The quiet and colors of the back streets of Venice. May 2013, Nikon D600, Nikon 24-85mm at 24mm at f/4.5 hand-held at 1/80 at ISO 400. Away from the tourist sites you can begin to appreciate a world without the dull, continuous hum of road traffic. This is one of my favourite shots from my trip to Venice and one I have printed many times - the best result has been to print on a textured watercolour inkjet paper (I use Canson papers, which I can highly recommend). To me it is about the colours, the light and the architecture. That is the joy of photographing in Venice.
When thinking of Venice, probably the most common images are of canals, gondoliers, the Rialto Bridge or St Marcos Square. But for the photographer, artist and cultural historian there is much more to the city that can be found in the streets that lie just beyond the tourists
Venice is a place that lives up to expectations. It is a beautiful city. As a photographer, it seems that no matter in which direction you look, there is another great picture. As such, it is too easy to forget that people live and work here, locals for whom visitors such as me must be both a boon and a bane.
Thankfully, for all concerned, most tourists tend to stick to well-mapped routes as they rush from one selfie to the next, and it is surprisingly easy to slip into the back streets where you can take time to absorb the history, colour and beauty of the city, enjoy a quiet moment or two over an espresso (surely one of the greatest contributions to the culture of the world since afternoon tea), and most of all appreciate a world without that dull, continuous hum of road traffic.
My last visit to Venice came after a series of business meetings in Milan and a need to take a couple days off to relax. Relaxing is not what I do, so this meant either hiking in the Alps or something cultural. A two-and-a-half-hour train journey from central Milan and I found myself caught up in a torrent of tourists as they rushed from the station to St. Marco’s Square, via the Rialto Bridge and then straight back home, the sound of roller trolleys rumbling in anything but unison. Thankfully my hotel was on the way and I could peel off onto a back street, and away from the turisti, of whom I was desperate not to be considered a part – wishful thinking.
A quiet evening on the Grand Canal, Venice, May 2013, Nikon D600, Nikon 24-85mm at 24mm at f/4.0 hand-held at 1/400 at ISO 400. Photographic clichés abound in Venice, and all are worthy of numerous frames, and few will disappoint. Here the view north along the Grand Canal from the Rialto Bridge
Photographic clichés abound in Venice, and all are worthy of capture and I am sure that few pictures you take will disappoint you. But it is the quiet, the colours and the textures of the back streets that photographically caught my attention. This is not a pristine city. The perpetual damp of the lagoon takes its toll, but that is part of its charm, photographically at least; I am sure it is less than ‘charming’ to try and maintain. The results are building whose walls are not one single colour, or finish, but where hues change on a single building, paint peels back to reveal a depth, and stonework varies as plaster gives way to the underlying building fabric. There is a story and history here at every turn, but also a recognition of city living through a perpetual battle against nature. I know that that is a cliché, but none the less true.
Character born of age and weather in Venice. May 2013, Nikon D600, Nikon 24-85mm at 24mm at f/6.3 hand-held at 1/160 at ISO 200. The details of many of the buildings make interesting compositions with a story. These are people’s homes, so do be respectful
A rainy evening in Venice, May 2013, Nikon D600, Nikon 24-85mm at 85mm at f/4.5 hand-held at 1/30 at ISO 1100. Photographing in the rain never quite captures the moment or the damp, but here in Venice, the mix of light, water and buildings makes the attempt a little easier. Helped in no small way by the presence of umbrellas. Next time I will take a tripod
Light and contrast in Venice, May 2013, Nikon D600, Nikon 24-85mm at 24mm at f/5.6 hand-held at 1/125 at ISO 320. The light and contrast in Venice, like so much of Italy and Spain, plays directly to photography. But in Venice the addition of water gives an added dimension as here. In programs such as Adobe’s Lightroom you can readily experiment with contrast levels. Here I have kept the interior quite dark to emphasize the light beyond. Black and white can work quite well in such circumstances.
The colors of Venice, May 2013, Nikon D600, Nikon 24-85mm at 32mm at f/8.0 hand-held at 1/250 at ISO 125. The canals are central to what Venice is, and the reflections in the water on a clear day make for a great colour palette to experiment with. But, be careful since canals are canals, so keep an eye open for interesting colours, textures and reflections. This may mean zooming into an area rather than a general canal shot as here
Venice, May 2013, Nikon D600, Nikon 24-85mm at 75mm at f/8.0 hand-held at 1/250 at ISO 100. There is so much going in any scene here. The mix of colours, shapes and textures and behind each a story.
