Physical Geology - Sedimentary Rocks Overview

Course Information

  • Course Title: GEOL 1403-012

  • Course Type: Lab (Physical Geology)

  • Semester: Fall Semester

Key Concepts in Sedimentary Rocks

1. Chert

  • Definition: Chert is a sedimentary rock that appears to have a distinctive "waxy" look and possesses similar physical properties to the mineral quartz.

  • Formation:

    • Can form as a crystalline chemical rock.

    • Typically deposited from groundwater.

  • Identification Challenges: Without proper context, identifying the source or origin of chert can be extremely challenging.

2. Coal

  • Composition: Coal is primarily composed of carbon that originates from compressed plant debris.

  • Formation Environment:

    • Occurs in wetland or mire environments where the organic material is subjected to burial.

    • The process involves chemical alteration during burial conditions.

  • Physical Characteristics:

    • Color: Typically black to brown, though variations exist.

    • May exhibit small amounts of minerals including calcite, sulfur, or pyrite.

    • Texture: Depending on the variety, coal can show noticeable differences, such as alternating dull/dusty and bright/shiny layers.