Active Archives
Rocks, Relationships, and Reasoning
An “active archive” is not only one that grows in size, but one with which a relationship is maintained—and which accommodates many perspectives, conversations, and approaches. In this contribution, Dr Catherine Russell, a researcher in sedimentology and the Anthropocene, documents her experiences with the University of Leicester geology archive, proposing that archives are teeming with potential for developing new understandings of and solutions for contemporary challenges. Acknowledging the inherent blind spots and bias of archival practices, Russell argues that archives await fresh curiosity so that new ideas can be found within and beyond them.
Hand specimens are crucial resources for geologists. They are samples of the rocks studied and allow for questions to be asked and answered from the laboratory. For teaching, hand specimens allow students to have their first encounter with rocks, minerals, and fossils. Image courtesy University of Leicester Students learn to identify rocks, minerals, and fossils in the field or from other collections. Inspection of hand specimens typically occurs under white light with a 10X magnification hand lens and reference cards to quantify observations. Image courtesy University of Leicester
Most days, we feed into an archive, such as a social media algorithm, and add to our own, perhaps by downloading a new music album or e-book. Such archives are passive and personal, and we readily recognize them to be growing, because we hold a relationship with them. In this text, I hope to show that an active archive is not only one that grows but one with which a relationship is maintained. By engaging with archives, observing them with curiosity, and postulating new ideas within and beyond them, we can learn a tremendous amount and think toward new hypotheses, and even develop solutions.
The geology archive at the University of Leicester, where I have both studied and taught, is full of amazing things. However, while the collections are regularly added to, the newest additions are not always the most frequently used. The classic specimens—splendid examples of rocks, fossils, and minerals—sit at the “surface” of the collections, as staff frequently use them to show potential students, current students, and visitors alike how each connects to the story of the natural world. However, these high-use specimens are just the tip of the iceberg.
When staff and students undertake research, they may work with specimens from the archive. Depending on the hypothesis and analysis required, the specimen under inspection may meet several people as well as analytical instruments during the research—and in some cases it will return to the archive in several pieces. For example, a hand specimen (a fragment of rock shaped to be easily held and examined) of hübnerite-bearing ore from Colorado in the US, pictured below, has been sliced to form a polished slab and a thin section (a sliver only 30 nanometers thick, about as thick as a human hair!) to allow for detailed inspection of the minerals in the rock.
A thin section is a very thin sliver of the hand specimen—30 nanometers thick—sandwiched between two pieces of glass and secured with resin. In plane polarized light (PPL), light is aligned to a direction (e.g. E-W) and transmitted through the thin section. The minerals are their natural color and may be inspected for many properties. Image courtesy University of Leicester The exception is for minerals that do not transmit light and are opaque, for which a polished slab is required. In cross-polarized light (XPL), a filter that is 90° different to the PPL direction (e.g. N-S), is inserted. The technique results in the minerals displaying more properties and often different colors, such that the origins and formation of the rock can be considered in more detail. Image courtesy University of Leicester
A polished slab is a slice of the hand specimen that has been polished so that opaque minerals may be identified, such as gold, copper, pyrite, and hübnerite. The microscopes used to inspect these slabs enable light to be reflected downwards onto the slab, as well as from underneath, and are therefore called “reflected light microscopes.” The color of the reflected light allows for identification of the minerals. The specks that you see in this image are those reflecting the light ready for identification. Image courtesy University of Leicester
Additionally, a specimen may need to be tested for its chemical properties. Such analysis can be done by nondestructive means, but some equipment requires a small part of the hand specimen be ground to powder and then compressed into a pellet for analysis, and these pellets themselves may then be archived. It is interesting to note the information that, through this process, will or will not change. In the case of the hübnerite-bearing ore, the sample will always be from Colorado and the minerals will always stay the same; however, what is known about the minerals may change, which, in turn, may result in alterations to how researchers understand the landscape changes that this rock endured over millions of years. Additionally, depending on the scientist’s access to analytical equipment, some mysteries may have to go uninvestigated.
While undertaking research, the scientist’s relationship with the archive is rather clear, and it runs deep to the core of discovery and curiosity. The teaching collections at Leicester have been curated from the wider geological archive of Earth history and are somewhat different in that they are selected samples that aim to teach students to see a question, and eventually the world, in a new way. The archive provides a critical and irreplaceable experience for students, enabling them to make first-order observations and derive stories from their findings. When constructing teaching exercises, educators sometimes don’t have all the required rocks from the same place, or the story is simply too complex to explain in full. As such, while teaching, educators may draw a map of an idealized and fictional locality and fit the available collections to it, so that the students can develop an understanding of reading the archive that is appropriate to their stage in the learning journey. While some might consider this to be false appropriation, it is simply a clever way to keep the archive accessible as a learning tool as it allows for students to actively learn about concepts, such as a new process or rock formation, in comparative isolation. When faced with more complex narratives later in their learning journey, students are then able to call upon their experiences of concepts that they can readily compile to develop hypotheses. Educators need archives to enable students’ active learning by providing them with pieces of the puzzle, from which they may develop a story.
