GEOL 462: Principles of Sedimentology and Stratigraphy

Lecture 04: Thursday, January 22, 2009

Topics
1. Weathering processes and soil formation
2. Transportation media
3. Basic fluid dynamics: flow and particle movement
4. Bernoulli effect and Hjulstrom diagram
5. Current ripples and cross laminations

Weathering processes and soil formation
• Types of weathering processes and products
• Weathering, erosion, and facies migration: the formation of stratigraphic discontinuities
• Controlling factors of physical and chemical weathering
• Soil-forming processes
• Basic soil profiles
• Characteristics useful for paleosol identification
• Weathering, erosion, and climate changes
• Concept of carbon cycle?

Transportation media
• A basic Understanding of the transport capacity of different transportation media

Basic fluid dynamics: flow and particle movement
• Three types of particle motion in flows
• The relationship between flow velocity and particle mass
• The change of motion due to velocity change

Bernoulli effect and Hjulstrom diagram
• Understand the Bernoulli effect and its implications for entraining particles in a flow
• Understand the meanings of the different regions in the Hjulstrom diagram
• Clay minerals need almost zero velocity to be transported, why do they appear in some sandy environments?
• What is the differences between graded bedding and coarsening/fining upward trends?

Current ripples and cross laminations
• How are current ripples formed?
• How are planar and trough cross laminations formed ?
• How are climbing ripples formed ? What are the potential environments for climbing ripples?
• What can be the depositional environments for current ripples? Why?