Conducting fieldwork on Pico da Neblina in the Amazon with Yanomami researchers and collaborators

Art by Valentina Fraiz

Mayara Teixeira

Most people probably picture a vast, dense green forest when they think of the Amazon. Yet the Amazon is more than just the world’s largest tropical rainforest. It is also a region rich in mountains and hills, including Brazil’s highest point, Pico da Neblina. As an Amazonian geologist, this is how I view the Amazon, as a mountain paradise.

In order to study the formation of the Amazon’s mountain ranges 2 billion years ago and their relationship to an ancient supercontinent—the focus of my research—I must go to the field and immerse myself in this mountain paradise. I study the formation of these ancient mountains in situ, investigating the tectonic plate movements that shaped them.

The Amazon is one of the oldest and most stable tectonic units in South America. Dating results suggest that it began to take shape approximately 3 billion years ago. My central hypothesis is that about two billion years ago, this region was part of the Columbia supercontinent, and its mountain ranges were connected to an ancient landmass corresponding to present-day northern Europe.

Reconstructing a supercontinent requires multiple types of geological data, such as rocks from specific tectonic environments like mountain ranges, large igneous provinces (extensive areas covered by volcanic and granitic rocks formed over a short period of time in geological history, approximately 5 million years), and dikes, (structures such as cracks in the rock filled with solidified magma). I look for these types of rocks in the Amazon to build a paleogeographic model of the region when it was part of the Columbia supercontinent.

When the project began in August 2024, reaching the summit of Pico da Neblina seemed unimaginable. Yet, by December of that year, I finally reached Brazil’s highest point, 2,995.30 meters above sea level. To the Yanomami, it is known as Yaripo. It is located in the Pico da Neblina National Park in Yanomami territory, between Santa Isabel do Rio Negro and São Gabriel da Cachoeira, in the Imeri mountain range in the state of Amazonas.

The Chico Mendes Institute for Biodiversity Conservation (ICMBio) in São Gabriel da Cachoeira invited me to take part in the expedition. It coordinated logistics and overall organization in partnership with the Yanomami Association of the Cauaburi River and Its Tributaries (AYRCA). The team brought together researchers from several institutions, including two geologists, Gilmar Honorato and Joana Sánchez, along with 17 Yanomami collaborators.                   

This was no easy journey. After nine days of trekking and sleeping in hammocks and tents in an intensely humid region, the terrain quickly took its toll: soaked boots and attempts to dry them over hot coals. Our clothes never fully dried. Our bodies groaned, but our determination held firm. It was only after three days of walking that we finally caught our first glimpse of Pico da Neblina.

Significant geological observations were made and samples were collected at strategic points. These samples include different rock types that offer clues about the formation of the mountain, including past environments and tectonic activity. This work is time-consuming, and the data is currently being analyzed in the laboratory to help solve the geological puzzle.

The final stretch to the summit of Pico da Neblina is the ultimate challenge. Mud, steel ladders, ropes, and chains stand in our way. Yet, the support of our colleagues and Yanomami guides pushes us forward. With each ladder we climbed, our hope of reaching the top grew, even as the summit seemed to grow farther away. When we finally arrived, an overwhelming emotion took hold of us. We stayed only fifteen minutes, but it felt like an eternity, a landmark engraved in our core. 

The descent is slow and painful, marked by stumbles and torn pants. No respite from the cold and rain. Every step on the way back becomes a silent victory. Our bodies ache, yet our minds are already laughing at what once felt impossible. The forest teaches us, the field reshapes us, and each rock in our backpacks holds the story of everyone who helped us get there.

Fieldwork has always been fundamental to understanding the long and complex history of the Earth. Geology builds on careful observation. Centuries ago, this approach led Charles Lyell to propose that the Earth was shaped by slow, continuous processes. This idea directly influenced Charles Darwin’s development of the theory of evolution. Similarly, our work begins by observing nature and studying rocks, landforms, and landscapes to then reconstruct the past and predict the future of the planet.

*

Mayara Teixeira is a geologist and professor at the Federal University of Amazonas, and a researcher with the Vital Insight into Precambrian Amazonia (VIP Amazonia) group.