Science Flashcards
Law of superposition
When the younger fossils are closer to the top and the older ones are deeper and closer to the bottom
Law of horizontally
The rock layers are horizontal
Law of crosscutting
when the magma cuts through the ground it is younger than the other layers since it has to have something to cut through
The type of rock fossils are most likely found and why
Sedimentary rocks, since they are the most prone to heat and pressure, and sedimentary rocks cover the floor slowly making the layers of rocks where most fossils are found.
What causes intrusions in rock layers
hot magma is less dense so it steeps through the layers causing an intrusion
IGNEOUS ROCKS
Relative dating of rock layers and fossils
When you estimate the age by the lay of superstition
Radiometric absolute dating
A closer actual age because carbon turns into nitrogen during its half life
geological timescale
long period of time separated by mass extinction events
Organism complexity
Over time animals get more features and develop more features to suit there lifestyle
Index fossil
Ex: When you find a Trilobites in the ground you know how old it is by the rock layer.
Strata
stacked up layers of rocks (usually sedimentary)
Fossil
Preserved remains of an organism that lived in the past, and turned into a mold or a cast.
Is this mold or cast:
shapes left in rock
Mold
Mold or cast:
When the original organism was replaced by minerals
Cast
How a fossil forms
When the original organism is replaced by minerals. Molds form when organisms decays leaving its shape; there may also be footprints