So, do take your photos of the Grand Canal, the Rialto Bridge and St Mark’s Square, and the obligatory gondola. They all make great pictures. But, consider taking time to wander. This will help you find some interesting photographic compositions, but it will also allow you to absorb the atmosphere and history of Venice, and a world less hectic. And you will quickly realise why: the dull hum of traffic is absent, and that is wonderful.
Gondolas. May 2013, Nikon D600, Nikon 24-85mm at 24mm at f/8.0 hand-held at 1/250 at ISO 140. Who can resist a cliché! Ahh…, Venice
Photos were taken using a Nikon D600 with a standard 24-85mm lens.
Data management and post-production was using Adobe Lightroom
Printed copies were made using an Epson R3000 A3+ inkjet printer and Canson papers: http://www.canson-infinity.com/en
I do have a photo book from this trip which I can make available for purchase via Blurb if there is interest.
A pdf version of this blog is available here PDF
The Fujitsu Scansnap ix500 scanner
During my Ph.D I built up a substantial research library of papers and notes, which have travelled with me for the past 30 years. For much of that time they been ensconced in boxes, which rather limits their use. Knowledge may be power, but only when its accessible.
Over the past decade the internet has become a resource for reviews of just about every product, device and service and I, like many others, have sought these out to help in deciding on what to buy. It is now time to return the favour and add to this online resource as an actual user of a product.
In this case the Fujitsu Scansnap IX500 document scanner.
Ok, so some of you have switched off already. And it must be said that document scanning tends to fall into the same category as project and data management when it comes to entertainment value.
But if you are faced with a mountain of physical documents and the need to make these accessible, you may start to feel a little differently.
The problem I had to solve was this: an extensive and potentially powerful library of 25,000+ physical documents, scientific notebooks and papers, stored in my basement.
During my Ph.D I built up a substantial research library of papers and notes, which have travelled with me for the past 30 years. For much of that time they been ensconced in boxes, which rather limited their use. Knowledge may be power, but only when its accessible.
Each paper and document was housed in a manila card folder, with a label and arranged alphabetically. This followed the data management methods used by in the Paleogeographic Atlas Project at The University of Chicago, where I did my PhD.
After my house was flooded a few years back, much of this library also ended up a little soggy. Sadly, some of my library was beyond saving, except as the stock for making papier mâché volcanoes, but it prompted me to act.
Although having physical copies is still often the best way to work, access is even more important. Today we have the technology to turn all this paper into searchable pdfs, technology we did not have back in the 1980s and 1990s.
The Fujitsu Snapscan ix500
The Fujitsu Snapscan iX500 is a dedicated document scanner that is compatible with both Mac and PC. The unit I have is still available (ix500) although it has now been replaced by an updated model, the iX1500
The Snapscan iX500 can scan documents up to a resolution of 600 dpi (Color, grayscale) and 1200 dpi (B&W). I have mine set at 300 dpi (color, grayscale), 600 dpi (B&W), which is a compromise of the need to have high enough resolution figure scans, but also ensuring that file sizes are manageable.
With 25,000+ documents to scan, speed is key and the iX500 makes the task tractable. The published numbers of 25ppm for color scanning seem about right in practice. I have included three examples from my scanning workflow in the table below. For each example I used the following settings:
As an explanation of the workflow stages:
“Preparation” refers to removing document covers and staples and ensuring that all pages are separated, especially where papers are water-damaged.
“Scanning” refers to the actual process of scanning through the scanner.
“Post-production” refers to the process of adding the results to my data management system, and where appropriate linking the file to my bibliography database. This also includes any rotation of individual pages using Adobe Acrobat.
OCR (text recognition)
The OCR software bundled with the ix500 is good. On occasions it does fail with an error message on the computer to ask if you want to save the file as images only. From experience if this happens then I recommend rescanning the document to see if it works the second time around. If that fails, turn the document 180 degrees and scan again. I am not sure why this would work, but in most cases, it solves the problem.
Ease of Use
The unit is incredibly easy to use, but here are few things to remember, especially if you ‘forget’ to read the instructions:
Wrinkling of paper sheets due to water damage. If you have a similar problem, make sure that you first separate all the sheets before loading them into the scanner. You may find that you have to load each sheet separately if the wrinkling is particularly bad. Also, be aware that this sort of damage can lead to sheets being fed at an angle through the scanner. Again, this why my setup has the <Continue scanning after last page> switched to “on” because you can then quickly reload the page. The other thing to aware of is that water-damaged paper may have spores and other fungal damage. This may loosen and get into the scanner mechanism. I use an air spray designed for photography to clean any loose material from the scanner.
Size of unit
The iX500 is relatively small and light in weight and sits easily on any desk or table. The quoted dimensions are 292 mm x 159 mm x 168 mm (11.5 in. x 6.2 in. x 6.6 in.). But this is probably easier to visualize in the photo below. The scanner size will not be an issue.
