When we meet on Teams on a morning in March, F. Javier Hernández- Molina is calling in from his office in Granada, Spain, where he works at the Andalusian Earth Science Institute (IACT-CSIC). In the background is a picture that fits the main topic of the conversation that we will have quite well – a large sailing boat navigating icy waters, probably somewhere around the poles. It reminds me of Shackleton’s expeditions to the Antarctic.
Looking at a map that is included in Javier’s CV, showing the projects he has been involved with over the years, it is not unlikely that around 100 years later, he explored the very same area at some point more recently. But where Shackleton was primarily interested in reaching the South Pole and doing some research on the side, Javier’s primary drive during all of the expeditions, field works and cruises he participated in was to better understand what happens beneath the surface of the sea, sometimes at great depths, unravelling the deep-water sedimentary systems that characterize these places.
And where some will intuitively argue that there is not much activity there, the sediments often tell another story. It is a story that Javier and his research team are trying to resolve, with the help of boreholes drilled through the International Ocean Drilling Programme, the energy industry, but also with seismic data and outcrop analogues.
Javier has long been interested in basin analysis and sedimentary geology. Though initially focused on continental shelves, since 1996, he has been working on integrated studies of continental margins where his current research focuses on deep-water sedimentation, including the influence of bottom-current / oceanic circulation in marine basins. Bottom currents and a series of secondary oceanographic processes interact at different scales to form sedimentary deposits referred to as contourites and mixed (turbidite-contourite) depositional systems. They can be found across major swaths of the continental margins and the adjacent abyssal plains in many of the world’s oceans.
Explorers in the energy sector have also cottoned on to the relevance of the work done by Javier and his co-workers. With the move to explore deeper parts of the world’s continental shelves, so has the industry shifted its attention to better understand the sedimentary environments of these places. This has put him in pole position to become one of the world’s best-known experts on deep-sea sedimentary systems with a strong link to the industry, as the lead of the successful “The Drifters” research group.
How it started
“Is it a coincidence that I ended up as a marine geologist? Maybe not so much, as I grew up in Cádiz, a beautiful town in the far south of Spain surrounded by the sea,” says Javier at the start of our conversation. “Also, once I began my university degree, I was very inspired by a lecturer who had a keen interest in stratigraphy and marine geology. It convinced me even more to go in this direction.”
It was the deep seas that most attracted Javier, following a PhD in shallow marine sedimentary systems in the Alboran Sea at the Spanish Oceanographic Institute (IEO). This was again triggered by the special location of the Gulf of Cádiz, near the mouth of the Mediterranean Sea into the Atlantic, where the mixing of Mediterranean and Atlantic waters takes place.
In those years, we’re talking the early 2000s, the Gulf of Cádiz appeared on the radar of the Integrated Ocean Drilling Program (IODP) as a candidate to better understand the effects of the Mediterranean Outflow Water (MOW) waters into the Atlantic circulation and how paleoclimatic variations affected those fluxes.
The cores that were retrieved from IODP expedition 339 not only resulted in increased knowledge about climatic variations but also revealed stunning examples of contourites and reworked turbidites by bottom currents. Or should they rather be interpreted just as turbidites? “That was the question we had many debates about when studying these cores in those years,” says Javier. In order to try to answer that question, the research group started to look for analogues in the ancient sedimentary record.
The timing of all this, and the realisation not only by Javier’s team but also by other different research groups that a lot of deep-water sediments are being affected and reworked by the circulation of water masses and by the bottom currents, sparked the interest of several industries. Not only were energy explorers interested in the results, telecoms companies having cables on the seafloor were also keen to learn more.
“The first companies that took an interest in the research we were doing were BG and Spectrum,” says Javier. “They identified some deposits in the seismic data they acquired offshore in the South Atlantic and involved us in having a closer look because they were different to other well-known deep-water sedimentary systems.”
“Over time, this resulted in more and more companies approaching us for input on deep-water sedimentary environments, which led me to start the first official Joint Industry Project (JIP#1) in 2017,” continues Javier. A few years before, he had moved from Spain to London to work at Royal Holloway University of London (RHUL).
THE DRIFTERS
“The Drifters” Research Group, led by F. Javier Hernández-Molina, studies deep-marine sedimentation and investigates the influence of bottom-current circulation along continental margins and adjacent abyssal plains. The group members routinely collaborate with high-profile industry partners and is developing successful research partnerships with other top-ranked research centers in the field. It also has a sustained impact on knowledge transfer in the discipline both through research projects and public engagements.
The group is sponsored by a wide variety of research projects and companies interested in energy geosciences, with whom results are shared on an annual basis. The group is currently in its second Joint Industry Project (JIP#2, 2024- 2027), following a successful first one that ran from 2017 to 2022.
The group is currently looking for new partners and if you are interested in joining the JIP and / or would like details about the activities of this consortium, please contact Javier (fj.h@csic.es).
“The Drifters” also organise regular online talks (Virtual Get-Together (VGT) sharing series) that are open to those interested in deep-water sedimentary systems to share the latest research or hear from other experts in the field for provoking discussions and promote a network between academia and the industry. As such, the group has established itself as the global centre of expertise when it comes to deep-water sedimentation and deposits.
More than gravitational systems
One of the main outcomes of the first phase of the research project was the realisation of how common contourites and mixed / hybrid systems are, and their importance in terms of the total amount of sediment moved within the ocean system. “That’s critical to be aware of, as some people may initially think that it is the gravitational systems such as turbidites, mass-transport systems (or complexes) that cause the bulk of sedimentation. However, it is the transport and deposition capabilities of water masses and bottom current by the oceanic circulation that should not be underestimated. These oceanographic processes are eventually able to transport major amounts of sediment,” Javier reiterates, “to a point where they can cause large depositional or erosional features themselves.”
