Outcrop Description

Systematic outcrop description ensures consistent, complete documentation. Description Sequence Follow a consistent order: 1. Rock type and name 2. Color fresh and weathered 3. Grain size and texture 4. Mineralogy 5. Fabric/structure 6. Alteration 7. Mineralization 8. Relationships and contacts Rock Type Classification Igneous Grain size, texture porphyritic, aphanitic , mineral assemblage. Sedimentary Grain size, sorting, bedding features, fossil content. Metamorphic Foliation, metamorphic grade, protolith interpretation. Weathering Assessment Describe weathering grade: - Fresh: no visible alteration - Slightly weathered: discoloration on fractures - Moderately weathered: partial decomposition - Highly weathered: completely discolored - Completely weathered: soil-like

All lessons in Field Mapping — Return to the complete Field Mapping course outline.
Previous lesson: Compass and Clinometer Use — The geological compass is the primary tool for measuring structural orientations. Strike and Dip Strike The horizontal line formed by the intersection of…
Next lesson: Contact Relationships — Understanding contact relationships is critical for interpreting geological history. Contact Types Sharp Contacts - Intrusive contacts: igneous rock cuts…

Verification resources

Cross-check terminology, classification, methods, and safety with these authoritative external resources.

Geoscience maps — Natural Resources Canada. Government bedrock, surficial, geochemical, glacial, and hazard map resources.
National Geologic Map Database — U.S. Geological Survey. Geologic maps, reports, standards, and mapping resources from geological surveys.

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Outcrop Description

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Verification resources