The scanner with the paper feed open, but not with the output tray folded down, which I don’t use. The DVDs provide a sense of scale.
Paper size limits
The scanner can scan up to A4, Letter and Legal sizes. The accompanying user guide states a maximum weight of 209 g/m2 and certainly I would not want to put anything thicker through the unit. For larger documents I use an A3 Brother MFC-J69300W All-in-one printer scanner, which has been great and is highly recommended especially when you can find it on offer.
This is not the cheapest scanner available, but frankly, for the price, it is worth every penny. Expect to pay anything from around $400-500 (c. £400 in the UK).
The ix500 receives great reviews on the internet. Here are a selection of the reviews I have used:
pcmag (UK): Review of Fujitsu Scanscap ix500
TechGearLab: Review of Fujitsu Scansnap ix500
ExpertReviews: Review of Fujitsu Scansnap ix500
Amazon (US): Customer reviews
Amazon (UK): Customer reviews
There are also numerous YouTube videos you can look at to see the scanner in operation.
Field photo of the base of a turbidite sandstone bed showing load structures, flute marks, and trace fossils. The obligatory scale. Early Eocene, Arro, Central Pyrenees.
Digital photography has made taking field photographs so much easier. Immediate results, high resolution, relatively low cost and the ability to take almost unlimited pictures. And then you can instantly upload them to the cloud. How can anything possibly go wrong? Here are 10 simple tips for ensuring it does not.
Photography is an essential part of fieldwork in the Earth sciences.
Today, digital photography makes capturing field information easier than ever before. Immediate, high-quality images can now be achieved even using a smartphone, and results uploaded to a computer or the cloud.
Go back 20 years and the ‘picture’ was very different….
Before digital there was film.
Now for those of you too young to know what film is and who may never have heard of "Kodak" (i.e. anyone younger than 20), imagine being limited to how many pictures you can take, which means that you must choose your field shots with care. Each roll of 35mm film could capture up to 36 images. And film cost. Imagine changing between rolls of film, ensuring the film was not exposed when you loaded it in your camera. Now imagine doing that in the rain, with the back of your camera open to the elements.
So far so good...
Now imagine that you cannot see the results until you have the film processed, which you cannot do until you return home or to a base with either a post-box or photo store, and then it might take a week or more turnaround time between sending, processing and return.
Only then can you see what you captured weeks before.
Imagine getting a nice blank film back... Doh!
There was an 'immediate' film option, which was to use a Polaroid instant camera. But prints were small, and the resolution limited. It was also still film technology, and as already said, film cost.
Thank goodness for digital.
What is there not to like and how can this possibly go wrong?
Well, of course, it can.
Whilst digital makes field photography easier, there are things that you must take account of whether you are taking field photos with Digital or with Film.
In this first blog on field photography, I want to provide 10 simple tips to remember. Although this list is largely designed to help students, it may be useful to others.
(We will look at camera kit in a future blog)
1. Record your location
You need to record where you are.
Some digital cameras have GPS (Global Positioning System) built in, and certainly many/most phones do (if you are within range of a signal). If not, you can buy separate units that plug into most makes of digital camera. I use a Solmeta Geotagger GPS attachment for a Nikon D810. It is pretty accurate, although I usually have a larger Garmin 64s GPS with me if I am in a new area and want more accurate results (and as a double check).
If you don't have a GPS then the traditional approach is to use a map grid reference. Be aware of local grid schemes and what system you will publish. Latitude and longitude are the clearest and most useful for international research (frankly the use of local grid schemes in publications only frustrates; it certainly drives me nuts, having spent my Ph.D trying to translate various national grid systems into latitude and longitude; and don't even mention the Township and Range system of the US).
It is then important to ensure that this location information is assigned to each photograph, either through metadata (digital) or physically written on slide frame borders or the back of prints.
Geographic orientation (azimuth) of the subject is usually derived using a compass, but again, this can now be done digitally. The Solmeta Geotagger GPS attachment I use also records the direction in which you are pointing the camera as well as elevation.
However, I recommend using a compass. This provides a double check of your digital equipment but is more reliable in its simplicity. It is better to do this in the field than question results once you are back in the office.
This information is then recorded in your field notebook; don't rely 100% on digital information. Record what your source of location and orientation was.
2. Get a picture of the overall context
Capturing the geological context of a field subject generally means stepping back and taking a photograph of the whole outcrop and, ideally, the landscape in which that outcrop occurs.
Panoramas are a great tool for this and allow you to then place your detailed shots; this also needs a sketch, so you don’t forget where each is.
