I går skulle vi flytte leieren, men været var ikke helt med oss. Sterk østlig vind skaper store dønninger på vår side av Tanafjord og vi kommer oss ikke fra stranda med den lille båten for å laste over til den store båten. Manndrapselva får vente til været tillater oss å flytte.
Så hva gjør geologer når de blir satt på vent av været?
Det primære er selvsagt å holde kontakt med våre fiskere og se om været forandrer seg og det da blir mulig å pakke sammen leiren.
En stor porsjon tålmodighet er å anbefale for slike dager. Magne, Zhiji og Jan Ove går i vei til trilobittlokaliteten bare for å titte en gang til og kommer hjem med den beste fangsten så langt!
Figur 1: Trilobitt fangst! Foto Magne Høyberget.
Vi setter oss ned i kjøkkenteltet, plukker fram ukens notater og diskuterer høyt å lavt; Frida, Zhiji og Bianca jobber med sine feltnotater, retter spørsmål og oppdaterer seg. Ikke alt fungerer, Guido må gi sin dator førsthjelp da den ikke vil starte, men til Guidos store lettelse er den nå med igen.
Figur 2: First Aid for en dator som ikke helt vil vare med. Foto Jan Ove R. Ebbestad.
Wendy tar sjansen til ett par ekstra stunder for å fiske og det blir sei til kveldsmat.
Figur 3: Sei fiske til kvelden. Foto Jan Ove R. Ebbestad.
During the hectic field days loads of fossils and sediment samples are collected. These make their way to the Tromsø Museum collection and are an absolutely essential part of the scientific documentation of the studies that we do, together with photographs, measurements and field notes. The Museum collection also becomes a permanent scientific archive that is available for researchers all over the world, so they don’t have to go to the field and try to find similar specimens. It is first of all very expensive and the Digermulen Peninsula is pretty remote. In addition fossils and samples do not just pop up but requires careful and diligent collecting. So therefore we try to bring back as many of the specimens we consider valuable for our studies.
But we can’t catch them all!
Sometimes a fossil cannot be extracted from the rock it is in simply because it is to tricky and any attempts to collect them may end up destroying them instead. Or the fossils may be too large to haul back. We do not have access to any help and have to rely on our own blood, sweat and tears to get the samples out. So what can we do to document them? Photographs or drawings help, but the next best to the real thing is a cast.
This year we therefore brought with us silicon rubber to cast specimens. We had previously selected a few prize specimens to cast and knew therefore approximately how much equipment and casting supplies we needed.
Figure 1. A large and very instructive trace fossils called Dimorphichnus that we decided to cast (photo Magne Høyberget).
We had a box with the stuff, including the silicon, the catalyst to make it cure, thickener to make it sticky, black powdered colour, a couple of containers to mix it in, a scale to get the proportions of silicon and catalyst right, protective gloves and aprons, paper tissue to clean, brushes to apply the ready mix, cloth to strengthen the silicon and plaster strips to make a casing (mother mould). The colour is added to the silicon to create a dark surface for contrast when we later will photograph the silicon casts.
The casting process is pretty straight forward, but requires warm and dry conditions to work. After mixing the silicon mass we applied it to the fossils with a brush, making sure to work it in thoroughly so that the silicon catches all the details and we get all the air bubbles out.
Figure 2. The casting process. A) selection of the equipment needed for casting, B) mixing the silicon. C) applying the silicon with a brush. D) applying the plaster to support the silicon (mother mould) (photos Wendy Taylor).
We applied three layers with cloth in between for added strength. We then left the silicon over night to let it cure, and the following they we prepared the mother mould with the plaster strips. These were simply dipped in water and applied to the silicon in several layers and left over night to dry and harden.
The end result is a cast of the fossil, but the ‘negative’ if you like. Back in the lab we can reproduce the fossil as it looked in the field by preparing a plaster cast from the silicon mould.
Figure 3. Sören with the finished silicon mould and plaster casing (photo Magne Høyberget).
