Forest destroyed 22 million years ago, rediscovered

News Excerpt:

Researchers have rediscovered a 22-million-year-old mangrove forest that was swept away by a massive volcanic eruption.

About the Findings:

  • The forest that once thrived with huge trees and lush green grasses on an island in the Panama Canal fell prey to natural disasters that triggered complete destruction.
  • The rediscovery was made by the scientists, who found the fossilised remains of trees on the Barro Colorado Island.
    • A total of 112 preserved fossilised pieces of wood were unearthed.
  • The fossils indicated that some huge volcanic eruptions triggered a lahar, eventually sweeping the entire forest land.
    • A lahar is a violent water flow with mud, ash, and rocks.
    • It almost flows like wet concrete at lightning speeds that can instantly cover an area into a whirlwind.
    • It leaves plants and animals with no opportunity to rot or decompose and instantly destroys the entire land.
    • It comes with silica-rich waters that seep deep into living matter and expunge their tissues, which results in well-preserved fossils locked in a moment in time.

Origin of the rediscovered mangrove forest:

  • As per the scientists, this old mangrove forest would have originated in the early Miocene Epoch, which existed about 23 million years ago.
  • The great land masses of South America and the Caribbean plate collided with each other, forming the landscape of Panama and the rest of Central America.
  • This was when the hill that would eventually become Barro Colorado Island rose from the ocean.
    • Around its edges grew a mangrove forest, whose trees rose as high as 130 feet, mainly because -
      • Sediment samples show that the forest grew in the brackish zone where salty and fresh waters meet, ideal conditions for mangroves.
      • Atmospheric carbon dioxide concentrations were much higher during the Miocene than now - over 500 parts per million (ppm) compared to about 419 ppm today.
  • The findings of the study will be published in the March 2024 issue of the Palaeogeography, Palaeoclimatology, Palaeoecology journal.
  • These ancient remains revealed a lot about the forgone forest but the study is still in its incipient stage.

Barro Colorado Island:

  • It is a heavily forested patch of land rising up out of the waters of Gatun Lake, situated at the northern end of the Panama Canal.
  • In the early 1900s, the area of Panama, now known as Barro Colorado Island, was a big hill called West Hill, located in the Chagres River Valley.
    • A lush green canopy of tropical rainforest covered much of the valley.
  • Natural events, such as volcanic activity or tectonic plate movement, did not form it. Instead, human activities are responsible for the island’s creation.
    • In 1914, engineers who were working on the Panama Canal constructed a dam to block the Chagres River’s outflow.
      • The dam changed how the river flowed and caused water to rise in the Chagres River Valley.
    • New lakes, like Gatun Lake, were created in the process, and entire towns, forested areas, and farmlands were flooded.
    • As the water rose, the lower portions of West Hill were covered by water, and the top part of the hill became an island — Barro Colorado Island.

Book A Free Counseling Session