Drivers of imbalance in machine learning uptake across geology and geophysics

Our Data Science Director, Samuel Fielding and Lorin Davies (Managing Director) recently authored an article for the Machine Learning special issue of First Break this September. In it they use machine learning to interrogate factors driving its uptake in various geoscience domains.

September 2019

Topics covered include visualizing discipline-specific drivers of machine learning uptake (using machine learning), and exploring different ways to facilitate machine learning in undersaturated disciplines within the geosciences.

Machine Learning augments our acquisition, preparation, and interpretation of the data, so our next great challenge is to unlock these advancements to realise the next great productivity leap in data analysis.

EAGE members can read the full article here or anyone can read the abstract here.

Tales from Texas

Back in May, Lorin and I headed across the Atlantic to visit friends (new and old) over in Texas. We planned to spend a week in Houston in the run up to AAPG ACE 2019, followed by a week in San Antonio at the conference.

It was a little different to your usual business trip. As a start-up, it means we had much more flexibility in terms of our travel and accommodation. For starters, we were able to choose from hundreds of Air B’n’B’s and take a few diversions adding in a little road trip here and there.

Nonetheless we had a few hiccups along the way. I had the bright idea of printing my AAPG poster while we were in Houston to save bringing it over on the plane. Apparrently this isn’t so straight forward (even if you put your order through and everything looks hunky dory!) and I strongly advise against trying to print an 8x4ft poster at Office Depot! We ended up having to adapt the design and print it in three 2ft wide panels. It actually worked out as quite a nice way to break up the poster and guide the reader through the content – every cloud and all that.

Watercolour by Jim Koehn

After a week spent in Houston visiting potential clients and sampling a local ‘Ice House’ (above), we drove west over to San Antonio. We arrived at our lovely little Airbnb a few days before the conference and gave ourselves some time off to relax (below) or should I say explore.

Our San Antonio Airbnb

After contemplating numerous road trip options (a particularly adventurous one of Lorin’s was to attempt to make the 16 hour drive to the Grand Canyon) we decided on a relatively short jaunt to the Mexican border city of Laredo.

Here, we thought we would just nip in to Mexico, get a stamp in our passports and head home after sampling some authentic Mexican food and culture. It was our intention to walk over the Rio Grande bridge into Mexico as foot passengers instead of going by car, which is not uncommon for tourists to do.

Our first port of call when we arrived at Laredo was lunch. We stopped at ‘El Maison De San Agustin‘ and I preceeded to order quesadillas for the millionth time on our trip thus far and drank a vat of hibiscus ice tea. Following said lunch, we were both stuffed and ready for our walk across the bridge.

El Maison De San Augustin

Crossing over into Mexico was predictably a lot faster than on the way back. As soon as we were over the border/bridge we had numerous offers of dentistry services!? We had a bit of a wander around, took some photos and then began to head back over the bridge. We didn’t have to queue for long to get back across but were a little disappointed that we didn’t actually get a stamp in our passports!

The Mexico-US border in Laredo over the Rio Grande.

Back in San Antonio a few days later, we kicked off the first day of the AAPG ACE conference at the Henry B. Gonzalez Convention Centre with the ice breaker reception where we bumped into many old friends and colleagues and put some names to new faces.

AAPG ACE Ice breaker reception

The conference had a packed schedule with topics ranging from unconventional reservoir characterisation, deepwater sedimentology, machine learning, and not one but two sessions on source-to-sink (a personal favourite of mine!). I spent Monday afternoon listening to talks from the “Fluvial and Deltaic Depositional Environments: Reservoir Characterisation and Prediction From Multiple Scale Analyses” theme. John Holbrook touched upon braided versus meandering systems and whether or not it is actually that black and white when it comes down to it. James Mullins discussed automated workflows for reservoir modelling using drone data and libraries of photo analogue systems, and Margaret Pataki presented her work on Rapid Reservoir Modelling (RRM) using sketch based models.

