification was probably formed in depths of 10–40 m by combined-flow storm currents representing along-coast geostrophic flows. Storms were frequent and the coastline faced a wide epeiric sea with a fetch towards the west of possibly 1000 km. The Hettangian of Bornholm represents an overall transgressive or deepening sequence passing from lacustrine over fluvial to tidal flat deposits. The recognition of hummocky cross-stratification in the Hasle Formation thus indicates that the deepening continued in the Pliensbachian. This conforms with published curves on eustatic sea-level changes.

High and low resolution sequence stratigraphy in lithological prediction—examples from the Mesozoic around the northern North Atlantic

The Mesozoic around the northern North Atlantic was characterized by a succession of extensional tectonic events separated by periods of regional subsidence governed by thermal contraction. Sedimentation was controlled by tectonic subsidence, sediment and water loading, isostatic compensation, sediment influx, climate, and eustatic and relative sea-level variations at several scales. A series of examples from the Upper Triassic–Lower Cretaceous from East Greenland and the Northern North Sea have been selected to illustrate the relative importance of the controlling factors on depositional systems of different temporal and spatial scale. A long-term eustatic rise, superimposed by short-term cycles thus started in the Hettangian and culminated in the Kimmeridgian, whereas the main tectonic events include uplift of a major dome in the Early Jurassic, subsidence of the dome in the Middle Jurassic, and domal collapse and rifting in the Late Jurassic. The syn- to early post-rift Wollaston Forland Group (Volgian–Valanginian) is an example of a strongly tectonically controlled coarse-grained deep-water system deposited on tilted fault blocks. Deposition of the partly contemporaneous Fynselv Member (Raukelv. Formation) took place during uniform regional subsidence mainly governed by thermal contraction; relative sea-level variations appear to be the dominant factor controlling the sedimentary architecture. The two successions differ dramatically in geometry, facies and sedimentary processes. The tilted fault block example seems, however, to include the same number of roughly contemporaneous large-scale cycles as the unit deposited in the uniformly subsiding basin. This suggests that a relative sea-level signal can be recognized also in the tectonically controlled deep-water succession. The effects of sea-level control on contemporaneous shallow marine successions are illustrated by the Middle Jurassic Vardekloft Formation and the Brent Group of the Northern North Sea. The two units show great similarity and contemporaneity in terms of facies, parasequence stacking patterns, and systems tract successions. This allows formulation of a combined age and lithological model, which can be used in prediction of spatially separated systems tracts, some of which may contain unrecognized reservoir bodies. The similar development is highly suggestive of eustatic control. However, both regions were affected by large-scale doming, and the uniform development of the two systems may thus be controlled by relative sea-level changes reflecting large-scale tectonic processes. Finally, a high resolution sequence stratigraphic analysis of the lacustrine Rhaetian–Sinemurian Kap Stewart Formation is presented to demonstrate a hitherto unrecognized play type. Correct identification of sequence stratigraphic elements in this formation allows prediction of significant deltaic reservoir sandstones interbedded with black organic-rich lacustrine mudstones with excellent source rock potential. Combined low and high resolution sequence stratigraphy can be used in large-scale lithological prediction and comparison between systems situated far apart, and in detailed within-system predictions on a reservoir scale.

Tsunami propagation over a wide, shallow continental shelf caused by the Storegga slide, southeastern North Sea, Denmark

The large Storegga slide, which occurred on the Norwegian Atlantic shelf ∼8150 yr ago, triggered a tsunami that has been identified in sediment deposits along the coasts of Greenland, Norway, the Faroe Islands, the Shetland Islands, Scotland, and the northernmost coasts of England, but hitherto not along the southeastern shores of the North Sea. It has generally been assumed that the shallow continental shelf of the North Sea attenuated and dissipated the energy of the tsunami before it reached those coastlines. We used radiocarbon and optically stimulated luminescence dating as well as stratigraphic, lithologic, chemical, and palynological analyses of sediment cores to identify tsunami deposits on the barrier island of Romo located on the southwestern North Sea coast of Denmark. We show that tsunami sediments were deposited in a freshwater paleolake that is located ∼16 m below present-day mean sea level. The tsunami sediment run-up was between 1.5 m and 5.5 m above the contemporaneous sea level. Our results demonstrate that the Storegga slide tsunami propagated across the wide (>500 km) and relatively shallow (depth <95 m) continental shelf of the North Sea and resulted in run-up along adjacent coastlines. In contradiction to earlier theoretical studies, the coastline of the southeastern North Sea cannot be regarded as being sheltered from impacts of North Atlantic tsunami incidents.