Past field seasons have intrigued us about what lies “beyond the horizon”. For a more complete picture of the traces of early life preserved in Digermulen rocks, the team would have to reach areas a long way away from the traditional campsites than attempted previously. Yet it is not always possible to reach these locations on foot. Either they’re too far away (Digermulen has no roads apart from thousands-of-years-old reindeer trails), and sometimes the outcrops of interest lie on steep cliffs impossible to get down to without climbing gear. As a solution to our exploration woes, we have decided to use a small boat to hop on/off various vistas and points of interest.
Figure 1. Team en route to check a few outcrops before getting to the first campsite at Breidvika valley. Photo Wendy L. Taylor.
The vessel is a simple fishing motorboat driven by the local fisherman Trygve (Figure 1).
While the group loaded the gear for the next couple of weeks and boarded the larger fishing boat of captain Joachim, a smaller party of three geologists/palaeontologists set out with the small boat to visit a few localities before reaching the first campsite. The initial leg of our journey was pleasant, with only light cloud coverage. We ate packed lunch on the boat, while scrutinizing the passing outcrops. The first stop was reached at 1 o’clock: the Mortensnes diamictite (Figure 2), a deposit of one of the global glaciation events in the Neoproterozoic Era (“Snowball Earth” ice house).
Figure 2. Large rock pieces deposited in the finer grained sediment are an indicator for glacial activity. Photo Jan Ove R. Ebbestad.
The sea got wavier as we approached our stop. Trygve deemed it impossible to take the boat ashore on a pebbly beach nearby. We would have to get out straight to the ledges. Thick coverage of slimy brown algae made it easy to grab onto something while climbing onto the cliff-face, yet it also made it tricky to balance on. As we eagerly sampled, the seas became even more restless. It was time to go. However, our blue boat couldn’t come as close to the ledge as before. Ok, samples first then – they’re more important than the geologists. A swing – and the sample box hit the boat. Phew. Geologists’ turn. The boat was swaying away, threatening to leave us on the diamictite for good, while the colleague on the boat desperately tried to hold onto the slippery, treacherous algae.
There will have to be a jump. So jump I did, as the boat suddenly jerked away from the rocks, and for a moment I thought I would end up in cold Arctic waters much like Ben Stiller in his faithful jump in “The Secret Life of Walter Mitty”.
Alas, I managed to land safety, albeit ungracefully. Soon, the entire party was on board, successfully avoiding a close encounter with the fjord. But not for long. The sea got choppier and the waves kept crashing inside the boat, blinding all three bespectacled geologists with salty spray. We kept clutching onto precious samples. Digermulen field season 2016 has begun with a free rollercoaster ride! A bumpy hour later, we reached dry land before the rest of the team in the bigger ship.
Figure 4. Trygve in the small blue boat, after dropping us off on stable ground. Photo Bianca Harrison.
The Digermulen Early Life Research Group has gathered again for two weeks of fieldwork on the Digermulen Peninsula. Our group is large with seven researchers, 1 PhD student (Zhiji from Tromsø University Museum) and two MSc students; Frida from Uppsala University and Bianca from Cape Town University. Leaving the harbor in Sjursjokk we are all very excited, two precious weeks in one of the best places to investigate the earliest appearance of animal life in the world. Several of the team members have been coming here since 2011 and it feels a bit like home now.
This year we are; Anette Högström, Jan Ove R. Ebbestad, Wendy L. Taylor, Sören Jensen, Guido Meinhold, Heda Agic, Magne Høyberget, Zhiji Ou, Bianca Harrison and Frida Hybertsen. People have come from all over the world with Bianca coming straight from South Africa. Local fishermen, Joachim and Tryggve, get all our equipment and us to our first campsite at Breidvika. The weather reports have been very promising, we´re just hoping it´s not going to be too to hot!
Setting camp is always a bit nerve racking, finding out what has been forgotten. When we can´t find the pole for our big kitchen tent panic feelings grow very quickly, luckily it´s there where it should be. Finally at night everything is done and located and the view from camp over Tanafjord and the Varanger peninsula on the opposite side is spectacular. After dinner we crawl exhausted into our tents. Tomorrow work starts and happy hunting for the next two weeks.
