Exploring Geologic History

This video tutorial from the Earth Science Department at Cretive Bomic Middle School covers the concept of geologic history, focusing on relative age and the sequence of events in Earth's history. It explains key principles such as uniformitarianism, original horizontality, and superposition, which help in understanding geologic dating. The tutorial also discusses cross-cutting relationships, including intrusions and extrusions, and the principle of inclusions. Finally, it addresses unconformities, which indicate gaps in the geologic record due to processes like uplift, erosion, and subsidence.

What is the primary focus of geologic history?

• Examining the Earth's core

• Analyzing the composition of rocks

• Understanding the sequence of events in Earth's history

• Studying the age of the Earth

What does the principle of uniformitarianism state?

• The present is the key to the past

• The present is the key to the future

• The future is the key to the past

• The past is the key to the future

According to the principle of superposition, which rock layer is the oldest?

• The layer with fossils

• The top layer

• The middle layer

• The bottom layer

What is an intrusion in geologic terms?

• Magma that cools and solidifies within existing rock

• A layer of rock that forms on the Earth's surface

• A type of sedimentary rock

• A type of fossil

What is contact metamorphism?

• The folding of rock layers

• The process of rock formation through sedimentation

• The breaking of rock layers by faulting

• The alteration of rock by intense heat from magma or lava

What is the principle of inclusions?

• Older rocks are found at the bottom

• Younger rocks are found at the top

• Fragments within a rock are older than the rock itself

• Rocks are laid down in horizontal layers

Which process is always younger than the rock it affects?

• Folding

• Sedimentation

• Erosion

• Weathering

What is an unconformity in geology?

• A type of fossil

• A gap in the geologic record

• A type of rock layer

• A volcanic eruption

What is the first step in the formation of an unconformity?

• Deposition

• Erosion

• Uplift

• Subsidence

In the given example, which rock layer is the oldest?

• Sandstone

• Shale

• Limestone

• Intrusion C