Historical Geology Flashcards

Questions and Answers

What is the principle of original horizontality?

The Principle of Original Horizontality states that layers of sediment are originally deposited horizontally under the action of gravity.

What is the principle of lateral continuity?

The principle of lateral continuity states that layers of sediment initially extend laterally in all directions.

Does age generally increase or decrease with depth?

Age generally increases with depth.

What do original horizontality, lateral continuity, and age-depth relationship tell us about deformed rocks?

They indicate the magnitude and sometimes direction of the rock's movement. Signup and view all the answers

What is a cross-cutting relationship?

Cross-cutting relationships state that the geologic feature which cuts another is the younger of the two features. Signup and view all the answers

What is relative age dating?

Relative dating is the science of determining the relative order of past events without necessarily determining their absolute age. Signup and view all the answers

What is inclusion in geology?

Inclusion is when a different kind of rock is found within another rock. Signup and view all the answers

Know how to date geologic features and structures relative to one another, describe the processes that may have caused certain features or structures to occur, and ____.

reconstruct the geologic history of an area using a combination of relative age dating and knowledge of the processes that form different structures/features. Signup and view all the answers

Study Notes

Principles of Geology

Original Horizontality: Suggests sediment layers are initially deposited horizontally due to gravity, important for analyzing folded or tilted strata.
Lateral Continuity: Indicates sediment layers extend continuously in all directions unless interrupted by erosional features like valleys; similarities in separated rocks imply original continuity.

Age-Depth Relationship

Age vs. Depth: Rock age generally increases with depth; deeper formations tend to be older.

Interpretation of Deformed Rocks

Deformation Analysis: When original principles are violated in deformed rocks, it reveals magnitude and direction of rock movement, indicating the types and extent of geological changes.

Cross-Cutting Relationships

Geological Dating: This principle posits that the feature which cuts another is younger, thus aiding in relative dating and understanding geological timelines.

Relative Age Dating

Understanding Relative Age: This method determines the sequence of geological events and ages of objects relative to each other without defining absolute ages. It involves assessing rock ages in the context of neighboring formations.

Inclusions

Inclusion Significance: Represents a scenario where one rock type is enclosed within another. This implies that the surrounding rock is younger than the rock encased within it.

Skills in Geology

Dating Features: Ability to date geological structures in relation to one another.
Feature Analysis: Describe processes responsible for the formation of geological features.
Geologic History Reconstruction: Combine relative dating techniques with knowledge of geological processes to reconstruct the historical context of an area.

Description

This quiz covers key principles in historical geology, focusing on the principles of original horizontality and lateral continuity. These concepts are essential for understanding sediment deposition and the geological timeline. Test your knowledge with these flashcards to enhance your learning in geology.