Ordovician

Benton (1995) adopted several standard methods to measure the magnitude of extinctions: simple counting, percent extinctions, total and per family extinction. From the percent extinction measurement, he identified five deadly mass extinctions at Late Ordovician, Late Devonian, Late Permian, Late Triassic, and Late Cretaceous. These five big mass extinctions were mentioned also by Erwin (2001) and Barnosky et al. (2011). Barnosky et al. (2011) measured the big five mass extinctions based on…

New York exists on bedrock that tells a tale of millions of years ago, going as far back as the late Mesoproterozoic (1.6 to 1 billion years ago). The layers that make up this bedrock show the conditions of the earth’s surface through many different orogenies, which are times of high grade metamorphism and where plate tectonics makes its biggest changes. The Fordham gneiss was formed a billion years ago (oldest) during the Grenville orogeny (Precambrian) which featured sediment deposits and…

The Permian Mass Extinction Introduction There are five major extinctions in history: the Late Devonian, the Ordovician-Silurian, the Permian-Triassic, the Triassic-Jurassic, and the Cretaceous-Tertiary. Known as the Big Five, these extinctions exceeded all others in size and destruction, each killing more than 60% of species from that period. Each one acted as a bottleneck, allowing the survival of only a fraction of the organisms that had been thriving before, from which evolution and life…

unexpected events happen that made the planet earth to transform radically. This event is known as the Permian Triassic Mass Extinction or also called by many the Great Dying. This mass extinction is known as the worst extinction comparing them to the Ordovician, Devonian and the Cretaceous Extinction. Some individuals are not award that the Permian –Triassic are two forming boundary between the end of the Permian and the beginning of the Triassic period. The Permian-Triassic Extinction almost…

Standing on what was once a piece of oceanic crust, laid down in the Ordovician period 450 million years ago, I was captured by the astounding power behind the forces that had moved this exact piece of crust over exceptionally long periods of time to be situated inland, adjacent to a river, to where it is in the present day. Taking on Geology was a decision I made based on my thorough enjoyment and fascination of the physical aspect of geography at GCSE, particularly learning about volcanoes,…

writer at The New Yorker. The Sixth Extinction won the Pulitzer Prize in 2015; I chose this nonfiction book because I hadn’t heard of the concept of a sixth extinction. I had previously learned of multiple extinctions that occurred in the Cretaceous, Ordovician, Permian, and Triassic-Jurassic periods, but I became curious just by the thought of what Kolbert meant by a sixth extinction. She claims that this extinction could be the most devastating yet due to humans, and gives different…

Introduction On September 12, and October 3, 2016, we stopped at 6 locations north of Northampton in the Deerfield Basin of the Connecticut River Valley (Figure 1). The purpose of these stops is to examine rocks, interpret depositional environments for each rock formation, and discuss the geologic history of the Deerfield Basin based on observations and interpretations. Early Mesozoic lithospheric extension led to the development of a long sequence of rift basins. The Deerfield basin is the…

things from fossilized shark teeth and scales even though it doesn’t seem like much. Their discoveries include information about species, size and behavior. While it is controversial, some paleontologists believe that the first scales are from the Ordovician Period 455 million years ago. Nonetheless, the scales found in Siberia and Mongolia during the SIlurian Period 420 million years ago are definitely from sharks. More complete fossilized shark remains are…

Gondwana is an ancient supercontinent that existed around 500 million years ago. In fact, Gondwana broke up and eventually created the continents we know today. These continents are known as Africa, South America, Australia, Antarctica, the Arabian Peninsula, and the Indian subcontinent. Just because Gondwana eventually created the continents we know today, does not mean that these continents will stay the same forever. Eventually, there will be different arrangements in an extensive history…

Precambrian time covers the tremendous greater part of the Earth's history, beginning with the planet's creation around 4.5 billion years prior and finishing with the development of complex, multi celled life-shapes very nearly four billion years after the fact. The Precambrian is the most punctual of the geologic ages, which are set apart by various layers of sedimentary rock. Set down over a huge number of years, these stone layers contain a lasting record of the Earth's past, including the…