Vocab Flashcards
The preserved remains or traces of an organism that lived in the past.
fossil
A type of fossil that is a hollow area in sediment in the shape of the organism or part of the organism.
mold
A fossil that is a solid copy of an organism’s shape, formed when minerals go into mold.
cast
A fossil in which minerals replace all or part of an organism.
petrified fossil
A type of fossil consisting of an extremely thin coating of carbon on rock.
carbon film
A type of fossil that provides evidence of the activities of ancient organisms.
trace fossil
Change over time; modern organisms descending from ancient ones.
evolution
Group of related organisms that has died out and has no living members.
extinct
the age of rock compared to other ages of rock.
relative age
The age of rock given as the number of years since rock formed; radio active dating
absolute age
The geologic principle that states that in horizontal layers of untouched sedimentary rock, the oldest layer is at the bottom and each layer is younger going up.
law of superposition
An igneous rock layer formed when lava flows onto Earth’s surface and hardens.
extrusion
An igneous rock layer formed when magma hardens underneath Earth’s surface.
intrusion
A break in Earth’s crust along which rocks move.
fault
Organisms that lived in many different places for a short amount of time fossils can be used as?
index fossils
A gap in the geologic record; layers lost due to erosion
uncomformity
atoms of one element break down to form atoms of another element.
radio-active decay
Time it takes for half of the radio-active atoms to decay.
half life
One of the 3 long units of time between Precambrian time and present.
(Think eras tour- big collection of all albums)
era
One of the units in geologic time in which scientists divide eras.
(Think T Swift albums she plays at eras tour)
period
A loose collection of ice and dust that orbits the sun typically in a long narrow orbit.
comet
How old is earth and moon?
4.6 Billion
First atmosphere gases?
Hydrogen + Helium
Blown away by solar winds- end
2nd atmosphere gases?
Carbon dioxide, water vapor, nitrogen
Volcanoes + comet collisions- how they got there
What era and period are we living in now?
Era- Cenozoic era
Period- Quaternary
Photosynthesis on Earth+ what did it do?
Produced oxygen
formed Ozone layer
cooled earth
organisms can live on land
2 types of evidence the fossil record provides?
Past environment and climate
changes in organisms
What is absolute age? 6.25 % of carbon 14 ( 5,730 years)
22,920 years old