AAPG ACE 2019 Exhibition Hall and Poster Sessions

Tuesday morning was spent swithching between the source-to-sink sessions and “Multi-Disciplinary Integration for Subsurface Efforts in the Age of Big Data”. There were lots of interesting provenance and sediment supply studies studies interspersed with sediment routing and recycling in the source-to-sink sessions, inolving talks from Peter Burgess and Jinyo Zhang. The integration and big data session touched upon multi-disciplinary approaches to subsurface studies, including the use of petrography, geochronology and biostratigraphy data in order to produce more accurate chronostratigraphic interpretations when correlating wells, presented by Eugene Syzmanski. It seems that the value of geochronology is gaining more and more momentum in the oil and gas industry recently as people realise that multi-disciplinary approaches lead to more robust interpretations.

That afternoon was our poster session where we presented on “A Source-to-Sink reservoir Quality Prediction Workflow: The Offshore Nile Delta”. It was great to see such a busy poster session (I’m guessing partly due to the proximity of the exhibition hall and free beer at the end of the day!) and we ended up chatting to lots of new and interesting folks about the work that we are doing at Petryx and how it can add value to real world geological problems – particulary with regards to taking the leg work out of data collection and standardisation. All in all, we were stood by the poster for about 4 hours and recieved lots of positive and constructive feedback.

Extended abstracts to be published online soon!

I also had judging commitments that afternoon and headed over to the poster session on “The Digital Transformation in the Geosciences”. There were loads of fantastic posters, all were presented exceptionally well with some great visualisations of some pretty cutting-edge data science.

Subjects included petrophysical facies classifications using neural networks, the use of clustering techiniques to define chemofacies and the application of decision trees to determine failure modes.

In addition to all the technical talks, there were also some great sessions focussing on sustanability and a DEG special session on the environmental impact of the oil and gas industry. Discussions were centered about how geology will remain key in the transition to a more carbon neutral society with the increasing importance of practices such as carbon cap and storage and geothermal energy. Consensus was that we need to stop thinking of ourselves as the bad guys and to start realising the potential that we have as an industry to help with the climate change challenges that lie ahead. This will also be crucial in continuing to attract bright and ambitious talent to the oil industry in order to help us adapt to the digital transformation culture and the ‘big crew change’ that we see on the horizon.

Unfortunately Tuesday was also the last day of the conference for us as we had to head back to Houston for a last minute meeting before catching our flight home. All in all Lorin and I had a great trip gathering lots of feedback, meeting lots of new faces and are looking forward to heading back to AAPG next year, in Houston.

Next week Lorin will be writing an article all about our week in the Start-up area of this year’s EAGE Annual in London.

PRESS RELEASE: Petryx and Getech announce database partnership

Petryx Ltd have partnered with Getech Plc, allowing customers in the Oil & Gas industry to view Petryx Database coverage alongside Getech data products. Covering every major continental mass in the world, the Petryx Database offers hinterland data essential to data-driven source-to-sink interpretations.  

Managing Director of Petryx Ltd, Lorin Davies says: “We are delighted to have partnered with Getech. This brokerage deal provides much higher visibility of Petryx datasets to Oil & Gas explorers and demonstrates Getech’s commitment to innovation. Deals like this emphasise the many ways in which the Oil & Gas industry can support innovative start-ups like ours.” 

Senior GIS Consultant, Thierry Gregorius says: “We are excited to add this valuable new data resource to the extensive product range that we offer our customers. Explorers and geoscientists will now be able to access global datasets from Petryx via Getech, including geochemistry, geo- and thermochronology, and more. With this step we are offering our customers a growing one-stop shop.” 

Petryx Ltd is an innovative digital geoscience start-up who have revolutionised data integration and acquisition processes, giving Oil & Gas explorers fast access to cleaned and standardised datasets. The Petryx Database is a multi-disciplinary geoscience dataset compiled from numerous sources with the collaboration of industry and academic partners. It offers an unrivalled view of the composition of the earth from a single unified platform. 

