Sine-Saloum Delta, Senegal. A tiny exploration.

I recently spent a few days in the Sine-Saloum delta in Senegal.  You have likely never heard of this delta and that’s not surprising. It’s small and not very well researched. As a delta sedimentologist, I was mesmerized by the little bit that I discovered on location and by reading up on it later. Like all deltas, people have interfered with it for a long time, thought not at the extent of e.g. the Rhine or Mississippi Deltas, but still – it’s impossible to write about it without mentioning human activity.

Western Senegal and the Sine Saloum Delta. The distance from the city of Kaolack to the coast is ca. 100 km. We explored the delta from the small fishing town of Djiffer

The delta is formed by two rivers, the Sine and the Saloum. This area, at roughly 13degN, is on the southern edge of the Sahel region, which has experienced increased and devastating droughts since 1970s, as as result of which the flow of the rivers is so small that this has become is a Reverse Estuary: the salinity of the water increases in a landward direction. Precipitation is controlled by the West African Monsoon, which has a regional variability across Senegal. In the area of the Sine-Saloum Delta, annual rainfall averages between 850-1000 mm, almost all of it falling between June and October (Raj et al., 2019). The tide range at the coast is semi-diurnal with a maximum range of ca. 1.5 m.

This area is part of the Senegal Basin, the sedimentary wedge here is more than 4,000 m thick. I have not been able to find what the specific geologic basis for this modern, relatively small drainage basin is. The much larger Senegal River basin is hundreds of kilometers to the North and the sizeable Gambia River basin ca 100 km to the South. Many of the big rivers on this side of the continent are situated along Precambrian basement structures, but again, I haven’t found out the reason of the Sine-Saloum topographic low.

Part of the delta coastline was was declared a Ramsar International Wetland in 1976 ( It deserves this recognition because it is an important wintering habitat for (northern) European migratory birds. Because we were there in February, we saw storks, spoonbills and many European wading and meadow birds such as oyster catchers and curlews.

The area received recognition as a UNESCO World Heritage Site in 2011 ( The WH designation is earned for its universal value as a cultural landscape, namely more than 200 magnificent shell middens, some hundreds of meters long and several meters high. Twenty-eight of the mounds have burial sites with remarkable artefacts. Prehistoric people lived here since at least 5,000 years BP.  UNESCO: “The middens are important for improving the understanding of historic cultures and testify to the history of human settlement along the coast of West Africa”. The historic middens consist mostly of the West African blood cockle (Anadare senilis). An analysis of the growth patterns and monthly resolved δ18O profiles of some of these bivalves in one of the prehistoric middens suggests that the West African Monsoon (WAM) has shifted over recent times. The time interval studied, 460-1090 AD, was consistently wetter than it has been in the 20th century, possibly because of a shift in the Atlantic Meridional Overturning Circulation (Gulf Stream)

One of the many middens, almost entirely consisting of shells of the bivalve Anadare senilis. This midden is on the grounds of a guest facility.

The conservation efforts have led to a bit of tourism and hence some income for the local population, the Sereer people. This group fled from ca. 300 km further north along the Senegal River to the Sine Saloum delta ca. 800 years ago. They fled the islamisation of the region and remain mostly Catholic to this day. They are therefore unrelated to the prehistoric people who built the middens.

The Sereer people do not eat blood cockles, they eat only the swamp oyster (Crassostrea gasar), which grows massively on mangrove roots in the delta. Only women harvest the oysters. They live for several months in makeshift camps in the delta. They harvest the oysters at low tide, cook, shuck and dry them. Then – so we were told – they are packed and sold. Oysters are highly prized so the women have a parallel (cash) economy. The oyster harvesting also results in middens, and they too are big, as we witnessed (see below).

The men fish offshore and in the mouth of the estuary in their big, colourful hand-built pirogues. The fishing stocks have declined and it’s hard to make a living. The fish (kettlefish and sole, among others) is exported in cooled trucks directly from the dock in Djiffer and shipped to Europe. There is sardine fishery too, but this is done only by Guineans, not by the Sereer. The sardines are cleaned and dried and exported.

Pirogues in Djiffer 

We boarded our pirogue in Djiffer, now the southernmost point on this long sandspit (the longshore current flows from North to South, obviously), but it hasn’t been the southernmost tip for long, because the spit was breached by a storm in 1987 and the breach has never healed. The Ramsar Wetland is the uninhabited spit remnant south of the river mouth.

Two pictures taken just South of Djiffer. River mouth is to the left in the LH picture. Active sediment reworking takes place. In the RH picture our guide (a local Sereer man who was very knowledgeable and spoke both French and English as well besides his native language Wolof) points to the remains of mangrove roots which were cut down by local people here until a few years ago. 

There was much wave breaking at the river mouth, so it’s very shallow – a dynamic sandy environment. After the spit breached, some shore parallel sediment reworking took place along the inner part of the delta. Mangroves were cut cut down for firewood until a few years ago. As our guide said “yes, they used to cut mangroves, they had to cook food and there was no propane, what choice did they have?” Now that propane is available again, the mangroves are beginning to grow back, providing much needed protection against erosion. They are also actively planted and are regrowing well.

Swamp oysters (Crassostrea gasar) growing on Mangrove roots along the tidal channels in the delta. 

We stopped at one of the modern-day Oyster middens. It was late morning and the women were asleep in their hut and we didn’t disturb them. This modern oyster day midden is enormous, it’s even visible on Google Earth!

Clockwise from top left: Modern Oyster midden that we visited visible on Google Earth; an impression of the relief of this modern midden; unvegetated area landward of the midden; processed oysters drying in the temporary camp of the women.

Behind the oyster midden, also visible on the satellite image are bare areas. My guess is that these flood only during Spring tide and that the soil has become so saline that nothing else grows there the rest of the time. But I’ll happily be corrected.

Artisanal salt mining

Small scale salt mining has massively changed the supratidal flat areas. It looks like this industry involves exclusively local, informal labour (including children), the salt is bagged and shipped off by large trucks.

Artisanal salt mining a few kilometers NE of Djiffer. Left hand panel: Google Earth image showing the supratidal flats dotted with hand-dug salt pans. Top Right: salt pans are ca 5 meters across. The humps in between are mounds of salt, usually covered with tarps, waiting until the salt can be bagged and exported. Lower Right: uncovered salt mound with some beautiful cubic NaCl on my hand. 

Fantasizing about the sedimentology here, I was trying to come up with a schematic sequence for this delta and realized I don’t quite have enough information to sketch one. Its main components are fine sand, mud, evaporites and colonies of Oysters and Cockles. I’d love to find out more. And I’d love to return.


Azzoug, M., et al., 2012, Positive precipitation-evaporation budget from AD 460-1090 in the Saloum Delta (Senegal), indicated by mollusk oxygen isotopes. Global and Planetary Change, v. 98-99, p. 54-62.

Azzoug, M., M. Carre and A. Schauer, 2012, Reconstructing the duration of the West African Monsoon season from growth patterns and isotopic signals of shells of Anadara senilis (Saloum Delta, Senegal), Paleogeography, Paleoclimatology, Paleoecology, v. 346-347, p. 145-152.

Ecoutin, J.M., M. Simier, J.J. Albaret, R. Lae, L. Tito de Morais, 2010, Changes over a decade in fish assemblages exposed to both environmental and fishing constraints in the Sine Saloum estuary (Senegal). Estuarine, coastal and shelf science, v. 87, no. 2, p. 284-292.

Hardy, K., A. Camara, R. Pique, E. Dioh, M. Gueye, H.D. Diadhiou, M. Faye, M. Carre, 2016, Shell fishing and shell midden construction in the Saloum Delta, Senegal. J. of Anthropological Archaeology, v. 41, p. 19-32.

