Science & Technology, India (Commonwealth Union) – The Palaeoproterozoic era is a time period that lasted from approximately 2.5 billion years ago to 1.6 billion years ago. It is a significant period in the history of the Earth, as it saw the emergence of several key geological, biological, and environmental changes that paved the way for the evolution of complex life forms.
During the Palaeoproterozoic era, the Earth underwent significant tectonic and climatic changes. The supercontinent of Kenorland is believed to have formed around 2.7 billion years ago and began to break apart during the early part of the era, leading to the formation of smaller continents. This process resulted in the formation of new mountain ranges and the emergence of vast sedimentary basins.
The evaluation of how the earth may have appeared roughly 2 billion years back as the planet’s environment was undergoing oxygenation was explored in a recent study.
The examining of ancient dolomite deposits discovered in Vempalle, in the Cuddapah district of Andhra Pradesh, scientists from the Indian Institute of Science (IISc) along with the University of Tennessee, USA made an estimation of the temperature and composition of a shallow, inland sea that had a high chance of existing back in that time, known as the Palaeoproterozoic era.
The results gave insight into the way the conditions at the time gave just the right atmosphere that led to photosynthetic algae and its blooming. It further indicated how a large amount of data regarding the history of our planet has been hidden within ancient rocks.
“The story of our planet is written in the different strata of rocks,” said Prosenjit Ghosh, who is a Professor at the Centre for Earth Science (CEaS), IISc, as well as the corresponding author of the research appearing in Chemical Geology.
The researchers indicated that our planet did not always have the most suitable conditions for life. It has had various phases of climatic extremes, consisting of periods when carbon dioxide levels were nearly too toxic for life on Earth, similar to the planet Venus. But many different studies of fossils from the Palaeoproterozoic era demonstrated that certain forms of life may have been present even under these extreme conditions.
The extensive quantities of carbon dioxide in the environment were absorbed by the sea and kept within carbonates in dolomites, according to Yogaraj Banerjee, who is a former Ph.D. student from CEaS and an author of the study.
“[Dolomite] is a direct precipitate from seawater. It provides a signal not only of seawater chemistry but also of seawater temperature,” said Robert Riding, who is the Research Professor at the Department of Earth and Planetary Sciences, at the University of Tennessee, and also an author of the study.
The study team gathered dolomite samples from chert – hard rock produced by the engagement of microbes with seawater and deposits below them known as dolomitic lime mud. Having 1st marked the strata of rock in the location of the discovery of the dolomitic mud, the scientist extracted and brought them back to the lab. Then, they applied a state-of-the-art method referred to as clumped isotope thermometry to analyze them. The method permitted researchers to narrow down both temperatures along with the composition of the deposits with the viewing of the arrangement of the carbon as well as oxygen bonds.
Following 2 years of intense evaluations, the researchers had the ability to work out from the dolomitic mud that the temperature of the seawater when its original time period took place was roughly 20°C. This is exactly the opposite of prior research that analyzed just chert samples from approximately the same period, with estimations that the temperature was more, which was roughly 50°C. A reduced temperature estimate from the present study falls more in line with the theory that the conditions were more suited for backing lifeforms.
