Tag Archives: sampling

Cruising Doggerland

By Dave Roberts (with selected photography by Alex Ingle)

Doggerland

Doggerland

The last week has seen the start of the epic trek north to south from Shetland to the Dogger Bank in the southern North Sea.

We spent the first 2 days looking at some enigmatic grounding wedge features on the sea-floor just west of the Norwegian channel where the British and Norwegian Ice sheets battled it out for supremacy during the last cycle. We also stepped boldly into the unexplored world of outburst floods and drowned coastlines with a some incredible seafloor geomorphology adding to the ice sheet story in relation to the uncoupling of the two ice sheets. Unbelievable geomorph!

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From the Norwegian Channel we headed SW towards the Moray Forth running a 100mile survey and coring transect NW to SE over a spectacular series of moraines before heading into the central North Sea and the urban heartland of the North Sea oil fields around Shearwater and Erskine. Our goal was the Great Fisher Bank (that renowned last bastion of the British Ice Sheet) where we enjoyed a cracking day out sampling Holocene sand and the arrival of a racing pigeon called Terry from Thurso. Needless to say, Terry proved more interesting than the seafloor that day!

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The great odyssey to the Far East was followed by 3 epic days surveying and coring east of the Firth of Forth and then down the east coast from Berwick to Sunderland chasing the imprint of the North Sea lobe. Moraines, deltas, eskers, outwash fans and tunnel valleys littered the bed of the Forth system; all soaked in metres glorious glacial sediment. Better was to follow as we moved south along the Northumbrian coast with the resplendent Whin Sill fracturing the seafloor and grounding zone wedges plastered on to the bedrock. There were also superb, quiet seafloor basins revealing the multi-coloured, muddy barcodes of the deglacial story of the Forth, Tweed and Tyne Ice Streams.

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The final push now. One week to go and on to Dogger Bank for the next two days. Can we prise out the some glacial secrets from beneath that sandy veneer? Huge sand banks seem to guard its peripheral moat warning against trespass, but we are committed now and on to its shallow, upper surface. Our early cores are showing promise; we will see. Hopefully, our target sites in the Humber and Wash area will bring a pot of glacial gold at the end of a cracking month at sea. Then home.

No rest for the wicked: T3 marine sector rumbles into life…..

By Richard Chiverrell

Sites and surveys for transect 3

Sites and surveys for transect 3

Leaving the Celtic Sea and the delights of the Celtic Deep, noon on Sunday 27th July, the Royal Research Ship (RRS) James Cook homed in on Britice-Chrono Transect 3 and the delights of the Irish Sea. For me work levels already high increased, with Transect leader duties to fulfil, and the challenges of finding till – glacimarine mud contacts throughout the sector, and do not forget the shells/fossils for the critical dating targets. That said without Katrien’s (van Landeghem) constant input and support it would have been ridiculous, the work in advance of the cruise identifying targets and new locations drew on considerable effort and collaboration focused on this marine sector of T3 over the past 2-3 years. The success of the efforts for T3 obviously relied on the excellent work effort, diligence and company of the cruise team, science crew, BGS and NOC Piston coring teams and the RRS James Cook captain and crew, all whom did everything they could to help us. Not singling people out, but I thank Katrien for constant input, advice and support as co-leader on this transect and Colm as Science Lead on JC106 cruise.

In the Celtic Sea, the ship was home to the friendly academic interplay between James and Daniel, the Irish Sea also offered up a number of longer standing and perhaps more vociferous historical debates! Understanding and interpretation of the nature and extent of glacimarine conditions in the Irish Sea basin has ebbed and flowed for 4-5 decades, with some proponents holding for a full glacimarine ice margin, others subaqueous margins with more restricted access to the ocean and the other end member glacilacustrine basins separated from the sea. For all these views a comprehensive borehole and geophysical survey targeting environments across the sea floor had the potential to advance understanding, but for Britice-Chrono we clearly needed glacimarine conditions and sediments to provide the marine shells and microorganisms that we can radiocarbon date to gain a chronology for retreat of ice from the basin. Marine fossils have been recovered from coastal glacigenic sediment sequences surrounding the Irish Sea for centuries, but debate continues over whether they are in situ or derived, eroded from the sea floor, during ice advance and then redeposited in glacial sediment. If in situ they offer the potential to constrain retreat of ice margins and the development of glacimarine conditions, if derived they cannot really advance our dating control. Some challenging fieldwork and some painstaking analysis of the fossils and microfossils lies ahead.