Micropalaeontology opens up a whole new world to be observed that is not visible with the naked eye. These are fossils of mainly single-celled organisms smaller than 1mm which is smaller than a pin head! When searching for these tiny fossils underneath the microscope, a sense of awe overcomes you as you realise that YOU are the first person to observe what the rock has hidden away for millions or even billions of years. But I am getting ahead of myself…
I am a first year MSc student in South Africa and had the opportunity to travel to Uppsala, Sweden to work with Malgorzata Moczydlowska-Vidal at Uppsala University. This was a tremendous opportunity to learn how to process rock samples for microfossils in a world-renowned scientist’s lab. This training was extremely vital as I plan to compare microfossils of the Vanrhynsdorp Group, South Africa and the Vestertana Group, Finnmark, northern Norway. These Groups are of significance as they span the Ediacaran-Cambrian boundary (~541 million years ago). The study will contribute to understanding the nature, behavior and diversity of microorganisms before and during the “Cambrian explosion” – a geologically sudden event when complex marine organisms become abundant for the first time. Microfossils are useful as biostratigraphic markers as the presence of different species at different intervals can pinpoint time periods and correlate rock formations from different locations around the world.
With all this in mind, I embarked on a week long journey in Malgorzata’s lab where we dissolved rock samples from South Africa. The fun side of lab work are the cool outfits you get to wear! Safety is of utmost importance but whoever said you can’t look good while doing it?
On a more serious note, hydrofluoric (HF) acid is used as it dissolves silica (a large component in rocks) whereas organic compounds are resistant and do not dissolve. However, HF acid is also capable of dissolving glass and human tissue, so extreme care is used when handling the acid. In light of this, a small disclaimer is needed – do not try this at home! Scientists have special labs and equipment that allow them to work with these dangerous chemicals. However, the exciting part begins once the rock is dissolved and this can take ~2 days.
Once the sample is dissolved, the moment of truth arrives. The bottom-line: the darker the residue, the higher the organic content in the rock and the higher the chance of fossils. From there, the samples are washed thoroughly, boiled in hydrochloric acid to dissolve other minerals, filtered and mounted onto microscope slides. Identifying microfossils underneath the microscope can be tricky but there are a few key things to look out for: 1) sharp boundary of the object, 2) shape, and 3) colour. Depending on the age of the rocks and the species of microfossils, the specimens can range from looking like wrinkled blobs to beautifully complex structures. Regardless, the information they can reveal is invaluable. At the moment, I am still in the preliminary stages and learning all I can about microfossil work before I find any of my own specimens! Wish me luck as I embark into this ‘small’ and exciting world!
The Cambrian explosion is one of the most well known events in Earth history, during which most major modern metazoan phyla appeared. Prior to the Cambrian explosion (namely in the Precambrian, the largest time span in Earth’s history) animals were scarce, skeleton-less, and weird looking. Although a few of them may show similar morphology to modern sponges, comb jellies and jellyfish, the majority represent unknown clades which are believed to have died out. During the transition from the Precambrian to the Cambrian, there were quite a few fossils, which look similar to some creatures living today. They are not easily placed in the tree of life tree just because of their simple appearances. One of these enigmatic organisms is called Sabellidites cambriensis.
Sabellidites was a tubular animal that lived about 542 million years ago. It has a pure-organic tube, giving it a black and sometimes shiny look. The surface of the tube is either smooth, with fine furrows or wrinkles. The characteristically wrinkled tubes are 0.2–3.0 millimeters wide and up to 16 cm long. But flattening always happened during burying, so most of the Sabellidites fossils have a ribbon-like rather than a tubular appearance.
This fossil was first found by a former Soviet Union scientist named Yanishevskii in 1925 in Petrograd, USSR. Later on, researchers claimed the occurrences of Sabellidites in other parts of the East European Platform, China, Serbia, Canada and northern Scandinavia. Contemporaneous to Sabellidites are other diverse animals, which have a hard bio-mineralizing skeleton, such as Sinotubulites, Cloudina, Namacalathus and Nama-poikia. Quite different from them, Sabellidites is unique for its organic tube The tube has discrete layers composed of differently orientated fibers embedded in an amorphous matrix. What´s more, evidence from biogeochemistry shows that this organic tube contains β chitin. The closest animal, which has both β chitin and similar morphology of the tube, is the family Siboglinidae. Thus some scientists group Sabellidites as an extinct member of the family Siboglinidae within the phylum Annelida.