When assessing the chemistry of a rock, a sample of the hand specimen needs to be prepared for the analytical equipment. It is ground into a powder and compressed into a pellet for the analysis. In this image you can see a bag of powdered rock and an associated pellet. Image courtesy Vicky Ward
Hands-on experience with rocks is widely considered to be the best way for earth science students to gain a physical understanding of their subject matter. However, during the COVID-19 pandemic, students could not access the collections in the same way, and educators were likewise unable to use them to teach in the usual ways—demonstrating once again that an archive is not a fixed notion. The archive may be objectively stable, but our relationship with it changes according to our requirements. In this case, the unique situation of the COVID-19 pandemic required us to shift our thinking such that the interactivity so critical to learning could be reimagined and brought to the students in a meaningful way. Consequently, the geology archive at the University of Leicester significantly extended its digital footprint and 3D scans of rock were made and provided for interactive sessions. Many of these rocks have existed in the collections for decades, only gaining a digital twin in 2020.
The archive roots learning and research by providing access windows to hands-on alternative realities in space and time. It creates an atmosphere that invites curiosity to discover what lies beyond the dusty boxes and cabinets. The geology archive at the University of Leicester contains not just rocks but also fossils, contemporary skeletons, minerals, sand, soil, and much else. To demonstrate the variety and excitement of the archive, in the next section I share an account of my first visit to the Leicester Rock Store, which occurred when I was preparing a sedimentology class for the university’s group of second-year geology students in January 2018. I hoped to uncover some new specimens to add to their learning journey.
Active in an archive: A trip to the Leicester Rock Store
To be invited to see an archive is a privilege; it is a behind-the-scenes tour like no other. Vicky Ward, curatorial and teaching support technician at the University of Leicester, says that “people seem to love being among the collections.” And I was no exception!
I remember feeling so excited to hunt through the rocks—an activity akin to being an explorer but with less hiking involved, and the best stuff already carefully packaged, transported, and labeled for you in advance. Before letting me in, Vicky paused with the key in the door, considered my excitement, and said, “All you’re going to see is whole lot of dusty boxes on racks.” I nodded, still grinning. Vicky was absolutely right, and yet the “mundane” piles of boxes were anything but—even their appearance demonstrated a deep richness of histories, stories, and projects past. There were many different shades of cardboard and various handwritings in various pens, mixed with printed labels, bags, and reference codes—the infrastructure of the curatorial system is an archive in itself, and one that has been active for a very long time.
In the room, the fantastic samples that are frequently brought out for display have prime real estate near the door, so once I had spent some time marveling at these (and the fact that the shelves were on wheels), Vicky and I got to work to find the samples I needed. Each box contains materials with the potential to evolve narratives and reveal exciting unknowns—hence my keenness to open them all. But, keeping on task, we carefully lifted lids off box after box, finding treasures and occasional mysteries. “Talking to people in the store reinforces why I love my job,” said Vicky. “I always learn new stories about our collections.”
Within each box, every sample sits in its own smaller box, with an information tray detailing where it’s from, its age, and what it has been identified as. While most of these labels are accurate, they are brief and there is always more to read from the rock itself. Students are trained to approach each sample as though they are the first person to look at it, and thus they are encouraged to make their own interpretations. Vicky and I likewise approached each sample with a balance of trust and healthy academic skepticism, just like being in the field exploring and developing primary observations to cross-check with the literature later. We loaded our selection onto the trolley to take upstairs and inspect more carefully.
The appearance of the archive boxes demonstrates a deep richness of histories, stories, and projects past. Different shades of cardboard and various handwritings, mixed with printed labels, bags, and reference codes—the infrastructure of the curatorial system as an archive in itself. Images courtesy Vicky Ward
Before this first visit to the Leicester Rock Store, I had been engaging with rocks from the archive for about a decade as a student. It was only when resetting the room to lock up that I realized how being among the archive and exploring it firsthand had made me feel rooted to something bigger, as if everything that happens in geology classrooms and on lab benches somehow comes back to this. Perhaps we geologists should take more time to explore these roots to really understand what grows from them. Vicky’s perspective echoes this: “I don’t think the collection changes as rapidly as the people do, which is great because we need new people and new knowledge to bring new sides to the stories.” So, then, there is something bigger at play. The archives go way beyond the physical specimens and digital archives, reducible to a list of entries; they are collections of ideas, memories of people, unfinished conversations, and discoveries that have been both literally and metaphorically set in stone. While the archive may appear stable and unchanging, it is our interaction with and attention to it that makes it evolve and grow.