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Our journey from the Celtic Deep ~ 51°25’N to our first survey and core sites west of Anglesey around 53°15’N took just over 12 hours at a steady ~10 knots. Our first sites, a bit of a late addition and product of general brain-storming, were ~ 13-14 miles west of Holyhead and targeted the deep waters of northern extensions of St Georges Channel. The location kind of bridges T4 and T3, and we wanted some indication of deglaciation of the deep waters between Holyhead and Dublin. On reflection I was not sure what to expect here, but we had planned a sub-bottom profiler SBP and multibeam survey line as an initial exploration, but circumstances and our temperamental SBP conspired against us. The multibeam data on the other hand were excellent, it was a decent trough 2 miles wide 30-40m deep and we used the multibeam to avoid surface sand waves. Our aims were to avoid surface sand and access the underlying laminated glacimarine units, 2.5 hours and two vibrocores later, some success >3m of mud ending in reddish (an Irish Sea glacial signature!) stiff muds. These laminated or bedded sediments hopefully were lain down under marine conditions fronting the ice sheet as the ice margin retreated to higher ground east and north between Anglesey and the Isle of Man.

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From noon 28th July we moved east and north between the Isle of Man and North Wales, and into a region a large part for me where my interest in this research started, working for and collaborating with Geoff Thomas on sections and sediment all around the Irish Sea. In the deeper waters between the Isle of Man and North Wales, our multibeam data gave us a view onto a very well preserved glacial landscape of drumlins and flutes, moulded elongate low hills shaped by the passage of ice. Uncovered as ice melted and then preserved beneath water probably ever since, their summits are grooved with markings probably formed by ice-bergs calving from and then grounding on the landform surface fronting this glacier. Guided by the multibeam sea floor topography and our shallow geophysical data we targeted hollows in the landscape with shallow fills of sediment overlying the glacial surface. Our vibrocorer can penetrate to ~5-6m depending on the sediments, absence of large cobbles or bedrock, heavy seas and luck. Fingers were regularly crossed and the only wooden items in the all metal BGS vibrocorer cabin are now getting quite worn by us touching them for luck and the right sediments. Broadly we divided the Irish Sea basin into four sub areas, 1. South of a line between the Isle of Man and Barrow-in-Furness completed by 21.30 on 30th July, the deeper waters between the Isle of Man and western Cumbria by 18.30 on 31st July, the Solway Firth (between the Isle of Man and Scotland) by 5am 1st August and finally the deep waters west of the Isle of Man by 11.30am 1st August. >500km of survey line, 34 cores in total, almost all of them reaching the reddish glacimarine muds often laminated some with dropstones and in many cores stiff diamicts with clasts typical in character of Irish Sea glacial tills seen in coastal cliff sections around the basin. We had the sediment contexts we desired, the subglacial to ‘glacimarine’ transition and water-lain ice marginal muds from settings across the transect. The nature of this water-body and answers to the Britice-Chrono geochronological questions must wait on many months of laboratory analysis, but I left the Irish Sea northwards for the Malin Sea and T7, satisfied and with the feeling that the sediments and geophysics alone will fill in a significant and long standing gap in our understanding of the last glaciation of the Irish Sea.

