A Bizarre Idea

 

The Orkney Riddle

The Bizarre Idea

This is a view of the Pentland Firth from a settlement called Skarfskerry, on the North Coast of Caithness in Scotland.

The low headland across the water is a neighbouring piece of Scottish coast and beyond that, at the horizon left of view, and almost invisible, is Orkney, an archipelago that sits beyond the northernmost coast of the Scotland.

It is part of the Northern Isles group, and consists of more than 70, mostly low-lying, islands and islets of which only about 20 are inhabited.

Orkney is renowned as the home of a Unesco World Heritage site. The islands were occupied over 5000 years ago by Neolithic people who created a group of settlements and monuments of a complexity and quality not surviving anywhere else in Britain at such an early date.

The Pentland Firth here that separates Scotland from Orkney is a strait of water about 8 miles wide, and is famously dangerous.

The average speed of water running through the Firth can reach 4 nautical miles per hour, and also a peak speed, in places, of 12 nautical miles per hour.

Watching the waters of the Firth from the safety of a capable boat is disconcerting as there are treacherous whirlpools and glassy surfaces where it is hard to imagine what turbulence might be happening beneath the vessel.

Even today with modern craft, the unpredictable nature of the seaway can cause real problems for seafarers.

Skarfskerry, the village where the above photograph is taken from, is a straggling group of dwellings dotted along the North coast of Caithness.

Caithness, the northern most county in Mainland Scotland, is otherwise a bare, some would say barren, landscape.

Here there are very few people, towns are small, and “Civilisation” is miles away.

In prehistory there is little evidence of any greater density of Neolithic population in Caithness than elsewhere in Britain, yet people are thought to have looked across to Orkney in the early years of the spread of farming practices, and decided to make boats and cross the Pentland Firth to establish communities there.

When these people arrived in Orkney they built settlements where they are thought to have farmed domestic animals, including pigs, cattle, and sheep.

Some of these animals are thought to have been domesticated locally, but others, like sheep would have been brought in to Britain by migrants from Europe.

Neither is Orkney the only offshore island that has hosted Neolithic populations around the British coast.

Known sites of occupation are found in Shetland, the Outer Hebrides, Ireland, the Isle of Man, and the Scilly Isles.

These, and Britain itself, are all places that are presently understood to have been accessed, between themselves and from Europe, by waterborne vessels in early prehistoric times.

The date at which this journeying is calculated to have happened is around 4000BC, a period known as the Early Neolithic, in Britain.

In the absence of actual evidence it is difficult to see how the import of domestic animals across a substantial waterway, like the Pentland Firth or the English Channel, was accomplished, and practicalities are often not discussed.

One of the earliest boats found in Britain is a Neolithic log boat which can be seen sitting in the sand of Grey Abbey Bay in Strangford Lough, Ireland. It is made of oak heartwood, measures 9.1m long by at most 0.89m wide, and would probably carry up to 5 people. A sample of the wood was radiocarbon dated to after 3499BC. (Nationaltrust.org.uk)

Such vessels were clearly being developed in Neolithic times, at least for enclosed areas of water, or for riding, and crossing rivers.

The possibility that a boat like this could cross a piece of water as violent as the Pentland Firth seems unlikely, and the shipping of livestock in it is even more doubtful.

Even now, Orkney is on the edge. It takes a degree of raw determination (and heating) to survive here. High winds and horizontal rain are normal weather conditions for an Orkney winter.

In spite of this, people are thought to have come here, with livestock, on boats, and settled.

*

I could never quite believe that Neolithic people came to Orkney by boat.

As it is thought that they brought cattle and sheep with them, I could not envisage any animal, or any human, surviving a sea crossing of any British tidal waters in any prehistoric vessel.

Standard sources tie themselves in knots to persuade us that Neolithic people had boats that could carry beasts of both sexes that, once landed, would reproduce and help their tribe to survive on the unknown territory across the dangerous waters.

However, evidence has recently emerged that added another dimension to the problem. It was discovered that the Orkney Vole, a species that is unique to the archipelago, had been found by DNA analysis, to originate from northern Europe, and that it was not directly related to the common vole in Britain.

“Much debate surrounds the origins of the Orkney Vole Microtus arvalis orcadensis (Yalden 1999; Corbet 1961). It is the only vole on Orkney and is found on eight islands, while in mainland Britain the field vole (M. Agrestis) is the only Microtus species.

M. Arvalis and M. Agrestis occur widely across continental Europe with overlapping distributions (Mitchell-Jones et al 2003). It is therefore clear that M. Arvalis did not colonise Orkney naturally (Haynes et al 2003; Haynes et al 2004), and although modern consensus supports a human introduction during the Neolithic (Hedges et al 1987), their geographic origin and mechanisms of introduction still remain uncertain. “ (Thomas Cucchi et al)

This meant that the animal that arrived in Orkney did not pass through England, Wales or Scotland.

I tried to imagine a boat leaving Ostend with a Vole somehow stowed away on board, with a prehistoric crew paddling, or sailing, to Kent and stopping there overnight at Dover. They would struggle to travel at night, I thought, and would need to rest, and sleep, as well as hunt for food, and find water. If they had a vole on board they would also have to feed it, and restrain it from escape. They would then set off again up the east coast of England stopping off at Lowestoft to sleep the night in a hastily erected tent, and then take off again at first light in the morning.

I was exhausted just thinking about it.

A vole arriving in Orkney, from Europe, without passing through Britain was a clue that all was not as it seems, and that in spite of the insistence of some that voles may have been carried as pets or food items, another possibility was probably more likely.

I therefore rather assumed that it must be necessary to question what places were passable around the coasts of Neolithic Britain, which areas were land, and which places were water, and when did land areas stop being land.

It is understood that much of the southern North Sea area was land at some point in the past. A piece of shallow sea called Dogger Bank has been named Doggerland as artefacts of 8000 years of age, and older, are frequently dredged up there. The rise in sea level which has occurred since the last ice age has clearly flooded lands here, but which lands, where, and when?

The obvious location, or so I thought, for a route to Orkney from Europe , that would be passable for people, cattle, sheep, and small rodents, on foot, and avoiding England and Scotland, would be somewhere in the middle of the North Sea which, of course, is a bizarre idea.

Indeed, it was such a bizarre idea that I followed it, to see where it took me.

Surely it shouldn’t be too difficult to prove that there was a piece of land, not attached to Britain that joined Dogger Bank to Orkney, in spite of the fact that the area now has seabed at over a 100 metres deep.

It would only take an understanding of the geology of Britain and the North Sea, knowledge of successive glaciations, study of the habits of ice, channel erosion, various dating techniques, and a close inspection of the archaeology of Orkney.

Not so much really, I’m surprised it took so long!

When I started to envisage this idea, that was all it was, an idea. I had nothing but the notion that somehow Doggerland, down in the southern part of the North Sea had once extended northwards to Shetland and Orkney without touching Britain.

I read everything I could find to understand who was where, and when, in prehistoric Britain, and the weight of opinion had it that waves of people came in boats and traded, or brought goods from western France to the western coasts of Neolithic Great Britain. These people bought domesticated animals and the skills to make pottery with them in boats, and every time I suggested in any context that a cow, or a sheep in a boat was not a realistic possibility for Neolithic people I was thoroughly shouted down.

