SSP
Stratigraphy, Sedimentology and Palaeontology

Stratigraphy, Sedimentology and Palaeontology

You wouldn’t go in the early basement during the upper afternoon, don’t you?

I remember it perfectly. It was 13 years ago, while writing my first manuscript, I was first confronted with that thing that challenges a lot of junior stratigraphers, especially when they are not a native English: Geochronology vs. Chronostratigraphy! Or to simplify, how to properly distinguish time and time-rock units in your writings.

Several papers have been published on this subject, out of which I would recommend the recent Zalasiewicz et al. (2013). But, although these papers do provide a very clear scientific explanation on this subject, I always remember myself 13 years ago and how difficult it was for me back in those days to understand these concepts!

So, is it that difficult? Or is there an easy way to spot the light at the end of the tunnel? Well, if you have spotted the oddness in the title of this blog, the good news is that you have already made 3/4 of the way. Of course, the trick is in the use of early/late vs. lower/upper, that is to say on the distinction between time (geochronology) and space (chronostratigraphy), respectively.

Let’s have a little test to check that. Which of the following five sentences are wrong?
1. The late Bajocian is 500m-thick in this region.
2. The upper Bajocian can be correlated throughout this region.
3. The lower Bajocian has experienced environmental changes.
4. A carbon cycle perturbation occurred during the early Bajocian.
5. The lower Bajocian carbon isotope excursion.

Without having too much suspense: it’s the sentences 1 and 3 that are wrong.
In sentence #1, the term “late” is used whereas the sentence makes reference to time-rock unit, i.e. chronostratigraphy. Here, Bajocian refers to the thickness of the sedimentary sequence, so one should use the term “upper”. However, if you insist on using “late”, then you should write the sentence as following: “The thickness of the sedimentary succession dated from the late Bajocian is 500m”.
In sentence #3, we have the opposite case, i.e. the use of “lower” while referring to time, i.e. geochronology. It is as odd as “having a meeting in the upper afternoon”.

There you go, you have done 3/4 of the way. What about the last quarter? The answer is in sentence #5. It is indeed correct, and refers to the carbon isotope excursion you have measured in the Lower Bajocian, i.e. in the section you have worked on. But writing “the early Bajocian carbon isotope excursion” is also correct, but this time it refers to the carbon cycle perturbation that has occurred during the early Bajocian. You know… the one that is recorded in the lower Bajocian! But never say that it is recorded in the early Bajocian, that would be wrong.

Reference:
Zalasiewicz, J., Cita, M.B., Hilgen, F.J., Pratt, B.R., Strasser, A., Thierry, J. and Weissert, H. (2013) Chronostratigraphy and geochronology: A proposed realignment. GSA Today 23, 4–8.

Author: Dr. Stéphane Bodin, University of Aarhus

 

Tiny but powerful

Oceans are “populated” by millions of specimens of microscopic organisms which constitute the phytoplanktonic communities (e.g. diatoms, dinoflagellates, cyanobacteria and coccolithophorids). These tiny organisms are important indicators of the “health” of present oceans and their remains constitute important tracers of past paleoenvironmental conditions. The ocean is in fact the oldest and largest ecosystem on Earth and best records global changes in climate and atmospheric composition, as well as major variations in physical, chemical and trophic parameters. This is particularly important since recent environmental changes, pose urgent questions regarding biota ability to cope with rapid and progressive climatic changes accelerated by anthropogenic emissions of greenhouse gases. A major issue of present global environmental perturbations, regards the impact of rapid warming and climate instability on ecosystems. Concerns are therefore addressed to the possibility that biodiversity loss will soon derive from biota failure in sustaining such profound alteration of ecosystems.

(http://darwinproject.mit.edu/)

 

It is well known that increasing COis inducing pH lowering. This has an effect on CaCOsaturation state and calcite compensation depth in the oceans with consequent problems for calcifying organisms such as corals and microplankton: these groups become vulnerable and unable to produce their shells-skeletons if the acidity passes a critical level. At present, decreased calcification could have negative impacts not only on marine ecosystems, but also on marine food chain (and resources) at global scale.