The raging waters of the Irish Sea

The raging waters of the Irish Sea

Cruise 1: meet our Marine Mammal Observer

By Marian McGrath
dolph
Hello everyone! It’s been one week since we joined the RRS James Cook in Southampton, even though we didn’t actually leave the port till Friday the 18th due to technical problems with the vibro corer. My role on board is as the Marine Mammal Observer (MMO). The role of the MMO is to ensure the safety and protection of marine mammals from man-made noise pollution in the ocean. This can damage or kill cetaceans which have very sensitive hearing. The Marine Mammal Observer (MMO) is required by law to be aboard any vessel which is carrying out seismic surveys within Irish waters. On this vessel, Sub Bottom Profiler seismic equipment and Multibeam echosounder equipment are being used. In unprotected marine areas an MMO is required to carry out a 30 minute pre Multibeam echo sounder and Sub Bottom Profiler watch followed by a 20 minute watch during the soft start. Sound activity cannot commence until the MMO gives clearance after the 30 minute watch. If marine mammals are spotted within 500m range of the equipment during this watch then a further 30 minute watch is undertaken till marine mammals have left the mitigation zone. If no marine mammals were seen within this time then a soft start would commence. Once the ramp up procedure is started there is no need to stop the equipment during night time hours. The Multibeam and Pinger systems remain active during the survey unless we are on a coring station for longer than an hour in which case they are switched off. They are also turned off during the mid-cruise port call in Killybegs.

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Marine mammal observations are carried out from the bridge. This gives the best view point of both sides and in front of the vessel. The equipment is always started during daylight hours to allow for MMO watches to be carried out prior to soft starts. Observations are undertaken using a reticular binoculars, a range finder and also by the naked eye. Distance to marine mammals is determined using this reticular binoculars and height above sea level. To determine the range one of the divisions present in the binoculars is placed on the horizon. A formula is then used to determine the distance of the mammal from the ship. The formula is: Distance (m) = (height of eye above sea level (m) x 1000/ no. of mils down from horizon). Throughout the duration of the survey, watches are undertaken throughout the day and any sightings are logged in a computer supplied by The Irish Whale and Dolphin Group. This will feed into a database which is constantly updated regarding location and numbers of various species. Throughout the day recordings are taken of precipitation, sea state, visibility, ship speed, water depth, cloud cover, latitude and longitude, wind speed and direction. So far on this survey Common Dolphins have been seen near the shelf edge of the Celtic Sea. First 4 adult dolphins were seen on the 21st July and later the same day 11 adults and one calf were seen.

Cruise 1: Days 1-6 trials, tribulations and triumphs

By Rich Chiverrell and co from the edge of the shelf

Developed as a concept 3-4 years ago, and planned over the last 2 years with massive input from across the Britice-Chrono team and Colm Ó Cofaigh (Marine Theme Leader), on Monday 14th July it finally began to happen, Cruise 1 (JC106) of the NERC Consortium Project Britice-Chrono. The vessel, the RRS James Cook was waiting for us moored at the wharfside of the National Oceanography Centre (NOC) in Southampton as the various team members mobilised. For me this would be a first, after running the terrestrial field programme for the past 18 months, and now for something completely different – having visited numerous boulders, quarries and cliff sections, the chance to see and sample the extensive offshore sediment and landform record of the decline/collapse for the former British-Irish Ice Sheet (BIIS).

The leaving of Southampton

The leaving of Southampton

Individual preparations for an undertaking like this began months ago; spending 3-6 weeks living offshore on a state-of-the-art research vessel does not happen overnight. In June marine survey or personal survival training qualifications were needed. This involved 7/8 hours of training and tests at the Fleetwood Nautical Campus, which covered survival equipment, how to abandon ship from a 5m platform and in the appropriate survival gear (immersion suites, life jackets, entering life-rafts, management of life rafts, individual and group mobility in the water). All this in a state-of-the-art 8-9m deep wave simulator, where for the finale we abandoned ship from 5m, in the dark, smoke everywhere, rainfall and spray, into a wave churning pool, after 5-10 mins in the life-raft mal-de-mer was looming! Medical certification testifying fitness to work was also needed. And then on to other tasks, helping with permissions for geophysical survey and coring in Irish, English, Welsh, Manx and Scottish waters all were required; remarkably all interpret EU law differently and this resulted in a major undertaking for Colm Ó Cofaigh amongst many others.