Nobody has found a Neolithic boat that would have crossed the English Channel or the Pentland Firth, but for some people, the existence of such a vessel is an article of faith.

To understand how land was passable, at least by rodents, in the middle of the North Sea, a magical mystery tour had to be taken, beginning in the last ice age.

 Since writing this further research has found that, in fact, the European Vole has actually landed on English soil, as noted in "The Orkney Vole".

All views and opinions expressed are my own, but it remains a work-in-progress for which positive criticism and comment is welcomed.

Jeffery Nicholls 

South Ronaldsay 

Orkney 

The Orkney Riddle (index here)  is a series of blogs promoting the notion that Neolithic people walked from Scotland to Orkney to build the Ring of Brodgar. 

#Orkney #archaeology #Neolithic #prehistory #British #SkaraBrae #NessofBrodgar #BIIS ##Britice-Chrono 

The Orkney Vole

Orkney Riddle

The Orkney Vole

"Orkney vole 

Microtus arvalis orcadensis

The Orkney vole is a sub-species of the common vole and unique to the Orkney Islands. It is larger and heavier than the common vole. It is bigger than a mouse, with a rounded head and a relatively short tail.

Behaviour

Orkney voles do not hibernate. The vole is the islands’ only rodent to be active during the day and is an important food source for hen harriers and short-eared owls. The diet of the Orkney vole consists largely of plant materials, seeds and cereal crops. Females can have several litters a year, each with 3-6 young. The young are fed by the mother for about 20 days, when they then switch from milk to normal feeding.

Size

Length: 9 – 12cm (tail length approximately one third of body length)

Average weight: 30g; up to 90g

Lifespan: 18 months

Status

Although once common, it is thought that the Orkney vole population has declined substantially over the past 50 years. This is linked to changes in agriculture, with the drainage of rough grassland and conversion to improved grasslands for livestock. More recently, their lives are threatened by stoats, which were first sighted in Orkney in 2010.

Distribution

Orkney voles are present on eight of the Orkney Islands. Formerly widespread, even in agricultural crops, Orkney voles are today confined to semi-natural habitats with maximum densities occurring in old peat cuttings and rough grassland.

When to see

January to December. It is active throughout the year, but is not so apparent in winter when it spends more time underground.

Facts

The Orkney vole has an enigmatic history. Its closest relative is the common vole which is found throughout Europe, but intriguingly not on the UK mainland or Ireland. Following numerous studies and theories, it required cutting edge DNA techniques to throw a definitive light on its origin. The most recent analysis of nuclear DNA suggests the closest match is with an archaeological specimen in Belgium.

The vole’s mode of arrival to Orkney is hotly debated. Genetic research has revealed that there is a large genetic diversity in both modern and ancient Orkney voles. This suggests that they arrived with humans, (deliberately or as unintended stowaways) around the Neolithic period when the first farmers settled on Orkney. Copious vole remains have been found in excavations of tombs and houses from that time.

The oldest known radiocarbon-dated fossil of the species in Orkney is 4,600 years old.

Locally, Orkney voles are also known as volo, cutticks, or cutoo." (Scottish Wildlife Trust)


"Much debate surrounds the origins of the Orkney vole Microtus arvalis orcadensis (Yalden 1999; Corbet 1961). It is the only vole on Orkney and is found on eight islands, while in mainland Britain the field vole (M. agrestis) is the only Microtus species. M. arvalis and M. agrestis occur widely across continental Europe with overlapping distributions (Mitchell-Jones et al 2003). It is therefore clear that M. arvalis did not colonise Orkney naturally (Haynes et al 2003; Haynes et al 2004), and although modern consensus supports a human introduction during the Neolithic (Hedges et al 1987), their geographic origin and mechanisms of introduction still remain uncertain."(Thomas Cucchi et al) 
 

THE CHANGING PACE OF INSULAR LIFE: 5000 YEARS OF MICROEVOLUTION IN THE ORKNEY VOLE (MICROTUS ARVALIS ORCADENSIS) by Thomas Cucchi et al

"In this article, our objective is to examine morphological change through time in populations of the Orkney vole, Microtus arvalis orcadensis (Major 1905)—an endemic subspecies of the common vole Microtus arvalis (Pallas 1778)—introduced to the Orkney archipelago (Fig. 1) by Neolithic farmers around 5000 years ago, from a source outside the British Isles (Martínková et al. 2013). (See below)

Large samples of archaeological Orkney voles, as well as good palaeo-environmental records revealing anthropization of the Orkney archipelago (Bunting 1994, 1996), provided an important opportunity to investigate the pace of evolutionary change in this insular rodent over the last 5000 years, within the context of an island environment impacted by humans. Orkney voles have evolved their own particular dental phenotype, likely the result of human agency influencing its evolutionary trajectory in different ways over the last 5000 years. This human influence began with its Neolithic introduction to the Orkney Mainland at a time when there were no terrestrial predators and only one competing species (the wood mouse). The Orkney vole population rapidly diverged from continental European M. arvalis to reach a new ecological optimum, that included evolutionary changes in morphology of the molar teeth. Neolithic farmers then dispersed the species to other islands of the archipelago—from Mainland to Westray and during the Bronze Age to Sanday—generating several founding events contributing to idiosyncratic differences in dental characteristics. This initial divergence and diversification in Orkney voles was not followed by morphological stasis because the Orkney environment was subjected to continued human disturbance.

The case of the Orkney vole presented here demonstrates how, from Neolithic times, humans have played a major role in species evolution and suggests that anthropogenic modifications of the environment may have repeatedly disturbed the phenotypic evolutionary stasis of insular species. Given the continental-scale and increasing intensity of human-induced impact on ecosystems in the last centuries, such changes in the evolutionary trajectories of vertebrates are likely not restricted to insular systems."

Divergent evolutionary processes associated with colonization of offshore islands, Natalia Martinkova, et al

"Colonization history of Orkney voles.