Raj, J., Hamza Kunhu Bangalath, G. Stenchikov, 2019, West African Monsoon: current state and future projections in a high resolution AGCM. Climate Dynamics, v. 52, p. 6441-6461. Open Access:

Vidy, G., 2000, Estuarine and mangrove systems and the nursery concept: which is which? The case of the Sine Saloum system (Senegal). Wetlands Ecology and Management, v. 8, p. 37-51.

Posted in coastal systems, General geoscience, Geoheritage | Leave a comment

Our First Full Year under Solar Power

The quiet revolution on our roof started a year ago and we’re loving it. So here’s everything you have always wanted to know about installing solar power (in Nova Scotia).

Location location

We live at 45N on the right side of the continent, exposed to the Labrador current. Result: very cold winters. We average 1,806 sunshine hours per year, distributed over 287 days (source).

In 2002 we rebuilt and expanded this modest 1950 bungalow into a roomy house. We did look into installing heat pumps then but the house never had ducts, and we didn’t want the (extra) construction. We added a studio (for my artist husband). The studio is expensive in winter: it’s a separate 324 sq ft (36 sq m) building on a concrete slab with in-floor heat supplied by its own hot water tank. It’s very well built and insulated but still costly. The studio heating system is completely turned off from mid-May June to mid-October. It has a programmable thermostat; the artist doesn’t keep it very warm and uses a stand-alone space heater (and special studio woolly!) when he is there on cold days. We don’t have air conditioning anywhere.

The original bungalow never had a furnace. It was heated with wood and electric baseboards. We upgraded the latter to efficient electric radiators and installed a programmable thermostat in each room. The house has an insulated basement which contains utilitarian spaces that don’t need (much) heat. The basement also contains the guest room which faces the garden and two of its walls underground. We have an airtight wood stove which essentially heats the main floor (living/dining/kitchen, our bedroom, my study). It burns through 2 cords (7.2 m3) of hardwood between early December and early April. In the middle of winter, the stove burns 24/7 for about two months. The house and studio are 3,200 square feet (356 square meter) large with standard 8 ft (2.30 m) ceilings.

Because it never had a furnace, the electricity bills were always high, wood stove or not.

Here is our house on Google Earth – the red roof is us. The solar panels are on the front (dark triangle). The front of the house is oriented SSE. 

This picture was taken in March from the front steps looking south. There is a big maple tree on the corner of the property (left in this picture) but it never gives shade. The big house to the right sits higher and is surrounded by large deciduous trees. When the sun is lowest in winter, those bare trees (on the right in the picture) do actually block the afternoon sun, as we’ll see later. 

Research and investment

Our research was made simple thanks to an energy expert friend who provided free advice. He organized a field trip to the house of someone who had installed solar panels and we got to see the whole thing and ask every question we could think of. They had also thoroughly researched solar panel companies so we went with their advice and recruited Fundy Solar out of Moncton, NB.

Before we continue, this fact sheet tells you what earth materials are used to make solar panels.

The prognosis for our house, given its exposure and the number of panels we could install, was that we would produce 4 to 4.5 MWh. We decided that would be worth the investment because that could be 1/3 of our annual total electricity bill (sneak preview: we produced 4.42 KWh, indeed almost 1/3 less than our previous power bills!).

We signed the contract with Fundy Solar in the late Fall of 2015. The total bill was Can$15,000 for 15 panels. The price has since dropped of course. Had we been able to add more panels, it would have been cheaper per panel (i.e. I’m not suggesting it was $1000/panel, that was an accidental outcome). There is no subsidy for adding renewable energy to the grid in Nova Scotia, the investment was ours.

We don’t store! We didn’t want batteries and a whole separate wiring system. We have a contract with Nova Scotia Power: we provide power to the grid and get reimbursed at the standard rate. Other (Canadian) jurisdictions have incentives for solar, such as a one-time subsidy and/or a higher price for energy produced, but that’s not the case here.

Because we are now an electricity supplier for Nova Scotia Power, they have a role in it as well. NS Power inspects the installation of the panels twice, once at rough-in stage and once at the very end. Fundy Solar installs the panels, but the electrician is independent and is licensed by NS Power. The licensed electrician meets twice with the NS Power technician at the property for the inspection. After the last inspection, NS Power installs the 2-way meter and flips the switch!


What it looks like on the outside of the house and in the meter-closed right behind it. The diagram shows all the technical details, the box below it is part of the Enphase system, which I talk about below

The bill from Nova Scotia Power now includes two meter readings, one for KWhs used and one for KWhs sent to the grid.

The panels will work efficiently for at least 20 years. By that time newer models will have come out and the future owners of our house will update the system.

Keeping an eye on those lovely data

The truly fun part of this adventure is Enphase, the internet-based system that lets you keep track of what your panels produce and do all the statistics. Enphase tells you every 15 minutes how much the panels have produced and there’s an app of course, so you can check your panels’ workings wherever you are in the world (and our solar company has access to our Enphase as well, so we can communicate about possible failures with them).

Enphase’s output for 4 very sunny days close to each solstice. The system gives a reading every 15 minutes. 


Cumulative production in Wh from May 6 2016 to May 6 2017, our first full year. The blue accolade shows that we produced not quite 500 kWh between early November and early March. In other words: almost 90% (the other nearly 4,000 kWh) was produced during 8 months. Production during the 4 winter months is almost negligible.


We have a metal roof from which the snow slides off fairly quickly. The panels are smooth and also function as a slide. But, depending on the amount of snow, it will be on for a few days. Enphase then gives an error warning, which would be the same in case of a power outage (which we didn’t have all year). See picture below. We lost 3 weeks of production to snow, but that was all during the season that the sun is so low and the days so short that we don’t produce anything meaningful anyway. The exception was late March when we suddenly had 2 sunny days under snow.

Panels covered in snow. Most inverters don’t get any input and produce an error message (orange icon in corner of panel)


You can’t not do this even in our jurisdiction which lacks subsidies for solar. We save money every day and we use fewer fossil fuels and are just as comfortable as we were before. So here we are: wood and solar are the way to go in Nova Scotia!

Posted in climate change, Energy | 1 Comment

My Brilliant Career: a woman geoscientist looks back (posted on #IWD2017)

Last November, I gave a talk to the brand new Dalhousie University Chapter of the Association of Women Geoscientists. When I asked the women what they were looking for in a talk, they weren’t very specific other than that they wanted to hear about my career as a woman in earth science. I decided to keep it light-hearted but pertinent.

The feedback was positive and there was even interest from further away (thanks to a Twitter announcement of my talk), so I decided that this was the opportunity for a blog post reflecting on “My Brilliant Career” (this title inspired by one of my favourite movies). Warning: there are Lessons for Women in here! 



1. Why Geology / Earth Science?


This is me in the summer 1969 when I was 16. I’m sitting on a rock in a lake in southern Norway on a family holiday. The picture characterizes me well: I would rather be outside anytime; I was a tomboy. I often say that I didn’t choose geology, it choose me. It suited me. I wasn’t conscious of that for many years because nobody in those days talked about those sort of things.

I’m from the Netherlands originally, a baby boomer. I grew up in the boring ’50s and ’60s (I was just too young for activist ’68 when it came along). Women were expected to be mothers. There was no discussion of careers or choices. Nowadays, women still experience those sorts of pressures although they are more subtle. We must learn to love ourselves for who we are and make choices regarding our future that suit our character.

2. The Netherlands: Undergraduate and MSc 


Left: the Geology department building of Groningen University (now a conference centre). Right: “Actually, we’re here looking for husbands, and if that doesn’t work, we’re getting into nuclear physics”

I did my undergraduate degree at Groningen University in the Netherlands. I started out in chemistry, but quickly migrated out. I then meant to major in biology, but ended up taking geology classes and loved the mapping part. It was eccentric, the department was housed in an iconic, beautiful building, there were hardly any students, I was the only girl.

