The snowball Earth Theory was hypothesized by British geologist Brian Harland in 1964. The core ideal of the theory is that during the Pre-Cambrian period, the continents of the Earth were located near the Southern Hemisphere, and the entire planet was covered in glacial ice sheets, from the Poles to the equator (Schrag, et al., 2002). The following essay will aim to explain the theory of the Snowball Earth in detail.
Brian Harland based his theory on the fact that he found glacial tillites with origins in Greenland, deposited in tropical latitudes. The Snowball Earth theory is still just that, a theory. The term “Snowball Earth” was actually coined by Joseph Kirschvink 40 years later. The theory proposes the simple idea that at a certain period …show more content…
Ecosystems dependent on sunlight would experience the most adverse effects of global ice cover (DUJS, 2010). This statement is supported by evidence that carbon-isotope ratios from this period are similar to those found in the Earth’s mantle, indicating that photosynthesis was non-existent, and most forms of eukaryotic life were destroyed. However, microfossils have been found that date back to this time, of both prokaryotic, as well as a few eukaryotic fossils. This suggests that not only did organisms survive, they adapted to shallow water carbonate environments. Furthermore, the fossils that were found resemble those that were discovered in rocks slightly younger than the snowball event, strengthening the idea that there were organisms that survived the mass glaciation. It is a well-known and well documented fact that anaerobic bacteria flourish in the vicinity of hydrothermal vents in the deepest oceans on earth, so the chances of bacteria surviving the glaciation while living near hydrothermal vents is rather plausible. With regards to early animal evolution, there are various possible implications of global glaciation. One such implication is a mass extinction of eukaryotic organisms, with survivors mostly being terrestrial. However this would not be seen in the fossil record (Schrag, et al.,
Brian Harland based his theory on the fact that he found glacial tillites with origins in Greenland, deposited in tropical latitudes. The Snowball Earth theory is still just that, a theory. The term “Snowball Earth” was actually coined by Joseph Kirschvink 40 years later. The theory proposes the simple idea that at a certain period …show more content…
Ecosystems dependent on sunlight would experience the most adverse effects of global ice cover (DUJS, 2010). This statement is supported by evidence that carbon-isotope ratios from this period are similar to those found in the Earth’s mantle, indicating that photosynthesis was non-existent, and most forms of eukaryotic life were destroyed. However, microfossils have been found that date back to this time, of both prokaryotic, as well as a few eukaryotic fossils. This suggests that not only did organisms survive, they adapted to shallow water carbonate environments. Furthermore, the fossils that were found resemble those that were discovered in rocks slightly younger than the snowball event, strengthening the idea that there were organisms that survived the mass glaciation. It is a well-known and well documented fact that anaerobic bacteria flourish in the vicinity of hydrothermal vents in the deepest oceans on earth, so the chances of bacteria surviving the glaciation while living near hydrothermal vents is rather plausible. With regards to early animal evolution, there are various possible implications of global glaciation. One such implication is a mass extinction of eukaryotic organisms, with survivors mostly being terrestrial. However this would not be seen in the fossil record (Schrag, et al.,