Panoramas using film take up a large number of shots. When I first experimented with 360 panoramas back in the 1990s using some of the early Apple stitching tools, a single 360 panorama would take at least 18 - 36 shots. i.e. a whole roll of film.
Digital means that the number of photos needed for a high-resolution panorama is no longer a constraint. What is more, the stitching software has improved tremendously, although it should be said that the Apple software was well ahead of the curve.
Many phones and cameras provide an automatic panorama tool, which is amazing.
As a recommendation always build panoramas using the camera in portrait orientation. This will increase your ability to accommodate for vertical movement when not using a tripod.
Panoramas built from single shots can then be stitched together using either a dedicated panorama stitching software such as PTGui which I use, or the extensions now available for Adobe Photoshop and Lightroom or other photo processing software.
One further thing about context using panoramas. Remember that the orientation of the image will, by definition, encompass a range of azimuths, so you need to ensure that you record this. For limited extent panoramas (not the full 360) record the azimuth of each end of the panorama as a minimum requirement.
If your camera appends azimuth (orientation) to each photography that builds a panorama then you will be able to revisit this later.
There is also another way to check on the context of an outcrop and that is to use Google Maps back in the office or basecamp. With the ability to now generate 3D views of landscapes in Google Maps you can go back to any locality and relook at the context from various orientations. This is a great tool. But it does come with a health warning. In most areas, the landscapes in Google are draped on an elevation model, which means that bedding dips and geometries will be compromised.
Google view of the panorama shown above. The position of person indicates the viewpoint, and the extent by the white lines.
3. Then focus on the detail
With the context captured, you can focus in on key features within the outcrop. This might be fossils, sedimentary structures, or tectonic structures, petrology etc.
If you are focussing in on detail, be careful especially of light and focussing (see below).
Ensure that on at least one version of each picture you have a clear scale that shows dimensions and any possible distortion (see below).
With a high-resolution digital camera with a large megapixel count, you will be able to zoom in and extract detailed clip-outs from a single overview photo in processing software such as Adobe Lightroom. This can help limit / manage the number of pictures you take if this is a concern.
4. Keep track of scale
Size is important. All field photos need to include an indication of the scale. Traditionally geologists have used coins and lens caps, all of which vary in size.
Today, it is easy to buy professional scales used for archaeology or, as I use, for crime scenes (evidence markers are great for drawing attention to key features for students to look at, although chalk body outlines might scare the more sensitive and are probably best avoided…).
The metric system is the standard measurement system for science. However, many of my scales have both metric and imperial given that much of my own audience is based in the U.S.
A word of caution, which also applies to coins as scales, is light reflection and exposure. Although I use white scales (see photos), I now also have a set of grey colored scales, which present fewer light issues.
A 5 cm (2 inch) scale used for smaller features
5. Watch out for distortion
Zooming into a scene can have an unwanted consequence. Distortion. This can get even worse if you get close to an outcrop and then decide to use a wide-angle setting. Not recommended. But is often done.
The scales I use have a circle drawn on which will give an immediate measure of distortion which you can then account for in Lightroom or Photoshop (or equivalent).
For larger extent field shots look for verticals that you can use to constrain distortion. For example, signposts, roadside lamp posts, etc.
A scale ‘square’. The right angle and circles allow for any image distortion to be quickly assessed.
6. Check your focussing and light settings
One of the real frustrations of using film was getting your slides or prints back and realizing that you had set the wrong aperture or shutter speed. The same is true for digital but can be checked immediately in the field.
The recommendation is that you frequently check your settings and that you go back through your last few shots to ensure that there is nothing amiss.
I shoot in Raw format on my Nikon, which gives me the ability to 'correct' many exposure issues in the office.
That’s ok at one level, but whilst light issues can be addressed to some degree, focusing problems cannot. If your image is out of focus, then no amount of playing with the clarity or sharpness options in Adobe Lightroom is going to rectify this. I know, I have tried.
Again, this problem can be avoided by regularly checking your focusing settings at each new locality if not more often. Be aware that on some cameras it can be very easy to accidentally switch off auto-focus, or vibration compensation systems on lenses.
Another way of mitigating the focusing problem is by stopping down the aperture to increase the depth of field (those parts of your image that are in focus). With most new digital cameras, you can stop down even in dark, overcast settings by simultaneously increasing the ISO. With film, high ISOs were equated with an increase in the graininess of the final result. This is far less of an issue with digital.
7. Make notes and sketches
Sketching an outcrop is an essential skill for field geologists and has not been eliminated by digital photography, no more than it was by film.
