A very brief Introduction to the Quaternary

By Joe Shimmin The Quaternary comprises the Pleistocene and the Holocene and is the youngest of the geological periods. It dates from approximately 1.8 million years ago right up to the present, with the large majority of this time being filled by the Pleistocene. The Holocene spans a geological ‘blink of an eye’, beginning only 10,000 years ago at the start of the present interglacial and continues today. What sets the Quaternary apart from other geological periods is a suite of high frequency climate fluctuations, with very cold stages being interspersed by warmer stages. This type of climate fluctuation is believed to have occurred at various other times in the Earth’s history, but most of the evidence for these has been wiped out over millions of years. However, the glacial/interglacial or warm/cold stages of the Quaternary have, in many cases, left us enough evidence of their existence for the Quaternary scientist to be able to attempt to reconstruct these past environments with some degree of success. Fig. 1. Glacial beds at Benacre, Suffolk Serbian mathematician, Milutin Milanković, formulated the accepted theory for why climate oscillations have occurred in this period, in the first half the twentieth century. According to ‘Milanković, Quaternary climate was, and is, influenced by three factors: Factor 1: the shape or ‘eccentricity’ of the Earth’s orbit around the sun, which varies over a cycle of approximately 100,000 years.Factor 2: The tilt or ‘obliquity, of the Earth’s axis, which varies over a cycle of approximately 41,000 years.Factor 3: … Read More