The perpetual dance of continents
2007; Nature Portfolio; Volume: 449; Issue: 7162 Linguagem: Inglês
10.1038/449540a
ISSN1476-4687
Autores ResumoTed Nield has a complex view of life and science.His skills as a writer successfully convey in Supercontinent the recent exciting work in grand-scale geoscience to a wide scientific audience.Nield's task is immense: to give an intelligible account of Earth's history, beyond the familiar story of wandering continents, drift and the simpler ideas of plate tectonics.He tells us what is thought to have happened way before Alfred Wegener's Pangaea (pictured here), following the trail of analogous earlier 'supercontinental' land masses: Pannotia, Rodinia, Atlantica, Columbia, Nena and Ur -the last probably appearing fairly soon after Earth's formation.To embrace a span of 10 billion years, Nield also envisages a whole succession of future supercontinents.Indeed, the next assemblage has already been named: Novopangaea.Geoscientists have long been reconstructing continents, and their results are wonderfully displayed at various websites (such as www.scotese.com).Nield wants to help readers understand just how such reconstructions have been produced and how more recent work is extending reconstructions into the future as well as the past.He links the perpetual 'quadrille' of the continents to plate movements, climatic and atmospheric changes, and life's causal role in the changes.Everything is driven by the great convection currents within Earth's mantle.Thus Supercontinent recounts geologists' debates about the 'introversion' and 'extroversion' of continents and describes the intricate geochemical and geomagnetic work that underpins their endeavours.Fearlessly, Nield plunges into the complex problems of the role of ophiolites, pieces of oceanic plate thrust onto the edge of continental
Referência(s)