Part 2 Flashcards
Do present day species occur naturally on both sides of the Atlantic?
There are not many present day species that occur on both sides of the Atlantic without human interference
What is the correct hierarchy of time divisions of geological time from longest to shortest?
Eon
Era
Period
Epoch
What does evidence from fossils show about the relation of flora and fauna on both sides of the Atlantic?
It shows evidence that the same species of flora and fauna were found on both sides of the Atlantic
What are the three basic kinds of rock?
Sedimentary
Igneous
Metamorphic
What is sedimentary rock?
Sedimentary rock has formed from accumulations of material (derived either from fragments of older rocks or from shells and he like)
What is igneous rock?
Those that formed from an originally molten state
What are metamorphic rocks?
Those that are originally sedimentary or igneous rocks but have been greatly changed by the subsequent effects of pressure or a later hearing event
How could geologists work out the relative ages of rocks? What is the easiest type of rock to age?
Sedimentary rock is the easiest to determine by age
Layer of sedimentary rock deposit one on top of the other as sheets of sediment using the principle that a younger layer ought to overlie and older layer rather than the reverse
What are ‘periods’ in terms of the geological time scale?
It is a division in a geological time scale
It is divided in to unequal chunks called periods
Based mainly on the different kinds of fossils that could be found in rocks of different ages
What percentage of time does the Precambrian era represent?
90%
What is the youngest eon of the Precambrian eon?
Proterozoic
What is he name of the eon that signifies visible life?
Phanerozoic
How many eras are there divided in to the Phanerozoic eon?
3
Paleozoic, Mesozoic, cenozoic
How many eons make up the Precambrian eon?
3
Proterozoic
Archean
Hadean
What periods make up the Palaeozoic era?
Permian Carboniferous Devonian Silurian Ordovician Cambrian
What periods make up the Mesozoic era?
Cretaceous
Jurassic
Triassic
What periods make up the cenozoic era?
Quaternary
Neogene
Palaeogene
What can periods in the geological timescale be subdivided in to?
Epochs
What can eons be subdivided in to?
Eras
What is radiometric dating?
It is the ageing of time periods in he geological time scale by measuring the products of radioactive decay within rocks and minerals
What is Pangea?
It is a theory that the land on earth was formerly united in a single supercontinent called pangea
Throughout time the continents moved through continental drift
What is paradigm shift?
It is the fundamental change in approach or underlying assumptions in the whole field of science
For example Pangea and continental shift was not believed until new information came forward about plate tectonics … this changed everything