Even the most basic sketch allows you to record what you have photographed, and to record locality and measurement information (azimuth, dimensions) as well as key features that you can observe in the field, annotations to help your memory once you are back in the office, and also any questions you have about the outcrop.
Given that with digital you can take a large number of images for any outcrop, it is important to ensure that you remember what you photographed, and this is where an annotated sketch will help (more on field sketching in a few weeks).
Another tip here is to use graphics or presentation software to create an annotated version of your photographs. These are then useful for presentations.
n this example from one of my own presentations, the panorama field photo is annotated with some key observations that I want to draw attention to and then related to the outcrops position stratigraphic chart using some animated graphics. In this case, the position is shown both temporally and spatially. If you are asked to give a presentation with limited time to prepare this sort of slide is relatively quick to produce. The stratigraphy is from a paper downloaded from the internet (in this case the excellent Ph.D. thesis of Elisabet Amorós, 2013) and the panorama can be generated at the outcrop. In MS Powerpoint the annotation and animation take 5-10 minutes depending on what you want to highlight.
8. Be organized
Ensure that once you are home you upload your images immediately and that you tag your pictures whilst they are fresh in your mind. (ideally, you should do this each evening when you are in the field).
If you leave it a week it will be too late, and likely you will never do it.
Tags are useful because they are attributed to each picture in your processing software as metadata and will allow you to search your photo libraries for location, subject, data etc., depending on what keyword system you use.
Adobe Lightroom will, by default, organize your photographs by date, which is still my preferred management scheme.
9. Use post-production to enhance your image library
Post-production in this definition means what happens after you have taken the photograph. With digital, you have much greater flexibility to correct or enhance images to show key features using post-production software, of which there is a range of options. I use Adobe Lightroom.
Whilst these tools are extremely useful, they do take time. So, unless you have unlimited time available, then you will need to be choosey about which images you process. This is about cropping photos for particular tasks or changing the light balance.
Post-production is a subject in its own right, but a couple of key things to think about:
10. Backup your pictures
As with anything on your computer, ensure that you make backups. Storage space is relatively cheap. Losing your photographs is forever.
I had an interesting discussion with a colleague a few years back who was very concerned at how vulnerable’ digital pictures were to loss. The threat of hard-drive failure, viruses, attacks on the cloud, etc. The reply was easy (1) back-ups (2) having one copy of a slide is much, much more vulnerable, and film can deteriorate with time (mildew for one)
My personal recommendation is that you have two backups on physical hard drives. This may sound like overkill but hard-drives do fail. SSDs (solid state drives) should be more resilient but the storage costs of SSD are currently incredibly high in comparison with traditional spinning patter technologies. I would also recommend using a cloud solution such as Dropbox, iCloud or oneDrive.
And make sure that one of these backups is off-site...
This blog is co-posted on the Knowing Earth website (www.knowing.earth)
Paleogeographic maps come in a variety of forms. But it is as reconstructions of past landscapes that they are the most useful. Why? Because it is on these landscapes that the geological record is built. A particle sees topography, rivers, and oceans. It experiences rain and floods and the heat from the sun. It does not see mantle convection nor crustal hyper-extension nor differentiate between a compressional or extensional tectonic setting, at least not directly. How sediment is formed in the hinterland through weathering and erosion, transported and ultimately deposited is a function of what happens at the surface and therefore what that landscape is.
A Google search for the term "paleogeography" reveals a wide range of maps and images. From simple black and white sketches showing past shorelines to maps of depositional systems or the distribution of tectonic plates, to full-color renditions of paleo-elevation and -bathymetry. Many, if not most, are informative, some are aesthetically quite beautiful.
For most geologists, such maps need little introduction. They have a long history of usage in the literature, and today have become something approaching de rigueur for conference presentations and corporate montages.
But paleogeography is more than just images in presentations. It is or can be, a powerful tool for managing, analyzing and visualizing geological information, for investigating the juxtaposition and interaction of Earth processes, as well as acting as the boundary conditions for more advanced Earth system modeling with which to better understand how our planet works.
Over the next few months, I will present a series of blogs that will explore paleogeography.
It will be a journey that will take us through the history of paleogeography, a look at how maps are generated, a guide to some of the pitfalls and caveats of mapping, a review of some of the mapping tools available, as well as examples of how paleogeographic maps have been used to solve real-world problems, especially in resource exploration where I have the most experience.
It is a journey that I hope you enjoy and find useful.
In this first blog, I want to set the scene by addressing two simple questions. What is paleogeography? And why should you care?
The Nature of the Problem: there is simply so much to take in.
If we look at any landscape and the processes responsible for forming it and which are acting on it, such as in the central Pyrenees shown above, we are faced with something of a dilemma: There is simply so much to take in.
