geological timescales Flashcards
(13 cards)
geological timescales definition
The geological timescale is the “calendar” for events in the Earth’s history.
how old is the Earth?
4.6 billion years old.
what period are we in now?
The Quaternary period (the last 2.6 million years).
interglacial definition
Warmer periods within ice ages.
glacial definition
Colder periods within ice ages.
what was the supercontinent called that existed 240m years ago?
Pangea.
continental drift definition
When the positions of continents have shifted.
who discovered continental drift?
Alfred Wegner.
what are the four different types of evidence of continental drift?
jigsaw
glacial scrapings
fossils(plants and animals)
mountain ranges
jigsaw-
The coastlines of multiple different continents fit together like a jigsaw puzzle.
glacial scrapings-
Multiple different continents had glacial scrapings and were mainly continents in the south.
fossils (plants and animals)-
Similar fossils and plants are found in continents that are extremely far apart.Land animals cannot cross continents by water.
mountain ranges-
Similar mountain ranges are found in different countries that are close, but seperated by water.