Coccosphere of E. huxleyi (http://www.nhm.ac.uk)

 

One phytoplanktonic group which can provide important information regarding past and present response to environmental perturbations is constituted by coccolithophorids. Coccolithophores are golden-brown algae (phylum Haptophyta) which live in the upper photic zone and that developed the ability to secrete tiny calcite crystals and arrange them to build an exoskeleton called coccospheres.

Although these algae are extremely tiny (a few microns), they are important primary producers. The biocalcification process made coccolithophores rock-forming organisms during the Jurassic and Cretaceous and they were/are directly involved in the total carbon budget by influencing the carbon cycle via photosynthesis and biocalcification. We understand how these organisms are widespread in the oceans and, consequently, important for the carbon cycle by looking at blooms of the coccolithophore E. huxleyi which are visible from space!

Under certain conditions, Emiliania huxleyi can form massive blooms which can be detected by satellite remote sensing. The white could is  the reflected light from billions of coccoliths floating in the water-column. Details: Landsat image from 24th July 1999, by Steve Groom.

One commonly used approach to derive projections of how ecosystems will look in the future is to perform experiments on living forms. The data obtained from several experiments over the last decades, evidenced a direct impact of increasing COemissions on coccolithophores but several questions are still open regarding the mechanisms involved during biocalcification and the role of combined high CO2 with other stressing factors. Scientists have to work to understand the capability (and velocity) of coccolithophores to adapt to these environmental changes as well as to understand the interaction of different parameters on biocalcification and their effect on the ocean/atmosphere system.

Additional methods of investigation can be applied to model the evolution of the ocean from the recent past to the near future, as for example presented in a published work based on satellite observations. The dataset indicates that the Arctic Ocean and its surrounding shelf seas are warming much faster than the global average, potentially opening up new distribution areas for temperate‐origin marine phytoplankton. The data already show that increased inflow and temperature of Atlantic waters in the Barents Sea resulted in a striking poleward shift in the distribution of blooms of E. huxleyi (Neukermans& Fournier 2018).

Fossil coccosphere of Watznaueria barnesiae (Black) Bukry 1969 (http://ina.tmsoc.org).

 

Last but not least, geologists can obtain important information which cannot be acquired via laboratory experiments. For example, it is not possible to capture the ability of organisms to migrate or to select and evolve. Experiments are often limited to a select few species and cannot represent the complexity of ‘real’ ecosystems. Moreover, “environmental scientists” deal with time scales of day to decades but geoscientists work on records of thousands to millions of years and look at the largest “natural laboratory” on earth captured in sedimentary rocks and their fossil content. Only through the combination of the information that can be gained via experiments, via new techniques and the study of microfossils, scientists will be able to help understanding the Earth system at longer time scales (than human observations) and make prediction about the response of our planet to profound climatic perturbations.

Outdoor water-based ceramic sculpture ‘Coccolithophores’ by Michelle Maher at Sculpture in the Gardens 2010 at Brigit’s Garden, Co. Galway. The piece was inspired by a microscopic algae organisms the Coccolithophore. www.ceramicforms.com

References

Griet Neukermans and Georges Fournier, Optical Modeling of Spectral Backscattering and Remote Sensing Reflectance From Emiliania huxleyi Blooms, Frontiers in Marine Science, 10.3389/fmars.2018.00146, 5, (2018).

When lava meets water…

When lava meets water…

Pillow-palagonite complex forming as a result of hot lava entering a former river channel or lake in the Columbia River Flood Basalt Province, Washington State, USA (c. 15 My). Individual sediment packages were picked up from the bottom of the water body and trapped within the lava complex (see white arrow). Orange-brown palagonite is a type of clay which forms through the break-down of volcanic glass that surrounds the basaltic pillows.