I started university in 1971. Girls in the Netherlands of my generation and background (upper middle class) typically did not have “working mothers”. None of my friends’ mothers “worked outside the home”. Yes, we did have a few women teachers in high school. They were mostly women who worked “because they had to” (i.e. they had no bread-winning spouse). The exception was my chemistry teacher, who was young, straight out of university, just married and fantastic. She was both demanding and hilarious and incredibly interested in her students as individuals. In hindsight, she was my earliest role model. I reconnected with her 40 years after my high school graduation!

I had many women friends who studied law, medicine, economics, chemistry, biology, but I cannot recall we ever talked about careers those first four years. I think many of us subconsciously assumed that we would end up like our mothers. But all those women friends did really well career-wise, whether they became attached and mothers or not.

I am the only woman to have ever graduated with a BSc in Geology from Groningen University. A dubious honour. But I never thought along those terms in those years. All my male fellow geology students were great pals. They had completely different backgrounds from me: many of them came from small rural towns close to Groningen. Not only was I the only girl, I was the only one “from away”. These guys weren’t part of my close social circle. In hindsight, I probably missed out on a lot of geo-socializing and likely also career-talk because of that situation, but I never thought about it. I was never very “girly” and I’m also not the timid type – I speak my mind. It was a good atmosphere.


Fieldwork in the early ’70s. 

Here is one of my long-haired fellow geology students. It was the ’70s, so all men looked scruffy. We went on many long field trips and I can’t remember how I negotiated the bathroom issue. More than 15 years later, when I began a teaching position at Utrecht university, the women geology students demanded that there would be two proper bathroom stops each day on each field trip. I was so impressed by this – completely reasonable! – demand. And I became acutely aware that I never asked for such a simple accommodation myself when I was a student. In my days, you simply adapted to the male world, you acted like a guy, because if you didn’t, you clearly couldn’t manage, you failed. Nobody thought that conditions should .change for women to enable them to fully participate.

I can’t recall finding the lack of bathroom stops a difficult challenge. Indeed, I did as the guys and when I had a period during long field days, I managed somehow – I can’t even remember how.

I was at a complete loss of how to proceed after my BSc. A year earlier I wanted to drop out and become a nurse. Fortunately my dad told me that was fine, but I had to finish my BSc first. Other than that, I experienced no career counseling. When I did get my degree (all in time and with good marks), becoming a nurse was no longer my ambition. I had decided to get my geography teaching certificate. So I ended up doing an MSc thesis on late glacial geomorphology of an enigmatic feature in the northern Netherlands, and – as a minor – I spent a semester learning about what is now called Geomatics and then I discovered Sedimentology, as a second minor (yes, it was a demanding program). Really, Sedimentology became my MSc more than the glacial thesis (which proceeded at glacial speed). I did get that teaching qualification. My parents approved.


Sedimentology fieldwork in the Oosterschelde estuary, Netherlands. Top left, our Research Vessel. Top Right: our 2×2 m tarp-covered observation station, on top of a large pylon rammed into the tidal shoal (picture at low tide). Below right: using the 4 hour low-tide window to insert hoses and pumps, enabling us to lower the water table temporarily, so we could dig a trench and make a lacquer profile (below left). The lacquer profile shows reactivation surfaces of multiple high tide events – I used these photographs for sedimentology classes in later years.

For my Sedimentology fieldwork, we worked on a tidal flat in the southwestern Netherlands where the tide range is about 4 m max. We studied the dynamics of sedimentation on the tidal flat, measuring currents and sediment movement throughout one entire lunar cycle. It was real team work and…. there were other women students. It involved a lot of responsibility, it required handling all kinds of gear, including a pontoon-like research vessel, in all kinds of weather and the best part was that sometimes (if it was your shift), you got to spend a night on the 2 x 2 m tarp-covered platform on a post 4 m above the tidal flat. You’d have to get off the platform at low tide to check the instruments out on the tidal flat and you’d be all by yourself on a shoal in the middle of the estuary in the middle of the night. It was terrific. I was hooked – I wanted to study sediments. Not one person had talked to me about what jobs one could pursue with a geology degree, but it was easy to see that studying sedimentology had huge relevance for coastal management (recall: it’s the Netherlands, they are kind of obsessed with battling the sea). Years later, I read John McPhee’s terrific “Rising from the Plains”, which contains this quote: “Geologists tend to have been strongly influenced by the rocks among which they grew up……. The wizards of sedimentology tend to be Dutch, as one would expect…..”. I don’t know that I became a wizard, but sedimentology sure felt like coming home.

It looks like such an odd choice: two thesis subjects in the Netherlands! In that minuscule country! Here’s another thing I learned about myself: I’m a backyard earth scientist: I have an urgent desire to understand the geology of my home base. I could have picked thesis areas in Spain, Germany, even Canada, but I stuck close to base. My furthest fieldwork area was in Belgium, in the Hercynian Ardennes fold belt, where I also worked as a TA during my MSc.

A few months before graduating with my MSc, I attended a conference on Holocene sedimentation in the North Sea. My sedimentology advisor displayed our tidal research theses prominently. There were lots of international participants, among whom quite a few Americans and Canadians: I made connections and ended up as a PhD student at Louisiana State University’s geology department.

3. The Deep South: Louisiana

Really, I didn’t want to to a PhD, but I wanted to leave the Netherlands and I didn’t want to work for an oil company, which would have been a secure and obvious way of getting international postings. Why not? I can’t really remember. So when a prof from LSU invited me to apply to the PhD program and I realized that Baton Rouge was pretty much at the apex of the vast Mississippi Delta  (sediments!), I decided to take the chance. As one of my woman-geologist friend said at the time: “these Dutch people, they can’t stay away from flat delta plains!”

I spent one year as a full-time PhD student and I struggled. I really didn’t want to be in school any longer. I felt incredibly lonely, and I hated being that poor. I considered going back home, but that would be giving up and what would I do there?

After my first year, I landed a summer job with the Louisiana Geological Survey (LGS). I worked on their Geopressured-Geothermal project, a post-oil crisis initiative funded by the US Department of Energy. As a result of the oil crisis of 1973, the world suddenly became aware of the risk of being dependent on oil imports from unfriendly or politically unstable countries. That awareness led to increased government-funded R&D into earlier untapped domestic reserves. Fossil fuel reserves, of course, nobody thought beyond those quite yet.

I loved the job and I didn’t want to go back to being a poor student. At the end of the summer, LGS hired me full time on this project. Less than half a year later, my director appointed me to lead their somewhat foundering “peat project”, also an outflow of the oil crisis (peat burns, in case you wonder). Well, he didn’t just appoint me. He suggested I take this responsibility, he thought I could do it. I was aghast. I had never been in the field in the delta on my own, I knew next to nothing about its modern sedimentology, I had never been a project leader, I was still very new to the country. I was petrified that I would fail. I asked my boss if I could think about it and then I accepted a day or two later.

Lesson for women: no guy would have questioned this obvious promotion the way I did. Not then, not today, 35 years later. Women tend to underestimate their own capabilities, men overestimate them. I know that’s a generalization, but nevertheless. This particular boss was a special human being, one who was a master at encouragement and letting people grow into their potential. I never had a superior like him again. He left LGS shortly afterwards.

The peat project was incredibly challenging. Fieldwork required roaring around the vast Mississippi Delta plain in steaming heat and humidity, having to watch out for alligators, snakes, mosquitoes the size of dragonflies and electrical storms, to name the most obvious. We took hundreds of up to 10 m long vibracores in what ended up being largely floating marshes and tried to make sense of meters and meters of black gooey muck. I had a lot of independence and a lot of responsibility. I talked to world-famous experts on Mississippi Delta sedimentation and found out they had never looked at the muck I was looking at. I took in their advice about how to tackle this material and slowly began to produce results.