Getting to sleep

This Friday, is world sleep day, and two weeks later some 1.5 billion people will participate in an exercise which will likely result in them getting one hour less sleep than usual. The shift to daylight savings time. If you’re in the US you did this last week. The next day there will be a spike in the number of heart attacks recorded in hospitals, this is a known phenomenon which occurs every year, and is matched with an inverse effect in the Autumn. 

Given that we will likely spend over a third of our lives asleep, it is perhaps unsurprising that it has a significant impact on our health. In actual fact, when I read about this topic in Matthew Walker’s excellent book, what becomes surprising is how little we have been paying attention to the implications of sleep deprivation on our mental and physical performance, as well as our general health. If you sleep less than is recommended you are more likely to be overweight; be or become diabetic; you are more likely to suffer from a heart attack; crash your car; have a bad memory; and even possibly have fertility issues. The list goes seemingly on forever. 

Our ability to perform even basic tasks, like driving a car or playing sports is severely impacted by sleep deprivation. We now also know that it goes further, making us struggle to retain information or complete complex mental operations. So why in so many industries and societies is lack of sleep still worn as a badge of honour? In the last 20 or so years a new breed of company has started to grow, from google’s well documented ‘nap pods’ to Nike’s flexible working hours aimed at accommodating different body-clocks, perceptions are beginning to change. Hopefully we are now at peak tiredness and we are beginning to wake up 😉 to the risks of not getting enough sleep. Along with presenteeism being responsible for the unwanted and unnecessary spread of the flu-viruses throughout organisations, sleep deprivation makes good people do bad work, and sometimes also become sick.

Why We Sleep: The New Science of Sleep and Dreams by Matthew Walker

We are trying to make sure that our company respects our bodies’ needs. Which is why unless there is a super-immovable commitment we expect people to arrive in the morning when they are rested and ready to roll. If you think you’re going to be arriving to work on the 1st of April exhausted because of an even shorter than usual sleep, why don’t you ask your boss if you can come in a little later? You’ll quite possibly do a better job, you could even promise to arrive early when the clocks go back in the Autumn.

How do you sleep at night? Keeping tech out of the bedroom and listening to white noise on repeat seem to be effective solutions for many people, what are your top tips for getting a good night’s sleep? Does getting a good night’s sleep give you an edge at work, or do you not notice a difference?

Pets at Petryx

Petryx has been a dog friendly company from day one. Juno (left), Chief Log Analyst and Bran (right), Head of Dog-ital Transformation accompany us to the office every day. Previously, we had to ensure that we had dog sitters in place to pop round to walk and give general fuss to the pups five days a week as leaving a dog on its own for eight-hour days is just not pooch friendly. Now they do the 30 minute commute with us and lounge around the office until it’s time for the ‘W’ word at lunchtime. Then, they are then unleashed on the North Wales countryside to romp, swim and roll in terrible things at their leisure.

Why should you bring your dog to work?

1.      45% of people who bring their pets to work claim having their pooch with them reduces stress and enhances their work-life balance.

2.   It creates a friendly atmosphere. A dog doesn’t care if you’ve missed a deadline or done something wrong, they give extra emotional support to you and your colleagues whilst at work. Studies show that over a third of employees are happier and healthier when allowed to bring their pets to work.

3.      Speaking of health, bringing your dog to work encourages us to take more regular exercise. This is known to be beneficial for our physical and emotional health.

4.      Encouraging pet ownership by allowing people to bring their dogs to work has the added benefit of a healthier workforce as pet ownership is shown to reduce cholesterol and lower blood pressure.

5.      It also saves employees shelling out for dog sitters during the week, creating an added financial incentive. Some pet owners claim they would be willing to stay in work later/longer if they had their pets with them so they weren’t rushing back home to let them out and feed them.