It was with a little trepidation and expectation that I first visited the RRS James Cook on Monday to drop of personal luggage and cameras (on board duties for me included amateur film maker and outreach obsessive). First impressions, a big and well equipped ship, and my cabin is more spacious than I expected. Second impression there was still a great deal to do before our scheduled departure noon Tuesday 15th July, with an impressive set of additional equipment being loaded as I arrived; the British Geological Survey waited on replacement cranes to load the 6m vibro-corer. The NOC 12m length piston corer was also working its way on board. A freight container that housed the University of Leicester Multi-Sensor Core Logger was also being loaded. The science team added research consumables to allow the sampling of ~200 core profiles and then on Tuesday ourselves for familiarisation and preparations to depart. It perhaps was more of a surprise than it should have been when our eventually departure lunchtime on Friday came around, because mobilising this scale of operation is challenging, and we did have a few issues with the vibrocorer that the BGS team worked largely round the clock to fix including extra and replacement equipment from Edinburgh. The wider BGS team got to know the route from Southampton – Edinburgh well…..

After some final repairs and tests of the vibrocorer and we met our Friday departure time, and headed for a date with the English Channel and a test location identified to the south of the Isle of Wight. Casting off and the journey to the Solent was in calm seas and glorious sunshine, within 3-4 hours we reached the test area, and the BGS and JC106 Science teams readied themselves for the fray. Using the RRS James Cook’s dynamic positioning system the crew manoeuvred the ship into position in 30-40m of water. The BGS team, thoroughly checking the physical operation of the equipment, lowered, sampled and recovered a vibrocore. The equipment was functioning fine, we were ready for the Celtic Sea and the Science team had materials on which to practice our procedures e.g. core cutting, splitting and description.

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On finishing the test core location, the geophysical equipment was powered up, so that the watch teams could gain experience and practice the 24 hr geophysics monitoring duties. My first watch was 12 midnight through to 4am! Actually pretty good fun, not sure how quickly my body clock will adjust to a warmed up dinner for breakfast, breakfast for lunch and lunch for dinner, and for that matter sleeping 4pm til 11pm……

Saturday through to Sunday was spent in transit; the shelf edge of the Celtic Sea is quite a long way ~ 36 hours at ~10 knots. In the mid-morning our safety skills were put through the paces, with a muster drill, the alarms sound we secure warm clothing and life jackets and convene in the muster point, from which we are led to and board the two life boats. Very spacious, well kind of, the each can take ~50 people and we are a crew of around 50. You can imagine they would get very warm and pretty unpleasant if full of people for a long time.

On waking 11pm after not much sleep, still adjusting to the new life cycle… Taking over from the end of my day watch partner, Catriona, my watch was good fun acquiring the data for the next 5-6 hours involving scouting for core sites as we began our target geophysics transect on the shelf edge, with some success finding some promising targets in between problems with the Sub-Bottom Profiler. Riccardo and then Kasper followed, with ever present input from night coring lead Sara, night geophysics lead Fabio and Margot. On this watch we completed an acoustic velocity profile as a calibration for the multibeam survey systems, and worked the geophysics transect. Once complete we arrived at the destination for our shelf edge piston core. The piston coring team from NOC made quick work of the 459 meter, recovering ~ 4m (JC106-002PC). Fabio and the RRS James Cook computation team carried out a further calibration of the multibeam survey using the sea floor topography. The core awaits acclimatising to the MSCL container and whole core analysis of the physical properties with Elke.

