science3 2
Terms
undefined, object
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- a princible that states the same geologic pocessshaping the earth today have been at work throughout the earths hitory
- uniformation
- a princible that states that all geologic changes occurs suddenly
- catastrophism
- published three volumes of books between 1830 and that reintroduced uniformitarianism
- Charles lyll
- determining wether an object is older or younger than other objects or events
- relative dating
- what are the two types of dating
- relative and absolute
- princible stating that younger rocks lie above older rocks in undisterbed sequences
- superposition
- an ideal sequence of rock layers that contains all the known fossils and rocks from oldest to youngest
- geologic column
-
fault
intrusion
folding
and tilting - disturbed rock layers
- a break in the earths crust
- fault
- molten rock from the earths interior that squezzes into an existing rock and cools
- intrusion
- occurs when rock layers bend and buckle
- folding
- occurs when internal forces in the earth slant rock layers without folding them
- tilting
- a surface thast represents a missing part of the geologic column
- unconformity
- exist where part of a sequence of parallel rok layers are missing
- diconformity
- most common type of unconformity
- disconformity
- exist where sedimetary rock lies on top of eroded surface of non-layered igneous or metamophic rock
- nonconformity
- what are the three types of unconformities
-
disconformitie
nonconformitie
angular unconformity - exists between horizontal rock layers and rock layers that are tilted or folded
- angular unconformity
- a process of establishing the age of an object
- absolute dating
- process by which radioactive(unstable) isotopes break down unto stable isotopes of other elements
- radioactive decay
- atoms of the same element that have the same number of protons but a diffrent number of neutrons
- isotopes
- origanal form
- parent isotopes
- more stable isotopes than the parent isotoope because a neutron is converted into a proton
- daughter isotope
- determining the absolute age of a sample based on the ratio of parent to daughter material
- radiometric dating
- the time it takes for one half of a radioactive sample to decay
- half life
- can be used to date rocks over 10 million years old
- uranium-lead method
- used for rocks older than 100,000 years old
- potassium argon method
- used on materials that lived within the last 50,000 years
- carbon 14 method
- what are the three types of dating methods from oldest to youngest
-
uranium lead
potassum argon
carbon 14 - any naturally preserved evidence of life
- fossil
- minerals that fill the pores and spaces of an organisms tissue
- permineralization
- occurs when an organisms tissues are compleatly replaced by minerals
- petrification
- whats an example of petrification
- petrified wood
- hardend tree sap
- amber
- fast drying organisms that prevent decay
- mummification
- animals and there remains that have been found in frozen glaciers
- frozen fossils
- natural, occurs in sticky , think pools of ____
- tar
- any naturally preserved evidence of an animals activity
- trace fossils
- ways things can be fossilized
- tar, amber, mummification, foxen, and trace fossils
- a cavity inthe ground or rock where an animal was buried
- mold
- an object that is created when sediment fills a mold and becomes a rock
- cast
- how fossils interpret the past
- changes in the enviorment and changes in life
- fossils of organisms that lived during a rather short but well defined life span
- index fossils
- a scale that divides earths 4.6 billion year history into distinctive intervals of time
- geologic time scale
- the largest divison of time
- eons
- second largest period of time
- eras
- third largest divison of time
- periods
- the forth largest divison of time
- epoch
- 4.6 billion-3.8 billion years ago
- hadon eon
- 3.8 billion- 2.5 billion years ago
- archean era
- 2.5 billion-540 million years ago
- proterozoic era
- 540 million years ago to the present
- phenerozoic eon
- what is the eon that we are living in
- phanerazoic
- "old life" lasted from 540 million years ago - 248 million years ago
- paleozoic era
- "middle life" lasted from 248 million years ago - 65 million years ago
- mesezoic era
- "recent life" 65 million years ago - the present
- cenezoic er