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Glossary

So this page is a little blank now, but it will have many more entries soon. I promise.

A

Absolute Dating– While this would be an absolutely fantastic name for a dating site (e-harmony, match.com, absolute dating) this really has nothing to do with you and your romantic life, or lack thereof. This is how we can find out how old something actually is. The most widely known method of absolute dating is radio-carbon dating, though scientists can use multiple different isotopes to go even further back in time, and date something accurately.

Archaeology– The study of past cultures through their material remains

Antiquarian- One who studies the Antiquities. Usually involved a good grasp of the classic languages, and a passion for adventure and collecting stuff

B

C

Cobalt- Symbol: Co Atomic number: 27 A transition metal, found compounded with others in nature. Used in superalloys that are used in medical prosthesis, and in high-speed transportation technology also used in pigments to create a dark blue color in glass and paint.

Copper- Symbol: Cu Atomic Number: 29 One of the first metals ever to be worked by humans, Copper is still used in telecommunications and electronic wires, piping, kitchenware, coins, the Statue of Liberty and a whole lot more.

D

E

Erosion- The movement of weathered or loose material from where it was to a new place. The terms weathering and erosion are often used interchangeably, and while they work closely together, they are not the same.

F

G

Geology- The study of the Earth, it’s processes and it’s history.

Geologic Time- The time scale used to describe relationships between periods of time seen in the rock family. A basic version is here.

Gold– Symbol: Au Atomic number: 79 It has a high value placed on it by many societies around the world.

H

Hutton, James- Widely considered to be the father of modern geology, Hutton came up with the theory of Uniformitarianism. He ‘discovered’ way more time in Earth’s history than had previously been known.

I

Igneous Rock- Rock that has been formed by cooling out of a rock melt (either lava or magma)

Index Fossils– Fossils of organisms that lived in a limited time range but over a large area. They are useful in relative dating because they can pinpoint an exact period of time. For example, lets say a geologist wanted to know how old a rock formation was. He knew that in the layer of rock beneath the rock that he was looking at was an index fossil that had been dated to around the same time as, say, the extinction of the dinosaurs. So long as this area hasn’t been entirely flipped over (lets assume it hasn’t) then the geologist knows that the rock he is interested in is younger than the extinction of the dinosaurs.

Iron– Symbol: Fe Atomic number: 26 A very strong naturally occurring metal used in many different industires

J

K

L

Lede- A form of “lead” used by journalists to refer to a “lead-in” to a story. The spelling is used to distinguish the meaning from lead (to lead some one from one place to another), lead (the metal), lead (the British way of saying leash), etc. Does not refer to German Suspenders (also known as Lede).

Lithification- The process by which a rock becomes a rock. Usually involving heat, pressure or both.

Lithium– Symbol: Li Atomic number: 3. A highly reactive metal, with uses in many different industries, in the news now because of it’s use in batteries and electronics

M

Metamorphic Rock- Rock that has been changed by heat or pressure. It could originally be either metamorphic, igneous or sedimentary before it undergoes metamorphism

N

O

P

Principles of Stratigraphy- the basic rules that rocks tend to follow, and geologists use to interpret them (and find out what they know!) Nicolas Steno came up with these in the 1600’s and they still work

  • Principle of Original Horizontality- When rocks were originally deposited, they were deposited horizontally, because gravity works. If you find sedimentary rocks sticking up in the air with their layers vertical, then they have been moved.
  • Principle of Superposition– Because rocks were originally deposited horizontally, unless they have been disturbed the one on the bottom is oldest. This can be applied to geology, archaeology, or anything else. It forms the basis for relative dating.
  • Principle of Lateral Continuity- A basic summary of this is; similar environments will exist next to each other in the rock record unless disturbed. For example, a beach environment should exist next to an ocean environment, or, a swampy environment can’t exist right next to a desert environment without something really weird going on, likely an unconformity.
  • Principle Of Cross Cutting Relationships- If there is a large piece of rock, with another cutting through it, the rock that has been cut through had to exist before the one that cut through it.

Q

R

Relative Dating- This does not in any way involve you dating any member of your family. Now that we’ve gotten that out of the way, relative dating is pretty self explanatory. You date an object, in this case, a rock, relative to other things around it. To do this you look at things like where the rock is in relation to other rocks (principle of superposition), or  index fossils. To use an example that doesn’t involve rocks and does involve relatives (just to confuse you) it’s like saying, I’m younger than my father but older than my sister, who is older than our cousin. That’s relative dating (get it?!). Absolute dating would involve me saying; I am 22, my father is 50, my sister is 17 and my cousin is 14.

Rock Cycle-The process by which different types of rocks are ‘related’. An excellent diagram is here

S

Seamount– A mountain on the sea-floor that has not broken above the waterline to become an island

Sedimentary Rock- A rock that is composed of little bits of other rock. A good example is sandstone, which is made from sand and lithified.

Steno, Nicolas-(1638-1686) A Danish scientist who established the principles of stratigraphy. Considered one of the fathers of geology.

T

U

Unconformity– A contact between two layers of rock that shows that there something missing from the rock record due to erosion. There are many types of unconformity.

  • Angular Unconformity– A great example is Hutton’s Unconformity. This is when the angles between two sedimentary rock surfaces don’t match up
  • Disconformity– This is an unconformity between two layers of parallel sedimentary rock
  • Nonconformity- An unconformity between two totally different types of rock (Metamorphic and Igneous, Igneous and Sedimentary, etc)
  • Paraconformity- Actually a type of Disconformity, but one where it it almost impossible to tell that there even is an unconformity there. You may ask; If it’s not easy or possible to spot, why is it on here? Answer, because now we can (sometimes) date layers of rock and figure out that one is waaay older than the other, which indicates missing time

Uniformitarianism- The idea that the processes that are shaping the earth now (erosion, deposition, compaction, etc), happened in the past and will continue to happen in the future.

Ussher, James– Calvinist Archbishop in Ireland. Also held the title of ‘Primate of all Ireland’, which is one that always makes me giggle. He performed one of the most detailed chronologies of time, and the history of the world using dates from the Bible and other historical documents.

V

W

Weathering– The decomposition of a rock while it is sitting in one place. If the little bits of decomposed rock move, then its erosion.

X

Y

Z