History of Historical Geology Flashcards
Who is Nicolaus Steno?
(1638-1686, Danish Physician) Well known for his studies in anatomy, usually known as the Father of Stratigraphy. Developed many of the principles that historical geology is based on including superposition, original horizontality, and lateral continuity.
What is the Principle of Superposition?
(Steno) In any sequence of undisturbed strata, the oldest layer is on the bottom. Every layer above that gets progressively younger. Not always easy to determine in areas where strata has been disturbed.
What is the Principle of Original Horizontality?
(Steno) Observed that strata was often titled, but sedimentary particles settle out from fluids under gravity. Because of this, sediments must have been deposited in nearly horizontal layers. Therefore, any tilting that is seen must have occurred after deposition.
What is Original Lateral Continuity?
(Steno) As sediments are deposited strata extends in all directions until terminated by thinning at the margin of the basin, or when blocked by a barrier, or when it grades literally into a different kind of sediment.
Who is Abraham Gottlob Werner?
(1749-1817, Germany) One of the most influential geologist of his time, and turned the Freiberg Mining Academy into an international centre. He believed that all of earths crust were deposited or precipitated from a great ocean that once covered the earth.
What was Abraham Gottlob Werner and his followers called?
Neptunists. (God of the Sea: all rocks come from the sea).
What criticisms did Abraham Gottlob Werner’s draw?
1) What happened to all of the water needed
2) His belief that all rocks were deposited from water precipitation despite lava flows that were shown to be volcanic in origin.
Who were Plutonists (God of Underworld)?
Opponents of Nepunists (Werner) who believed that fire was the source of igneous rocks not water.
Who was James Hutton?
(1726-1797, Scotland; Edinburgh physician and geologist) A prominent Plutonist and interpreter of geologic processes. Believed in Uniformitarianism.
What did James Hutton see that Earth as?
A dynamic, ever-changing place with new rocks and landforms being created and destroyed all the time, and took a cyclic view of the Earth. He believed that “the past history of our globe must be explained by what can be seen happening now”: Uniformitarianism.
What did Abraham Gottlob Werner see the world as?
Linear; things happen in order.
What did Uniformitarianism mean to James Hutton?
Hutton used it to mean that he could observe geologic processes happening around him and use those to interpret what happened in the past: so, if he saw marks on a rock that were identical to water ripple marks then he believed that’s what they were even if that rock was now far away from the water. “The present is the key to the past”.
What is a criticism of Uniformitarianism?
It works fairly well but it’s important to remember that the past wasn’t always like the present; for example, the Earth’s early atmosphere was very different than it is today. But at the same time, the chemical and physical laws in operation today also worked in the past.
Who was William Smith?
(1769-1839, England) A man who spent 24 years mapping the strata of England. He worked as a surveyor for building canals, and was the first person to figure out that fossils could be used in correlation to the strata. He produced the first geologic map of England and Wales in 1815.
What is the Principle of Biologic Succession?
Life forms of each age of the earth are unique to that age and they allow a geologist to recognize contemporaneous units from other locations around the world. Smith did not know wh y fossils worked this way.