The Upper Jurassic Hareelv Formation of East Greenland: A Giant Sedimentary Injection Complex

The Upper Jurassic Hareelv Formation in Jameson Land, East Greenland is one of the worlds finest outcrop examples of a giant sand-injection complex. The contrast between the black, organic-rich hemipelagic mudstones and the injected light yellow sandstones is striking and allows easy recognition of geometries both in close-up and from a distance. The formation is 200–400 m (660–1310 ft) thick, and in the lower part (Katedralen Member), the sandstone/mudstone ratio is roughly 1:1, increasing to about 9:1 in the upper part (Sjllandselv Member). All sands in the upper Oxfordian–Volgian Katedralen Member have undergone postburial remobilization and injection into the surrounding mudstones, and virtually all primary sedimentary structures have been obliterated. It is thus not possible to provide detailed interpretations of the primary depositional processes. On the basis of sand-body geometry and comparison with the undisturbed underlying Olympen and overlying Raukelv formations, the depositional system is interpreted as comprising slope gullies and laterally extensive base-of-slope lobes. The sandstones occur as thick, virtually structureless bodies, which may be laterally extensive or form mounded or pod-shaped masses. Smaller dikes and sills are ubiquitous, and their geometries range from orthogonal or polygonal to extremely irregular, reflecting injection into mudstones with various degrees of consolidation. Mudstone slabs and fragments of all sizes occur in the sandstones and may easily be mistaken for clasts transported in concentrated gravity flows. They are formed, however, by excavation and rip-down of the mudstone during forceful injection of fluidized sand. Vertical or lateral organizational trends of sandstone bodies are not observed, and no clear indications exist if intrusion of dikes and sills were upward, downward, or lateral with respect to the larger sandstone bodies. The mudstones above large convex-upward sandstone bodies seem, however, to be relatively undisturbed by dikes and sills. Close inspection of some thick, laterally extensive sandstone bodies show that they contain subhorizontal mudstone leaves or layers, indicating long-distance lateral injection and splitting of the injected mudstone package. The thick convex-upward sandstone bodies were, however, clearly intruded vertically upward into the mudstones. No evidence is present for sand extrusion on the sea floor, and remobilization and injection clearly were postburial, probably under a cover of tens to perhaps hundreds of meters. Several generations of injection can be demonstrated based on crosscutting relationships of dikes and sills and the presence of both straight and strongly ptygmatically folded dikes at the same levels. Similar injections are unknown from both older and younger formations in Jameson Land. The Hareelv Formation was deposited during the climax of the most important Mesozoic rift event in East Greenland, and the pervasive remobilization of all sands in the formation is interpreted as caused mainly by cyclic loading triggered by seismic shocks. Additional factors may have included slope shear stress, buildup of pore pressure caused by sediment loading, upward movement of pore waters expelled from the compacting muds, and possibly biogenic and thermogenic gas. The well-exposed Hareelv Formation is an excellent analog for subsurface hydrocarbon reservoirs, which have been modified by remobilization and injection of sands. It provides one of the best field examples known, illustrating the degree to which a sediment can be altered and all primary features destroyed by remobilization, fluidization, and injection.

Cretaceous faulting and associated coarse-grained marine gravity flow sedimentation, traill ø, east greenland

