“Uniformitarianism” is a time-honoured theory that suggests the evolution of our mother planet –Earth. Since long, the question “Did the modern plate tectonics that earth current has, start forming straight away or come into origination after Earth went through a long evolution period, with a secure shell sheltering the entire planet” has been intriguing scientists, and the global geological research community have constantly been going gaga over this question. But now a new international study has come to the forefront that can solve this long-established mystery.
A new research paper, published in the influential science journal Nature on 27th February 2017 has suggested that Earth, in its earlier period used to have a single, unyielding, and non-foldable outer shell, which in the course of evolution, started forming into broken, multi-layered, and cracked layers. The study, conducted by the scientists at the University of Maryland in the US, also has put forward the surprising view that, Earth, soon after formed and started becoming icy, started housing a distinct, obstinate but deformable outer layer, which afterwards began crinkling and breaking more extensively, resulting in the creation of contemporary plate tectonics.
For the study, the lead author of the survey, Michael Brown, Professor at the University of Maryland in the US and his associates from Curtin University and the Geological Survey of Western Australia thoroughly took the most ancient rock samples, collected from the East Pilbara Terrane – a granitic crust province located in Western Australia into account. The rock samples, found in the region of Pilbara Terrane were one of the oldest known rock samples and dated back 3.5 to 2.5 billion years. As estimated by scientists, the age of our mother planet Earth is approximately 4.5 billion years, and hence, these close-born rocks were expected to hold many necessary pieces of evidence to the evolution of the earth.
From the wide range of rock samples, researchers specifically selected the oldest granites that have a chemical composition – a symphony commonly linked to volcanic arcs – a blabbermouth sign of plate tectonic activity. After analysing the granites, the US-based researchers arrived at the conclusion that the new plate tectonics began forming in the later period of Earth’s history. In its juvenile stage, Earth used to be protected by a single, extremely sturdy, and non-foldable outer shell, which changed into multi-layered with the course of time.