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A Brief History of Earth Science
Why Geology? The study of geology is much more expansive than studying rocks and minerals under a microscope. Geology includes a variety of sub disciplines involving the causes behind natural disasters, such as volcanic eruptions, landslides, floods, and earthquakes; discovering hydrocarbons (oil, natural gas, coal) for fuel and energy; measuring varying climate throughout Earth history and predicting future climate; and comprehending the nature of other planets in the universe. Geologists also work in academic disciplines whereby they gather information about the processes of mountain building, sea level rising and falling, continental separation and merging, and even study extinct animals. In fact, paleontology is a combination of geology and biology, requiring detailed knowledge of prehistoric geologic settings in order to understand things like diet, behavior, and environments of which extinct animals where accustom to. Floods, Fossils, and Heresies Some of the earliest ideas of why the surface of the Earth is not smooth and uniform revolve around Biblical flooding. Even before Biblical times, ancient civilizations recorded stories of catastrophic floods on proportions only capable of execution by malevolent deities. The general idea is that a great flood transformed the planet from a flat and tranquil place to a mountainous and harsh world. Interests in the workings of the Earth spurred from catastrophic events such as perpetual flooding in Mesopotamia and the destruction of Pompeii in 79 CE; and the interest continued for economic reasons, for instance locating precious stones for trade and locating coal during the Industrial Revolution.
Correlations between the UK and continental Europe occurred during the 1700s, but it was not until the early part of the 19th century that geology really stepped up. In 1811, Frenchman Georges Cuvier published a monographic map of the Paris basin, correlating fossil types to rock layers and creating a geologic column (ordered layers of sedimentary rocks). Cuvier's work, along with the work of English geologist William Smith (1815), put fossil and rock strata correlation in the limelight. Using the correlation of fossils and rock strata, future geologists were capable of identifying relative ages for deposits and extinct animals! Cuvier postulated that all organisms were created in the past and were subject to selective extinctions. He discovered extinct archaic elephants and recognize the differences of species between rock layers, leading to the theories of catastrophism and special creation. Catastrophism showed Cuvier that extinctions of millions of organisms occurred followed by deposition due to catastrophes. Another Frenchman by the name of Alcide D'Orbigny suggested that new species developed after major catastrophes. Modern Geology Although critical thinkers of the past greatly contributed to modern geology, one name stands above all: Alfred Wegener. In the early part of the 20 century, Wegener proposed the idea of continental drift in his Die Entstehung der Kontinente und Ozeane (The Origin of Continents and Oceans). He proposed that all the continents were once combined as a supercontinent (which he named "Pangaea"), and drifted apart sometime in the past. His concept of continental drift was the first idea of plate tectonics. Unfortunately for Wegener, he was unable to provide a mechanism behind the movement of continents and was largely ignored, met with global skepticism. Wegener's 1915 theory of continental drift was embraced by Arthur Holmes, who provided the mechanism of heat convection in 1929. Heat convection explained that thermal processes in the Earth's mantle caused the continents, and any surface material, to be mobile, pulling apart and converging elsewhere on the surface. Sadly for Alfred Wegener, he died a year later in Greenland pursuing other work. Even if Wegener had lived, however, he would have had to wait 30 years before his theory was globally accepted.
Geology in Flux
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GEOLOGIA CODEX
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In
the time of ancient Greece, fossils embedded in rocks were classified
as remnants of old gods. In addition, certain fossil finds were
attributed to deceased monsters of Greek mythology. For example, the
skull of an elephant looks a lot like a cyclops! It probably was not
until the early part of the 16th century that fossils were considered
on a scientific level. Leonardo Da Vinci is known for his art, but, in
fact, he was much more a critical thinker, a scientist, than a
traditional artist; art was a talent he used in order to better present
his ideas. Da Vinci looked at fossils more critically and made a few
astute observations. Particularly in the case of fossilized fish he
noticed they were far from oceans, were present in communities just as
the day, and appeared in strata (layers), meaning they were not victims
of a single deluge. His ideas proposed that rock strata represented
different periods in Earth history, and fossil remains were not a
direct result of a single flood. Less than 200 years later, in 1669, a
new thinker, Nicolas Steno, published his Dissertationis prodromus,
which introduced the laws of stratigraphy. Stratigraphy is a branch of
geology which studies rock layers (strata) and layering
(stratification). The laws included in his dissertation include the law
of superposition, whereby layers are deposited in sequence by age:
older layers exist on the bottom and more recent layers are deposited
toward the top; original horizontality, which states that "strata
either perpendicular to the horizon or inclined to the horizon were at
one time parallel to the horizon;" and lateral continuity, stating
layers are deposited continuous over the surface of the Earth unless a
solid body (e.g. a mountain range) stands in the way. Steno's laws
supported Da Vinci's ideas that fossils form together with the rocks
they exist within and that the events are relative, not the result of a
single event, such as a global flood. Around the time of Steno, Robert
Hooke published his Micrographia (1665), hinting at fossils being ideal for chronologic correlation and that extinctions within species occurred in the past.
As
technology advanced in the wake of the 20th century, most was halted or
diverted to war efforts. After 1930, geology remained stagnant until
the early 1960s. By the late 1950s the West's navies began upgrading
their instruments, and technologies used during WWII (e.g. sonar)
became unclassified and available to public industries. As one example,
sonar became available for use in civilian fields, where it was
utilized to survey the sea floor. With the use of military technology,
geologists were able to confirm Wegener's theory on continental drift,
detecting the existence of surface "plates." Arthur Holmes used the
results of these new technologies to further Wegener's theory on
continental drift and sea floor spreading with his thermal convection
as the mechanism. 
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