6.      Lots of companies have adopted bring-your-dog-to-work policies: Amazon, Google, Brewdog, Etsy, Ben & Jerry’s, Purina, and Build-A-Bear Workshop to name a few. It may also help to attract new talent to your work force as it is seen as a unique privilege or benefit to be able to bring your pup to work with you.

7.      Last but certainly not least (unless you are a cat person), it’s good for dogs. They are social creatures and it will have a positive impact on animal welfare.

 Fancy making your workplace dog friendly?

We know that lots of people like the idea of being able to bring dogs to work with them but it’s another thing convincing the boss that it’s a good idea. Purina have helpfully put together a presentation that you can use to win them over. Here is another helpful checklist for creating a bring-your-dog-to-work policy. It includes things like establishing pet-free zones and taking turns or limiting the number of pets per day.

If you don’t fancy making it a permanent set-up, then try having a one-off Bring Your Dog to Work Day (Friday 21st June 2019) to raise money for charity. Once you are able to welcome dogs through your office doors, you will have to make the place pooch friendly in order to limit bin diving and cable chomping.

All that remains to be said is good luck in your quest to a dog-friendly workplace and Merry Poochmas from the Petryx office hounds.

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Petryx at PETEX

This week we have been showing off our wares at the PESGB YP Summit and PETEX conference. If you haven’t had the opportunity to chat to us already, or found one of our web-app postcards then drop me a line.

We are showcasing two unique offerings this week. The first is our web-app. The web-app is a demonstration tool which shows the kind of bespoke coded solution we can provide. It is particularly useful for quick-look analyses or when conducting routine plotting or charting tasks and can probably save you a load of time. We dropped in some XRD data, but we can build tools like this for you quickly and easily for virtually any geoscience dataset. Get to the web-app by clicking here.

Secondly we are showing the Petryx Database. With an estimated 80% of data science projects devoted to aggregating and cleaning data. The Petryx Database offers a global geoscience data resource unequalled in the market. What’s more, Petryx offer a one off purchase commercial model, so you needn’t buy the same data from anyone year-after-year.

If we missed you, or you want to hear more about our data or services then drop us a line!

Lorin Davies

Some notes on the use of heavy minerals in provenance studies

Past industry experience has shown that when geoscientists start to think about sediment provenance, people’s first thoughts often go straight to traditional methods such as petrographic point counting and heavy mineral analyses.  However, it has long been known that the resistance of heavy minerals to weathering and transportation is highly variable and can therefore alter provenance signals.

“Perhaps the most general problem is that of heavy-mineral resistance to both mechanical and chemical processes…The co-operation of all sedimentary petrologists is needed in solving these major problems.” – Sindowski, 1949.

The complexity of heavy mineral analyses means that only a small minority of specialist labs still focus on the method whilst fully taking into account all possible source of bias (e.g. hydraulic sorting effects on grain size, and chemical and mechanical weathering). Automated mineralogy is becoming increasingly popular but still brings its own set of problems. Just as traditional point-counting relies on the experience of the operator, automated mineralogy is highly dependent on the dictionaries used to calibrate the software. However, the reproducibility and the number of samples that can be run means that more data (some might say more noise) can be generated and more samples can be analysed in-situ, removing potential mineral separation bias.

Current academic provenance studies tend to focus more on robust single-grain geochronological techniques, whole-rock radiogenic isotopes or thermochronology. U-Pb zircon geochronology in particular continues to gain popularity when it comes to detrital provenance studies (Spencer et al., 2016).

Figure 1. The increase in popularity of single grain U-Pb analyses (Spencer et al., 2016)

As the popularity of zircon studies continues to rise, an increasing number of studies are also highlighting how the diagenesis of heavy mineral assemblages under burial can severely alter provenance signatures (e.g. Morton and Hallsworth, 2007; Milliken, 2007; Garzanti et al., 2010; Ando et al., 2012; Garzanti et al., 2018). Unstable minerals are rapidly leached out down-section whilst moderately stable minerals increase their relative abundance, giving a skewed representation of the original heavy mineral assemblages associated with a given source area.