Siboglinidae, also called beard worms, are composed of about 100 tubular species, which live in sediments at ocean depths from 100 to 10,000 meters. Most siboglinids are less than 1 millimeter in diameter but 10–75 centimeters in length. The tubes are often clustered together in large colonies. The worms have a complex closed circulatory system and a well-developed nervous system, but as adults, siboglinids lack a functional mouth, gut and anus. But that does not mean adult siboglinids can survive without assimilating any nutrients. These worms derive energy from a special storage organ, which is called a trophosome. Tons of microbes live here and produce enough organic matter for their hosts. Siboglinids are dioecious, which means each individual is either male or female. The fertilized eggs hatch to produce small paramecium-like larvae. But after they grow up, they lose the ability of free movement and become sessile.
However, there are still a lot of unsolved puzzles and debates about this fossil. Recently, scientists from all over the world gathered in Tromsø (Norway) and Uppsala (Sweden) to study and discuss the morphology, phylogeny, taphonomy and palaeo-ecology of Sabellidites from the Digermulen Peninsula and the East European Platform.
For the 32nd time the Nordic Geological Winter Meeting was launched, this time hosted by the Geological Society of Finland at the Kumpulan Campus in Helsinki, January 13th – 15th. A well-attended meeting it was, with the wonderful mixture of geological subjects this kind of meetings bring together over the short span of three days. Besides presenting your latest work and projects, much of these conferences is about meeting friends, colleagues, and chat about all aspects of geology. E-mail, Skype and similar cannot compete with the human experience of talking to each other face to face, really.
This time the Digermulen Early Life Research group was only represented by one participant, and a synopsis of the two GSA talks last autumn on the Ediacaran part of the succession was given. Because of new data presented at the meeting, the talk had to be adjusted to accommodate for this.
The breaking news is this: on the Digermulen and Varanger Peninsulas the Mortensnes glacial deposits have traditionally been tentatively correlated with the Gaskier glaciation, that is around 580 million years old, being separated downwards from the Marinoan (Cryogenian) glacial deposits of the Smalfjord Formation by some 400 m of siliciclastics. This very characteristic tripartite succession is typically seen in several places along the Caledonian mountain chain, all the way to the Mjøsa area in southern Norway.
Now, Risto Kumpulainen, Johan Petter Nystuen and colleagues have dated a dike that cross this tripartite package, giving a minimum age of 596 million years. Therefore the Mortensnes equivalent glacial deposits must be older than this and older than the Gaskiers which is at ~580! For our favourite succession, this means that a massive gap should be present somewhere between the Mortensnes Formation and the overlying Stáhpogieddi Formation where we find our Ediacaran fauna. Fascinating possibilities that will lead us to even more questions, no shortage of work for our group in other words.
The feeling just before heading out into the field for a few weeks is chaos but also a great deal of anticipation. Especially the food supplies can be challenging. Eight people for two weeks means a lot of food that needs to be brought along and suited for everyone. This year our group has an addition to which all this is very new. Zhiji Ou, a PhD student from China arrives late Sunday night, and the following Monday morning we leave Tromsø heading north with Tanafjord and the Precambrian – Cambrian of the Digermul Peninsula as our goal. To Zhiji this entire trip may be confusing with lots of new things to take in, including different food, but he sorts things out and settles in.
The cars are packed with everything from dried food, chocolate bars, tents, sampling bags and a toilet seat. The drive from Tromsø to Lakselv, where we meet up with Magne and Guido, is long, but well worth the time.
Arriving at the harbor in Sjursjok and meeting with our local fishermen Trygve and Joakim is always good, it means a large part of the journey to the field site is done, everyone is in place and what remains to be done is get to the campsite and set camp for the night. There´s even time to fish for dinner making it easy to fall asleep in your tent.
Our targets for the coming two weeks are some of the earliest trace fossils of complex animals we can find and the evolution of ancient seafloor communities in the Early Cambrian, 540 million years ago. We also hope to find fossils of the first complex, visible animals, part of the even earlier Ediacaran fauna, on Digermulen they can be as old as 570 million years. Happy hunting!