First Antarctic amber discovery opens new window to ancient climate

First Antarctic amber discovery opens new window to ancient climate
by Robert Schreiber
Berlin, Germany (SPX) Nov 13, 2024
Approximately 90 million years ago, Antarctica's climate supported resin-producing trees, marking an unexpected chapter in Earth's geological story. Researchers from the Alfred Wegener Institute (AWI) and the TU Bergakademie Freiberg recently unveiled a significant discovery in the journal *Antarctic Science*: the first documented find of amber on the Antarctic continent.

Before this revelation, Antarctica was a blank spot on the global map of amber sites. That changed with the efforts led by Dr. Johann P. Klages from AWI and Dr. Henny Gerschel from the TU Bergakademie Freiberg. During a 2017 expedition aboard the research vessel Polarstern, the team used the seafloor drill rig MARUM-MeBo70 to extract sediment cores at a depth of 946 meters in Pine Island Bay, Amundsen Sea Embayment (73.57 South, 107.09 West). The discovery, now named "Pine Island amber," has pushed the boundaries of what scientists know about ancient environmental conditions.

Dr. Klages, the study's first author, highlighted, "The analysed amber fragments provide direct insights into environmental conditions that existed in West Antarctica 90 million years ago. This find gives us a clearer picture of the forest ecosystem reconstructed in our 2020 Nature study." He further emphasized, "It was remarkable to realise that, historically, all seven continents supported climates suitable for resin-producing trees. Our next goal is to explore the ecosystem's history further, searching for signs of past forest fires or life trapped in the amber."

The analysis of the amber was meticulous. Researchers prepared tiny 1 mm-diameter fragments for examination with reflected-light and fluorescence microscopy. Despite the small scale, intriguing details emerged. "The Antarctic amber appears to contain remnants of original tree bark as micro-inclusions. The high quality of the transparent and translucent pieces suggests burial near the surface, avoiding the degradation typically seen with greater thermal stress and depth," explained Dr. Gerschel, now with the Saxon State Office for the Environment, Agriculture and Geology. She noted that the amber displayed signs of pathological resin flow, indicative of a defensive response to damage from parasites or fires.

This finding supports the view of a conifer-rich, swampy rainforest near the South Pole during the mid-Cretaceous, adding crucial data to understanding ancient climatic conditions.