“Interpretation of provenance using heavy-mineral data from sandstones likely to have suffered burial diagenesis must carefully consider the possibility that some heavy-mineral species have been eliminated through dissolution.” – Morton and Hallsworth, 2007.

Figure 2. Heavy-mineral dissolution in the Nile Delta succession (Garzanti et al., 2018). This figure illustrates the chemical stability of unstable to stable heavy minerals in Miocene to Pleistocene Nile Delta sands. Unstable heavy minerals are absent in the oldest Nile Delta sample. In the past this has been interpreted as the absence of a particular hinterland (the Ethiopian Highlands), although this has now been shown not to be the case (Fielding et al., 2017).

Geoscientists in industry and academia alike are becoming more aware of this source of bias and are approaching the method with caution. Heavy mineral laboratories such as that at the University of Milano-Bicocca specialise in untangling the complexities of heavy mineral analyses whilst others incorporate the technique into studies using an integrated, multi-disciplinary approach.

Diagenesis aside, the method by which petrographic and heavy mineral data is arrived at has recently come under scrutiny. Dr István Dunkl from the University of Göttingen presented the findings of an Inter-laboratory Comparison for Heavy Mineral Analysis at this year’s Working Group on Sediment Generation (WGSG) in Dublin. The aim of the Heavy Mineral Round Robin was to find a common language when reporting point-counted heavy mineral data. This required each participant to point count two synthetic heavy mineral mixtures to compare the identification of heavy mineral species and quantify their proportions. Trained operator and automated mineralogy techniques were both used as a comparison and found varying results, with the automated methods proving to be much more accurate and reproducible. Several explanations were discussed as to why this could be:

1.      Counting statistics varied across all laboratories.

2.     Aliquot separation techniques. Numerous methods were reported when describing the preparation of the aliquot.

3.     Mineral identification vs operator experience. Mineral identification was inconsistent regardless of operator experience. In many cases, some operators did not detect all 8 mineral phases and occasionally added up to 5 or 6 phases which were not present in the sample at all.

The presentation was certainly an eye opener and I believe the intention is for the findings to be submitted to Sedimentary Geology this autumn. There was talk of a second phase of comparisons where it was suggested that the samples be pre-processed to reduce variation in results based on aliquot separation techniques.

This great study highlights issues not only within the method of heavy mineral point counting but also biases that may occur within other provenance techniques. It also reinforces the need for standardisation when it comes to recording heavy mineral point counts. Wouldn’t it be easier to compare like-for-like if counts were published as points as well as percentages? In the past I have attempted to amalgamate large provenance datasets and have found petrographic and heavy mineral counts to be the most difficult method to standardise (that and fission track!).

Let’s not forget that many heavy mineral studies do work well when specific problems are addressed with a through understanding of sources of bias (e.g. Kilhams et al., 2013; Morton and Milne, 2012).  Heavy mineral analyses of the Clair Group (Morton and Milne, 2012) has been very successful and enables high resolution correlation between wells. This is likely due to factors such as no operator or laboratory variability, and a well understood reservoir, where heavy minerals are a proven discriminator.

Figure 3. High-resolution heavy mineral analyses in use down section in the Clair Group (Morton and Milne, 2012). Analyses focus on the more stable heavy mineral indices, which is key as you can see the point at which the unstable (Unst) heavy mineral concentrations drop off within Unit V .

There is no one ‘silver-bullet’ for provenance studies and the multi-disciplinary approach is key when it comes to accurately recording the evolution of a source-to-sink system.

“Detangling the various interacting factors controlling mineralogical and chemical compositional variability is a fundamental pre-requisite to improve decisively not only on our ability to unravel provenance, but also to understand much about climatic, hydraulic, and diagenetic processes.” Garzanti et al., 2010

For the purposes of this article I have focussed primarily on petrography and heavy mineral analyses. However, surely all other provenance techniques can also be subjected to this kind of bias and alteration? Perhaps the new LinkedIn “Source to Sink” Group could be used as a platform to discuss other sources of bias such as:

–       The controls of mineral distribution on radiogenic isotope concentrations (e.g. Garcon et al., 2014).

