Montserrat. Week one.
Peeling Back the Layers of Montserrat's Geological History
Day two was an eye-opening expedition into Montserrat's formation, led by our geology guru, Mike Bergman. The curriculum for the day offered us a deep dive into the volcanic history and processes that sculpted Montserrat. Mike walked us through the gradual transformation of sediment into solid rock, a process known as lithification. This process, unfolding over countless millennia, has given rise to the unique geological formations we observe today on Montserrat. Montserrat's volcanic geology is displayed in 'Ignimbrites,' deposits resulting from explosive volcanic eruptions. These deposits, appearing as layers in the cliff faces of the Belham Valley, underscore the profound and lasting impact of Montserrat's volcanic history. Each layer has a distinct color, and sediment size, and from this you can determine which volcano formed each layer. Eruptions from volcanos close in proximity result in layers with large chunks of rock and sediment, while explosions further in proximity result in layers with fine sediment.
Image of cliff face in Belham Valley
The most informative part of the day, was Mike's recounting of the volcanic genesis of Montserrat. Montserrat isn't the product of just one or two, but four volcanic centers: the extinct Silver Hills and Centre Hills, and the more recent and active Soufrière Hills and South Soufrière Hills. Each has played a significant role in the island's formation, creating a landscape that's as diverse as it is beautiful.
Soufrière Hills at 5 am.
Silver Hills, the oldest of the four, has etched its story into the northernmost part of the island. Its extinct volcanic remnants are a silent testament to the earliest chapter of Montserrat's volcanic history. Centre Hills, also extinct, has left a tangible imprint on the island, shaping the lush, rounded, hills that paint the landscape in the northern regions. The Soufrière Hills, awoke around 176,000 years ago, and continues to actively mold the island's topography. The southern area of Montserrat, distinguished by its rugged and dramatic landscapes, bears witness to the more recent and powerful eruptions from Soufrière Hills. The 1995 eruption, resulting in the establishment of an exclusion zone, is a stark reminder of the volcano's dynamic power and its continual influence on the island's geography. Finally, the South Soufrière Hills, although less prominent, has contributed to the island's volcanic complexity. Together with Soufrière Hills, they continue to shape the island's future
Next, Dr. Jessica Allen introduced us to the fascinating world of lichens. Lichens, are not just individual organisms but complex partnerships between fungi and algae or cyanobacteria. They're not only remarkably resilient, able to survive in extreme environments, but also significant bio-indicators, providing valuable information about air quality and environmental health. The untouched tropical rainforest of Montserrat is home to hundreds, if not thousands of colorful and diverse lichens.
Make it stand out
Lichens come in a plethora of colors ranging from rusty red to bluish green. The colors of lichen are influenced by their photosynthetic partners and environmental conditions. Green or yellowish-green lichens are often associated with green algae, like Trebouxia or Trentepohlia, which produce chlorophyll. Cyanobacteria contribute to a darker, sometimes blue-green color in lichens due to a pigment called phycocyanin. Certain cyanobacterial lichens can absorb atmospheric nitrogen, vital in nutrient-limited habitats.
Additionally, secondary pigments in lichens create red, orange, or yellow shades, serving protective roles against UV radiation. The lichen genus Xanthoria is an example, producing vibrant hues due to a pigment named parietin. Environmental factors, including light, humidity, temperature, and substrate type, also affect lichen coloration. Lichens can produce more pigments under intense light, and their colors can change dramatically between dry and wet conditions.
After a break, we reconvened for a botany session with Dr. Donald McClelland. We took a field trip to the Belham Valley, a coastal area that hosts a rich diversity of plant life. The lush greenery around us served as a living textbook as Donald pointed out various plant species, explaining their unique adaptations to the salty environment and ecological roles.
After a day rich in exploration, we aimed to soak in some local culture at a local festival parade. The parade was running a few hours late so we decided to head back to our houses, as I retired to my bed, my mind buzzed with excitement for what awaited me fishing along the beach in the morning, and the tale of an island born from fire and time.
