The Breaking And Getting Together Of Earth’s Continents

Lately a new research has been conducted w.r.t to rocks. The study focuses on those rocks that were formed about more than billions of years ago. The study has provided a new insight into how Earth's plate tectonics, or the movement of large pieces of Earth's outer shell, have re shaped or evolved themselves over Earth’s 4.56-billion-year history. As per the report talking about the revelations, it has been stated that tectonic plates have evolved over the last 2.5 billion years. On the contrary, the previous studies on the same subject has depicted that tectonic plates operate throughout Earth's history or that it emerged only 0.7 billion years ago. The new revelations have impacted the researchers' models to a large extent for understanding that how Earth has undergone change over this period of time. Robert Holder, a Postdoctoral Fellow in Earth and Planetary Sciences at Johns Hopkins University is of the view that one of the important ways to understand and analyze that how Earth has evolved into a planet that we know is plate tectonics. Tectonic plates explain the mechanism by which continents fall away from each other and come back together. They also throw light on the places where the volcanoes and earthquakes occur along with making assumptions on the cycles of erosion and ocean circulation. Further, they also depict that how life on Earth has evolved over years. In order to draw clarity on how and when plate tectonics emerged on Earth, Holder and the research team undertook close analysis of a global compilation of metamorphic rocks that have come into existence for past 3 billion years at about 564 sites. The Metamorphic rocks refer to those rocks that, with the help of a process of being buried and heated deep in the Earth's crust, have taken the shape of a new type of rock. Scientists have the capability of measuring the depth and temperatures at which metamorphic rocks develop, and resultantly restrict the heat flow at various places in the Earth's crust. Plate tectonics have a impactful influence on heat flow, because of which the ancient metamorphic rocks can be used to conduct a study on plate tectonics in Earth's past. The team of researchers produced a compilation of data on the temperatures and depths at which the formation of metamorphic rocks takes place. This data was then used in order to evaluate how these conditions have undergone change systematically through geological time. Resultantly, the team found that plate tectonics, has undergone development gradually over the last 2.5 billion years.

By: Anuja Arora
Content: https://www.sciencedaily.com/releases/2019/08/190807131926.htm