Tuesday, July 23, 2019
The Quaternary period Essay Example | Topics and Well Written Essays - 3000 words
The Quaternary period - Essay Example 1). In order to accurately gauge the occurrences of the past in preparation for the future, it is necessary to establish a system or a scale of timing of these occurrences. In addition to knowledge of all the operations of the earth, having in mind a specific (or even general) idea of the time that it takes for events to occur gives historians, scientists, and even the man in the street an idea not only of the future impact of actions done today, but also when to expect those effects to materialize. Because of this, many scientists have worked hard at developing different techniques to date the past. Techniques have developed over the years, from those that rely on myth to ones that rely on scientific evidence. The general trend of these techniques as the were developed was to posit an older and older earth. The time for the beginning of the earth was at first "estimated" at about 4 ka BP (Walker, p. 2); now there's evidence of its beginning approximately 15 ba BP (Greene, 2003, p. 347) . Though no one technique is conclusive, they counterbalance each other to produce a general timescale concerning the evolution of the earth., These techniques have proved useful in examining the evidence for the geological and climactic activity of the earth during the Late Glacial and Early/Holocene era, and the possibilities for human activity resulting from it. Modern Quaternary science began when Louis Agassiz posited the former existence of a "Great Ice Period" (Walker, p. 3). Later, when scholars got accustomed to the Ice-Period idea, Albrecht Penck of Germany attempted to "estimate the duration of interglacial periods" by measuring the "depth of weathering and 'intensity of erosion' in the northern Alpine region of Europe" (p. 3). Other attempts at gauging the length of periods in the Quaternary include the analysis of laminae, which give evidence about the types of activity of the soil and its vegetation through the analysis of layers of sedimentation in the earth's crust. In this study, this technique is used to analyze the layers of soil existing in the British Isles and make conjectures about what sort of climate or geological occurrence produced them. Looking at the size of the layers also gives an idea of the duration of each phase and sheds light on probable oscillations within each phase. Dendrochronology was developed during the early part of the twentieth century, which uses the analysis (counting) of tree rings to gauge the age of a tree and by extension the age of a period. This kind of measurement is useful in establishing the age of civilizations. This works because "trees within a small region often share the same experiences of good and bad years, with resulting patterns of wide and narrow rings that can be matched from tree to tree, from living trees to dead trees, and even to timber, charcoal, etc., used by human beings" (Calder, 1984, p. 224). Because trees also show, from their rings, the type of weather experienced in a given year, tree-ring analysis has been applied here to the study of the climates experienced during the Holocene epoch. This technique is called dendroclimatology (Walker, p. 3). Tree-ring analysis, though able to give only a comparatively short view into the past, is useful in this study, as the entire Holocene epoch lies just within its range. With the advent of radio-carbon dating came a very important tool in the
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