The first and sixth sentences are given in the beginning a s S1 and S6. The middle four sentences in each have been jumbled up and labelled as P, Q , R , and S . You are required t o find the proper sequence o f these four sentences
S1 : The primary evidence for climate change that occurred many million years ago is the rocks and deposits themselves.
S6 : In other words, despite the clear legacy in many parts of the world of recent glaciation, the vast majority of sedimentary rocks were laid down in warm climatic conditions.
P : Sediments and fossil in the poles tell us a great deal about the environment in which they were laid down.
Q : We must, of course, bear in mind when interpreting this information that, because of the movement of the continents, no one latitude of the Earth has necessarily gone through such marked climatic vicissitudes.
R : Nevertheless, even allowing for this factor, one of the most remarkable discoveries about the climate change of the past is that the two poles of the Earth have been free of ice for at least 90 per cent of the known history of the planet.
S : We may find in close proximity to one another, coal deposits indicating the humid conditions of the tropics, red sandstones laid down in deserts and morainic materials reflecting polar conditions.