7-GO Sedimentary Rx Properties
Page 1: Sediments and Sedimentary Rocks
Introduction to sediments and the process of sedimentation leading to the formation of sedimentary rocks.
Page 2: Clastic Sedimentary Rocks
Definition: Clastic sedimentary rocks consist of grains transported by natural processes.
Grain Size Relationship:
Large grains indicate high energy environments (e.g., fast rivers).
Small grains correlate with low energy settings (e.g., quiet waters).
Page 3: Examples of Clastic Sedimentary Rock
Shale: Formed from clay particles, resulting in fine-grained texture.
Sandstone: Comprised of sand from beaches or dunes, often visible grains.
Conglomerate: Contains rounded rock fragments, indicative of more aggressive transportation.
Breccia: Composed of angular rock fragments, suggesting minimal transportation.
Page 4: Biogenic and Chemical Sedimentary Rocks
Overview of how biogenic processes and chemical precipitation contribute to sedimentary rock formation.
Page 5: Biogenic Sedimentary Rocks
Composition: These rocks form from biological materials like shell fragments and plant matter.
Example: Limestone - derived from ancient coral reefs (e.g., Guadaloupe Mountains, Texas).
Bituminous Coal: Formed from decomposed plant material.
Page 6: Biogenic Sedimentary Rocks
Skeletal Limestone: Composed of fragmented shells of marine organisms.
Chalk: Formed from microscopic marine organism remains.
Coquina: Rock comprised of loosely cemented shell fragments.
Page 7: Chemical Sedimentary Rocks
Types of Chemical Rocks:
Gypsum: A sulfate mineral.
Travertine: A form of limestone that precipitates from calcium carbonate.
Rock Salt: Composed of halite (sodium chloride).
Chert: Hard, dense sedimentary rock composed primarily of silica.
Page 8: Grain Size and Composition of Clastic Rocks
Grain Sizes:
Clay: <0.0039 mm
Sand: 0.063 mm to 2 mm
Silt: Intermediate size range.
Composition Listed: Identifying minerals like quartz, feldspar, and clay as part of clastic rocks.
Page 9: Sedimentary Rock Analysis and Classification Steps
Composition: Identify materials that make up the rock (e.g. clastic, biochemical).
Texture Properties: Examine texture, shape and angularity of grains.
Rock Naming: Based on previous analyses (e.g., Breccia for angular rocks, Conglomerate for rounded rocks).
Page 10: Detrital (Clastic) Sedimentary Rock Analysis
Step 1: Composition determination focusing on weathered materials.
Step 2: Texture analysis for determining rounded vs angular grains.
Step 3: Assign name to the rock based on criteria.
Page 11: Detrital Sedimentary Rocks Overview
Charting: Summarizing the different types of detrital rocks based on particle size:
Conglomerate (coarse, rounded), Breccia (angular), Sandstone, Siltstone, Shale.
Page 12: Chemical, Biochemical, and Organic Sedimentary Rocks Overview
Discusses classification based on composition and texture:
Inorganic and organic sedimentary rocks based on texture and minerals present.
Page 13: Detrital and Organic Sedimentary Rocks Classification
Lists the rock names and composition parts through various categories, helping identify specific sedimentary types through their grain and chemical structure.
Page 14: Sedimentary Rock Data Chart Sample
Provides a guideline for recording different sedimentary rocks based on their composition and classification types (clastic, chemical, or biochemical).
Example: Rock identification based on grain size and composition.