Wegeners ideas were proved even further, increasing our knowledge of tectonic events. Sea floor spreading shows that rock is being both created and destroyed. In the 1950s and 1960s, ages of the ocean floor were measured. The surveys suggested that very young rocks, ageing less than 1 million years old, are found near ridges and older rocks, ageing over 200 million years, are found near the continents. Evidence of sea floor spreading can be found in the Atlantic, where it is believed that the North American and Eurasian plates are moving apart at a constructive plate margin.
He claimed that each of the present continents was once joined together as part of a super continent called Pangea. He believed this because he saw that in certain areas continents would fit together for example the west coast of Africa fits together with the east coast of South America, therefore they must have moved apart from one central mass. Other evidence was shown to back up this theory such as the fact that glacier derived clays are found in all of the continents in Gondwana forming one half of Pangea, as one striations in rocks of Carboniferous age. Presently they cover half the globe but would form a reasonably sized polar ice cap if Wegener’s theory was true and the globe was reconstructed in his image of how it used to be. Despite Wegener having no concrete proof as to why this was the case his theory was proved to be accurate, physicists had believed that the earths crust was far from strong enough to be able to force itself apart.
The dating of the human remains is vital in not only establishing the age of the first Australians, but gaining a sense of their culture and society. ‘The skeletons are by far the earliest evidence found anywhere in the world of human remains being interred with burial rites’ (Grose, 2003). From a cultural perspective this implies a complex society that respected its dead and had some sense of spirituality and notion of an afterlife (Grose, 2003). The evidence gained at Lake Mungo has put a time frame on the climate change that occurred around 50,000 years ago allowing the commencement of occupation. The human occupation peaked during drying of the climate over the next 10,000 years.
The Arctic Small Tool Tradition, also known as Pre-Dorset, is a circumpolar cultural development which probably originated in Siberia. The oldest sites in North America appear suddenly on the west coast of Alaska about 4,000 years ago. Similarities to the Plano and Northwest micro blade traditions, as well as to Siberian Mesolithic blade technologies have caused considerable debate over origins (Irving 1962; Laughlin 1962, MacNeish 1964; Damas 1969). The technology bears no resemblance to the complexes which were previously present in the coastal regions of Alaska. The warming trend which was still evident at this time may have assisted in the rapid movement of people across the High Arctic.
Whereas Eyjafjallajokull is in Iceland, an MEDC. The initial eruption of Eyjafjallajokull lasted from 20th March- 23rd June, however the eruption was declared officially over in October 2010. It is located on a spreading ridge, where convection currents are driving apart the North American plate (moving west) and the Eurasian plate (moving east) along a divergent plate boundary. This is creating the Mid Atlantic ridge, along which the age of the rocks either side of the ridge and the palaeomagnetism have been used as evidence of the plate tectonics theory. Both eruptions caused disruption to aviation, particularly Eyjafjallajokull which was a relatively small eruption.
Physical changes include; changes in climate, succession, disease and natural disasters. Human factors in change include; urbanisation, deforestation, cultivation and tourism. Which are arguably the most important factors in changes to vegetation. The British Isles were largely covered in deciduous forests, until around 5000 years ago when humans began to cut down these trees to build their homes, which can be seen as first stages of ‘urbanisation’. However the trees they cut down were put to use in firewood and fuel for cooking.
These first people migrated to the North American continent around 35,000 B.C.E. During this time period, the world was experiencing a pre-historic glacial period which resulted in huge amounts of the world’s water beginning frozen over. Additionally, sea levels dropped so dramatically that areas such as the Bering Strait became grassy plains. The Bering Strait for all purposes became a land bridge that enabled humans and animals to cross over into grassy Alaska from Icy Siberia.
o Because this date corresponds approximately to the beginnings of village life in a few parts of the world, the first undisputed peopling of the Americas, the end of the Pleistocene Era and last Ice Age, and the start of what geologists term the Recent Era. Plants and animal domestication began in at least one part of the world within a few thousand years of that date Chapter Two: A Natural Experiment of History How does the fact that the Maori defeated the Moriori (a “natural experiment of history) support Diamond’s
By 3,000 BCE, they learned to cultivate plants. The population of North America hit 1,000,000. Different cultures developed in different regions in the Americas. Slavery had been a part of European and African history for a long time. Between 1450 and 1750, new trade patterns were set up.
III. In my research I have found some interesting information pertaining to the Appalachian Mountains. IV. Today, I will define the age, length, and width of the mountains and some information about the Appalachian Trail and Mount Mitchell. Body I.