Isotope Anomalies Across The Frasnian Famennian Extinction Boundary

Large amounts of iridium – a chemical element that is not a part of the Earth’s crust composition – were originally found in rocks of Europe and United States, and have been found everywhere ever since. Iridium, common in meteorites, is a testable evidence of the disaster hypothesis. Gould continues that the Cretaceous debacle, which is one of five episodes of mass dying, occurred at the same time as the large comet might have smashed into the Earth. The author believes this is not merely a coincidence, rather, it is a proof of the cause-effect relationship. The demise of a wide range of habitats along with the extinction of dinosaurs gives an inestimable advantage to the disaster theory over other claims, the author adds. The comet struck the Earth, and habitats, from terrestrial to marine, died with geological suddenness. Finally, this hypothesis has had an impact on the study of an atomic war and its consequences. A nuclear war, Gould says, may cause a huge drop in temperatures and result in the extinction of humanity. Testable evidence, study, development, contribution – all this makes good science.

The Cretaceous-Paleogene boundary that occurred around 65 million years ago marks one of the three largest mass extinctions in the past 500 million years. The hypotheses of Cretaceous-Tertiary boundary impact on Yucatán Peninsula, Mexico shows evidence in the Gulf of Mexico of turbidity currents, and giant waves occurring because of the impact. There is also other evidence that impact ejecta were distributed all over the world. The mineral that was ejected during this impact was iridium. Iridium is a mineral that is commonly used to indicate a rock layer from the K-T boundary. Iridium is only found naturally on extraterrestrial bodies. In addition to Iridium, shocked quartz is used to indicate the K-T boundary. Shocked quartz is unique and

During the Devonian period, most of the oceans were filled with stromatoporoids, brachiopods and corals. The Devonian period gave rises to some of the first tetrapods, amphibians, sharks, insects and boney fish. The first real land plants were also formed, giving rise to the first forest. The first plants were only about a foot tall and had no roots or leaves. By the late Devonian, plants had formed roots and leaves.

At the end of the Carboniferous Period the North Sea basin was a land area, and the earliest Permian deposits were terrestrial. A series of marine incursions occurred during the later Permian, but true open-sea conditions seldom if ever prevailed. Each marine incursion led to an evaporite cycle, and at the end of the Permian the North Sea basin was again a

Using the taphonomic number described above and displayed in Table 2; I examined the relationship between diagenesis of the recently dead to the variation seen in both of the stable isotope records acquired here (Figure 3). The average value of each taphonomic number is not as important as the fact that one standard deviation (represented by error bars) increases from about 0.2 ‰ to 0.8‰ in δ13C values, and 0.3‰ to 0.9‰ in δ18O values as the taphonomic number increases. If this relationship is universal, it represents a significant impact on the records acquired by damaged, fossil or recent shells. As stated in the introduction some studies have examined the impact of

The late Devonian extinction events were actually two sharp pulses of death about 360 million years ago, each just 100,000 to 300,000 years apart. Each pulse was accompanied by a massive drop in temperature, with the steaming seas of the Devonian—surface temperatures of which were about 93 degrees F (34 degrees C)—dropping to about 78 degrees F (26 degrees C), "and marine organisms would not have liked that at all," McGhee said. As to what caused these cold snaps, the ever-popular suspects are ash and dust kicked up by either astronomical impacts or massive volcanism. At that time, plants had made it onto land, as had spiders, scorpions and similar creatures. Right before the extinction events, the first proto-amphibians

The Late Devonian mass extinction is well-known for having one of the most drastic extinction rates. During this extinction period, which spans over a few million years,

“Intrinsic gradualists” are scientists that believe that the cause of the Cretaceous-Tertiary extinction was mainly from Earth's natural process that gradually took place over several million years. The “Intrinsic gradualist” had two main hypotheses that are strongly supported till this day. The first hypothesis is volcanism. Studies have suggested that towards the end of the Cretaceous period, there was an increase in volcanic activity (Keller, 2014). This increase in volcanic activity could have blown enough ash and soot to block out sunlight, thus lowering the global climate. The magma arising from these volcanic eruptions are high in iridium, which are found throughout Earth in the Cretaceous-Tertiary stratigraphic boundary (Bajpai, 2000). Around this time of high volcanism, a mantle superplume deposited great amounts of basalt, which flooded into the Deccan Plateau, to form large lava beds, which are now called the Deccan Traps (Keller, 2014). The Deccan Traps cover about 200,000 miles, and at such large scale, these traps also dispersed tremendous amounts of dust and ash in the atmosphere (Keller, 2014). The second “intrinsic” hypothesis revolves around plate tectonics. During the Cretaceous-Tertiary time frame, the continental plates were drifting apart and experiencing large amounts of tectonic activity. As a result, large bodies of water, such as the Interior Seaway in North America, experienced regression (Nordt, 2003). This regression of the sea resulted in the increase in humidity, which was associated with the middle to high latitude cooling over several million years (Nordt, 2003). These “intrinsic” hypotheses support one another, because volcanism, in many cases, is a result of plate