It is striking that there is substantial cytb variation in M. arvalis in Mainland Orkney and over the whole archipelago (Fig. 3, Table 3). Island populations often show low genetic diversity (Frankham 1997). This can relate to small population sizes and/or population bottlenecks associated with colonization of islands, particularly by sweepstake dispersal or human introduction. The high cytb diversity could indicate that the Orkney population of M. arvalis represents an island relict of a previously continuous mainland population, perhaps dating back to before the LGM (Beirne 1952). This would fit with the long tMRCA for the molecular variation on Orkney, potentially dating back to 25 400 BP (within the 95% CI). However, there are strong arguments against glacial survival of the Orkney vole population. First, the IMa analysis based on microsatellites and cytb and the ABC analysis based on microsatellites provide a date of arrival around 5000 BP, considerably more recent than the LGM. Second, all the other species of small mammals on Orkney are most reasonably viewed as human introductions (Yalden 1982), necessitating a special case for M. arvalis as a glacial survivor. Third, it is very difficult to make this special case given that M. arvalis is not a species currently associated with arctic or even moderately high latitude conditions. Its range extends eastward beyond Lake Baikal and yet barely traverses north of the 60th parallel (Fig. 2; Shenbrot & Krasnov2005). Orkney was under or near a glacial ice sheet at the LGM (Bowen et al. 2002) and M. arvalis is not part of the fossil fauna known from Britain from the last glacial period (Yalden 1999; Currant & Jacobi 2001). Fourth, M. arvalis is not currently found in Britain(Fig. 2). It is therefore contrary to think that M. arvalis should be a glacial relict on Orkney rather than M. agrestis, when the latter occurs further north in Eurasia (beyond the 70th parallel) and is distributed throughout Britain, including on many offshore islands, while M. arvalis only occurs on Orkney. There have been no land connections between mainland Britain and Orkney after conditions ameliorated following the LGM (Yalden 1982), and hence why M. agrestis (and other wide-ranging small mammals in Britain, such as common shrews Sorex araneus and bank voles Myodes glareolus) failed to colonize Orkney. If M. arvalis did not survive on Orkney itself during the last glacial period, the absence of the species in Britain means there are no grounds to suggest sweepstake colonization from there. It is conceivable that there could have been sweepstake colonization of Orkney from Doggerland, the landmass connecting Britain, the Low Countries and Denmarkuntil about 8000 BP (Weninger et al. 2008) – but this would require the survival of small mammals on floating mats of vegetation over a substantial marine gap between Doggerland and Orkney. Thus, human introduction is by far the most likely explanation for the occurrence of M. arvalis on Orkney.

From the IMa and ABC dates, this introduction at about 5000 BP fits well with the earliest radiocarbon dates for archaeological M. arvalis from Neolithic contexts (5100 years old: Table 2) and the beginnings of the Neolithic culture on Orkney (5600 BP: Ritchie 2001; Schulting et al. 2010). Voles could have been brought to Orkney by Mesolithic hunter-gatherers, as early as c. 9000 BP, but no vole remains have been found in the one excavated Mesolithic site on Orkney (Lee & Woodward2009), in contrast to their abundance at Neolithic and later sites (Yalden 1999; Thaw et al. 2004). If, as appears most likely, the voles were introducedby Neolithic settlers about 5000 BP, various other implications flow from our molecular data, which are of considerable archaeological interest. First, the introduction implies long-distance maritime travel by Neolithic people between continental Europe and Orkney, extending on findings from elsewhere (e.g.Broodbank 2006). Our study highlights the Belgian coastline as the most reasonable source of the Orkney voles on the basis of available genetic data. This suggests Neolithic cultural linkages between Belgium and Orkney, of worthwhile focus for future archaeological investigation. Microtus arvalis were not introduced successfully into mainland Britain, which is consistent with relatively direct transport to Orkney from the continental source area. Second, if the introduction occurred about 5000 BP, then, because the tMRCA for the Orkney voles is so long (15 400 years), substantial numbers of femalevoles must have been introduced to explain the cytbvariation observed in modern and archaeological Orkney voles. High genetic diversity is already evident in the 16 aDNA sequences dating to 4200 BP or earlier, separated by up to 10 mutations (Fig. 3 and Table S3,Supporting information) and which produce an estimate for the tMRCA (14 780 years; 95% CI of 4681–36 379 years) similar to that of the full ancient and modern data set. To explain a substantial number of voles arriving accidentally on Orkney implies transport of plentiful grass livestock bedding/fodder in which the vole stowaways could have survived. This in turn may suggest the direct movement of livestock as part of the proposed Neolithic linkage between Belgium and Orkney. Alternatively, deliberate transport of voles onto Orkney could explain the large numbers introduced (Thaw et al. 2004). It is conceivable that voles were taken as food items, pets or for cultural/religious purposes – M. arvalis is docile in captivity (Berry 2000), so could theoretically have been ‘tamed’. This suggestion of deliberate transportation of small rodents has a precedent: it has been argued that Pacific rats (Rattusexulans), now present on islands throughout Oceania, were intentionally conveyed by Polynesians as a foodsource (Matisoo-Smith & Robins 2004). Evolutionary processes affecting voles on Orkney and the continental source area Compared with continental European M. arvalis, those on Orkney and another offshore island (Guernsey) are divergent in terms of tooth morphology, including increased tooth size. For Orkney, this divergence may have occurred over c. 5000 years, if introduced during the Neolithic. In addition to having larger teeth, the Orkney and Guernsey M. arvalis have a larger body size than continental voles (Gorman & Reynolds 2008). Quick-evolving rodent gigantism has been described previously on islands of the northeast Atlantic (Corbet1961; Angerbjorn 1986), but not within such a precisely defined time frame. A range of selective factors have been proposed to explain this gigantism, including an absence of small mammalian predators (Lomolino1985), and a genetic basis for gigantism has been identified in island house mice (Chan et al. 2012). Elsewhere,we further explore the dynamics of morphological evolution for the Orkney M. arvalis using archaeological specimens (T. Cucchi, R. Barnett, N. Martınkova, et al.submitted) extending substantially on previous studies (Berry & Rose 1975; Corbet 1986). Despite their similarity in large tooth and body size,Guernsey and Orkney voles exhibit distinctive mtDNA haplotypes (Fig. 3). It is therefore most reasonable to consider that the Guernsey and Orkney voles attained their large body size independently. It is not clear whetherGuernsey was colonized naturally before it became an island, as part of the continental European late glacial/postglacial species expansion (Haynes et al. 2003; Heckelet al. 2005; Tougard et al. 2008), or whether the voles were introduced by people after it became an island (Gorman& Reynolds 2008). However, given that Guernsey voles are likely to come from the same general (northernFrance/Belgium) source area as the Orkney voles and that they are also different in mtDNA from current northern France/Belgium populations, there would be much interest in further detailed comparison of Orkney, Guernsey and northern France/Belgium voles. In addition to the operation of selection in the evolution of Orkney voles suggested by morphology, stochastic processes appear to have been important based on microsatellites. The population on the largest island, Mainland Orkney, has retained much of the microsatellite variation found in continental Europe, while all theother Orkney Islands (which are considerably smaller:Fig. 1) show very low levels of microsatellite variation,consistent with founder events and genetic drift. Similar stochastic processes can also explain microsatellite variation among Scottish Island populations of common shrew (White & Searle 2007a). Our findings with regard to morphology and microsatellites in M. arvalis are unsurprising in comparison with previous studies on island small mammals, but the results from our mtDNA analyses are more unexpected. Although the cytb sequences from Orkney andthe proposed source area for the Orkney colonization both belong to the Western-North lineage of M. arvalis, the sequences are remarkably divergent given the timeframe for colonization. Also, it might have been expected that (as for the microsatellites) variability would have been lower on Orkney than in continental Europe. In fact, the opposite is the case. Taking either the principal island (Mainland Orkney) or the whole archipelago, mtDNA diversity is higher in Orkney than in coastal France/Belgium (Table 3). Our dating analysis also shows that the mtDNA sequences in coastalFrance/Belgium have a much more recent derivation than the Orkney sequences. So, here we are seeing another facet of evolution in association with the colonization of offshore islands, in this case occurring in the mainland population. Thepresence of derived sequences in coastal France/Belgium suggests a replacement event in M. arvalis, with one mtDNA type (the current type) replacing another(the Orkney type), similar to aDNA findings in other species (Barnes et al. 2002; Pergams et al. 2003; Hofreiteret al. 2007). The fact that there is an affiliation between coastal Belgium and Orkney on the basis of microsatellite genotypes argues against a complete population replacement (e.g. by extinction–recolonization) as an explanation for the mtDNA result. Instead, within-population processes of selective sweeps or genetic drift are implicated, and more likely expressed in the mtDNA data, as a single locus with small effective population size than in the microsatellite data. We cannot be surewhat environmental factors promoted the replacement. There could, for instance, have been a local, unrecorded disease outbreak. However, it is notable that the replacement occurred over a period when M. arvalis populations would have changed dramatically due to human land-use change, and this appears the most likely driver of the replacement. Over several thousand years, sustained forest clearance in continental Europe (Rackham 1998; Cyprien et al. 2004) created new agricultural habitats and associated selection pressures that essentially expanded the opportunities for M. arvalis as a species that particularly exploits managed grassland(Niethammer & Krapp 1982). In such a habitat, M. arvalis populations can undergo massive population expansions and crashes (Delattre et al. 1992) that reduce longterm effective population size, promoting genetic change through drift. On Orkney (which saw the rapid decline of low shrubs and tree species with the arrival of Neolithic farmers: Bunting 1996), M. arvalis utilizes a range of open habitats and does not show the same dramatic population fluctuations as seen in parts of continental Europe (Gorman & Reynolds 2008). 