Changing archives in a changing world
Archives of every kind are teeming with potential and await fresh curiosity so that their stories can be told and built upon. Their ability to accumulate material and information makes them fascinating, almost wise, such that searching through their dusty cartons is like uncovering memories. The volume of knowledge, the number of stories, and the cleverly cross-referenced and curated records make it easy to see why so many comparisons exist between the archive and the human mind. However, just like a human mind, archives can fall prey to blind spots and bias, which is simultaneously a challenge and what enables each collection to be unique and a reflection of its history. If we consider rocks to be memories (as many geologists do!), then it begins to make sense that the landscapes most often experienced by an archive’s collectors have the highest representation in the collection. For example, the Leicester collection has proportionally more rocks from Leicester than from, say, Edinburgh, and vice versa. An archive in its entirety is biased toward the interests of the individual(s) who contribute material to it, and in the case of archives containing research materials, the stored samples may themselves be biased toward projects that received funding from internal or external bodies, each of which have their own interests. Particularly in research, it is critical to address any marked biases in an archive, if only to highlight the limitations of a data set, which may unfortunately be unavoidable due to access or financial constraints. As such, the roots and models of organization within an archive may be revisited periodically, to aid our use of their information.
As time goes on, archives continue to grow, adapt, and shift to accommodate new questions and requirements. With a changing world at our feet, geology archives around the world have begun to incorporate plastic, pollutants, and other anthropogenic materials, as researchers seek to understand the impact of human activities on Earth’s natural systems and what Earth’s future natural “archive” may contain. As such, some collated samples at Leicester are remarkably recent—for example, I have been researching sediment from the Mississippi River in the US and looking for microplastics.
The Mississippi River sediment samples were treated to an initial chemical analysis, to check for any harmful concentrations of pollutants, before undergoing a laser scan to assess the size of each grain of sand in a sample. The sediment then entered many phases of preparation in search of microplastics, including sieving and mixing the sediment with zinc bromide (ZnBr2), a corrosive solution that allows for easier separation of microplastics from the sediment.
The sediment and zinc bromide were then safely disposed of, and the captured microplastics were prepared for assessment. We are now able to find and account for all the microplastics, kept in glass petri dishes, one by one. So far, paint flakes, plastic fibers, fishing line, and many other, as yet unidentified, microplastics have been found.
As the story unfolds, the juxtaposition of the anthropogenic Mississippi River sediment sitting within Leicester’s geology archive is remarkable and striking to me. The plastic-littered sand is stored alongside core from a petroleum reservoir. I wonder if the hydrocarbons found in the petroleum reservoir from which the core was taken could have been refined into plastic pellets, manufactured, used, and disposed of, and now their fragments sit in the Mississippi sand, right by their sisters. I have similar thoughts about sand and its sandstone, but in the ancient record, such relationships are (largely) geographically constrained; the Anthropocene, by contrast, presents geologists with the novelty of seemingly unconstrained transportation across the entire globe. So it might remain impossible to know for sure where the hydrocarbons in the Mississippi sample originated from and if they are connected somehow to the adjacent core. Hence, sediment samples like this one capture a new process of material flow into the geological archive, giving rise to new questions and opening up countless possibilities.
Today, researchers have access to the most complete picture possible of the causes and effects of change and response in natural systems than from any other time in geological history. So, when we compare selections of modern archival materials with those of the ancient past, we find a similarity in researchers’ decisions to choose samples for their novelty or impressive nature. However, until now, this has also always meant choosing from the limited windows of preserved material that Earth has passively archived. When collecting Anthropocene material, researchers don’t need to worry about basins, partial preservation, and interpretation in the same way at all. For the first time, it is possible for us to make the decision on what will be archived, and thus to select the story that future scientists and societies will tell about Earth. How will this be done? Who has the power to decide what will be important? How much of what is considered “normal” will be lost because it isn’t deemed interesting today? Each of these questions will be answered differently by everyone, and perhaps an active archive built by everyone—one that accommodates many perspectives, conversations, and approaches—is precisely the archive that we need to make, and indeed may already be making.