–       Introducing bias to U/Pb zircon studies. Hand picking, CL and target analyses vs the ‘blind-dating’ approach (e.g. Fielding et al., 2017 and Garzanti et al., 2018).

–       Hydraulic sorting and biasing effects on ALL provenance techniques (e.g. Malusa et al., 2016, Cascalho and Fradique, 2007, and Nesbitt et al., 1996).

 By Laura Fielding, Geoscience Director.


Andò, S., Garzanti, E., Padoan, M. and Limonta, M., 2012. Corrosion of heavy minerals during weathering and diagenesis: a catalog for optical analysis. Sedimentary Geology, 280, pp.165-178.

Cascalho, J. and Fradique, C., 2007. The sources and hydraulic sorting of heavy minerals on the northern Portuguese continental margin. Developments in Sedimentology, 58, pp.75-110.

Fielding, L., Najman, Y., Millar, I., Butterworth, P., Ando, S., Padoan, M., Barfod, D. and Kneller, B., 2017. A detrital record of the Nile River and its catchment. Journal of the Geological Society, 174(2), pp.301-317.

Garçon, M., Chauvel, C., France-Lanord, C., Limonta, M. and Garzanti, E., 2014. Which minerals control the Nd–Hf–Sr–Pb isotopic compositions of river sediments? Chemical Geology, 364, pp.42-55.

Garzanti, E., Andò, S., Limonta, M., Fielding, L. and Najman, Y., 2018. Diagenetic control on mineralogical suites in sand, silt, and mud (Cenozoic Nile Delta): Implications for provenance reconstructions. Earth-Science Reviews, 185, pp.122-139.

Kilhams, B., Morton, A., Borella, R., Wilkins, A. and Hurst, A., 2013. Understanding the provenance and reservoir quality of the Sele Formation sandstones of the UK Central Graben utilizing detrital garnet suites. Geological Society, London, Special Publications, 386, pp.SP386-16.

Milliken, K.L., 2007. Provenance and diagenesis of heavy minerals, Cenozoic units of the northwestern Gulf of Mexico sedimentary basin. Developments in Sedimentology, 58, pp.247-261.

Morton, A.C. and Hallsworth, C., 2007. Stability of detrital heavy minerals during burial diagenesis. Developments in Sedimentology, 58, pp.215-245.

Morton, A. and Milne, A., 2012. Heavy mineral stratigraphic analysis on the Clair Field, UK, west of Shetlands: a unique real-time solution for red-bed correlation while drilling. Petroleum Geoscience, 18, pp.115-128.

Nesbitt, H.W., Young, G.M., McLennan, S.M. and Keays, R.R., 1996. Effects of chemical weathering and sorting on the petrogenesis of siliciclastic sediments, with implications for provenance studies. The Journal of Geology, 104(5), pp.525-542.

Sindowski, F.K.H., 1949. Results and problems of heavy mineral analysis in Germany; a review of sedimentary-petrological papers, 1936-1948. Journal of Sedimentary Research, 19(1), pp.3-25.

Spencer, C.J., Kirkland, C.L. and Taylor, R.J., 2016. Strategies towards statistically robust interpretations of in situ U–Pb zircon geochronology. Geoscience Frontiers, 7(4), pp.581-589.

Source-to-sink workflows for de-risking the oil and gas reservoir

Over the last few weeks we have been spending lots of time talking to clients about some of the datasets offered by Petryx. In a few cases we have been talking to sedimentologists and geoscientists who are experienced with manipulating and interrogating datasets like ours. However, even experienced geoscientists still have questions about how to get the most out of these datasets, particularly when doing source-to-sink work. This blog explains the approach we take at Petryx when puzzling out sediment routing and prediction of reservoir quality. We outline a generalised approach, followed by some of the outputs you would expect to see from a workflow like this.

