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56 Cards in this Set

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a princible that states the same geologic pocessshaping the earth today have been at work throughout the earths hitory
a princible that states that all geologic changes occurs suddenly
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
an ideal sequence of rock layers that contains all the known fossils and rocks from oldest to youngest
geologic column
and tilting
disturbed rock layers
a break in the earths crust
molten rock from the earths interior that squezzes into an existing rock and cools
occurs when rock layers bend and buckle
occurs when internal forces in the earth slant rock layers without folding them
a surface thast represents a missing part of the geologic column
exist where part of a sequence of parallel rok layers are missing
most common type of unconformity
exist where sedimetary rock lies on top of eroded surface of non-layered igneous or metamophic rock
what are the three types of unconformities
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
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
minerals that fill the pores and spaces of an organisms tissue
occurs when an organisms tissues are compleatly replaced by minerals
whats an example of petrification
petrified wood
hardend tree sap
fast drying organisms that prevent decay
animals and there remains that have been found in frozen glaciers
frozen fossils
natural, occurs in sticky , think pools of ____
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
an object that is created when sediment fills a mold and becomes a rock
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
second largest period of time
third largest divison of time
the forth largest divison of time
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
"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