THE FOURTH DIMENSION

INSTRUCTIONS
GENERAL INTRODUCTION
PART I: ROCKS AND ROCK-FORMING PROCESSES
WHAT IS A ROCK?
HOW DO ROCKS FORM?

Attachment by Intergrowth
Attachment by Cementation
~ ENVIRONMENTS OF ROCK FORMATION ~
Introduction
IGNEOUS
In a Magma Chamber
In a Lava Flow
SEDIMENTARY
In a Deposit of Sediment:
~ Origin by Grain Overgrowth
In a Deposit of Sediment:
~ Origin by Cementation
In a Salt Water Lake
In a Hypersaline Part of the Ocean
METAMORPHIC
Under Heat and Pressure
HOW CAN THE WAY IN WHICH A ROCK FORMED BE DETERMINED?
~ FOUR CLUES TO ROCK ORIGIN ~
1. Rock Mineralogy
Igneous Rocks
Sedimentary Rocks
Metamorphic Rocks
Conclusions
2. Rock Texture
3. Rock Structure
Primary Structures: Layering - 1
Primary Structures: Layering - 2
Other Primary Structures
Secondary Structures
4. Field Relationships
The Secondary Character of Slaty Cleavage
The Origin of Slaty Cleavage
The Origin of Cross-Cutting Rock Bodies
Igneous Origin: Observed and Inferred
Metamorphic Origin: Observed and Inferred
Sedimentary Origin: Observed and Inferred
Conclusions
PART II: ROCKS AND EARTH HISTORY
INTRODUCTION
Time: Introduction
Relative Age
Absolute Age
Unfolding the History of the Earth
Questions and Conclusions
© 2006, David J. Leveson