Paul Lyle – författare

Stratigraphy is the branch of geology which studies rock layers (strata) and layering (stratification).Stratigraphy deals primarily with sedimentary rocks but also embraces layered igneous rocks where layers result from successive lava flows.A common goal of stratigraphic studies is the interpretation of sequences of rock strata, thus understanding the time relationships involved, and correlating units of the sequence with rock strata elsewhere. Nicholas Steno described four principles of stratigraphy in the seventeenth century, including the law of superposition which states that states that, in undeformed stratigraphic sequences, the oldest strata will be at the bottom of the sequence. These ideas still underpin modern stratigraphy which is governed by The International Commission on Stratigraphy. Its primary objective is to precisely define global units (systems, series, and stages) of the International Chronostratigraphic Chart that, in turn, are the basis for the units (periods, epochs, and age) of the International Geologic Time Scale.Stratigraphy has application in many scientific fields, including archaeology, palaeontology and in the search for natural resources. This succinct and accessible introduction to stratigraphy will prove helpful to students and amateur geologists alike.

Geologists are among that group of scientists who must factor the passage of time into their investigations and they thus have a perspective on time that sets them apart from many other researchers.The proposition that geological time is vast, encompassing thousands of millions of years, is relatively recent. It is a concept that remains controversial and unacceptable to many people today who still consider the Earth to have been made to a timetable covering no more than ten thousand years.Paul Lyle examines how our fascination with time has developed from our earliest ancestors' recognition of the cycles of the sun and the moon. It considers the passage of time as a series of non-repeatable events, Time's Arrow, in contrast to time as a series of repeated processes, Time's Cycle, both of which can be used to explain geological features on the Earth's surface.The author argues for a greater understanding of geological or ‘deep time’ as society becomes more aware of the vulnerability of the Earth's resources to over-exploitation by an expanding consumer society. This debate and the controversy surrounding global warming emphasises the importance of geological time to the process of economic and political decision-making.It is a book for those interested in the intellectual challenge presented by the extent of geological time. It is written for environmentalists and policy-makers who wish to better place their concerns and decisions in proper context but, above all, it is a book that offers to share a geologist’s appreciation of time with the widest possible audience.