Offshore islands as field laboratories 

There has been a tendency to view offshore island populations of small mammals (and other organisms with low density and low dispersal) as genetic deviants fromthe ‘norm’. This is because studies of various species have shown results similar to ours for morphology(substantial change) and microsatellites (loss of variation) (Lomolino 1985; Frankham 1997; Boessenkool et al.2007; Millien 2011). These have included detailed studies on small mammals such as wood mouse Apodemussylvaticus (Angerbjorn 1986; Michaux et al. 1996),masked shrew Sorex cinereus (Stewart & Baker 1992)and common shrew (White & Searle 2007a,b, 2008).However, as we have demonstrated with our M. arvalis mtDNA studies, island populations can also represent genetic ‘arks’, retaining the ancestral genetic variation,while evolutionary and other processes on the mainland may lead to a loss of that ancestral variation. Islands may have importance therefore in conservation of genetic variation. A further example involving human introduction of a small mammal onto an offshore island is provided by the Eurasian red squirrel Sciurus vulgaris. Thus, Irish red squirrels have genetic variants that apparently derive by introduction from Britain, but these are now absent in that source population (Finnegan et al. 2008; Searle 2008). For low density and low dispersal organisms such as small mammals, we suggest that genetic surveys of mainland areas should, where available, include populations from neighbouring offshore islands. It is very likely that those island populations will provide a new perspective on the temporal and spatial dynamics of the genetic variation in that region.The ‘ark’ concept that we discuss here is of course more general. Populations colonizing new areas will take the genetic and nongenetic characteristics of the source population, and some of those characteristics may subsequently be lost in the source population but retained in the population in the new area. In this way, for instance,the United States is a ‘linguistic ark’ for various English words that would have been common in the British Isles at the time of settlement of North America by the British, but which have subsequently fallen into disuse in the homeland (e.g. ‘fall’ meaning ‘autumn’). Returning to genetic characteristics of offshore islands, in addition to their potential as genetic ‘arks’, they also hold potential as field laboratories to study genetic change in the islands themselves. Compared with the classic evolutionary studies on oceanic islands, those based on offshore islands will tend to view events over shorter timescales and thus provide a different perspective on evolutionary processes. Offshore islands are particularly valuable for studying initial stages of diversification, with the opportunity (as in the current study together with T. Cucchi, R. Barnett, N. Martınkova,et al. submitted) to follow island populations from their foundation to the present day using advanced genetic and morphometric tools as applied to modern and ancient populations of different ages. Extremely accurate dating of ancient populations may be possible (e.g. in archaeological settings). With this short time duration and close proximity to the mainland, there is also a greater chance to find the precise source area for the island colonization, which allows interesting comparison of evolutionary processes on the mainland and island. This brings us back to the value of offshore island populations in interpreting mainland processes. Offshore islands are an underutilized resource for evolutionary analysis, with great potential. In some ways, they represent study systems intermediate between those in a continental setting and those on oceanic islands; they have the simplicity of the oceanic island system yet are clearly relevant to continental situations."

Recent research suggests that s population of European Vole origin survived in south-west england during the final deglaciation of Britain, about 11,000BP,. The report on this research is entitled "Diverse responses of common vole (Microtus arvalis) populations to Late Glacial and Early Holocene climate changes e Evidence from ancient DNA" by Mateusz Baca et al

"Two radiocarbon dated specimens from Trou Al’Wesse (Belgium) yielded a pre-LGM age, 30,000BP to 28000BP. They belonged to the Western/Northern lineage although they diverged earlier than the coalescence of the extant populations. This suggests that population continuity existed in the region throughout the last 30 ka rather than there being a turnover, even if the population decreased in numbers as a result of the LGM. Although the genetic evidence is still very limited this is concordant with the cryptic northern refugium hypothesis (Stewart and Lister, 2001). The other interesting case is the single specimen from Bridged Pot cave dated to the Early Holocene. At present there are no common voles in the British Isles with the exception of the Orkney Isles, where they have been introduced by humans ca. 5000 years ago (Martínkova et al., 2013
). Microtus arvalis has not been considered to be part of the British fauna of the Last Glacial and only the field vole has been identified in the fossil record (Coard and Chamberlain, 1999; Currant and Jacobi, 2001) although there are problems distinguishing these two species based on dental characters (Navarro et al., 2018).

Recently, a number of common vole remains were identified using collagen fingerprinting from Pin Hole cave (Creswell Crags, UK) (Buckley et al., 2018). Although the deposits Pin Hole have been shown to be mixed (Stewart and Jacobi, 2015), this suggests that the common vole was present in the British Isles during the Late Pleistocene and/or early Holocene. The phylogenetic position of the individual from Bridged Pot cave suggests that it was a part of the continuous population of mainland Europe. Given the age of the specimen, 11,000BP, possible scenario explaining its presence in the British Isles may be that the common vole may have expanded to Britain during the Late Glacial warming and their local extinction was then caused by either YD cooling or the Holocene reforestation. The disappearance of the connection between the British Isles and continental Europe during the Early Holocene may have prevented the species’ subsequent recolonization. In other small mammals inhabiting Britain today such as the field vole, bank vole (Clethrionomys glareolus), water vole (Arvicola amphibius) and pygmy shrew (Sorex minutus) the populations of these taxa, which colonized Britain during Late Glacial, retreated to fringes of the island possibly as a result of YD cooling (Brace et al., 2016; Searle et al., 2009). Subsequent populations of all these species were able to recolonize Britain at the onset of the Holocene. This was not the case for the common vole. Recently Martínkova et al. (2013)
showed that recolonization of the northern areas of France and Belgium by the common vole was relatively late and started not earlier than 2000 years ago, long after the disappearance of land connecting the British Isles and mainland Europe"

Radiocarbon dating of vole at Bridget Pot Cave , UGAMS 43,314 MI1371 11,125BP

   

Fig. 2. Distribution of mtDNA diversity of common vole in Europe. 