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At noon, the baton passed to day watch (Katrien, Lou, James, Catriona, Daniel, Zoe) and the challenges of obtaining five vibrocores along the geophysics transect in search of that Holy Grail, a contact between subglacial diamicts and glaciomarine deposits in 280m of water. JC106-003VC, the first stop, was on the flank of the western side of Little Sole Bank near an earlier BGS vibrocore. The materials were very tough penetrating ~1.6m, with a much consolidated stony diamict at the base; admittedly a little/lot early to say it looks a lot like what we were hoping for, and there are four more sites to follow, but….

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Minching about on a sunny Isle of Lewis

By Rich Chiverrell

Port Skigersta delta

Port Skigersta delta

One of the smaller ice-masses draining the former British-Irish Ice Sheet, the Minch palaeo ice stream drained much of the NW sector of the British–Irish ice sheet (∼15,000 km2) feeding sediments to the large Sula Sgeir fan fronting the continental shelf. But if this is small, standing on the east coast of Lewis (Outer Hebrides) looking across the sunlit, blue seas and skies east to the feeder fjords and mountains of the Summer Isles and Wester Ross helps one visualise how large this former ice sheet really was. Our aim for this ongoing Briticechrono Transect 8 fieldwork was to secure a series of targets for Optically Stimulated Luminescence (OSL) dating from outwash sands from Lewis, one of the outermost land-masses on the western flank of the Minch Ice Stream. This work will support previous sampling efforts targeting boulders on the Scottish Mainland and the Hebrides for cosmogenic nuclide dating. Previous OSL sampling had targeted the inner sector of the Minch on Skye and north of Ullapool. The team (Rich Chiverrell, Matt Burke, OSL Postdocs Rachel Smedley and Alicia Medialdea) set off first thing on Tuesday morning to join Transect Leader (Tom Bradwell) on Lewis. Departing a cloudy Manchester via Glasgow Airport we landed before lunchtime to blue skies, sunshine and searing temperatures at Stornoway Airport.

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Inspired by our surroundings, the weather and the prospect of excellent sediments the four newcomers sped off to meet up with advance team Tom Bradwell, Adrian Hall and Maarten Krabbendam (from the Netherlands) at Port Skigersta in the far north of Lewis. The site an embayment on the western flank of the Minch Ice Stream gave stunning views across the water back to the ice source areas in western Scotland and beautiful turquoise seas. The sediments were very impressive with the sequence a stacked delta sequence with steeply dipping fore-set sands capped by top-set horizontally stratified gravel. Intriguingly the basal delta is buried by laminated bottom-set muds, in turn buried by a second delta fore-set and top-set couplet. The repeating delta suggests changes in water level probably lake level, dammed between the ice stream and bedrock rise into Lewis. We sampled both deltas close to the fore-set – top-set contact. And then for some geological tourism, the raised beach at Galsom guided by Adrian Hall, stunning and confusing sediments, all contributing to produce a plethora of hypotheses. Difficult to address under the banner of Briticechrono, the beach deposits (guess the isotope stage) appear altered by over-ride by ice, locally there is a surface diamicton and the beach pea/rounded gravels are probably thrust or stacked. We have targeted an outwash (ish!) deposit above a glacial diamicton, fingers-crossed for contributing to the debate. Excellent food followed at the Cabarfeidh Hotel our home for the next few days (well some of us!).

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Day 2, still warm, still still (no winds) and the sunshine popped in later! After an epic breakfast (Lewis did us proud) back to the north and just south of the Butt of Lewis the west coast Swainbost Sands offered much promise. The sections were epic more glaciotectonics, tills, shells than you can shake a stick at, and the beach!!!! One of the best beaches I have seen in the British – Irish Isles…. Selecting targets was challenging, much of the outwash deposit was rich with shells, thrust, tectonised and not where it was deposited! How? Well by marginal movements and override by ice and at a substantial scale. Three sample locations were found and in the back, along with crucial in gamma detector comparisons, duplication with different detectors at some of the samples. The sampling completed our targets after ~36 hours on the islands, and so we racked our brains for other targets. After a quick visit ~5/6km south down the west coast of Lewis where we encountered convincing striae in steeply foliated Lewisian gneiss, where the glacial lineation trends cross obliquely the metamorphic structure heading northwest. We also prospected for sites further up-ice around Stornoway; another fine meal at the hotel and some gin-assisted colour-by-numbers approaches to former ice geometry and let’s see what tomorrow brings for our last 3-4 hours on this eye-opening island (hopefully a final sample)….

