Rock On!

Rock On! Presentation by: Maive Falconer Ada Topaz Rascon

Rock on!

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Learning Objectives • Explain the phases of the rock cycle and identify the 3 main types of rocks it forms • Identify basic rock types based on their physical and chemical properties Aligned with PDE standards:

S11.D.1.1.1 Classify and describe major types of rocks (i.e., igneous – granite, basalt, obsidian, pumice; sedimentary – limestone, sandstone, shale, coal; and metamorphic – slate, quartzite, marble, gneiss) and minerals (e.g., quartz, calcite, dolomite, clay, feldspar, mica, halite, pyrite) by their origin and formation. Rock on!

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What is a Rock? • Definition: a solid mass of mineral or mineral-like matter that occurs naturally • 3 main types: igneous, sedimentary, metamorphic • Basic characteristics for identification: texture, mineral composition, color

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Rock Cycle Processes • The rock cycle describes the continuous processes that cause rocks to change and form • These processes include: Erosion Deposition Heat and pressure Melting Volcanic activity Cooling Rock on!

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The Rock Cycle

Molten rock beneath the surface is called “magma.” When magma reaches the surface through volcanic vent it is called “lava.”

Cooling – As magma & lava rise toward the surface, they cool & solidify, forming Igneous Rock

Erosion – surface rock is broken down into sediments by wind, water chemicals, & biological activity

Deposition – Sediments are dropped by wind or water, then compacted and cemented, forming Sedimentary Rock

Melting – increased pressure & heat deep inside the earth causes the rock to melt, forming molten (liquid) rock

Extreme heat & pressure beneath surface transform sedimentary rocks to Metamorphic Rock

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As layers of sedimentary rock build up, older layers are pushed down beneath the earth’s surface

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Basic properties used in rock identification 1.)Texture – arrangement of materials in the rock as follows: • Crystalline – size and placement of visible crystals within the rock • Frothy or Vesicular – rock contains pores, spaces or vesicles • Glassy – shiny, solid (non-crystalline) glassy texture • Fine or course grained – fragments in the rock are visible (course grained) or can only be seen with a hand lens (fine grained) • Layered – rock has visible evidence of layers • Banded – layers within the rock show distinctive differences in thickness, color or texture. 2.) Composition – minerals and other materials that form the rock • Specific types of minerals and mineral compounds • Form of the minerals (whole pieces, dissolved, precipitated particles) • Fossils • Clay

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Comparison of Basic Rock Types Property

Igneous

Sedimentary

Metamorphic

Origin

Extrusive – on surface Intrusive – beneath surface

Clastic – formed from physically weathered sediment Chemical – formed from mineral precipitates

Foliated – magma moves into rock and cools Nonfoliated – magma forms into a solid mineral vein

Texture

Extrusive – large crystals, course grain,

Clastic – crystal and grain depend on mineral composition and can vary greatly within the same rock

Foliated: Slate – very fine grain, smooth dull surface Phyllite – fine grain w/ glossy surface Schist – med. to course grain w/ layering Gneiss – med to course grain w/ banding Nonfoliated: Marble – med to course interlocking grains Quartzite – med. to course fused grains Anthracite – fine grained shiny/glassy texture

Intrusive – small crystals, fine grained or glassy extrusive - fine Banding indicates varied age and rates of cooling

Major Composition features

Granitic –, light colored silicate minerals Basaltic – dark colored silicate minerals

Chemical – most are fine grained w/ small crystals (i.e.. limestone, chalk, coquina, bituminous coal). Those made from quartz, gypsum, halite and NaCL can have course texture w/ large crystals.

Clastic – clay minerals and quartz Chemical – Calcite, CaC03, Quartz, Gypsum, Halite, NaCl, altered plant fragments Rock on!

Foliated – shale, slate, granite, volcanic rock Nonfoliated – limestone, quartz, bituminous coal 7

Sedimentary Rock

sandstone conglomerate

Coral

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Igneous Rock

Feldspar

Peridot

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Metamorphic Rock

Non-foliated (anthracite)

Foliated

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