What is strata?
Q: What is strata?
A: Strata are layers of rock or soil.
Q: What is the study of strata called?
A: The study of strata is called stratigraphy.
Q: How are strata formed?
A: Strata are formed by sediment being slowly changed by pressure, heat and chemical action into rocks.
Q: How can geologists use strata to relate rocks in different places?
A: Strata are often typical of a particular time and place, which allows geologists to relate rocks in different places. For example, chalk was laid down in the Upper Cretaceous period and consists mainly of the remains of microscopic algae called coccoliths.
Q: What causes gaps in the sequence of strata?
A: Gaps in the sequence of strata can be caused by erosion such as weather when they rise above sea level, or from huge forces such as volcanism or orogeny (mountain building).
Q: What do geologists call these gaps?
A: Geologists call these gaps unconformities.
Q: How do changes to Earth's history affect the sequence of strata?
A: Changes to Earth's history can cause deformation to sedimentary rocks which requires research to work out what has happened to the strata.
