UPSC CDS 1 2018 GK Paper

The Chamberlin–Moulton Planetesimal hypothesis was proposed in 1905 by geologist Thomas Chrowder Chamberlin and astronomer Forest Ray Moulton to describe the formation of the solar system. Jeffreys postulated ‘thermal contraction theory’ to explain the origin and evolution of major reliefs of the earth’s surface (continents, ocean basins, mountains, island arcs and festoons) but his major objective was to explain the origin and distributional patterns of mountain systems of the globe. Kober put forth Geosynclinal Orogen theory. His main objective was to establish relationship between ancient rigid masses or tablelands and more mobile zones or geosynclines, which he called orogen. Daly postulated his theory of sliding continents in his book 'Our Mobile Earth' in the year 1926 to explain the origin and evolution of different relief features of the earth's surface. So, first option provides the correct code for the answer.