A modern, 

B Holocene, 

C post-LGM.

Colour correspond to mtDNA lineages 

pink, Eastern;

yellow, Central; 

orange, Italian; 

green, Western-North; 

violet, Western-South; 

navy blue, Balkan. 

*

All views and opinions expressed are my own, but it remains a work-in-progress for which positive criticism and comment is welcomed.

Jeffery Nicholls 

South Ronaldsay 

Orkney 

The Orkney Riddle (index here) is a series of blogs promoting the notion that Neolithic people walked from Scotland to Orkney to build the Ring of Brodgar. 

#Orkney #archaeology #Neolithic #prehistory #British #SkaraBrae #NessofBrodgar #BIIS ##Britice-Chrono 

The Ness of Brodgar Excavation

Orkney Riddle

The Ness of Brodgar Excavation 

Trench P, which includes Structure 10

While, in recent times, the stone circles of Stenness and Brodgar were a present reminder of times past for Orkney folk, Barnhouse was unknown, and completely hidden from view. So also was the Ness of Brodgar, which is now one of the most exciting archaeology projects to explore Neolithic Britain, in recent years.

It is directed by Nick Card, and is best described by him, as follows.

“The Ness of Brodgar (Fig. 49) sits on the south eastern tip of the Brodgar isthmus separating the Loch of Harray to the east, and the Loch of Stenness to the west, at the centre of the large natural bowl of hills of the West Mainland of Orkney. From it the Ring of Brodgar (0.75 km to the NW), the Stones of Stenness (0.5 km to the SE) and Maeshowe (1.5 km to the E) are clearly visible. On the south side of the Bridge of Brodgar, barely 300 m distant, is the Neolithic settlement of Barnhouse (Richards, 2005).

Ness of Brodgar, aerial view

Between 2004 and 2008 trial trenching to investigate the nature of the mound and the threat from agricultural practices gave indications that this massive mound (c. 250 m by 100 m, lying NW–SE, and over 4 M high), previously considered a natural feature of the landscape, was mainly artificial and consisted of a sequence of Neolithic buildings, middens and midden-enhanced soils. Since 2008, area excavation (though still less than 10% of site) has been carried out (Fig. 50). This has revealed a complex sequence of monumental buildings contained within a massive walled enclosure. In it’s latter phases the site is dominated by several large buildings which, judging by their scale and architectural finesse, would appear to be outside the norm for the domestic sphere. This is also reflected in the artefactual assemblage and over 700 examples of decorated stone (Card & Thomas, 2012).

Due to the depth and complexity of the stratigraphy, and the exceptional preservation of the architecture, only the later phases of the site have so far been investigated in detail.

Other activity pre-dating the construction of the large piered buildings is represented by several lengths of walling revealed between, under, and in some cases incorporated into, the buildings presently under investigation. Other earlier buildings are also implied by the subsidence, collapse and the undulating nature of wall lines of later buildings. These earlier buildings where revealed utilise orthostats partially built into wall lines to define internal space similar to stalled tombs and early Neolithic houses. It is presumed that the surrounding walled enclosure is first constructed during these earlier phases.

In the later phases, orthostats are replaced by the use of opposed stone-built piers to create recesses along internal wall faces as in Structures 1, 8, 12, 14 and 21, each of which saw several phases of reuse and remodelling. These buildings (which are the present focus of excavation) can be seen as exaggerated or elongated versions of Neolithic houses of the kind seen, for instance, in the early phase of Skara Brae (Clarke, 1976). A paved area with a standing stone is central to the whole of the walled enclosure at this stage.

The last major construction so far identified, Structure 10 (Fig. 4), is a departure in style and scale from earlier building styles. It partially overlies the collapsed remains of the piered Structure 8. Its internal square chamber with rounded corners bears close comparison with Structure 8 at Barnhouse (Richards, 2005), as does its scale (some 20 by 19 m externally), which mirrors a general trend to monumentality in the Late Neolithic of Orkney. As with the piered structures at the Ness which mirror other house plans but on an exaggerated scale, so too does Structure 10 reflect later house styles, such as House 1 at Skara Brae (Clarke, 1976). Although the foundations of Structure 10 show the overall monumentality of its build, as with the majority of other late structures at the Ness it suffered from subsidence. That may have been the cause of the collapse of its SW corner. It was rebuilt with extensive remodelling of the interior into a cruciform plan with the addition of new wall faces and corner buttressing.

At the end of these monumental phases, the buildings at the Ness were partly demolished and suffocated with layers of midden and rubble. The placing of a structured deposit of mainly cattle bone around Structure 10 has been seen as part of this decommissioning process (Mainland et Al., 2014). This has been suggested as ‘a single depositional event’ or ‘at the least a series of events occurring over a fairly short period of time’ (Mainland et al., 2014: 875). Later, some of the walls of the structures were systematically robbed of stone. Ephemeral activity continued, but on a much reduced scale.

The exceptional architecture, the diversity of structures, and the evident size and spatial complexity of the Ness of Brodgar all emphasise its special character. “(Card)

Jeffery Nicholls 

South Ronaldsay 

Orkney 

The Orkney Riddle (index here) is a series of blogs promoting the notion that Neolithic people walked from Scotland to Orkney to build the Ring of Brodgar. 

#Orkney #archaeology #Neolithic #prehistory #British #SkaraBrae #NessofBrodgar #BIIS ##Britice-Chrono 

Modern Sweat Lodge Practices

 

Orkney Riddle

Modern Sweat Lodge Practices

At Barnhouse,  Structure 8 has good evidence that it was built to function as a sweat Lodge. There may be as many as three other sweat lodges on the Orkney Archipelago. 

Sweat Lodges in present cultures may help us to understand better the culture of Neolithic people in Orkney. 

“Sweat lodges are heated dome-shaped structures used by Indigenous peoples during certain purification rites and as a way to promote healthy living. The intense heat generated — often by steam created from pouring water onto heated rocks — is meant to encourage a sweating out of toxins and negative energy that create disorder and imbalance in life. In this way, the sweat lodge ceremony cleanses the body, mind and soul.

Each sweat lodge is slightly different, depending on the community or person who operates it, and the purpose for which it is used. For example, some sweat lodge ceremonies are restricted to men, women, children or members of certain clans; at other times, the lodge is open to all. There are also sweats specific to fasting rituals, or in celebration of the Sun Dance and other cultural traditions.

