May 09, NOTES Metamorphpic Rocks.notebook. change. form. pre-existing. application HEAT. oldest. Pressure. metamorphic rock. pressure.

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1 (are nice) Name originates from Greek: Meta = form Morphe = change pre-existing Formed when any other rock igneous sedimentary metamorphic type (,, or ) is changed into a new form by the of HEAT application PRESSURE and oldest Earth s rocks are metamorphic rocks. The bedrock known as the Canadian Shield is estimated Pressure metamorphic rock 4 billion to be years old. Heat and are normally a result of during formation. Therefore, most metamorphic rocks are found in regions such as the and the range. Heat pressure deep burial mountain mountainous Adirondacks Taconic Heat and result in the formation new crystals of or the existing of crystals in a process known as recrystallization pressure. This occurs Stays in the state of matter realignment WITHOUT MELTING solid 1

2 Changes in rocks that have undergone metamorphism include: 1. (chemical change) Changes in rocks that have undergone metamorphism include: 2. Increased mass density volume More in a given Changes in rocks that have undergone metamorphism include: BANDING 3. Arrangement of aligned in banded layers minerals Bands formed when rock subjected to heat PRESSURE extreme and Jun 16 8:09 AM 2

3 Banding normally a result of Lithostatic pressure Pressure applied equally in directions deep as a result of burial. all Changes in rocks that have undergone metamorphism include: 4. structure, curving, and/or bands. Distorted Wavy folded shape smaller Retains, only Result of extreme pressure in two different directions Foliated 1. Types of parallel Mineral crystals arranged in layers (banded or deformed) Can break into Foliated 1. Types of Mineral crystals arranged in layers (banded or deformed) sheets Can break into parallel Gneiss Add to notes: "Slaty cleavage" 3

4 Like the pages of a book... May 10 2:38 PM Quick review -- FOLIATED TEXTURE Minerals rearranged in a parallel or layered fashion Low Grade = tiny mineral grains that 'cleave' easily High Grade = coarse grains -- easily seen banding Nonfoliated 2. NOT Types of Do have. NOT bands Will break into. uniform sheets Often have a appearance and are somewhat (or very). shiny ("sugary") Jan 27 4:58 PM Quick review -- NONFOLIATED TEXTURE Quartzite Mineral grains = no preferred orientation (no banding) Anthracite Coal Instead...a mosaic of roughly equidimensional minerals (large grain size result of recrystallization) Jan 27 4:58 PM 4

5 SUMMARY : Banding Distorted (wavy) Looks like it would break into sheets (slaty cleavage) Uniform in color and crystal sizes Contact 1. Temperature Types of Metamorphism heat ( ) is the primary factor. Occurs when surrounding rocks come in material border with molten. Normally occurs along the between intrusions contact igneous and other rock types. May 1 2:39 PM Discontinuity (Unconformity) Regional 2. Temperature Types of Metamorphism Both (heat) and play a role. Normally occurs at tectonic plate boundaries. large convergent pressure Usually cover areas (for example, Himalayas) 5

6 NOTES Metamorphpic Rocks.notebook parent rock (original rock) will determine the The metamorphic rock. Table 1: Foliated Shale Shale () parent rock (original rock) will determine the The metamorphic rock. Table 1: Foliated (Metamorphic) Metamorphic Shale Schist 6

7 NOTES Metamorphpic Rocks.notebook (Metamorphic) Shiny Schist (Metamorphic) Granite (Igneous) parent rock (original rock) will determine the The metamorphic rock. Table 1: Foliated Metamorphic Igneous Shale Granite Schist Gneiss Gneiss (Metamorphic) Limestone () Table 2: Nonfoliated Limestone Marble Marble (Metamorphic) 7

8 Table 2: Foliated Limestone Quartz sandstone Marble Quartzite May 2 1:12 PM Quartz sandstone (Sed) Quarzite (Met) May 2 1:12 PM Table 2: Nonfoliated Bituminous coal (Sed) Limestone Quartz sandstone Bituminous coal Marble Quartzite Anthracite coal Anthracite coal (Met) 8

9 NOTES Metamorphpic Rocks.notebook May 2 1:13 PM 100% mica 100% Carbon 100% Quartz 100% Calcite Which one is quartzite, which is marble? Grain size May 2 6:17 PM Which one is quartzite, which is marble? Acid test May 2 6:17 PM 9

10 Marble May 9 7:49 AM Phyllite (fine vs. medium) Schist May 9 7:49 AM 10

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