New techniques uncover ancient biomass secrets in Australian rocks

New techniques uncover ancient biomass secrets in Australian rocks
by Staff Writers
Gottingen, Germany (SPX) Feb 22, 2024

Researchers from the University of Gottingen have shed new light on the Earth's earliest life forms by analyzing ancient rocks from the Pilbara Craton in Western Australia, one of the few places on Earth where the primordial crust is still accessible. These rocks, approximately 3.5 billion years old, contain carbonaceous particles that offer clues to the microorganisms which inhabited our planet in its infancy. Published in the journal Precambrian Research, this research provides unprecedented insights into the earliest ecosystems on Earth.

The Pilbara Craton's significance lies in its ancient rocks, which are direct windows into the Earth's early history. The area is renowned among geologists and researchers for its well-preserved rock formations that date back to the Archean eon. Within these formations, scientists find traces of the first biological activity on Earth, offering a rare glimpse into the conditions and life forms of the early planet.

The research team employed high-resolution techniques such as Nuclear Magnetic Resonance (NMR) spectroscopy and Near-edge X-ray Absorption Fine Structure (NEXAFS) to analyze the structure of microscopically small carbonaceous particles embedded in rocks made of barium sulphate. These methods, known for their ability to provide detailed information about the molecular and elemental composition of materials, were instrumental in determining the biological origins of these particles. The findings suggest that these particles were deposited in the waters of a caldera, a large, cauldron-like hollow that forms following volcanic activity, and were subsequently altered by hydrothermal waters just beneath the volcano's surface.

Further analysis of various carbon isotopes led the researchers to conclude that a range of microorganisms, similar to those found in modern-day environments like Icelandic geysers or the hot springs of Yellowstone National Park, thrived in the vicinity of this ancient volcanic activity. This comparison not only illustrates the continuity of life's adaptability to extreme conditions but also enhances our understanding of Earth's earliest life forms.

Lena Weimann, the first author of the study and a researcher at Gottingen University's Geosciences Centre, highlighted the significance of combining multiple high-resolution techniques. "It was very exciting to be able to derive information about the history of how the organic particles were deposited and their origin. As our findings show, original traces of the first organisms can still be found even from extremely old material," Weimann stated. This methodological advancement not only illuminates the past but also sets a new standard for studying ancient biological materials.

This research not only deepens our understanding of Earth's biogeochemical cycles in its formative years but also showcases the effectiveness of advanced analytical methods in uncovering the secrets of ancient life. By drawing parallels with contemporary microbial ecosystems in extreme environments, the study underscores the resilience and diversity of life from its earliest stages to the present day. The insights gained from this study are not only crucial for our understanding of early life on Earth but also for exploring life in similar extreme environments, possibly even on other planets.

The full research report, titled "Carbonaceous matter in ~3.5 Ga black bedded barite from the Dresser Formation (Pilbara Craton, Western Australia) - insights into organic cycling on the juvenile Earth," is available in the journal Precambrian Research and provides a comprehensive look at these groundbreaking findings.

Research Report:Carbonaceous matter in ~3.5 Ga black bedded barite from the Dresser Formation (Pilbara Craton, Western Australia) - insights into organic cycling on the juvenile Earth