Fieldwork in the Mississippi Delta. 

Then came the baby.

I had met a man and fallen in love and gotten pregnant. I was nearly 30, it seemed the right time.

Lesson for women: carrying a baby is still only a woman’s privilege. And whereas times have changed, it’s the woman whose body will get whacked by pregnancy and who has to navigate (field) work around breastfeeding, work travel and other such issues. The mother’s career will likely suffer a greater punch than that of the non-childbearing spouse. And the mother’s career choices will subsequently be more influenced by the question of whether that next career step has any possibility of improving the balance between her, her work, and the the needs of the offspring.

The US is an uncivilized country in many aspects: paid maternity leave is a luxury for some. LGS offered none but my director was extremely helpful given the circumstances. I ended up with 8 weeks, half of which unpaid. Other than cuddling baby, I used my maternity leave to write a paper and lo and behold, it got a ‘best paper’ award! My career was launched.

The fact that our income was insecure and small was a career saver. Lesson for women: once you have a baby, you want to take care of it – your brain actually changes so that taking care of baby is the only thing you want to do (call it instinctive if you wish). But that means that going back to work a few weeks after giving birth is not easy. It feels wrong (guilt feelings!). But I had no choice, we needed the money badly. Had I had a husband with a fancy income, I would likely have caved – at least for quite a while – and just cuddled that little creature in her onesie.

But I went back to work, and was happy quite soon. When my daughter was a year old I realized that I should revive that PhD ambition because I was likely going to remain the bread winner. My “peat project” had become part of LGS’s Coastal Geology Program (turns out you can’t burn Louisiana peat, but it’s a very sensitive part of the Holocene stratigraphy; delta plain erosion and stability depends much on its properties), a program to find solutions for the rapidly disappearing Louisiana coastline and delta plain (I wrote about that subject here). We were now a team of seven young geoscientists and we all pursued our PhD as part of our job, encouraged by our employer.

So when the baby was a toddler, I became Dr. Kosters

Before moving on to the next phase, I need to emphasize one thing. We have just covered 15 years of study and work. I was in the field a lot during those years. Often, I was the only woman in a crew.  I was never sexually harassed, bullied, made to feel inferior or jeered at by any of my male supervisors, colleagues or assistants. This study showed that, out of 666 respondents, only a shocking 25% was never harassed. With many more of these stories now coming to the surface, I feel it’s important to salute the men I was surrounded by for all those years. At the time I thought that was normal (as it should be).

Somewhere in these first few years in the US, I became a feminist. Indeed, it took that long and I have often wondered why because the second feminist wave was almost over by the time I became convinced. I’m pretty sure that I finally started thinking about women’s rights because one of my friends in Louisiana was an Equal Rights Amendment activist and those discussions brought me around.

4. The Deep South: Texas

Shortly after getting that much desired title, I started a job with the Texas Bureau of Economic Geology (= Geological Survey of Texas). “The Bureau” was and is a highly reputable organization, this was an upward move, although I was of course leaving my research behind. I did not mind that. I was ready for new explorations.

At BEG I worked on yet another post-oil crisis project: the “Atlas of Major Texas Gas Reservoirs” (they still sell it!), a data compilation and analysis of more than 4,000 individual gas reservoirs and their specific parameters. I became a walking encyclopedia about Gulf of Mexico gas reservoirs. I was unhappy at times about what seemed an endless tunnel of database building, but I did learn an immense amount about energy security and natural gas reserves.

Had my relationship not gone on the fritz, I would likely have wanted to stay at the Bureau for a long time. It was a well run ship with great job opportunities. I had terrific colleagues and Austin is a nice city on the edge of the beautiful Texas Hill Country.

But that wasn’t to be. I became singularly responsible for my daughter and was in much need of family support. I accepted an academic position at Utrecht University’s Department of Earth Sciences after only two years at BEG. The logistics of single parenthood would be much simpler in the Netherlands, and doesn’t everybody with a PhD want an Academic career? It was very hard to leave terrific colleagues and this reputable organization.

5. Back in the Netherlands: Utrecht University

On the personal side, this was a great move. I found a lovely townhouse across the street from a superb public elementary school. I found a terrific local babysitter. I had supportive family members close by and a lot of old friends. After a bit of a rough start, my daughter (then 5) started to thrive. That made it all worth it.

On the professional side, I found it difficult. The Dutch university system is very different from the North American one. Departments are organized into groups of different specialties (for earth science those may be structure/tectonics, sedimentology, stratigraphy/paleontology, geophysics, petrology, etc.). These groups are run hierarchically by the head of the group, the only person who is a full Professor. You may be an assistant of associate prof your entire career (you would be tenured). The only person entitled to graduate a PhD student is the full professor.

But I was hired in a hybrid position, the result of an effort to break down some of the existing silos between some of these specialized groups. Several profs had successfully argued for increasing the marine geoscience research effort. They were a geochemist, a micropaleontologist/paleoceanographer, and a geophysicist. They made the case for hiring a sedimentologist – me. That pretty much defined the context for my future research.

I got along well with them from the start. I dreamt up new projects, getting generous access to ships from the Netherlands Institute for Research of the Sea (NIOZ) and I went to work on existing data of my new colleagues.

Fieldwork with NIOZ’s amazing RV “Navicula” in the Dutch tidal sea at low tide. This flat-bottomed vessel draws 50 cm water and can be set on the tidal flats as a lab / workspace. It also had a fantastic crew of 3. 

But as a faculty member I resorted within the Departmental Sedimentology Group where I taught sedimentology and stratigraphy classes. I really liked teaching and the interaction with the 18-24 age group. I put a lot of time and effort into developing new classes and labs. That’s typical for a new faculty member. I also reached out to Big Oil and managed to convince them to support some of my early research projects. Later, they funded a multi-university project (6 MSc theses) with me as the academic partner in the Carboniferous fluvio-deltaics of eastern Kentucky (a few weeks fieldwork in the US again).

Left: pondering tidal rhythmites in Carboniferous deltaic distributary mouth bars in eastern Kentucky. Right: fluvio-deltaic sedimentary sequences (including coal) in eastern Kentucky

But the then-head of that Departmental Sedimentology Group had his own ideas about how that group should profile itself and a “non-fundamental” sedimentologist (me!) wasn’t his preference for what he considered a stolen job opening (stolen by what he considered the “marine geoscience coup”). I wrote earlier about my thoughts and experience regarding women and fundamental research. He managed to find funding to hire a “fundamental” sedimentologist as a post-doc. The guy was excellent, a wonderful person, older than me, with more publications. He got the office next to me. Did this make me feel insecure? You bet. Did it create stress within the Sedimentology Group? You bet.

And whereas I did spend time in the field doing research, I did not join in teaching multi-week undergraduate field schools in Spain and Italy because it meant leaving my daughter alone for longer than I thought was good for her. While I had no problem making that decision as the best option for our little family, I didn’t think it helped me in improving my reputation within the department. In all honesty, I had no reason to be worried, because nobody ever suggested I wasn’t fulfilling my duties. In fact, two of my colleagues (all male, I was the only female faculty member) expressed explicit support for me in my specific situation. But I felt insecure nevertheless. Imposter syndrome was rearing its head, especially with my brilliant colleague in the office next door. Because I had always behaved as ‘one of the guys’, I had not allowed myself to become aware of the (subtle) differences that make Academic women feel less appreciated, such as in academic publishing.