Many a mickle makes a Muckle (Roe)….

Contributed by Tom Bradwell (1.75m tall) and Rich Chiverrell

Dawn broke at 0430 (we understand but not by experience) with clear skies and wide views across the hills around Lerwick. The team assembled slightly later than this, well 4 hours later actually – at around 0830 – after a good night’s sleep following our 2-day extravaganza on Unst. The prospect of great weather called for a slight change of plan and we decided to split into 3 teams for the day: Derek, David & Tom headed west in the Hilux to hopefully find some nice big rocks on Muckle Roe; Rich and Matt went south in the Vito MPV in search of glacial sands; and Chris, Saskia and Vince went to gather more footage of the Project Leader in his well worn and very practical Drizabone field gear.

The island of Muckle Roe lies in St Magnus Bay but is only 25 m from the Shetland mainland at its closest point and is conveniently joined by a sturdy bridge spanning Roe Sound. Taking advantage of this team Hilux drove to the end of the public road at Muckle Ayre, parked and set off on foot into a chill NW wind towards the furthest tip of the island. Muckle Roe is composed almost entirely of Silurian/Devonian granite and is quite rightly a national scenic area. The landscape is quite different to that across much of Mainland Shetland, with distinctive red granite crags, precipitous cliffs, and an abundance of glacially transported boulders – so many boulders in fact that it soon became apparent that the cosmogenic sampling team were in for a good day! After a couple of kilometres walk they found the first signs that glaciers had once crossed the island from east to west, with a number of rounded ultramafic and meta-sandstone boulders scattered across glacially polished and broken bedrock surfaces. These boulders could only have come from the Shetland mainland and their presence was a clear indicator that a large ice mass covered the whole island group probably with a 30-km wide ice lobe flowing into St Magnus Bay. Unfortunately, these boulders in particular could not be sampled as they don’t contain quartz: the mineral needed for the cosmogenic nuclide analyses. Instead the team took quartz-rich granite samples from a glacially deposited boulder, a smaller cobble and some ice-worn bedrock. If only all sample sites were this good!

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The team enjoyed a brief lunch stop of cornish pasty, squashed sandwiches, dried mango and caramel logs sat on glacially polished granite slabs overlooking the western cliffs with fine views to Foula and Eshaness. Derek even found the time and signal strength to send a couple of tweets. More sampling followed in the afternoon including a very prominent granite erratic nicknamed simply “big white” taking the final tally to 9 for the day. As the sun beat down, and temperatures soared into the low teens the weary 3 made their way back to the Hilux via the coastal path taking in some of Shetland’s (if not some of the UK’s) best cliff scenery. Vertiginous granite cliffs at Picts Ness and the Hole of Hellier were carefully navigated around before the samples were safely deposited in the truck.