Despite these differences, there are important commonalities among sweat lodge ceremonies. Most importantly, the sweat lodge is a sacred place, likened to the womb of Mother Earth. Sweats are therefore deeply spiritual and cultural experiences for many people. For this reason, sweat lodges are run by special operators — sometimes called keepers, and oftentimes an elder or healer — who are well versed in traditional healing and sweat lodge practices. The operator knows how to conduct sweats safely and effectively, and for various purposes. The great majority of conductors do not charge a fee to participate in the sweat lodge, although it is customary to offer them cloth or tobacco for their services. The purpose of the sweat lodge is not to generate revenue, but to heal and cleanse. Elders strongly caution against those who disguise themselves as healers, but are not trained in the sacred teachings. Non-traditional sweats can be dangerous. On 8 October 2009, for example, three sweat lodge participants died at a New Age “Spiritual Warrior” retreat near Sedona, Arizona.

Historically, there were two sweating techniques reflected in lodge construction. Indigenous peoples in Alaska, California and parts of Central America used a system of direct exposure to fire within the confines of a small, often semi-subterranean (partially underground) structure. The more common system, used by most Indigenous peoples in Canada, was to heat stones in a fire, place them inside a small, domed structure draped with buffalo or deer hides, and pour water on them to produce steam. Direct fire sweathouses doubled as men’s houses, but steam lodges were often used by a single person.

Today, sweat lodges heated by the steam of hot rocks are the most common. The majority of modern structures are made out of wood, covered with tarps and blankets. Tobacco is usually placed somewhere underneath the structure’s base. Altars and the sacred place where the heated rocks are kept before the ceremony are kept outside the structure. The direction of the lodge’s doorway often faces east, but this differs depending on the conductor; some teachings indicate that the doorway should face another direction or that its direction should change throughout the year. 

Conductors will indicate how to best prepare for a sweat. Usually, participants will be told to abstain from alcohol and drugs beforehand. After making an offering to the conductor, participants also make offerings to the altar outside the lodge, and to the Grandmothers and Grandfathers — the heated rocks — before entering the sweat lodge. The fire keeper is in charge of heating the rocks and placing them inside the fire pit in the centre of the lodge. Other items are also placed inside the lodge, such as water (used to pour onto the rocks, thereby creating steam), tobacco (a sacred offering), medicines (certain herbs), and musical shakers and drums (used during prayers).

Once inside, participants sit in a circle around the fire pit for a length of time determined by the conductor and depending on the purpose of the sweat; often, this is a few hours. The fire keeper closes the door before the ceremony begins. Music is played and prayers are recited throughout the ceremony, inviting healing spirits into the lodge. In turn, participants are asked to talk about themselves and their reasons for using the lodge — this is their opportunity to speak to the Creator, to share their personal stories and to meditate on life. At the end of the ceremony, the conductor says prayers to thank the Creator and spirits. Elders might also smoke sacred pipes at this point. The fire keeper then opens the door to the lodge.”

René R. Gadacz in the Canadian Encyclopedia  

“In one form or another, the sweat bath has been practiced in many Native North American Tribes, from the Inuit in the north, to the Navajo in the Midwest, the Sioux/Lakota/Cree in the plains, the Mickmaq in the East and all the way down south into the land of the Mayans (Bruchac). This sacred religious/healing ceremony has been in practice for thousands of years. The purpose usually went far beyond cleaning the body. The sweat bath (Sweat lodge) provided a cure for illness, revitalization for aching muscles, and a sense of identity for Natives participating in and reclaiming their culture. It heals the mind, the body, the emotions and the soul. Finally the Sweat lodge is a holy place where we can connect and communicate with Creator (God), the Spirit Helpers (comparable to the angels and others depending on your spiritual or religious practices) and our ancestors (our grandmothers and grandfathers and all the generations who came before us).

The Sweat lodge is used as a place of teaching, planning, praying, singing, and communing with others. Furthermore, a sweat is often performed in preparation for other rites, and as a means of returning to the non-ritual world after the completion of other holy ceremonies such as the Sun Dance, the Ghost Dance or the Winter Dance ceremonies. “ 

(The author continues, describing in detail the building of the Sweat Lodge and the process and management of the ceremonies) 

The Eagle Spirit Society

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All views and opinions expressed are my own, but it remains a work-in-progress for which positive criticism and comment is welcomed.

Jeffery Nicholls 

South Ronaldsay 

Orkney 

The Orkney Riddle (index here) is a series of blogs promoting the notion that Neolithic people walked from Scotland to Orkney to build the Ring of Brodgar. 

#Orkney #archaeology #Neolithic #prehistory #British #SkaraBrae #NessofBrodgar #BIIS ##Britice-Chrono 

Barnhouse Sweat Lodge

Orkney Riddle

The Barnhouse Sweat Lodge

Structure 8

Some time after the initial establishment of the Barnhouse Settlement, this building was added, Structure 8.

The inner part of Structure 8, the near-square building, is surrounded by a clay platform within the circular surrounding wall.  

Stone hearths, boxes, pits, and spreads of ash suggest that the outer clay platform around the outside of the square building was used for a range of activities, that might have included cooking and food preparation

Barnhouse, Structure 8, plan

 

Barnhouse, Structure 8, entrance

The above photograph shows the entrance into Structure 8 with a fire hearth in the foreground, and what may or may not be a second hearth in the middle of the room beyond. 

The stonework has been designed to survive Orkney weather, but it does not accurately depict the design of the building that Neolithic people built. 

The above image shows a plan of the entrance to the structure, as it was excavated. At the middle of the entrance feature is a lobby which links the sweat lodge interior to hearth in which stones are heated for the sweat lodge ceremony. On either side of the lobby are entrances into the lobby, and threrby into the sweat lodge room.

Within the structure a group of artefacts was found :-

 

 

“A series of pits and hollows were dug into the floor on the left side (north-east). One of these contained a hoard of 14 prepared large flint nodules... “ (Richards) 

 

 

“a complete Grooved Ware vessel (that) was set into the clay floor adjacent to the eastern wall (left side on entry). The vessel was undecorated except for two horizontal grooves directly below the rim. Interestingly, the decorated portion was the only visible area of the pot projecting above the floor surface.” (Richards) 

Also, a tiny pinch-pot was found in a stone sided channel that drained water from the Structure. 

In the hearth outside the entrance to the Sweat Lodge, prepared stones like the large flint nodules would have been heated. They would then have been carried to the pit in which they were found, and water sprinkled over them to create steam. 

The water for the ceremony would have been stored in the Grooved Ware vessel, and the pinch pot would have been used to carry small amounts to the heated stones. 

The building has a hearth-like feature at the centre of the room, but it is far from certain that this was indeed a hearth. 

 

 

 

It is possible that this is a base pad for a centre post at the centre of the room that may have supported sloping roof beams leaning in from boundary edges of the structure to an apex at the top, a pyramid shaped building. 

An assistant to the Conductor of the meeting may have been stationed in the external lobby to manage the fire, heat the stones, and attend at the entrance while the Sweat Lodge Ceremony was ongoing. The fire pit was probably in open air to allow combustion without smoke getting into the lodge.

The structure that is represented by circular bank around the exterior of Structure 8 would have been tall enough to act as a windbreak for celebrants before and after the ceremony,  but chiefly to protect the fire in the hearth.