When I look back at my academic production of those 4 years at Utrecht University now, I am impressed. I taught 5 different classes, started up new research, had 3 cooperative projects running with my marine geoscience colleagues and was coordinator for a European marine geoscience exchange program with 11 departments in 10 countries. I started to publish my new research.

But at the time I thought I was under-performing and more than anything I dreaded having to leave my daughter for 6 weeks for an ocean-going research expedition. In addition, I began to wonder whether I was fit for Academia. I wasn’t “fundamental” after all. And would I be able to keep up the drive to be “original” for another 25 years? In addition, being back in my home country fueled my interest in the political drivers of universities.

I started looking for other opportunities. By some weird fluke, a new opportunity presented itself soon, right around the time that I got tenured. I accepted tenure and resigned a week later. The fundamental post-doc next door ended up getting my position. I was happy for him (he had 3 kids to support!). He did well, he retired from that post last year. My colleagues were stunned by my departure and I felt forever sorry for those who had worked hard to recommend my tenure. But I knew that this move would be better for my/our personal situation and hoped it would eventually better for me professionally.

6. The Advisory Council for Education

I was almost 40 years old when I left my profession for a job as a policy advisor for Higher Education in a brand new government-funded think tank of the Ministry of Education. The pay was excellent, the hours predictable, the commute the same. This was a much more balanced life for my daughter and me.

The job was a crazy roller coaster. I felt like a complete novice when I entered the policy-advice arena. Nothing that I thought I knew or understood, applied here. I learned about policy and politics. I relearned to write in Dutch. I read and read and read and debated and debated and I learned tremendous amounts from my sparkling colleagues who had backgrounds in linguistics, anthropology, history, geography, physics, sociology and …. education. I built a completely new network.

The Government always wants to be an exemplary employer. I was offered a top notch women-only training and self-awareness program. About two dozen women were selected to participate. For the first time I learned about myself, how I functioned in organizations, what complementary talents other people had, how one should build a team with explicitly diverse talents. Until that time, I had only been judged on the basis of content (scientific production), never had I been asked to think about how I functioned within a group. I take that experience with me the rest of my life.

I call these 2.5 years my highly paid sabbatical. I’m pretty sure I didn’t say or write anything that improved Higher Education in the Netherlands, but I learned an immense amount and I can confidently say that I applied that later.

Shortly after I started this job, my director asked me what I hoped my next job would be. I thought that was an excellent question: do not assume your employees will hang around the rest of their career. As it was, he was also encouraging us to think about our future careers because he knew that the political future of this think tank was insecure. He was right, Parliament voted it out of existence within 3 years after its much publicized start.

But when he asked me that question, we didn’t know that yet. So I answered truthfully: that I’d ideally like to combine what I was going to learn at the Advisory Council with my international expertise as an earth scientist. He thought that made sense.

And I ended up being able to do that.

7. The International Institute for Geoinformation Science and Earth Observation / ITC

 ITC’s new building in 1997. 

ITC was, from 1950-2010, an independent graduate school, focused on training young professionals from non-western countries in what we now call Geomatics and its applied fields (geology, hydrology, soil science, ecosystem management, agriculture). ITC was created by the Netherlands government in 1950 as a contribution to brand new UNESCO. The Dutch government provided fellowships to young professionals from relevant organizations in non-western countries to be trained with new technologies in aerospace surveying and applications. Dutch students could also take courses, as I did in the late ’70s as part of my MSc.

In the early ’90s ITC was being challenged as an independent institute. Dutch universities were internationalizing and wanted access to these fellowships so that they too could offer money to foreign students (not: young professionals – major difference). The political powers wanted ITC to – eventually – become part of the University system, but ITC itself felt that the time wasn’t right – yet. Its visionary director was convinced that the Institute should first get serious in research. Until the mid ’90s, it offered a 1-yr postgraduate diploma and a 2-year MSc degree. Because ITC wasn’t part of the university system, it couldn’t offer a PhD degree and wasn’t easily capable of developing PhD supervisory capability since many of its faculty didn’t have PhDs themselves.

By some weird coincidence I became aware that ITC’s director was looking for a qualified interim person to advise them how to move forward. I became that interim person and was seconded to ITC for 4 months at the end of which I presented them with advice, after which I was hired as their Dean of Research & Graduate Studies, a brand new position.

The job required a move, something my then nearly 12-year old did not take easily. It was very hard to have to move, but I had confidence that Enschede had more to offer for her as a soon-to-be teenager than the small town where we had just spent 6.5 years. It did, eventually, but this was a difficult time.

In cooperation with ITC’s science advisory committee, I developed a tailor-made PhD program that involved PhD candidates having a university-based advisor as well as an ITC-based advisor and it also included options for non-PhD faculty who wanted to move ahead. It was very challenging because – again – the institute didn’t have PhD granting status and not a big research tradition, Dutch universities weren’t used to cooperating with non-PhD granting institutes and some universities saw ITC as a threat. In addition, some of ITC’s faculty saw me as a threat, because I sat on a rather large pile of money and they were used to dispense that money amongst themselves without much interference from others.

This loss of purse-grabbing prompted one of them, a rather archaic man with a particularly large ego, to tell me “nobody likes you” (because, you see, a woman is supposed to be “nice”). Aha! Whereas I don’t think very well on my feet, I was able to calmly tell him that being nice wasn’t part of my job description. Lesson for women: don’t concern yourself with being “nice”! You’re hired to do a job – it’s not a popularity contest. That’s hard, most women have to unlearn being nice.

When I left 7 years later, ITC’s PhD program had the best time-to-degree rate in the Netherlands and it became part of the Dutch university system a few years later.

So I didn’t work as an earth scientist for what ended up being 10 years. But I was active and visible in the earth sciences. I attended conferences and published a few papers. I became president of the Royal Netherlands Earth Sciences Society KNGMG, I served on a government panel for the management of the tidal sea and on review panels of the Netherlands Science Foundation and of the EU. I wasn’t “just” a paper pusher.

I was also active in two professional women’s networks – an immensely rewarding experience and I can’t stress enough how important such a connection is. Real face-to-face networking is still of utmost importance. Of all my jobs, only the Advisory Council job came through an ad and I didn’t know a soul at that organization. Every other job or contract came through people I knew personally.

 Green River Basin fieldtrip in the late ’90s

I also met my Canadian husband at ITC. After 7 years at ITC my daughter graduated from high school, my husband retired, I resigned and we all moved (back) to Canada. It was not an automatic choice. We thought about staying in the Netherlands, where I had twice been invited to apply for senior leadership positions in government / academic institutions. No doubt my career would have evolved in an exciting and professionally highly fulfilling direction if we had stayed. But I thought that it would be better for our new family to be in Canada. Did I make a typical woman’s choice? Maybe. But I haven’t regretted it despite the fact that this move professionally didn’t pan out as I hoped it might.

8. Across the ocean again: Nova Scotia

We arrived in Nova Scotia a few months before I turned 50. I took my first long “sabbatical”. It ended up being two years. We rebuilt a house, we found a new balance in our life, we built family relationships. My husband had a couple of challenging health issues and all this took time and energy.

Professionally, Canada was completely different from the US, where they simply throw you in the deep end and you’ll find out if you sink or swim. That can be exhilarating and scary and I had loved it early in my career. In Canada they are interested in whether you have “Canadian experience”. I didn’t have that and because I wasn’t a young starter, that was a big problem.  But I did have professional contacts in Canada. I didn’t count on working as a geologist at all, but geologists were the people I knew and that’s how I ended up getting work.

I worked as an independent for 12 years. I taught sedimentology & stratigraphy at both Acadia and Dalhousie Universities. For five years I served as executive director of the Canadian Federation of Earth Sciences and in between I was involved in running field schools for young professionals in the petroleum industry. I served as president of the Atlantic Geoscience Society. I tried hard to get a foot in the door in the R&D around tidal energy development here in the Bay of Fundy and Minas Basin, but despite attending conferences and workshops and presenting papers, I got nowhere. To this day I don’t understand that.


