Unlocking billion-year-old mysteries, Dr. Chris Spencer challenges orthodoxy in geological research

Posted on June 14, 2021


Just as astronomers use light to draw inferences about objects across incredible physical expanses, Dr. Chris Spencer uses rocks to try and unlock the secrets of the Earth’s distant past.

“Time travel is to geologists what space travel is to astronomers,” he said.

Dr. Spencer, an assistant professor in the Department of Geological Sciences and Geological Engineering, uses field work and geochemistry to further our understanding of the billions-of-year-old, or “deep time,” processes behind the formation and evolution of the Earth as we know it today.

For his efforts, he was awarded the 2020 Young Scientist Award by the Geological Association of America. He says receiving the distinction felt “terrifying and humbling.”

“My research efforts have been critiqued by some because I’ve not been able to secure funding from the mining industry or the petroleum industry,” he said. “What has motivated me in my research is curiosity and an almost selfish pursuit of knowledge.”

Spencer
Geological Engineering professor Chris Spencer looks to the distant past as a “tectonochemist” with a lifelong commitment to geology.
His work often challenges the doctrine of ‘geological uniformitarianism’ which posits that geological processes have proceeded in the same way throughout Earth's history. “Unchanging physical principles does not mean that the geological processes have not changed through time,” he said. Dr. Spencer pointed to volcanoes as an example. “If the composition of the magma, or the temperature of the magma changes through time, how is that going to affect the nature of volcanic activity?”

That sort of probing skepticism has led Dr. Spencer, who calls himself a “tectonochemist,” to postulate all sorts of unique, alternate explanations for geological phenomena and specifically using the field of geochemistry to address tectonic problems. Take the Grenville Orogeny, for example, a mountain chain that arose a billion years ago that touches much of eastern Canada. The mountains that formed as part of the chain are posited to have been relatively low, a trait that some geologists attribute to muted tectonic activity during the period. Spencer suggests that it may instead be due to a quality not often associated with continental crust: viscosity.

“The crust was too mushy, so as you try and squish those continents together they won’t rise very high, because they just spread laterally,” he said. “Although widely considered in numerical modelling, viscosity of the crust had not been widely evaluated in the geologic record.”

Spencer’s theories are usually backed up by two streams of isotopic data derived from Lutetium-Hafnium (Lu-Hf) geochemistry, and Uranium-Lead (U-Pb) geochronology. Lu-Hf geochemistry provides information about the original formation of a given rock, by telling researchers when its precursor magma was originally extracted from the Earth’s mantle. U-Pb provides information about when that magma cooled to the point where minerals called zircons formed within it. “What happened between those points is a bit of a mystery, and it requires a degree of interpolation,” he said.

Spencer developed expertise in the techniques as an isotopic apprentice at the Geochronology and Tracers Facility at the British Geological Survey (BGS). While there, he noticed the reams of U-Pb data being created worldwide, and sought to clarify the methods for its proper analysis and interpretation. “We published a paper specifically trying to elevate the quality of data and provide a framework for amateurs to produce reliable geochronological data.”

These sorts of technical contributions serve as the bedrock of future discovery, and they may be especially impressive coming from Dr. Spencer, who’s never taken an official course in geochemistry, and at one point doubted that he would even attend university.

Spencer’s mother always said that her son had been a geologist since the day he was born. On his first day of kindergarten she asked him what he wanted to be when he grew up. “I said, ‘I want to be a geologist.’” He attributes his interest in large part to having spent his formative years adjacent to the majestic peaks of southern Utah, where he said “the geology was all around us.”

Growing up, his interest shifted from paleontology to geology and back again as he considered career paths, but eventually the grand scale of geology won him over. “I started to realize that there was something bigger than just the dinosaurs and ancient life,” he said, “whether it’s the bombardment of a meteorite, or volcanic degassing that changes the composition of the atmosphere, these things influence the evolution of life as we know it.”

Despite his passion for the geological sciences, through much of his childhood and adolescence his conception of the field remained somewhat constrained by his environment. “The people I knew as geologists were guys who worked on the oil rigs,” he said, “so my initial goal was to be a roughneck, to work on an oil rig.” He relayed this plan to a science teacher in his senior year of high school who told him it was “unacceptable” and encouraged him to apply to the geology program at Brigham Young University, where he was admitted under scholarship. “My eyes were opened to a level of detail in geological analysis that I didn’t realize was possible,” he said.

He spent much of his undergraduate degree hiking in the mountains surrounding the BYU campus—blowing off any class that wasn’t related to geology—but he was nonetheless accepted into a master’s level program at the school, and quickly shipped off to do fieldwork in the Himalayas. “I lived alone in the mountains of northern India for four and a half months,” he said, “it was this period of pure unabashed exploration.”

During his time in India he became fascinated with the process through which mountain ranges arise and, more specifically, how these processes are governed by the principle of uniformitarianism. “If mountains like the Himalaya formed in the past 50 million years, what do similar mountain ranges look like that are a billion years old, and how have those mountain building processes changed over time?” he said. The interest led him to pursue a PhD at St. Andrews University in Scotland, where he was given the opportunity to travel to mountain ranges all over the world, from Labrador to Namibia.

He moved on to the British Geological Survey, and afterwards spent five years as a research fellow at Curtin University in Western Australia before arriving here in his current position at Queen’s University.

One of his current areas of interest is an ancient supercontinent called Nuna, whose emergence between 1.5 and 2.5 billion years ago may be related to the appearance of atmospheric oxygen. “Is there a connection between changes in tectonic processes and changes in the biosphere and atmosphere? It’s one of the overarching research questions that we’re trying to address,” he said. He’s working on a related inquiry that aims to figure out when, exactly, continents originally rose above sea level, an event that was integral to the development of life as we know it. If continents had remained submerged, he says we humans “may merely be protoplasmic ooze, just floating around as melanogenic cyanobacteria.”

While the petroleum industry isn’t a key focus for Dr. Spencer’s work, its representatives have shown no hesitancy when it comes to hiring his students. “Sometimes the students that do detrital zircon geochronology go on to work in the petroleum industry where they will never see another zircon for the rest of their lives,” he said. “The skills they learned provide them with a framework that helps them become successful in their careers.”  

In addition to his work as teacher and researcher, Dr. Spencer heads an organization called TravelingGeologist. The endeavour began as a series of videos he posted while doing field work around the world (primarily as a way to reassure his mother that he was safe). It has since grown into a platform that receives contributions from hundreds of geologists worldwide, and reaches over a million people. “The aim of TravelingGeologist is to provide a platform on which Earth scientists can disseminate their knowledge to the general public and to inspire the next generation of scientists,” he said. 

By seeking to fill gaps in our knowledge of events that took place billions of years ago, Dr. Spencer has, in effect, begun an investigation that he knows will have no real resolution. Rather than being frustrated by that, he sees value in the pursuit.

“I believe that scientific inquiry is asymptotic to the truth. We are always approaching it, but we will never arrive at it,” he said. “When you talk about our pursuit of understanding deep time, it really is exciting to know that there are always more mysteries out there.”