For example, if we are teaching field geology in such an area do we focus on the structural evolution, or the stratigraphy, or the depositional systems or the climate, or vegetation or any one of the many components that together comprise the Geological record and the Earth system in this view?
Or do we try and cover all the bases?
Ideally, we want to try and cover everything. But we have limited time. We also do not want to overwhelm all concerned with diverse technical vocabulary and concepts. The risk of losing our audience.
Consequently, we usually focus on a specific field of study.
The same is true in exploration. Whether we are assisting management to make strategic decisions about where to explore or are a member of an asset team identifying and evaluating blocks and then prospects. We need to understand all the components of the Earth system if we are to make informed decisions.
30 years ago, companies would have had an army of in-house specialists on whom they could call for help to do this, and even more academic experts on retainers. But, those days have long since gone.
Unfortunately, one thing that has not gone is the budget constraints of the commercial world.
Exploration is, by its very nature, a net cost to an energy exploration business.
So, in addition to the scientific challenges, in exploration, we are also faced with trying to extract the maximum value from limited budgets.
So, what do we do?
Finding solutions: Paleogeography as a key tool in the geologist’s toolbox
We need a tool with which we can bring together (gather), manage, visualize and interrogate diverse geological information, information which is often sparse (especially in frontier exploration areas), sometimes questionable, and often equivocal.
If we look to history for guidance, we find 19th-century geologists faced with the same problem. A growing volume of diverse geological information and how to deal with it.
Over the preceding 100 years, scientists had tried to encapsulate the contemporary knowledge of the Earth system into a single book or series of books. Humboldt's Cosmos or Lyell's Principles are examples. But this had become next to impossible by the middle of the 19th century due to the sheer volume of information, resulting in an exacerbation of the scientific specialism that we have today. Humboldt’s opus itself was unfinished at his death and completed based on his notes.
One solution to this problem was to use maps to distil visually this wealth of information. Ami Boué’s maps of the World, more commonly known through Alexander Keith Johnston's “Physical Atlas of Natural Phenomena” (Johnston, 1856) in the middle of the century., or Élisée Reclus’ excellent “The Earth” (Reclus, 1876)
Reclus’s book on the Earth (Reclus, 1876) included maps showing the distribution of mountains and volcanoes. With the distribution of seismicity and you have all the information necessary for plate tectonics.
With geology, the problem was exacerbated by the time dimension. This was not simply a matter of mapping the current physical state of the Earth and its processes but how this had evolved over time. The past geography of the Earth. This is Paleogeography.
It is no coincidence that Thomas Sterry Hunt, the author attributed with first coining the term “paleogeography”, was also one of the first petroleum geologists, looking for ways to manage and analyze geological data for exploration. (We will revisit this in a later blog).
Paleogeographic maps can summarise a wealth of geological information in a simple, visual way by distilling the record into representations of depositional environments and structures. This then allows additional information to be added and juxtapositions and relationships investigated.
Such maps can also show lithological distribution and character, although strictly speaking facies maps are distinct from paleogeography’s in that they represent the product of processes, i.e. the rock record (as do GDEs for that matter), whilst a paleogeography represents the environment and landscape in which and on which those processes act and upon which the geological record is built.
The late Ypresian paleogeography for the central Pyrenees showing one transport pathway that takes in the three outcrops shown. From Markwick (2019)
In practice, this definition of paleogeography has become blurred. Facies maps, GDEs (Gross Depositional Environments), and plate reconstructions are all frequently referred to as “paleogeography”.
The original definition of paleogeography proposed by Hunt was as a field within geology to describe the “geographical history” of the geological record, which to him included the depositional environments, such as deserts and seas (Hunt, 1873).
This view of paleogeography as being the representation of the depositional environments that comprise a landscape is useful for two important reasons.
First, because it allows us to distinguish between the landscape, the processes acting on the landscape, the processes that created the landscape, and the rock record that is the product of all of the above. This makes the Earth system more manageable. It also means that when building a map we can audit each step (something we will look at another time).
But second, it allows us to deconstruct what the rock record directly responds to. What is important to consider. Where we need to focus our time (and monies). If we think of a sedimentary particle formed in the hinterland through weathering and erosion, transported and ultimately deposited, what does it really ‘see’ (i.e. respond to – at the risk of personifying clastic particles too much). A particle sees topography, rivers, and oceans. It experiences rain and floods and the heat from the sun. It does not see mantle convection nor crustal hyper-extension nor differentiate between a compressional or extensional tectonic setting, at least not directly.
It responds to the contemporary landscape and the processes acting on it.