Source to sink: Detailed study of processes and products relating to clastic sediments, from their origins in the hinterland, to the sedimentary basin.

Normally, the quickest route to good interpretation is through good scientific method. In source-to-sink questions this means observing the data, be that subsurface and/or hinterland data, and formulating a question: “where and when are the good reservoir sands being deposited”, or “does my block contain good quality sand?”. Maybe we have questions about seal capacity, or maybe a group of people have a bunch of questions which we could really do with some quantifiable answers to.

The next step is to build a hypothesis based on the data we have observed. This may mean integrating drainage-basin polygons with hinterland geology and geochemical data. We can take thermochronological data and further refine our drainage basins, or adjust the expected sediment generation based upon these inputs. Paleocurrent data help us to verify where clastic systems were flowing, and further refine the drainage story. We bring in any climatic data we have and use this along with total drainage length to quantify sediment breakdown, and therefore the cleaning potential of our sands. Plate models and paleogeographic interpretations can be significant, but throughout this process it is paramount to be able to segregate the interpretative inputs from the hard data, and weight accordingly. Once we have mashed together all these data and interpretations we can make a prediction: “Given what I have observed, I think that there is lots of good quality sand going from A to B at this time”. If we have enough data, and time to work with it, we might even quantify this hypothesis with some degree of certainty (see this great book for an explanation of why you should be sceptical of predictions that people won’t put a number on).

Now the fun bit! We take some data which we have held in reserve and test our hypotheses. A great game if you are asking a service provider to give you a bespoke source-to-sink interpretation is to keep a few petrographic analyses in reserve to test some of their predictions. We sometimes get a bit upset about not getting all the data, but it is a fantastic way of testing the veracity of the predictions being made. After all, it’s better to test our hypothesis before you drill the well, rather than afterwards.

Above: One output of a hypothetical source-to-sink workflow, with mineral composition predictions from given hinterland zones. Multiple datasets can be used to give a qualitative estimate of reservoir potential, and then mixed into sediment packages. Image credit: Petryx Ltd (CC BY-SA 4.0)

Now we can start to iterate. It is OK to get it wrong as long as we find out why. Often the predictions will need to be refined and improved to reflect new data. Once we have a model which we are happy with we can take our outputs and make some quantitative statements about the subsurface. Often a report or study will stop here and not fully translate a working model into useful quantitative data, as if it is enough to say, “We have a model which explains the data well”. Let’s take that hypothetical model and share our insights with our colleagues:

  • Thermochronological data suggest up to 6 km of exhumed lithosphere over our target interval.
  • Uplift rates around our target interval suggest a significant influx of clastic material into the area around our block (15 km3) derived from hinterland A (65% certainty).
  • Siliciclastic packages in package α are likely to be composed of 55% quartz, 25% plagioclase and 20% K-feldspar.
  • Package β, whilst relatively significant in the sediment pile is likely to be largely (85%) derived from hinterland C, so could be problematic. This may mean that where it is interleaved with package α it risks washing in diagenetic fluids.
  • Package γ appears to be a distal equivalent of package α, but also contains chemical sediments. It is likely to contain up to 6% chert.
  • Package ζ is a regional seal with an expected clay content of 30%.

Finally, we want to say loud and clear what the sensitivities and testable parts of the model are. So if someone finds some data which doesn’t fit, we can iterate our model further.

  • Paleoclimatic conditions indicate high potential for sand cleaning and improved reservoir quality. Lower weathering rates and stable climatic conditions will result in lower chemical abrasion and reduced sand cleaning.
  • Little compositional data was available for the upper part of our target zone, resulting on heavy reliance on UPb data, which can be blind to mafic hinterlands.
  • We would expect little or no metamorphic minerals in package α.