The Cretaceous succession of the Traill O region in East Greenland is more than 2 km thick and is dominated by mudstones. It occurs in a system of fault blocks, about 5–10 km wide, delimited by roughly parallel, NNE-trending faults. The main faults in the area are from west to east the Post-Devonian Main Fault, the Bordbjerg Fault, the Manedal Fault and the Mols Bjerge Fault. Cretaceous subsidence was governed by thermal contraction following the protracted Late Bajocian-Valanginian rift phase. The regional subsidence was punctuated by several possibly rift-related fault episodes marked by deposition of breccias, conglomerates and sandstones. Transport was by sediment gravity flows and clasts were derived from the uplifted footwalls and fault scarps of the main basin bounding faults. Four coarse-clastic deep-water units represent different types of depositional systems which are described to illustrate the variety of fault-associated deposits. Three of the coarse-clastic units form the basis for defining the new Rold Bjerge, Manedal and Vega Sund Formations. A chaotic breccia of earliest Middle Albian age forms the new Rold Bjerge Formation. It contains blocks, up to 60 m long, and has a clast assemblage characterised by Upper Permian and Lower Triassic carbonates. It is truncated to the west by the Manedal Fault, and the Lower Triassic Wordie Creek Formation which is exposed in the footwall, is considerably younger than the dated clasts. The breccia was thus derived from the area further west delimited by the Post-Devonian Main Fault, while the Manedal Fault appears not to have been active at the time of deposition. Transport was by submarine, probably hydroplaning, debris avalanches, and the estimated runout distance was about 20 km. An allochthonous succession comprising mudstones and sandstone turbidites of Late Albian age is also exposed immediately adjacent to the Manedal Fault. It was formed by extensive downslope sliding and slumping along discrete, densely spaced detachment planes, and the mudstones and sandstones were folded during transport. The age of the slide-slump event is not known, but a Late Turonian-Early Coniacian age is tentatively suggested, by analogy with conglomerates and pebbly sandstones of the Manedal Formation which are situated in a similar position along strike. Remobilisation, downslope transport and subsequent redeposition took place during an important phase of footwall uplift. A conglomerate-sandstone package forming the new Manedal Formation is limited to the west by the Manedal Fault. The age is not precisely known, but macrofossils indicate a Late Turonian-Early Coniacian age. The common presence of boulders composed of Upper Permian carbonates indicates that the Manedal Fault was not yet formed or played only a minor role at the time of deposition because the rocks exposed in the footwall are of Early Triassic age. The main source area was again situated in the area west of the Post-Devonian Main Fault, and the conglomerates and pebbly sandstones were transported downslope by turbidity currents and related processes towards the east-southeast at a right angle to the faults. The system shows a crude fining-upward in the top part and is interpreted as a faulted slope apron. A thick succession of planar sandstone turbidites forming the new Vega Sund Formation is exposed 6 km east of the Manedal Fault. The age is highly uncertain. A Cenomanian age has been suggested previously but an Early-Middle Coniacian age is very tentatively preferred. Transport direction was again towards east-southeast at a right angle to the faults. The sheet-like bed geometry, lack of channeling and scouring, and gradual fining-upward of the top part suggest deposition on the outer part of a sand-rich basin floor fan. The four systems differ greatly in grain size, sorting, downslope transport processes, geometry and lateral extent. The transverse eastward transport directions and the clast provenances indicate, however, that the Cretaceous fault blocks were wider and not yet fragmented into the narrow present-day blocks. This interpretation contrasts with previous accounts which suggest that the Manedal and Bordbjerg Faults were active and exerted a profound control on sedimentation during Cretaceous time. It is, however, possible that an early expression of the Manedal Fault was formed in post-middle Albian time. The systems provide evidence for phases of possibly rift-related faulting accommodated by the old faults and associated footwall uplift and erosion in the earliest Middle Albian, and Late Turonian-Early Coniacian. The absence of Hauterivian and in part Barremian strata virtually throughout East Greenland may reflect marginal or probably regional uplift during an earlier fault event; the scarcity of Upper Aptian deposits and the presence of a Lower Cenomanian basal conglomerate may likewise reflect rifting and marginal uplift. The coarse-clastic deep-water deposits of the Traill O region were emplaced by a variety of sediment gravity flows and may serve as useful field analogs for the deeply buried correlative strata of the outer Norwegian Shelf. They illustrate the variability and complexity of the depositional systems, and allow identification of several significant Cretaceous possibly rift-associated fault pulses superimposed on the long-term regional subsidence governed by thermal contraction following the protracted Late Bajocian-Valanginian rift phase.

Ancient DNA extracted from Danish aurochs (Bos primigenius): Genetic diversity and preservation

We extracted DNA from 39 Danish aurochs specimens and successfully amplified and sequenced a 252 base pair long fragment of the multivariable region I of the mitochondrial control region from 11 specimens. The sequences from these specimens dated back to 9830-2865 14Cyr BP and represent the first study of genetic variation of Danish aurochs. In addition, for all specimens we address correlations between the ability to obtain DNA sequences and various parameters such as the age of the sample, the collagen content, the museum storage period, Danish geography and whether the specimens were found in an archeological or geological context. We find that aurochs from southern Scandinavia display a star-shaped population genetic structure, that is indicative of a local and relatively recent diversification from a few ancestral haplotypes that may have originated in the ancestral Western European population before migration northwards during the retreat of the glaciers. Scenarios suggesting several invasions of genetically distinct aurochs are not supported by these analyses. Rather, our results suggest that a single continuous migration northward occurred. Our findings also suggest, although with only limited support, that aurochs in Northwestern Europe underwent a population expansion beginning shortly after the retreat of the glacial ice from Denmark and had a stable population size until the population decline that must have occurred prior to extinction. The absence of haplotypes similar to modern domestic cattle in our aurochs suggests that introgression between these species must have been limited, if it occurred at all. We found that the successful recovery of genetic material for PCR amplification correlates with sample age and local geographic conditions. However, contrary to other studies, we found no significant correlation between length of time in museum storage or the type of the locality in which a specimen was discovered (archeological or geological) and amplification success. Finally, we found large variances in our estimates of collagen content preventing an evaluation of this as an indicator of preservation quality.