Group N°1 Diego Delgado

Adriana Mera Marcela Nuñez

Historical Geology

Principle of Steno Catastrophism Fixism Creationism

PRINCIPLE OF STENO As is true of most historical science, only a very few

principles underlie the study of layered rock and the fossils it contains. Three of these principles were recognized by Nicholas Steno (1631–1687), a Dane working in Florence, Italy, as physician to the Grand Duke of Tuscany. In 1667 Steno was one of the first to understand that fossils were the remains of past life that had been deposited with the sediment, although he supposed that fossils had been deposited by the biblical deluge or, in the case of fossil elephants, were the remains of Hannibal’s army as it crossed the Alps to invade Rome in 218 bce. Previously, many supposed that fossils grew in the rock under the influence of emanations from heaven or perhaps had been placed supernaturally into the rock as a test of religious faith.

Steno seems also to have been one of the first to understand that the Earth has a history that is worthy of study, and he applied his principles of stratigraphy in his attempts to understand the geological history of the area around Florence.

 

PRINCIPIE OF STENO Superposition

If you are playing cards or tossing dirty laundry into a pile, you know that the first item played or tossed is the one at the bottom of the pile. As one moves up the stack or pile, the items were deposited more and more recently. This is all there is to the principle of superposition (Figure 1-1). Steno recognized that in any undisturbed sequence of sedimentary rock, the oldest is on the bottom and the youngest is on the top. It is not rocket science, but Steno’s recognition of this fact grew from his recognition that the rocks have a history, and it allowed him to begin interpreting that history.

PRINCIPLE OF STENO

PRINCIPLE OF STENO Original horizontality

Steno recognized a further principle—that sediment is deposited from a fluid medium—air or water—and that the upper surface of a layer of sediment should be horizontal if the layer has not been disturbed subsequently.

PRINCIPLE OF STENO Original lateral continuity

Finally, Steno understood the principle that layers of sedimentary rock are laterally continuous so that a layer of rock cropping out on opposite sides of a river valley was once continuous across the valley. Today his principle tells us that layers of rock continue until they reach the edge of a basin of deposition or thin to zero thickness as the supply of sediment runs out.

PRINCIPLE OF STENO Cross-cutting relationship

You may not know how old your grandmother is, but you can be sure of two things: she is older than your mother, and your mother is older than you. Somewhere along the line in the development of geology this principle was applied to the rock, the idea that the sand grains that comprise a sandstone must pre-date the sandstone.

Similarly, the chemicals that cement the sand grains together must be younger than the time of deposition of the sandy sediment. Finally, if one feature cuts across another, such as a fracture in the rock or a cave dissolved in limestone, it must be younger than the rock.

PRINCIPLE OF STENO

CATASTROPHISM Clergymen and scientists believed that the earth had been

created a few thousand years ago

CATASTROPHISM The concept of

catastrophism, was proposed by Georges Cuvier (1769–1832)

“Father of Vertebrate Paleontology”

CATASTROPHISM

According to Cuvier, six major catastrophes had occurred in the past…

…Biblical creation?

CATASTROPHISM

Cuvier believed that the floods were caused by episodes of crustal subsidence, which alternated with sudden crustal uplifts

CATASTROPHISM Some catastrophists were

convinced that canyons, were simply giant cracks in the ground

Tidal waves and floods were caused by huge meteorites or comets

Catastrophism

Other catastrophists postulated that the thick sequences of sedementary rocks in the earth’s crust had been deposited during the worldwide flood

CATASTROPHISM William Buckland (1784-

1856), English theologian, geologist and paleontologist

Popular professor of geology at Oxford university during the nineteenth century

CATASTROPHISM Most of the catastrophists’ proposals were related to

observation of natural events, they were generally by gross exaggerations in scale

FIXISM

Fixism affirms that the current existent species were identical to species of the past

Fixism opposes evolutionism

FIXISM Continents were maintained stable and fixed in their

present places through all geologic history

FIXISM The religious version of fixism is called creationism

Modernized religious interpreters teach creationism as a metaphorical wisdom

CREATIONISM The creationism is the

movement of certain religious fundamentalist sectors that are against accepting the evolution as scientific fact it is. Charles Darwin was referring to the evolutionary anti arguing the tenets of his book The Origin of Species (published in 1859 ), not based on empirical evidence of science , but by appealing to faith and literal belief of what is written in the Bible . So creationism is not a scientific movement that opposes evolution, but a set of religious beliefs.

CREATIONISM

The creationism is what sustains all living things on Earth were created by God and exist today.

CREATIONISM

Intelligent Design The intelligent design it says is that there is no

chance or adaptation , but the hand of an intelligent being who form rationally guide the changes that were occurring in the species throughout the history evolution. As you can see in other articles in this section, if anything characterizes the current living beings, it is the total lack of rationality in their "design". If there was a being who has designed us, clearly it was not smart, but rather daft, since we have a biological "design" rational and intelligent, but is the result of various adaptations over millions of years which today we see in living creatures on our planet. And if we see postcards of this evolutionary path, we can go to the fossil .

CREATIONISM Intelligent Design

The intelligent design is not a scientific movement, or is a legitimate scientific proposal, as it has dogmatic characteristics, is not based on the scientific method, it is a religious justification of a proven scientific fact. Science and religion should not compete . The evolution should not compete with religious beliefs. They are totally different issues that do not overlap. 

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