To quote statistician George Box, who we think had it about right: “All models are wrong, but some are useful”. Hopefully this idealised workflow can help you get closer to that useful model and know what these datasets should be able to tell us. If you are interested in source-to-sink modelling, or want to discuss more, drop a comment below or head over to a short survey which we will be promoting in the coming weeks. We think we have some great workflows, but your opinions can really help us make them more relevant to you.

George Box. Image credit: DavidMCEddy at en.wikipedia (CC BY-SA 3.0).

By Dr Lorin Davies

Less isn’t always more. Sometimes it’s less.

Welcome to the third instalment of the Petryx Blog series! After @SamFielding confessed that his programming know-how and obsession with automation was fuelled by his laziness, I will be discussing how programming isn’t just a way to save time, but a fantastic tool when it comes to making sense of large unwieldy compilations of geoscience data.

Large, multi-technique datasets (notice how I didn’t use the term big data, such a wildly overused and little understood phrase in our book) are becoming more common throughout geoscience. This is partly due to the integration of an ever-increasing number of disciplines, but mostly due to the sheer amount of raw data available to us when carrying out analyses using several different techniques on a single project.

So why exactly do we need multi-technique studies? Sometimes a single dataset will give you the specific answer you require. However, if you have a small sample size or if you are faced with a particularly complex problem, you’ll likely need to incorporate data from other methods to meet these requirements. This is where a multi-technique approach can really add value.

Let’s take provenance studies for example. In my own work I have often found U-Pb zircon geochronology to be invaluable due to zircon’s robust nature and ubiquity regardless of tectonic setting. However, when I was faced with a reduced sample size, multiple episodes of recycling and the need to record multiple geothermal events, this method on its own was not enough. The same is true for other methods too, like heavy mineral analyses or fission track, which, while great under certain circumstances, can both prove insufficient depending on what information you are trying to glean from your data.


Using a multi-technique dataset can be an art form, but like any other art, its quality, not quantity, that counts. More is not necessarily better in all cases. Choosing which techniques to use and in which combination to use them requires careful consideration and knowledge of what each technique brings to the table; something we at Petryx pride ourselves on. When done right this delicate balancing act can reveal vital information and shed light on areas that would have been otherwise obscured.

Working on multi-disciplinary projects in both academia and industry over the past 10 years has exposed me to an ever-changing array of data generated from numerous different techniques. Dealing with this constant stream of datasets often means folders full of spreadsheets which must be organised and worked through before any useful analyses can take place or any meaningful conclusions can be drawn. Simply handling multi-technique data can prove a mammoth and intimidating task which gets in the way of what really needs doing.

Here at Petryx we want to make analysing data, and getting the answers you need, easier. Our Petryx Database provides an extensive, ever-growing, compilation of data which can be easily accessed and queried from the Petryx Data Lens web front-end. Designed and developed by geoscientists and data science experts, the Database and Data Lens provide valuable tools which aim to minimise the amount of time our clients need to spend on data management. The Data Lens allows users to query, visualise, and pull together their own data alongside those from peer-reviewed datasets. Most importantly, our Data Lens isn’t a generic data handling platform, but is instead a specialist tool for geoscientists and the specific applications and problems they encounter.

In the early stages of any project, knowing what types of data are available for your area of interest can help you to plan more effectively. You may have a penchant for thermochronology, but if fission track data is looking a bit thin on the ground in your study area, and you have a limited budget, then you might want to consider either tapping into some other methods that have better coverage or enquiring about our data acquisition service.

Perhaps you are further along in your research and find yourself needing to compare the results of several different datasets to a multitude of signatures from potential source areas. Instead of laboriously plotting them individually using different tools, why not check out the different signatures on the fly or filter through thousands of rows of data in seconds to find similar samples that could be the source of your clastic reservoir at that crucial interval. Here at Petryx, we can help you do it. By having a small team of geoscientists and data scientists working closely together, we’ve created a product that takes the best bits from both worlds and puts you in control without all the hard work, allowing you to make the most out of your all-encompassing multi-technique dataset.

By Laura Fielding, Geoscience Director