Ch4 Flashcards
A Hollow area in sediment in the shape of an organism or part of an organisms
Mold
Preserved remains or traces of living things
Fossils
A solid copy of the shape of an organism
Cast
Fossils in which minerals replace all of an organism or a part such as a dinosaur bone
Petrified fossils
Extremely thin coating of carbon on rock
Carbon film
Provides evidence of the activities of ancient organisms
Trace fossils
Scientists who study fossils are called
Paleontologist
The change in living things over time
Evolution
No longer exists and will never again live on earth
Extinct
A rock is it’s age compared to the ages of other rocks
Relative age
A rock is the number of years that have passed since the rock formed
Absolute age
Determine the relative age of sedimentary rock layers
Law of superstition
Lava that hardens on the surface and forms igneous rock
Extrusive
Magma cools and hardens into a mass of igneous rock
Intrusive
A break in earths crust
Fault
A fossil must be widely distributed and represent an organism that excited for a geologically short period of time
Index fossil
A gap in the geologic record
In conformity
These elements release particles and energy in this process
Radioactive decay
A radioactive elements is the time it takes for half of the radioactive atoms to decay
Half life
A record of the geologic events and the evolution of life forms as shown in the fossil record
Geologic time scale
Time and present are split into three long units of time called
Eras
Eras subdivides into units of geologic time called
Periods
The key principles that guide scientists when the make inferences about earths past is the principle of
Uniformitarianism