Teaching sedimentology – ancient and modern – along the shores and on the tidal flats of Nova Scotia’s Minas Basin. 

Maybe I should have been more aggressive about finding work, but I also cherished our new life. So at times I struggled a lot with my diminished professional life and – in extension – my diminished income and therefore independence. And at other times I was ok with it. My husband was supportive, he was completely prepared to move again if I had found a dream job that would require a move. But our happiness here was more important to me in the end.

9. Lessons for women

There are lots of lessons for women, some of which I already highlighted above.

My career changes were heavily influenced by the fact that I became a single parent. That is life. I don’t regret it. My daughter is a happy, successful professional with global work experience in an important field, working on her PhD. I’m immensely proud of her. If I sacrificed parts of my career for her, it was worth it. Read this article by a famous feminist on how other women of my age may look back at such choices.

I have been spared sexual harassment but not discrimination. Today there is much more transparency about pay scales. The media regularly publicize the shameful “gender pay gap”. That notion didn’t really exist until this century so while I always assumed that I was paid the same as my male colleagues (why wouldn’t I?), that may not have been the case at all and it certainly wasn’t the case at ITC (I wrote about that here).

I was never sexually harrassed, but I know that is exceptional. I am astounded at the amount of sexual harrassment that surfaces in recent years and I truly wonder if things have changed for the worse over the years or whether I was just lucky.

But while I was spared sexual harrassment, I wasn’t spared bullying. I was bullied by my director during my time at the Advisory Council for Education but that was eventually managed well because it was part of the national government and they had good HR policies and professionals. I was very rattled, but then ITC recruited me and things turned around. I was bullied by 1 of my directors at ITC (not the one who hired me), but his turned out to be a very short tenure so I lucked out there (two male colleagues resigned as a result of his bullying – it wasn’t because I was female). I was bullied to such an extent by one of the CFES presidents that I resigned from that position. By that time I was nearly 60 and I decided that life was too short to suffer from big male egos. I’m happy that those egos have disappeared from CFES and that it is doing well now. The problem was that it was such a small organization that there was no way to turn.

Role models are very important especially for women and they were few and far between for me. I wrote about two of my role models here and here. Earlier, my above mentioned high school chemistry was important to me. During my first real job in Louisiana, I was immensely encouraged (although I met her maybe only four times) by the legendary Doris Malkin Curtis.

So what are the lessons I’d like to pass on to women of the next generation? Be true to yourself, don’t be afraid to ask for help, don’t worry about being (too) nice, join a women’s network, know your rights, be suspicious of big egos and just Carry Yourself With The Confidence Of A Girl Holding A Massive Owl

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New Banner picture! Cobequid-Chedabucto Fault at Cape Chignecto, Nova Scotia


Figure 1. The western extremity of the Cobequid Chedabucto Fault complex in Nova Scotia. The Cape in the distance is called Cape Chignecto

It is a glorious view from the beach at Advocate Harbour. We look West towards Cape Chignecto. The coastline is straight. Eroding cliffs dip steeply down to the Bay of Fundy. This peninsula, the Cape Chignecto Peninsula, is a Provincial Park and the popular hike around it a tough three day journey. Kayaking around it is possible too even though the tide range averages 15 m here (I’ve done the kayak trip, the hike not yet). We also hope that this stretch of coastline will become a Geopark (I wrote about Geoparks earlier here).

chignecto  Fig. 2 Google Earth Image showing the location of the photo


Fig. 3 – Relief map of Nova Scotia, Prince Edward Island and part of New Brunswick. The white circle indicates Cape Chignecto. 

The relief map above clearly shows several linear relief features extending eastwards from Cape Chignecto. These linear features are a series of faults, collectively known as the Cobequid Chedabucto fault zone, which extends East for more than 300 km from Cape Chignecto. Another name for it is the Glooscap Fault. Glooscap was the Creator God of the Indigenous Mi’kMaq people, the original inhabitants of this part of Canada. The fault is visible in the landscape as a clear, steep scarp.


Fig. 4 – Google Earth Image of the Cobequid-Chedabucto fault (looking East) as expressed in the landscape east of Cape Chignecto. A road runs at the bottom of the scarp that marks the fault.

What happened here?

The fault zone separates the Meguma Terrane, the southern mainland part of Nova Scotia from the Avalon terrane, which stretches – in bits and pieces – to the North. Ok, so – What is a terrane and is that how you spell it?


Fig. 5 – Schematic map showing the southern Nova Scotia Mainland, representing the Meguma Terrane and the Avalon Terrane north of it, separated by the Cobequid-Chedabucto Fault zone. 

A terrane (yes, that’s how it’s spelled) is a clearly identifiable fragment of continental crust, usually bounded by faults. So that means that the geologic origin of a terrane is different from that of its surrounding areas. The earth’s crust is formed by continent-size plates (continental and oceanic) that move around throughout geologic time. Moving around also means that plates and plate sections collide and slide along each other, sometimes causing pieces of crust (terranes) to break off from one side of a continental plate and become reattached to another one. Sometimes these terranes move around independently for millions of years before becoming attached again. Dozens of terranes have been recognized and we don’t always know where they came from and how they moved around over time.


Fig. 6 – A very schematic representation of the movement of the continents over the last 225 million years. The Meguma terrane likely broke off from NW Africa (now Mauretania) after Pangea broke up and reattached itself to North America (from Encyclopedia Brittanica). 

The Meguma terrane (southern Nova Scotia mainland) was most probably a piece of the margin of the Pangea supercontinent and came from the margin of the African plate, from what we now call Mauretania. When Pangea broke up, this piece of crust broke off and ended up attaching itself to the North American plate. Southern Nova Scotia is the only piece of Meguma terrane anywhere on the planet.

The Avalon terrane is bigger and very fragmented. Pieces of it are recognized from Connecticut all the way to Newfoundland and across the Atlantic Ocean into the UK and as far as Poland (the Atlantic Ocean didn’t exist yet when the Avalon terrane docked on to the continent, so the later opening of the Atlantic Ocean broke it up). It’s not clear where the Avalon terrane came from, but experts do have some evidence that these two terranes traveled together for a while before attaching themselves on the Northeastern margin of the American continent.

The Cobequid Chedabucto Fault zone marks the zone where the Meguma terrane docked and wrenched along the margin of North America after the Avalon terrane had become attached. Such faults are called “strike-slip faults”, a term that indicates that pieces of crust slide along each other (instead of over each other). The fault was probably active for 150 million years, from about 350 to about 200 million years ago. This sliding process wasn’t smooth – it would have been periodic and each movement would have been felt as an earthquake. The friction along these pieces of crust caused heat and fluidization of rocks, injection of hot fluids, and this together led to the concentration of valuable minerals and metals such as Iron, Copper, Cobalt, Barite and Fluorite.

The fault expresses itself in the landscape as a scarp, but when you put your nose to the rocks, the messiness of the grinding, sliding and friction is apparent. Here are a few examples.


Fig. 7 A mixture of granites and dark colored igneous intrusions exposed along the beach close to Cape Chignecto itself. Person for scale


Fig. 8 – Intensely folded and faulted rocks exposed along the Cape Chignecto beach close to Advocate Harbour. Walking pole ca 1 m high


Fig. 9 – A piece that I retrieved from the outcrop of Fig. 8. These are ripples, formed on a beach some 300 million years ago. They became preserved as sedimentary rock and then the fault movement (my finger is on the fault line) displaced the ripple crests!