EGU’s lost strata… what happens to conference carpets?

Being a stratigrapher or not, there’s one stratum you have all trod upon if you ever went to the General Assembly (GA), without probably noticing it. The uppermost unit of EGU’s GA floor, a ca. 5 mm thick layer with a soft rubbery texture and peculiar light-grey colour, outcropping over the whole poster halls: Carpet! Yes, the focus of this post is the carpet draping the GA’s floor with its lifetime of 5 days and yearly recurrence.

We never thought about it, until we thought about it all the time. This brand new carpet, specially produced for our yearly geoscience event, 12.000 m2 (1), put here for 5 days of conference. And then what?

The growing queue on Friday evening to enter the conveners’ party is the perfect occasion to take a walk through the halls and observe the methodical deconstruction that happens during the whole night. And yes, carpet seems to be thrown away. After asking Copernicus (the company that organizes the EGU meetings, 2), which called the company taking care of mounting and taking care of the infrastructure, which explained that they employ another company for carpet disposal, it is uncertain what actually happens with this material.

This beautiful grey carpet…

Carpet waste in numbers
As far as we know, this process repeats every week for every meeting, and at most conference centers in the world. That sounds like a consequent amount of carpets… The topic has actually already attracted the attention of the “ZeroWaste” environmentalists, and there is a huge amount of information and references in their reports which we will not retranscript here (3, 4). Here is a brief summary in numbers:
-700 Mio. m2 of carpet were sold in 2016 in the EU, 11.7 Bn. m2 in the USA;
-1.6 Mio. tons of carpets are thrown away yearly in the EU;
-Without transparent information, the authors of the report “believe” that only 3% of this carpet is recycled (actually down-cycled);
-97% (= 1.552.000.000 kg) ends up in landfills or is incinerated;
-Some organisations claim that they recycle large parts of their carpets, however, in many countries, incinerating waste to collect heat is considered as recycling. The Cannes festival for example claims that they recycle 100% of their carpet (5), comparing numbers from the French website, it’s actually 16 tons out of 80 that come to recycling, which is barely 20%.
THAT’S OUTRAGING, SOMETHING HAS TO BE DONE!

We, the EGU community, can change the norm
We truly believe in EGU, we truly believe in our good intentions, we embrace EGU’s motto that “we are a bottom-up organization”, that our Early-Career-Scientists (ECS) are given a special place and voice, and that we all agree that wasting carpet makes no sense. We really see that EGU can become an environmentally-friendly meeting that will find a solution and become a model for recycling conference carpet. EGU already offers reduced train fares for their participants, the possibility to compensate carbon emissions, they made an effort on reusable water-skins. This carpet challenge is only the reachable next step!

We thought about it for the case of the GA, and well, there are a few constrains that cannot be tackled easily:
Noise reduction: In a hall containing 15.000 geoscientists hydrating themselves with free beers, the sound volume increases rapidly, and carpets might be useful to reduce resonance (although this should really be measured);
Flexibility: The event industry should be able to transform the space for its need, so that swarms of different holes in the carpets will be created for each occasion. Thus consequent parts of a carpet floor still need to be changed on each occasion;
Cleanliness: Carpets can become dirty very fast, especially with free red wine. It is not sure that chemical cleaning products would be better for the environment than recycling carpets;
Industry: There is a strong “event-carpet” market. Forcing the re-use of products would have a negative impact on it, and it is often wise to find a solution together with the industry.

Under these conditions, it seems that single-use carpet remains the easiest solution for a while. Other solutions would imply consequent re-structuration of the halls for noise reduction, force a fixed exhibition format to the event industry, and disturb a well-established market. This could confront us with more opponents than supporters.

The Austria Center of Vienna (ACV, the building hosting EGU, 1) is neither in charge of carpet, nor of waste management, yet they provide containers for disposal. This is somehow a good news, since it means that Copernicus has the full freedom to decide what happens with the waste of EGU.