The outer stones of the inner structure would have supported the pyramid roof, and the inner stones would have been a bench for participants to sit on.

 

All views and opinions expressed are my own, but it remains a work-in-progress for which positive criticism and comment is welcomed.

Jeffery Nicholls 

South Ronaldsay 

Orkney 

The Orkney Riddle (index here) is a series of blogs promoting the notion that Neolithic people walked from Scotland to Orkney to build the Ring of Brodgar. 

#Orkney #archaeology #Neolithic #prehistory #British #SkaraBrae #NessofBrodgar #BIIS ##Britice-Chrono 

Archaeology in the North Sea

 

The Orkney Riddle

 Archaeology in the North Sea 

The Orkney Vole is thought to have been imported, by uncertain means, to the archipelago from mainland Europe without setting foot on mainland Britain. 

How this happened is a bit of a mystery. 

  

At present, the scope for a small rodent to migrate between Denmark, Germany,  the Netherlands,  or France,  and Orkney,  without touching Britain seems a bit limited.

"Orkney voles have evolved their own particular dental phenotype, likely the result of human agency influencing its evolutionary trajectory in different ways over the last 5000 years. This human influence began with its Neolithic introduction to the Orkney Mainland at a time when there were no terrestrial predators and only one competing species (the wood mouse). The Orkney vole population rapidly diverged from continental European M. arvalis to reach a new ecological optimum, that included evolutionary changes in morphology of the molar teeth. Neolithic farmers then dispersed the species to other islands of the archipelago—from Mainland to Westray and during the Bronze Age to Sanday—generating several founding events contributing to idiosyncratic differences in dental characteristics." (Cucchi et al)

"M. arvalis is not a species currently associated with arctic or even moderately high latitude conditions. Its range extends eastward beyond Lake Baikal and yet barely traverses north of the 60th parallel (Fig. 2; Shenbrot & Krasnov2005).....

"M. arvalis is not currently found in Britain(Fig. 2)......

"It is conceivable that there could have been sweepstake colonization of Orkney from Doggerland, the landmass connecting Britain, the Low Countries and Denmarkuntil about 8000 BP (Weninger et al. 2008) – but this would require the survival of small mammals on floating mats of vegetation over a substantial marine gap between Doggerland and Orkney. Thus, human introduction is by far the most likely explanation for the occurrence of M. arvalis on Orkney......

"From the IMa and ABC dates, this introduction at about 5000 BP fits well with the earliest radiocarbon dates for archaeological M. arvalis from Neolithic contexts (5100 years old: Table 2) and the beginnings of the Neolithic culture on Orkney (5600 BP: Ritchie 2001; Schulting et al. 2010). Voles could have been brought to Orkney by Mesolithic hunter-gatherers, as early as c. 9000 BP, but no vole remains have been found in the one excavated Mesolithic site on Orkney (Lee & Woodward2009), in contrast to their abundance at Neolithic and later sites (Yalden 1999; Thaw et al. 2004). If, as appears most likely, the voles were introducedby Neolithic settlers about 5000 BP, various other implications flow from our molecular data, which are of considerable archaeological interest. First, the introduction implies long-distance maritime travel by Neolithic people between continental Europe and Orkney, extending on findings from elsewhere (e.g.Broodbank 2006). Our study highlights the Belgian coastline as the most reasonable source of the Orkney voles on the basis of available genetic data. This suggests Neolithic cultural linkages between Belgium and Orkney, of worthwhile focus for future archaeological investigation. Microtus arvalis were not introduced successfully into mainland Britain, which is consistent with relatively direct transport to Orkney from the continental source area. Second, if the introduction occurred about 5000 BP, then, because the tMRCA for the Orkney voles is so long (15 400 years), substantial numbers of femalevoles must have been introduced." (Martinkova et al)

The possibility that walkable land was present in the middle of the northern North Sea has not been addressed. To  establish this possibility that land was present in the middle of the North Sea in prehistoric times the undersea features there need to be recognised.  These are in simple terms, Dogger Bank,  the Witch Ground and the Norwegian Channel. 

Fig. 1, The British Isles and North Sea (Emodnet)

The Norwegian Channel is a deep water trench that follows the Norwegian Coast from the Skaggerak, (an even deeper section of the same trench), between Norway and Denmark, out to the North Atlantic Ocean. 

Dogger Bank is an area of shallow water in the southern North Sea known to have been walkable land in prehistoric times, Doggerland. 

The Witch Ground is one of a group of deep water features in the North Sea. These gullies are cut into older sediments, and are all the result of impact erosion.  Ice sheet edges collapsed,  between around 21,000BP and 17,000BP,  cutting valleys in underlying ground that was at that time mostly dry land.

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The Norwegian Channel is an impact valley that has for millions of years been cut out by ice sheets on Norway and scoured by mobile ice streams rolling off from Sweden, into the Skaggerak, and out to the Atlantic Ocean. 

The sea level charts for changes in relative sea-levels for points along the Norwegian Coast, are published in "Post Glacial Relative Sea Level Change in Norway" by Roger C. Creel. These charts are attached to the map of the Norwegian Channel below.

Fig. 2, Sea level charts for the Norwegian Coast (Creel)

There is, on the charts, a consistent pulse of 10 metres higher water level onto the Norwegian coast at 12,000BP when the ice sheets on Sweden were melting and draining into the Skaggerak. Evidence of high temperatures in Scandinavia during this period is reported in:

"Floral evidence for high summer temperatures in southern Scandinavia during 15kaBP-11kaBP" by Frederik Schenk et al

".....we compiled and quantified N ¼ 96 climate indicator plant species from 15 sites that allowed us to reconstruct minimum July temperatures in Denmark and SSweden for ~15 to 11 ka BP. Although the number of sites and hence indicator species is very low during the pre-BØ, BØ and OD, the presence of indicator species with high thermal requirements such as Herniaria glabra (TJuly  16.5
C), Silene nutans (15.1
C) or Alisma plantago-aquatica (14.4
C) at Bjorker € odsmosse and possibly € Lotus corniculatus (14.5
C) at Slotseng, indicates near-modern July temperatures even by ~15 ka BP in close vicinity to the FIS margin at that time. We also find clear evidence for equally high July temperatures during the YD stadial of at least ~14
C and possibly up to ~16
C consistent with high summer temperatures found in previous studies (e.g. Birks and Birks, 2014; Schenk et al., 2018)."

Elsewhere I calculate that the amount of meltwater entering the sea, off the coast of Norway, Sweden,  or Britain,  any time may have been half or a whole cubic kilometre of water, ice and sludge. This would significantly raise local sea-level at coastlines. 

The  sea level in the Norwegian Channel, inferred from  "Global sea-level rise in the early Holocene revealed from North Sea peats" by Marc P. Hijma, et al, was 60 metres below present at 12,000BP, but the peak of the meltwater  surge out of the Skaggerak was then 10 metres above 60, therefore 50 metres below our sea level. 

This surge of 50 metres below sea level was supported at the Skaggerak between  the coasts of Norway and Denmark,  and not diminished in any way until it had followed the Norwegian Coast and reached the Atlantic.