A particle eroded from the hinterland and transported to its depositional location responds on its journey to processes at the Earth surface
Paleogeography defined: the problem of time
We now need to add another component to our definition of what paleogeography is. And that is time.
This is something that was identified by Charles Schuchert, a professor at Yale and colleague of Joseph Barrell, one of the founders of modern stratigraphy.
Cenomanian – Turonian section, Steinaker Reservoir. What would a Cretaceous paleogeography meaningfully represent? The transgressive shales or prograding sands or any range of other units through the Cretaceous
The Earth is dynamic and landscapes and depositional environments and their products the rock record can change over relatively limited geographic distances and short temporal intervals. For Schuchert, a global Cretaceous map was meaningless, for the very simple reason of what exactly did it represent? A landscape at the beginning of the Cretaceous, the end, the maximum extent of marine conditions, or as more likely, a pastiche of lots of different parts of that Cretaceous record? Schuchert’s recommendation was to use the finest stratigraphic intervals possible, which for him were represented by stratigraphic formations.
Kay went further to suggest that ideally paleogeography should represent a “moment in time”. Rather like looking at a satellite image. In this definition, paleogeography was a snapshot of the depositional environment and the landscapes at a specific moment. That makes perfect sense, but there is a problem. In the absence of a global correlation tool that can pick out a moment in time, this is next to impossible to achieve, especially over large distances. But it is an aspiration. It is also a reminder to ask of a map, what does it represent? Again, this is something we will return to in a later blog.
What is paleogeography?
Paleogeography is the representation of the past surface of the Earth, at a ‘moment’ in time.
Why is it important and why should you care?
Because it allows us to bring together diverse information that will help us better understand the Earth system, whether we are teaching in Spain or faced with deciding on where to explore. Paleogeography gives us the spatial context for gathering, managing, visualizing and analyzing a wide array of geological information in a way that is easy to digest.
At the end of the day, paleogeography is far more than just an image in a presentation.
Maastrichtian paleogeography showing the distribution of DSDP and ODP sites (small red circles) and vertebrates (Markwick and Valdes, 2004; Markwick, 2007)
This blog is one of a series based on a lecture course on paleogeography. Readers are also directed to a new paper on paleogeography published in the Geological Magazine: https://www.cambridge.org/core/journals/geological-magazine/article/palaeogeography-in-exploration/444CC2544340A699A01539A2D4C6E92A
Hunt, T. S., 1873, The paleogeography of the North-American continent: Journal of the American Geographical Society of New York, v. 4, p. 416-431.
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Markwick, P. J., 2007, The palaeogeographic and palaeoclimatic significance of climate proxies for data-model comparisons, in Williams, M., Haywood, A. M., Gregory, F. J., and Schmidt, D. N., eds., Deep-time perspectives on climate change: London, The Micropalaeontological Society & The Geological Society of London, p. 251-312.
Markwick, P. J., 2019, Palaeogeography in exploration: Geological Magazine (London), v. 156, no. 2, p. 366-407.
Markwick, P. J., and Valdes, P. J., 2004, Palaeo-digital elevation models for use as boundary conditions in coupled ocean-atmosphere GCM experiments: a Maastrichtian (late Cretaceous) example: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 213, p. 37-63.
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Paleogeographic maps are common throughout the Earth sciences. There seem to be few geological presentations today, in either Academia or Industry, that do not include at least one paleogeography, some of which have become aesthetically quite beautiful. But, despite this, the full power of paleogeography as a tool in geological problem solving remains underutilized. In many, if not most cases, maps are used simply as a backdrop image for locating data. That is a great shame.
When Thomas Sterry Hunt first coined the phrase 'paleogeography' in 1873 (Hunt, 1873), it was not just as a 'pretty' picture for a presentation, but as a way to bring together diverse geological information to better understand the Earth system.
Hunt was one of the first petroleum geologists, and by the time of his paper, he was faced with the problem of a rapidly expanding library of geological observations and ideas that needed to be managed. A situation that is all the more applicable today.
Earlier geologists had used land-sea maps as one means of managing and visualizing this wealth of information. But, it was Hunt who applied these maps to exploration and who established the first systematic workflow for building paleogeography by stressing the importance of the underlying crustal architecture. This workflow was expanded and developed by Charles Schuchert in the early 20th century (Schuchert, 1910, 1928) and later by Fred Ziegler (Ziegler et al., 1985) and the Paleogeographic Atlas Project (the subjects of future blogs).