Is this relevant? You bet. First of all, ancient fault activity like this can cause concentration of valuable minerals and metals. Second, currently active faults like this one are seismic hazard zones. The best known similar strike-slip faults are the San Andreas Fault in California and the Great Anatolia Fault in Turkey. Understanding tectonics like this has lots of practical implications


White, C.E., and Barr, S.M., 2012, Meguma Terrane revisited: stratigraphy, metamorphism, paleontology and provenance. Geoscience Canada, v. 39 no. 1

Posted in General geoscience, Geoheritage, Nova Scotia, outcrops | Tagged | Leave a comment

Exxon, climate change and sequence stratigraphy

My favourite periodical is the New York Review of Books. It is a high-brow magazine that contains in-depth articles by outstanding writers and thinkers on a range of topics from fundamental physics to poetry and everything in between.

And excellent article in two parts – in the December 8 and December 22 2016 issues – discussed the Exxon climate change scandal. In case you missed it: Exxon (Exxon-Mobil since years, but generally known as Exxon) has known since 30+ years that our massive fossil fuel burning causes global warming, sea level rise and untold droughts and other catastrophic climate disruptions. The company chose to hide this information from the public and from policy makers and even financially support(s)(ed) climate change denial institutions and individuals to counter the growing scientific literature on the subject. All in their own financial interest, of course.

Exxon is now taken to court by the Rockefeller Family Fund. The accusation is that the company has failed to disclose the business risks of climate change to their shareholders and that this constitutes consumer (or securities) fraud. The articles in the NY Review present the evidence and the cover-up.

But that’s not a reason for writing this blog post. The reason is that in the December 22 article, reference is made to the man who conceived of what we now call sequence stratigraphy: Dr. Peter Vail. Quoting the article: “The company tried to use the work of one of its most celebrated earth scientists, Peter Vail, to predict how alterations to the planet’s surface made by the changing climate could help it discover new deposits of oil and gas”.

Readers of the New York Review of Books are knowledgeable intellectuals, but I decided that this paragraph was worthy of an annotation. So I sent the following to the Editor of the New York Review of Books. I consider this a bit of science communication, so I’m sharing it here because I’m curious whether my followers (geologists or non-geologists) find what I wrote correct / understandable / interesting / insightful. At this point, I don’t know yet whether the NY Review of Books will publish it, but that’s neither here not there. I have edited my original submission minimally and have included illustrations in this version. Here it is:



Pete Vail (born 1930 – there’s lots about him on the internet of course) is a sedimentary geologist. He worked for Exxon his entire career. Among other things, sedimentary geologists have knowledge about so-called reservoir and source rocks.

Reservoir rocks are rocks with the right porosity and permeability, enabling (natural) storage of fluid or gaseous hydrocarbons (oil or gas). Source rocks are rocks that contain the right amount of organic matter and that have been “cooked” enough – i.e. experienced high enough temperature and pressure deep in the earth for a sufficient amount of time – for that organic matter to become transformed into oil or gas. Organic matter is the remains of living organisms, either plants or microscopic animals. Under certain conditions, organic matter doesn’t oxidize & disintegrate into the air (like the dead leaves you rake from your lawn in the fall) but becomes incorporated in sediments. Coal is simply dead plant material, “cooked” and incorporated in the rock record in the place where it originated (a swamp). Natural gas is mostly “cooked coal”. Oil is the end product of microscopic organisms that lived and died in oceans (and rarely in lakes) over time, then became buried and “cooked”. Oil and gas are mobile and will move under varying pressure conditions, thus ending up in reservoir rocks where they may stay trapped if other conditions are right. Petroleum geologists look for reservoir rocks and they need to understand the origin and architecture of these rocks. They also must understand and predict where and during what time interval the best source-reservoir rock combination may become preserved.

In 1977, the American Association of Petroleum Geologists published a bombshell. Memoir 26: “Seismic Stratigraphy – applications to hydrocarbon exploration” laid out a revolutionary new method of analyzing seismic data. Recall that this was three years after the oil crisis at a time when the western world and the US in particular was extremely panicky about its dependence on foreign oil. Anyone who could improve the prediction of hydrocarbon reservoirs in order to improve domestic production was going to be popular.


The cover of AAPG Memoir 26

Only oil companies have the financial resources and the motivation to collect seismic data. For Exxon to allow for their best kept secret – this new methodology – to be published in the public domain was mind boggling. The other mega company at the time, Shell, was humiliated and baffled by the insights presented in this publication.

Until the time of this publication, sedimentary geologists had developed models for understanding the rock record that relied on much smaller scale, i.e. field-based data collection. Seismic data reveal the architecture of sedimentary systems at the scale of tens or hundreds of kilometers, whereas field exposures are a few hundred meters at best. This is a difference of orders of magnitude, comparable to the difference between a standard land-based telescope and the Hubble when you want to study the universe.

outcrops-and-seismic-linesWhat the Exxon team, led by Pete Vail (a bright, boyish man gifted with contagious enthusiasm ), showed was that the location and preservation of recognizable packages of sedimentary rocks (“depositional systems”) depended on the position of sea level at any point in geologic time. Although much research had hinted at such a relationship, it had never before been demonstrated with so much conviction. So this was revolutionary but there was more: Pete Vail’s team claimed that these sea level changes were global in nature and they subsequently produced a global sea level curve showing sea level movements through time to substantiate their claim.


The first version of the “Vail/Exxon global sea level curve” (published in AAPG Memoir 26). The vertical scale on the left is time in millions of years. The two sea level curves on the left and right are the same, but the right hand one is at a higher resolution. The sea level curve on the left indicates that global sea level rose to a level higher than present from 500 until about 325 million years ago, then gradually dropped until about 225 million years ago, after which it slowly rose again, reached a peak at ca 90 million years ago and then dropped again. The curve has since been refined to a much greater detail. As an example, this article contains detailed sea level curves for the last 800,000 years – a time interval that isn’t even visible at the large scale of this diagram. 

Geologists had accepted for a long time that global sea level danced up and down through the ages, but since sedimentation is capable of overwhelming the effects of sea level regionally, the idea that you could trace global sea level movement by analyzing sedimentary sequences seemed too ambitious. In addition, studying rock outcrops (or drill cores, for that matter) doesn’t give us a clear indication of time horizons. Our colleagues the paleontologists help us distinguish time by detailing small evolutionary changes in the fossils in the rocks, but we don’t actually see it. Yet Pete Vail demonstrated that variations in wiggly lines on seismic images represented time horizons, another revolutionary idea. Here is a video (one of a series) where he explains how he came up with that idea.

What followed were about 20 incredibly exciting years of research in sedimentary geology (I was one of many contributing to this field it in my own small way as a government and academic researcher) in which we sedimentary geologists started to look at sedimentary rocks from a completely different perspective. Our understanding of the timing and deposition of sedimentation expanded exponentially during these years. This knowledge revolution resulting in a methodology that we now call Sequence Stratigraphy. During that same period, roughly until the mid to late 1990s, the global discussion on climate change was marginal at best. Basically we lived by the paradigm that development required energy and that our field of expertise contributed to finding that energy even if we studied for example a thin, recently deposited sedimentary package. We worried about Peak Oil and about pollution but not about burning hydrocarbons as a factor in climate change.

Of course, as the decades progressed, the understanding of global sea level changes as a reflection of global climate changes also evolved, as did the understanding that Homo sapiens was becoming a geologic force itself, capable of changing climate. That’s where knowledge expansion is taking place now. Such is the nature of scientific progress.

So yes, the sentence in the article was correct “alterations in the planet’s surface, made by changing climate, can help discover new oil and gas deposits” but the road to that insight was long and the original objective was not climate study.

Of course, this doesn’t change the fact that Exxon brass, once they realized the importance of these findings and the potential damning consequences for the future of their business, took part in a massive cover-up, as outlined in these articles.