This means that there was land along the west bank of the Norwegian Channel at better than 50 metres below current sea level, where the seabed is now over 100 below.

This suggests that there was land at the west coast of the Norwegian Channel at shallower that 50 metres below sea-level that people and animal may have used to walk from Doggerland north to the Atlantic coast of the North Sea. 

Figure 3, a flint found in a borehole drilled in the seafloor of the northern North Sea. 

To confirm this possibility, There is evidence of human activity in the middle of the North Sea. 

In a report entitled "A flint artifact from the northern North Sea" .  Caroline Wickham-Jones discusses a struck flint artefact found in a borehole in the North Sea, half way between Shetland and the North Sea, ("A flint artifact from the northern North Sea" By Long, D., Wickham-Jones, C.R. and Ruckley, N.A. 1986).

The location of the find, the "Findspot", is indicated in the map above, and the artefact itself is drawn. This may indicate that people were foraging in this area in prehistory. It is certainly difficult to conceive how a knapped flint got to that place otherwise. 

 

Figure 4, bathymetry maps of the northern North,  3 slices, deepest at the top, shallowest at the bottom.

The bathymetry maps above are slices of seabed depths across the northern sector of the North Sea. 

The upper chart shows purple, 190m, to yellow 150m.

The middle chart shows purple 150m to yellow 120m

The lower chart shows purple 120m to yellow 90m.

The 120 metre depth of the lower chart delineates a potential coastline that may have joined the findspot of the flint to both Doggerland in the south and Orkney/Shetland in the east. The coast encircles a huge embayment.  Some of this embayment will have been cut out by the impact erosion of collapsing ice sheets, but during human prehistory would have been a marine feature. 

Evidences combine to suggest that a lagoon was present off the east coast of Aberdeenshire,  an area of shallow "estuarine" water, this appears not to have frozen over during the last glacial maximum,  and may have retained vegetation and fauna populations around its perimeter. This may be one source of migrant species that may have colonised Orkney. 

Whether this lagoon was connected with the Shetland embayment is moot, but at some stage the lagoon filled sufficiently that waters in it flowed out in a southerly direction,  along the coasts of England, Holland, Germany and Denmark,  into the Norwegian Channel 

During the cold period of the last glacial maximum, all of eastern Britain  from Dover to Orkney was ice covered. Thick ice also covered Dogger Bank/Doggerland,  and the peninsula that extended north from there to the findspot, and the Atlantic Ocean. 

There are then the two routes by which the Orkney Vole may have migrated to Orkney.  The first is as a population surviving through the last glacial maximum on yhe shores of a lagoon, and the second, perhaps more plausible, would have been north from Doggerland,  and around the south coast of the Shetland embayment.

The materials that built up the peninsula would have arrived in their current locations by deposition from large volumes of mobile sludge waves derived from the collapse of ice sheets on Shetland. As the deposits on the peninsula would not have been overlaid by a great thickness of ice they would have been reasonably soft. It was only when sea levels rose that these, otherwise stable deposits began to collapse.  

The Inundation of the North Sea 

  

The ridge of land that joined the "Findspot" to Doggerland has been removed as a result of rising sea levels. 

The date at which this happened may be found in a report of excavations of raised beaches on the Norwegian Coast that was carried out by Lisbeth Prøsch-Danielsen (Sea-level studies along the coast of south-western Norway, by Lisbeth Prøsch-Danielsen) At the "Stavanger Airport Sola Site"

Fig, 5. The Rogaland coast of Norway (Prøsch-Danielsen)

Danielsen demonstrated that there were a couple of transgressive rises in sea level after the end of the last ice age. She also found an anomalous event which she could give no explanation for, in which an alder tree was ripped from its roots at a site in Rogaland, near Stavanger. “The layer consisted of organic and sand (mica schist) lenses sandwiched on top of each other, dipping towards the east.  Between layer 3 and layer 4 there is an erosional angular unconformity. Also roots of black alder (Alnus glutinosa) (identified by Aud Simonsen) penetrating into the upper part of the marine gyttja have been cut of discordantly. A piece of root has been dated to 4320±70 yr BP (ß-171185).”. The  date was calibrated to just after 3000BC, and I interpret that the roots may have been stripped of their tree by a very local tsunami wave, rolling  across the Norwegian Channel from the collapse of cliffs along the west coast of the channel. 

Similar results to those at Stavanger airport Sola site, were found at other archaeological sites in Rogaland, where tsunami-type deposits are found.

Talking to Bård Amundsen, a journalist for sciencenorway.no , Svein Vatsvåg Nielsen and his German colleague Martin Hinz say:- "We now consider it certain that the sea level rise was brief. It also seems likely that a tsunami struck the Stone Age people in Rogaland – and probably also Vest-Agder – sometime between 3445 and 3396 BCE,"

Nielsen and Hinz suspect that it may have been the Garth tsunami, named after the Garth Loch lake in Shetland.

Jåsund 2 is the name archaeologists have given to one of the most well-known Stone Age settlements in Rogaland. It is located on the Tananger Peninsula in Sola municipality, just outside Stavanger. Evidence suggests Jåsund 2 was flooded by a wave possibly as high as 10 metres. 

They have also discovered evidence of the Garth tsunami, which may have hit southwestern Norway 5,400 years ago, on Shetland. The sediments left behind by this tsunami are similar to those from the Storegga tsunami. In this case, the wave run-up on land is over 10 metres. 

Håkon Glørstad, who first proposed the tsunami theory in the 1990s, is pleased that Nielsen and Hinz have now confirmed it in a new scientific article. "At the time, much of what we uncovered in archaeological digs in Rogaland didn’t make sense," Glørstad tells sciencenorway.no. "But I realised something dramatic must have happened, something involving water, that was unique to Rogaland. It had to be a fairly local phenomenon," he says. (Amundsen, edited)

The last ice age is not well understood at present, but the research that has been necessary to plot a path by which the European Vole transformed itself into the Orkney Vole required a series of shifts in my perception of Quaternary landscapes.

The theories of how the ice-sheets affected the land upon which they rested, as they are proposed by scientists in existing polar science,  often bear no relation to the actual conditions as they survive. A common feature of these theories is that ice-sheets are believed to move, and in some circumstances can move uphill. Although there may be some truth  in these statements,  they are generally physically impossible. 

I have completely redefined the processes that modified the geological landforms, and submarine seascape of Britain.  I cannot say that this applies to other regions, or to what is happening now, but the geology tells its own story.

Find out more in "Ice-sheetBritain". 

All views and opinions expressed are my own. Many assertions stated have not been thoroughly justified here, simply because space prohibits it in this format. The evidence exists elsewhere to demonstrate that these assertions are, at their core, valid.

Jeffery Nicholls 

South Ronaldsay 

Orkney 

The Orkney Riddle (index here) is a series of blogs promoting the notion that Neolithic people walked from Scotland to Orkney to build the Ring of Brodgar. 

#Orkney #archaeology #Neolithic #prehistory #British #SkaraBrae #NessofBrodgar #BIIS ##Britice-Chrono #EarthSciences #LastGlacialMaximum #IceSheets #RelativeSeaLevel #Glaciers