Many geologists are nowadays working on 3D seismic datasets that may reveal a lot on the area imaged, but the bigger picture is sometimes obscured this way. Regional 2D seismic lines still have a significant benefit in that regard.
“Another important thing that we found is that through the actions of bottom currents, especially in relationship to the opening of ocean gateways as the modern oceans started to form during the Mesozoic and Cenozoic, is that most of the sediments shed into the oceans over time did not find its way directly into the abyssal plains. Instead, they were transported laterally by bottom current to different parts along the continental slopes. This means that there is a lateral transport factor involved at the end of the source-to-sink chain that caused a significant part of bulk of the sediments to be stored on slopes lateral from where they were dropped by gravitational force, rather than all straight into the abyssal plains.”
The bigger picture
“When it comes to identifying contourite deposits, normally they are not difficult to interpret based on seismic data, because they are so prominent and large-scale and different from other deep-water systems,” explains Javier. “The problem arises when you are looking at more detail or using outcrop or core data where the “bigger picture” is missing and you rely on just making observations on a little postage stamp area.”
“During the first part of the Joint Industry Project, we specifically developed criteria to better distinguish between contourites, turbidites and hemipelagic deposits. First of all, evidence of sedimentary condensation, reworking, reactivation surfaces, smaller grain-size variations, small-scale hiatuses, and omission surfaces are some of the criteria in identifying contourite deposits. All of these vary depending on paleoenvironmental conditions, especially current velocity and sedimentation rate. Turbidites, on the other hand, are sometimes reworked by bottom currents. But at the end of the day, we do need to look at a multidisciplinary approach, to allow the discrimination between deep-water facies.” Javier also highlights the importance of primary sedimentary structures, microfacies and ichnological features, often complemented by geochemical proxies, as the best diagnostic criteria to distinguish reworked turbidites and contourites at the sedimentary facies scale.
What do you recommend someone who is new to the industry to do when it comes to becoming more familiar with contourite deposits? “There are key areas, such as Brazil, Mozambique and the Gulf of Cádiz where researchers and explorers identified good examples of cored contourite or mixed deposits if you’d like to have a look at these things yourself. But in a way, there are many parts of global continental margins and abyssal plains, as we discussed earlier, where these deposits can be found at different scales, from the seismic to sedimentary facies,” says Javier.
“The first thing I would always recommend people to do is to familiarise themselves with the regional setting of an area, both the geological features as well as the (paleo)oceanographic characteristics; look at the bigger picture before zooming in on your field area. There is a risk these days of immediately zooming in on a newly acquired 3D volume, without having a look at the broader area first. It may be very helpful to look at some regional 2D lines initially, and then dive into the 3D, also because the contourite depositional systems are commonly developed at a basin scale.”
Implications for energy geoscience
“One of our current lines of research, as part of the JIP#2, is to look at a larger scale than we did during the first project when the focus was more on differentiating deep-water deposits. Knowing that contourites are so common in recent sedimentary systems, we now try to better understand when contourite and mixed depositional systems formed at various stages of the geological record during the Mesozoic and the Cenozoic. We also try to better quantify their stratigraphic significance within the paleoceanographic framework that we’ve built during the last decade. Since we know that fine-grained contourites can act as a seal while the coarser-grained equivalents can be potential reservoirs, there is potential to discover new plays in areas where no one has looked before. It is an exciting thought that has also triggered significant interest from the energy industry.”
The power of collaboration between academic and industrial partners
Javier lived and worked in London for 11 years, where he taught and performed research at Royal Holloway University of London. “Before I moved to the UK,” Javier recalls, “my thinking was that academia and industry were very separate entities that did not interact with each other very much.”
“However, UK universities took this to another level. They turned out to be really adept in setting up Joint Industry Projects, and I realized that collaboration between academia and industry was normal,” Javier says. “It was a new thing to me at the time, and it gave me the inspiration to start up the first consortium back in 2017, which was sponsored by seven companies.”
“To me, it shows how beneficial this type of research collaboration can be,” Javier says, whilst he reiterates that he and his colleagues can still perform the research they want. “There is no overall steer from the industry in which direction we need to go, they are just interested in being part of the team that does the work and hear directly from the researchers what the latest results are.”
Academic research and the energy sector
Despite the academic value that the research into contourite depositional systems has achieved over the past 10 years, it is well known that universities are experiencing pressure not to work with companies operating in the energy sector anymore. “It is certainly an issue these days,” Javier admits.
“It is clear that in the face of global climate change, we must change the way we use energy resources, and therefore a transition towards clean energy is essential. However, I don’t think it’s positive to stigmatize the industry. Not only is the energy transition a gradual process, but the collaborative efforts by many research groups and companies also focus on aspects of interest to the energy transition, such as gas, CO2 capture and storage (CCS), and perhaps, hydrogen in the future.”
The future
“What is the future of your research,” I ask Javier near the end of our conversation.
“The growing interest in and implications of contourite and mixed depositional systems demonstrates that there is a demand for the work we do. At the start of our second phase in 2022, I wasn’t so sure about the appetite for research collaborations, as the energy sector was very much hit by the pandemic and the loss of hydrocarbon demand. However, looking at the current situation, we have eight companies involved in our programme and we keep on talking to new ones frequently as well. It definitely seems that there is a strong industry interest in deep-water research.”
And what are those lines of research going to be? “The link between tectonics and sedimentation, timing of ocean gateway opening and the dynamics this resulted in when it comes to bottom-water currents is something that will keep us going for quite some time,” says Javier. “There is the numerical modelling aspect of oceanographic processes and sedimentation as well that we will further develop over the next few years. In short, there is enough to do and I see plenty of room to continue this collaborative work.”