In the early Aeronian (440.8 million - 438.5 million BP) the Gondwanan ice sheets was melting as a result of climatic changes, and thus led to a rapidly rise in the sea level (Loydell, 1998). Cretaceous was a period where Gondwana was almost free of ice, and possibly one of the warmest in recorded history (Carvalho et al., 2010). Cretaceous was a highly active period, where tectonics uplift, atmospheric circulation, volcanism and several configurations of landmasses occurred (Hay, 1996), the locomotion of lithospheric plates led to one of the major volcanic event in the history of Earth (Bellieni et al., 1984). The many volcanic events in the Early Cretaceous led to the break-up of South America and Africa in Western

It is further divided into three eras: Paleozoic Era (542 to 251.0 million years ago), Mesozoic Era (251.4 to 66 million years ago), and Cenozoic Era (66 million years to present). In the Paleozoic Era plants moved from water bodies to land for the first time and soon transforming to seed-bearing vegetation. The Earth starts looking like its current position, bugs flying in the sky and sharks swimming in the ocean being the top predators. At the end of this era, Permian–Triassic extinction event took place which is considered most severe mass extinction eliminating about 96 % of marine life and 70 % of terrestrial creatures. It took almost 30 million years to recover the species lost in the event. However, it helped in ensuing new biodiversity leading to the start of Mesozoic

The second possible cause relates to waste water from agricultural industry which is rich in nutrients but ends up being dumped into lakes and rivers. This nutrient rich water runs down to the ocean where it ends up and stimulates growth of various types of algae. These algae produce CO2 as a product and therefore raise levels of CO2 in that area of the ocean. This causes other organic material to die off and continues with the vicious cycle described above. (6)

When carbon dioxide (CO2) is absorbed by seawater, chemical reactions occur that reduce seawater pH. This is called “ocean acidification.” Due to the Industrial revolution in the 1800s, the use of fossil-fuels have resulted in billions of tons of Carbon dioxide into Earth's atmosphere (Ocean Acidification). Over time, oceans have absorbed large amounts of the carbon dioxide emitted. On the pH scale, solutions with those with higher numbers are considered basic, while low numbers are considered acidic. On a scale one to 14, seven is neutral. Over the past 300 million years, ocean pH has been close to basic, averaging at about 8.2. Today, it is around 8.1, which indicates a drop of 0.1 pH units. Based on the last two centuries, this represents

Both climate change and ocean acidification, consequences of changes in water lifer cycle due to the absorption of anthropogenic CO2 in our atmosphere. The carbonic acid that gets formed decreases the PH and concentration of carbonate ion, building blocks of the shells and skeletons for many marine organisms. This is tipping the balance of biodiversity and ecosystems. Time-series records of ocean carbon chemistry over the past 25 years show clear trends of increasing ocean carbon and decreasing pH in lockstep with

The ‘leak’ in the biological pump in the Southern Ocean can be influenced by a variety of processes, changing the Southern Ocean’s influence on the concentration of atmospheric CO2, and global climate over glacial-interglacial timescales (Sigman et al. 2010). Reduced ventilation in the Antarctic, as a result of decreased Antarctic Bottom Water formation, decreases the amount of CO2 released to the atmosphere and increases the storage of CO2 in the deep ocean (Sigman et al. 2010, Hayes et al. 2014, Galaasen et al. 2014). Increased sea ice coverage would have also limited the release of CO2 to the atmosphere during glacial periods (Sigman et al. 2010). Greater nutrient utilization due to increased supply of Fe either by upwelling or dust input would lead to greater rates of CO2 sequestration in the deep ocean (Sigman et al. 2010). Increased productivity in the Subantarctic Zone during glacial periods, coupled with reduced Antarctic overturning would have also increased the amount of carbon in

Stratification can reduce the escape of CO2 form the deep ocean and increases the biological pump efficiency. We have the evidences showing the prominent decrease in atmospheric CO2 during ice age. The possibility of high nitrate consumption during ice age can be because of the supply of the iron bearing dust from the atmosphere to the surface water which will increase the iron to nitrate ratio and increases nitrate