Team ‘Elusive Quaternary Sediment’ following up some precise instructions from T1 Leader of go to behind ‘a well-known supermarket chain store’ there will be something there, and failing that drive around and find some stuff…… Pausing for some quick digital recognisance, emergency lunch supplies and then the section- bedrock and 1-1.5m diamict, job well done part one at least. The driving around aimlessly took much much longer! The coastal sections on the journey down to Hoswick proved equivalently disappointing, though interesting if you like windblown sand and peats inter-bedded of Holocene age overlying a thin glacial diamict. Matt and I then headed for Burn of Mail, and an eventual rendezvous with ‘the making of….’ documentary team. A cracking valley and showing the first set of convincing retreat moraines with ice flow down the valley eastwards from the mainland of Shetland. No sections but cracking geomorphology and a good boulder spread with the potential to record passage of the ice margin on land from the east. There was the tremendous opportunity to watch a future movie star in the making, as our film and outreach crew (Vince and Saskia) collected some of the final footage on Shetland for the U-rated comedy prequel to ‘Silence of the Lambs’. We then headed west to check out the southern flanks of Papa Sound, a stretch of marine waters extending from our destination on Wednesday ‘Papa Stour’ to the hinterland of ice on Shetland around Voe. Our brief ‘brief’ was to find boulder and if possible OSL datable materials, lo and behold we did, much of the lower terrain between Voe and Aith was ornamented with moraine ridges and glacial sediment documenting in this case the retreat of ice margins from the west onto Shetland. 15 m off the road inland of Gon Firth a 5m thick borrow-pit section through a moraine shows a sequence of a coarse grained boulder (>1 m) diamict overlain by a finer grained (>0.3m) poorly stratified till, but separated by 0.5m of stratified outwash sands probably lain down as wash down the front of the moraine. OSL samples were recovered and have the potential to add to the age control in this sector of the former ice sheet, particularly with paired cosmogenic ages if possible.

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C3W team Vince and Saskia departed for home this afternoon, overloaded we know with excellent footage documenting the work of Britice-Chrono and the T1 team on Shetland, we thank them for their company, hard work and efforts, and wish them a speedy journey home…. A fine evening meal (cooked by chef Fabel) of Jalfrezi chicken with rice, poppadoms and indian snack selection was enhanced further with David’s home-made onion pickle accompaniment (recipe available on request). With ready made plans for tomorrow and Papa Stour hopefully on Wednesday, Transect 1 (onshore) feels like it is rounding the bend onto the home straight…..

Transect 1 Shetland – Day 3: Northmaven

By Derek Fabel

The writing is in the sand

The writing is in the sand

After a leisurely start we were on the road 8:45 to North Maven, the northern most part of Shetland Mainland. The target areas for sampling were a very distinct set of bedrock ridges extending for several kilometres in a northwest direction on the west coast of North Roe. We had spotted the bedrock ridges on air photos and satellite images, but now it was time to set foot on them. Tom, David and I drove to the end of a 4×4 track, shouldered our packs and set off looking for the ridges. After strolling through 3km of rocks, heather and bogs we were standing on what we previously had only seen on a computer screen. The shapes of the ridges, and smooth bedrock features on them, show they have been covered by flowing ice. When the ice melted away it left behind boulders that had been carried by the moving ice to the area. The boulders are of different rock types and thus were eroded from different source areas. The boulders are what we were after, and we quickly collected samples from the tops of six of them.

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While we were sampling boulders, Matt and Richard, the sedimentologists in the team, went along the Esha Ness coast looking for sedimentary deposits related to the last ice sheet that covered Shetland. In the afternoon the two groups met up in North Roe and did a vehicle swap so Matt, Richard and Tom could visit a famous Quaternary site at Fugla Ness at the northwestern tip of Northmaven. Fugla Ness was a stunning location, with a well exposed interglacial peat deposit between two glacial tills, apparently 130,000 years old and containing roots and stumps of Pine trees. For Tom, Matt and Rich the most exciting new (?) finds were a set of striations in the gabbro bedrock and these were buried by the Fugla Ness interglacial deposits and so are at least 130,000 years old and testify to previous glaciation of Shetland.

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David and I went north towards Fethaland, to look for some more rocks. After collecting three more samples, we looked at some glacial moraines near Skelberry, and promptly collected another three samples from some large, very, very, very hard granitic boulders. It was now 7pm and we were supposed to meet Chris, Vince and Saskia, who had flown in from England today, at Frankie’s fish and chip shop (the most northern chippy in the UK) in Brae. They were duly seated munching on fish and chips. Unfortunately Tom, Matt and Richard did not get back in time for a sit in meal. They enjoyed their fish suppers at Mavis Grind while the sun was setting.

Well worth the rushing and much deserved

Well worth the rushing and much deserved

Another long and very productive day, done. Out Skerries tomorrow.