A recyclable design, that gets recycled
The current dominant carpeting is manufactured with multiple layers (the face fiber i.e. what we see, and several backing layers, where the fibers connect to) made of different types of material (nylon, polypropylene, PET, PVC, latex) that are glued together and really hard to separate. This sandwiched mixture is thus, in its design, near impossible to recycle. But solutions exist for almost 100% recyclable carpets.

Now come the subtle differences of the green washing vocabulary. It’s not because something is recyclable that it is created with recycled material, and unless they are collected and sent to a recycling platform, recyclable materials won’t recycle themselves.
There’s also a consequent difference between “down-cycling”, i.e. recycling into a product of lesser quality and real “closed-loop” recycling, whereby a carpet is recycled as… a carpet.
Finally, many claim to “recover” their waste without further explanation. It usually means that the waste is burnt to produce heat (energy recovery). -Germany, the European leader in recycling claims to recycle 65% of its total waste. Actually they collect 65% of their waste in a sorted fashion, but 35% of it is actually incinerated for “energy recovery” (6). There seem to have been a law proposal in the EU to exclude burning from the numbers, but guess who voted against? Germany did, but we’re going off topic here.-

Money
The commonly used “partially” recyclable carpet costs about: 1.20 Eur/m2 for an area of the size of the AVC halls (12.000 m2), according to quotes by French carpet company “Beaulieu”. This is a cost of around 14.400 Eur for one of our GA. The cost for a 100% recyclable carpet floor would be only 0.2 Eur/m2 higher, adding a total extra-charge of 2400 Eur). Using carpets 100% recyclable would thus induce an over-cost of less than 0.16 Eur per participant in the GA. Who would disagree?

Existing solutions
There is another large meeting hosted by ACV, the “European Radiology Congress” (>20.000 participants, 7), which took care of their carpet problem. They are provided by the company Alma, which produces the “Kenafloor” (8), a needlefelt carpet made of kenaf (9) and 100% biodegradable, as well as the “Alma Green” a carpet 100% recyclable …into carpet (10). And the waste management company of the European Radiology congress confirmed that all carpets ends up in a recycling chain. One step further, the European Radiology Congress is also organized as a “green meeting” (11). This is a Austrian certificate that a meeting can reach by accomplishing some environmentally friendly points, and the ACV Vienna is habilitated to deliver it. The ACV even provide assistance to reach as many points as possible.

So in conclusion, solutions and working examples exist. We’d love that our whole EGU community, members, Program Committee, ECS representatives, the Copernicus office, and the ACV work together to walk on sustainable carpets for the next GA. And why not target in the same time to reach the “green meeting” standards?

Guilhem Amin Douillet & Vanille Ritz

References
(1) The website of the Austria Vienna Center states that they have 22.000m2 of space, 12.000 of them for the four exhibition halls (https://www.acv.at/planen/raeume/index.html?0)
(2) Copernicus is the society that organizes the EGU meeting, as well as became an ethical open access publisher, and offers its service for organization to other meetings. https://www.copernicus.org/
(3) http://changingmarkets.org/wp-content/uploads/2017/04/French-Carpet-Report-English.pdf
(4) http://www.no-burn.org/wp-content/uploads/SWEPT-UNDER-THE-CARPET_high-res-DECEMBER-2016.pdf
(5) https://waste-management-world.com/a/red-carpet-recycling-for-veolia-in-cannes
(6) http://ec.europa.eu/eurostat/documents/2995521/5180394/8-25032014-AP-EN.PDF/a266b63d-3fb3-4b27-8a97-4dcc44c600c1?version=1.0
(7) http://ecrcongress.org/
(8) http://almaspagreen.com/Alma_Green_Eng/files/assets/basic-html/index.html#1
(9) https://en.wikipedia.org/wiki/Kenaf
(10) http://almaspa.com/prodotto_ted.php?id=64&c=6
(11) https://www.acv.at/planen/green-meeting/green-meeting1.html