Paleogeography has long been a passion with me ever since I was an intern at BP’s research center in Sunbury-on-Thames back in the mid-1980s. The first atlases of global plate reconstructions had been published 10 years before (Briden et al., 1974; Smith and Briden, 1977; Smith et al., 1973) and by the 1980s were becoming much more widely used. In Chicago, Fred Ziegler’s Paleogeographic Atlas Project was developing new methods for mapping and applying the results directly to exploration problems (Ziegler et al., 1985), including the use of paleogeography with paleoclimatology to retrodict (predict the past state) the distribution of source rocks. This had demonstrated to the oil and gas exploration industry that there might be a better and cheaper way to do preliminary basin screening.
This is where I came into the story, working on paleogeographic maps, paleoclimatology, source rock databases, and retrodictions. It was a great time with so many new developments and ideas about the Earth.
Many groups have developed paleogeographies over the years. Too many to mention in one blog or paper. One could mention the influential atlases of Peter Ziegler at Shell (Ziegler, 1982), the ground-breaking Russian atlases of Vinogradov (1968, 1969; 1967; 1968) and then Ronov (1989; 1984) and their teams in Moscow, the coastline maps of Smith et al., at Cambridge (and BP) (Smith and Briden, 1977; Smith et al., 1994); the maps of Dore in Statoil (Doré, 1989), and Dércourt in France (Dercourt et al., 1993), and more recently the excellent work by the University of Rennes research group of Francois Guillocheau (Chaboureau et al., 2013). Not forgetting, of course, the highly influential and widely used maps of Chris Scotese (Scotese, 2008; Scotese et al., 1979; Scotese and Golonka, 1992), who has perhaps done more than most geologists to promote plate reconstructions and paleogeography. It was on Chris’s maps that Ron Blakey from Arizona first generated his beautiful 'Photoshopped' maps which many of you have seen and probably used.
But, for me, it was the developments by what I refer to as the 'Chicago School' that were the most influential, especially in the exploration Industry. It was at Chicago that Chris Scotese published his initial work as a post-doc of Fred's, where Dave Rowley and Ann Lottes published a series of papers on plate modeling, and where many of Fred’s students, including Mike Hulver (now at Saudi Aramco), myself (Markwick and Valdes, 2004) and others learned and developed our understanding of geology and paleogeography, as well as methodologies for data management, auditing, and visualization.
The Paleogeographic Atlas Project is important to the story of paleogeography and its applications in two principal ways:
1. The reconstruction of paleolandscapes, not just depositional systems or facies.
2. Data management, data verification, and auditing and digital databasing, building on the ideas of earlier workers such as Schuchert (1910) and Kay (1945)
Paleolandscapes are key because at the end of the day this is what the rock record sees. A particle weathered from the highlands in the hinterland of a basin, does not see mantle anomalies, or hyper-extended crust, at least not directly. It sees the vegetation, rivers, lakes, and sea. It sees the surface of the Earth, which is the landscape.
Data management, because without an audit trail how do you know how good the maps are? This was and is critical for the exploration industry with their need to understand exploration risk, in order to make informed decisions. Decisions that have a financial cost.
The Paleogeography Atlas Project was sponsored by the oil and gas industry and so these questions and drivers were foremost in Fred's mind. It was also this link with the Industry that stimulated the work of Judy Parrish in the early 1980s and her seminal publications on source rock retrodiction using early parametric paleoclimate models and paleogeography to reconstruct the location of ocean upwelling. These models were subsequently computerized by Scotese and Summerhayes (1986).
Over the last 18 months, I have been revisiting this story.
One result is this paper on “Paleogeography in Exploration” (Markwick, 2018).
This is designed to provide an introduction to the history and methodologies of paleogeography, including the latest version of Hunt’s mapping workflow. Associated with this is a new mapping legend, which is available through the publication as supplemental data, as well as online as digital .style files for use with ESRIs ArcGIS. Three case studies are given which show how paleogeography can be applied at different scales to solve different exploration problems.
There is much more to add to this story and more will follow. But, for now, my aim to get the next generation of geologists, and especially explorationists, thinking about how they can use paleogeography maps more effectively in their workflows. And also, I hope, to get them excited about reconstructing the Earth system, an excitement I first discovered back in BP in the mid-1980s.
At the very least I hope that readers will see that paleogeography is so much more than just a flat image, beautiful that these may be.
"Palaeogeography in Exploration" was published online in June 2018 in the Geological Magazine and will be published as part of the “Advances in Palaeogeography” volume in early 2019.
I wish to thank the volume editor, Guido Meinhold, for all his hard work in putting together a very interesting collection of papers on this important topic and for his kind inclusion of my research. I am also indebted to the reviewers, especially Tony Doré, for their perseverance in reading the original draft, which as they described it, read “more like a book…” The final version greatly benefited from their suggested changes and their dedication to the review process. They will be relieved to hear that the final version is considerably shortened. A book will be out shortly.
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