Set 1 scheme for metamorphic rock identification answer key – The Set 1 Scheme for metamorphic rock identification provides a systematic approach to classifying and identifying metamorphic rocks. This scheme utilizes key diagnostic features, including texture, mineralogy, and fabric, to distinguish different metamorphic rock types. Understanding the Set 1 Scheme is essential for geologists and petrologists working in metamorphic terrains.
This comprehensive guide explores the rationale behind the Set 1 Scheme, its key diagnostic features, and the step-by-step procedure for identifying metamorphic rocks using this scheme. Additionally, we discuss the limitations and considerations of the Set 1 Scheme and suggest alternative methods for metamorphic rock identification.
1. Metamorphic Rock Classification
Set 1 Scheme
The Set 1 Scheme is a comprehensive classification system for metamorphic rocks based on their texture, mineralogy, and fabric. It was developed by the International Union of Geological Sciences (IUGS) Subcommission on the Systematics of Metamorphic Rocks and has become widely accepted in metamorphic petrology.
The rationale behind using the Set 1 Scheme lies in its ability to provide a systematic and consistent framework for identifying and characterizing metamorphic rocks. It enables petrologists to accurately describe and compare rocks from different geological settings and to establish relationships between metamorphic processes and the resulting rock types.
2. Key Diagnostic Features
The Set 1 Scheme utilizes several key diagnostic features to identify metamorphic rocks. These features include:
- Texture:Refers to the size, shape, and arrangement of mineral grains in the rock. Grain size, grain shape, and grain boundaries are important criteria for classifying metamorphic rocks.
- Mineralogy:Involves identifying the mineral composition of the rock. The presence or absence of specific minerals, as well as their relative proportions, can provide valuable clues about the metamorphic conditions.
- Fabric:Describes the overall structural arrangement of the minerals within the rock. Fabric elements such as foliation, lineation, and shear zones can reveal information about the deformation and recrystallization processes that occurred during metamorphism.
By carefully observing and interpreting these diagnostic features, petrologists can distinguish between different metamorphic rock types and infer their metamorphic history.
3. Identification Procedure, Set 1 scheme for metamorphic rock identification answer key
The Set 1 Scheme provides a step-by-step procedure for identifying metamorphic rocks:
- Examine the rock’s texture:Observe the grain size, shape, and arrangement of minerals to determine the rock’s texture.
- Identify the mineral composition:Use a petrographic microscope to identify the minerals present in the rock and estimate their relative proportions.
- Analyze the fabric:Look for evidence of foliation, lineation, or shear zones to determine the fabric of the rock.
- Compare the observations to the Set 1 Scheme:Use the diagnostic features and criteria provided in the scheme to match the rock’s characteristics to the appropriate metamorphic rock type.
A flowchart or decision tree can be used to illustrate the identification process and facilitate accurate classification.
Helpful Answers: Set 1 Scheme For Metamorphic Rock Identification Answer Key
What are the key diagnostic features used in the Set 1 Scheme?
The key diagnostic features used in the Set 1 Scheme include texture, mineralogy, and fabric. Texture refers to the size, shape, and arrangement of mineral grains. Mineralogy refers to the mineral composition of the rock. Fabric refers to the preferred orientation of mineral grains.
How do I use the Set 1 Scheme to identify metamorphic rocks?
To use the Set 1 Scheme to identify metamorphic rocks, follow these steps: 1) Observe the texture of the rock. 2) Determine the mineralogy of the rock. 3) Analyze the fabric of the rock. 4) Use the key diagnostic features to identify the metamorphic rock type.
What are the limitations of the Set 1 Scheme?
The Set 1 Scheme is not applicable to all metamorphic rock types. It is primarily designed for identifying common metamorphic rocks found in low- to medium-grade metamorphic terrains. Additionally, the scheme may not be effective for identifying highly altered or deformed metamorphic rocks.
