A Trip Through Geologic Time Flashcards
What is sedimentary rock
The type of rock this is made of hardened sediment.
Fossils in which minerals replace all or part of an organism are called?
Petrified fossil
What are the preserved remains or traces from a living thing?
Fossil
________is the process by which all living things change over time
Evolution
When a species no longer exists on Earth, we call it _________.
Extinct
What is a paleontologist?
A scientist who studies fossils.
What provides evidence of the activities of ancient organisms?
Trace fossils
What is a mold?
A Hollow area in sediment in the shape of an organism or part.
Organisms with little or no change
Preserved remains
What is a cast
A cast is a solid copy of the shape of an organism. A cast is the opposite of a mold.
A scientific theory is……..
A well-tested concept that explains a wide range of observations
What is a petrified fossil?
They are fossils in which minerals replace part or all of an organism.
What is an extremely thin coating of carbon on rock?
Carbon film
What is law of superposition?
The law of superposition is used by geologists to determine the relative ages of sedimentary rock layers.
_______ ____ is the age of a rock given as the number of years since it was made.
Absolute age
The surface where new rock layers meet a much older rock surface beneath them is called an __________
Unconformity
An _______ is always younger than the rock layers around and beneath it.
Intrusion
Beneath the surface, magma may push into bodies of rock. There, the magma cools and hardens into mass of igneous rock called intrusion.
What is the relative age of a rock?
The age of a rock compared to the ages of other rocks.
A _____ is a break in Earth’s crust.
Fault
The Mesozoic ___ is the Age of Reptiles.
Era
One of the three long units of geologic time between the Precambrian and the present.
Eras are subdivided into units of geologic time called _______.
Periods
The process where elements break down or decay by releasing particles or energy is called?
Radioactive decay
What is a geologic time scale?
A geologic timescale is a scale of time periods to show Earth’s history.
_______ create all mater including rocks
Atoms
Atoms create all matter including rocks
Certain fossils, called _____ ______, help geologists match rock layers.
Index Fossils
To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed only briefly.
What is a half-life?
The rate of each radioactive element’s decay.
What is extrusion?
Extrusion is lava that hardens on the surface.
What is a warm-blooded vertebrate that feeds it’s young with milk?
Mammal
What has scaly skin, lays eggs with tough, leathery shells?
Reptiles.
What is a ball of dust and ice that orbits the sun?
Comet
The ice in a comet consists of water and frozen gases, including Carbon Dioxide.
_________ _________ moves a few centimeters per year.
Continental drift