Posted in climate change, Energy, General geoscience | Leave a comment

#Katrina10. #Louisiana is still disappearing


I wrote this blog post in November of 2014. I am reblogging it today, on the 10th anniversary of Hurricane Katrina.


Land loss map of South Louisiana. Image source here. Click on image to enlarge. 

Is it the weather? No fewer than three long, detailed and well-researched articles in important media discussed the continuing story of increasing land loss in South Louisiana. The Globe and Mail’s Omar el Akkad wrote an insightful piece about disappearing Louisiana in the October 18 paper. The October 5 New York Times Magazine’s main article was a heart-sinking rendering of the fight of a few individuals against the sheer unwillingness of anyone to do anything to save the State of Louisiana. The New Republic Magazine ran an article on September 30. The latter two articles particularly focused on corruption.

All three articles were excellent, so why should I want to add anything?

I am a sedimentary geologist. I worked for…

View original post 1,181 more words

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Why I haven’t blogged for a long time: medical science and society in #Canada

Four months since my last post and only one person has wondered why I haven’t blogged in such a long time. Apparently I am not much missed, something that shouldn’t surprise anyone in this digital world of fleeting contacts. But I’m back. I am updating this post tonight and will resume my earth science blogging activities.

So what happened?

On March 31 of this year my husband suffered a small heart attack. He is in his mid 70s. He had a small heart attack 18 years ago after which he underwent heart catheterization, from which it appeared that there was little or no damage to the heart. At the time he was in a stressful job. He was put on a blood thinner (aspirin) and did a stress test each year which never gave any reason for concern. He was prescribed cholesterol medication for a mildly elevated cholesterol a few years later. He was always physically fit and didn’t smoke. He quit the stressful job almost instantly and retired 6 years later.  Since that time, he kept up his fitness through regular walking, swimming and bicycling. We have disgustingly healthy eating habits and live a happy life.

So we were surprised when it happened this time. Surprised and a little angry: how can you get a heart attack when you live so healthy and are so happy? The cardiologist in the local hospital told us that my husband simply wouldn’t have lived this long if he didn’t have these very healthy habits. He did a couple of tests and determined the need for a heart catheterization, after which he expected that a balloon and stent procedure would solve the problem.

These procedures take place in the heart centre in the city hospital. A week later, my husband underwent the procedure. Surprise number two: his arteries were toast. There was nothing to send a balloon-and-stent through. He needed triple bypass surgery. We were shocked and scared, but were assured that this was routine surgery and that he was an excellent candidate for the surgery given his good physical condition and the good condition of his hear. The heart clinic has an excellent reputation and his surgeon would be one of the best of the clinic.

The bypass surgery took place nearly a week later, two weeks after the heart attack. By this time, he had been in hospital for about two weeks. Despite having walked around as much as possible, he had of course been rather inactive and had also been on a significant dose of blood thinners. As the surgeon said later: “that is excellent medication, but when we do surgery, it becomes our enemy”.

Then he drew the short straw: as the heart was lifted from the chest cavity to remove and replace the arteries, there was “a tear” at the back of the heart where it is attached to the back of the chest wall by membranes (if a medical person reads this and concludes this is not the proper way to describe it, please correct me). And since the heart is a vascular organ, full of blood, the flood gates opened: bleeding, serious bleeding. Instead of 5 or 6 hours, the surgery lasted 9 hours (yes, I had a friend with me during that agonizing wait). Nine hours on the heart-lung machine: the heart is stopped, the lungs are collapsed and the blood runs through the medical equivalent of a sewage treatment system, getting supplied with enough oxygen.

After nine hours, the sternum having been wired together again, he was moved to the Intensive Care Unit and we got to see him briefly. Of course, he was still sedated, intubated and mechanically ventilated. His hands were swollen, the skin tight. It was scary and very emotional. We went home, it was 1:30 am.

Three hours later (no, I had not been able to sleep) my phone rang: “your husband has to go back”. Go back? What does that mean? The only thing I managed to say was “should I come?”. The kind person asked me where I was: in the house of friends, not 10 minutes from the hospital. “you should get some sleep, we will call you”. Well, I didn’t sleep, of course and at 9 am, my phone rang again, he was back in the ICU. When I went to the hospital, I was told that they had to bring him back in because there was too much bleeding for the regular wound drain (so yes, the wires in the sternum were loosened again, he was opened up, back on the heart-lung machine). At this time, I didn’t know yet about the tear, I just knew there was ‘bleeding’.

He stayed sedated and ventilated another 24 hours and was then allowed to wake, but still ventilated. So he couldn’t speak, but he could squeeze my hand. Mostly he slept. The next day they removed the tubes, but he struggled to re-inflate his lungs properly: he was too weak to do it himself. Another day later he was again intubated and put on the ventilator. By this time he had not eaten anything in nearly a week. I was assured “his digestive system doesn’t need it, he gets nutrients via the drips”. But the ventilation was torture: his mouth was unbearably dry, but he was so confused that he refused the sponge to help moisturize him and the confusion (and frustration, I assume) made him aggressive, so they actually had to restrain him. It was terrible. He only left the ICU a week after the surgery and I had barely exchanged a word with him then.

During the next week he was in the ‘step down unit’, where the care is somewhat less intensive. They made him sit in a chair, where he would consistently fall asleep immediately. They tried to convince him to eat, they tried to feed him, but next to nothing went or stayed in. They began to try to walk him, but his legs simply buckled. He couldn’t keep his eyes open for more than a half a minute, he was confused (at one point he thought he was part of a movie set), he had no energy. Not until nearly two weeks after the surgery did he first speak a few lucid sentences (this for a man who is brainy). It was a scary period.

Three weeks after the surgery, he was allowed to be transported back to the local hospital, where he stayed another two weeks. All this time, I tried to get him to eat healthy food. Hospital food is terrible but I don’t blame the hospitals. The majority of patients isn’t used to healthy and wholesome food and many patients have difficult dietary restrictions. Thankfully, hospitals have patient kitchens. I have never spent so much time trying to prepare food that I would hope he would like (under normal circumstances, he is a good cook and does a lot of it) but most of the time, it went uneaten. He had no appetite and the thought of food revolted him. He had no energy to read or talk, he slept – most of the time.

He finally came home four and a half weeks after the surgery. He could only walk 50 meters, he still barely ate. He was completely deconditioned: his muscles had atrophied. I had rented a hospital bed and put it in my study. That was a life saver: he needed the height, he needed to adjust his position frequently, and I don’t think I would have been able to sleep next to someone in his condition.


That was two months ago. He now walks 2 kilometers each day and eats normally again. The hospital bed was here three weeks.  The first few weeks I walked with him twice a day up and down the sidewalk. I pushed a borrowed walker, which he didn’t use, but he used it as a seat at the turnaround point or at any other point in time when he felt exhausted, which was often. Getting dressed was a major exercise. Taking a shower was the equivalent of running a marathon: he needed a serious rest afterwards. Fortunately, our house is ideal: a former bungalow, we kept our bedroom on the main (ground) floor after the renovation more than a decade ago. He has a studio (he is a photographer) also at ground level so no matter where he was, he didn’t feel isolated in an upstairs bedroom. Our house has an amazing view, which is nothing but therapeutic.

I read a lot about our “failing health system”. We didn’t experience anything as ‘failure’. The specialists (cardiologist, cardiac surgeon, residents) were expert and their communication skills were excellent. The nurses and physiotherapists were nothing but amazing: helpful, always there, always friendly (even when he was growling and angry and confused and frustrated), ready to talk to me at any time of the day or night. The pharmacists had all the time for our questions. The family doctor sees us regularly and takes his time, never rushing us out. And – this is Canada: we haven’t seen a single bill. We pay taxes, we don’t mind.


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