Chapter 1: Problem 8

Describe three kinds of relationships between two bodies of rock that indicate which of the two bodies is the younger one.

Short Answer

Expert verified

In order to determine the younger rock body, we can use the following three geological principles: 1. Law of Superposition: In a sequence of sedimentary rocks, the rock body that is higher in the sequence is the younger one. 2. Cross-Cutting Relationships: If a rock body cuts across another, the one that cuts across is the younger one. 3. Inclusions: If one rock body has inclusions of the other rock body, the rock body with the inclusions is the younger one.

Step by step solution

1. Law of Superposition

The law of superposition states that in a sequence of undeformed sedimentary rocks, the oldest rocks are at the bottom, and the rocks become progressively younger as we move towards the top. To apply this principle, we need to identify the sequence of rock layers and see which one of the two rock bodies is at the top or bottom. The rock body that is higher in the sequence is the younger one.

2. Cross-Cutting Relationships

The principle of cross-cutting relationships states that a geological feature (such as a fault or an intrusion of magma) that cuts across another geological feature must be younger than the feature it cuts. To apply this principle, we need to examine the relationships between rock bodies and look for any features that cross-cut others. The rock body that cuts across another is the younger one.

3. Inclusions

The principle of inclusions states that fragments or pieces (inclusions) of one rock type found within another rock are older than the rock they are found in. To apply this principle, we need to identify any inclusions within the rock bodies and compare their ages. If one rock body has inclusions of the other rock body, then the rock body with the inclusions is the younger one.

Unlock Step-by-Step Solutions & Ace Your Exams!

Full Textbook Solutions
Get detailed explanations and key concepts
Unlimited Al creation
Al flashcards, explanations, exams and more...
Ads-free access
To over 500 millions flashcards
Money-back guarantee
We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

Recommended explanations on Geography Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Describe three kinds of relationships between two bodies of rock that indicate which of the two bodies is the younger one.

Short Answer

Step by step solution

1. Law of Superposition

2. Cross-Cutting Relationships

3. Inclusions

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Geography Textbooks

Geographical Skills

Migration and Identity

Changing Economic World

Superpowers of the World

Living With The Physical Environment

Globalisation

Study anywhere. Anytime. Across all devices.