Rocks & Minerals

Rock Cycle - Geological processes the form rocks

Karl Schleicher 3/23/2023

Sedimentary Environments

Regional and Contact Metamorphism

Igneous Environments

Intrusive, Extrusive

Lithification - cementation and pressure converts sediments to rock

• Sand -> Sandstone

HGMS 50 -> HGMS 26

• Clay ->Shale

HGMS 17

50. SAND - unknown location

This is pure quartz sand which would be suitable for glass manufacture. Most sand, like what you find in Galveston, has too many non-quartz grains in it for glass making. Put sedimentary rock sand into Google. Sand is used in the manufacture of cement and as a binder for concrete in buildings and roadways.le for glass manufacture. Most sand, like what you find in Galveston, has too many non-quartz grains in it for glass making. Put sedimentary rock sand into Google. Sand is used in the manufacture of cement and as a binder for concrete in buildings and roadways.Sand is mostly quartz, Silicon Dioxide, SiO2, the most common mineral.

26. SANDSTONE — Arkansas and Texas

Sandstone is a sedimentary rock that is made up of visible grains of mostly quartz. sand, other minerals and small rock fragments with a small amount of quartz cement. Put sandstone photomicrograph into Google and sec the fine structure of sandstone.Sand is mostly quartz, Silicon Dioxide, SiO2, the most common mineral.

17. SHALE - Texas or Pennsylvania

Shale is a sedimentary rock that is made up of very small clay and silt particles. Put shale. photomicrograph into Google and see the fine structure in shale. Black shale also contains abundant organic matter, which can be a source for hydrocarbons if buried deeply and heated to the right temperature.

Metamorphism due to pressure and temperature

• Sandstone -> Quartzite

HGMS 26 -> HGMS 21

Sand is mostly quartz, Silicon Dioxide, SiO₂, the most common mineral.

• Shale -> Slate -> Garnet Schist

HGMS 17 -> HGMS 18 -> HGMS 22

• Limestone -> Marble

HGMS 19 -> HGMS 20

Metamorphism due to pressure and temperature

26. SANDSTONE — Arkansas and Texas

Sandstone is a sedimentary rock that is made up of visible grains of mostly quartz. sand, other minerals and small rock fragments with a small amount of quartz cement. Put sandstone photomicrograph into Google and sec the fine structure of sandstone.

21 QUARTZITE - Texas

Heat and pressure will convert (metamorphose) sandstone into quartzite by strongly cementing the grains together. The bond is so strong that a fracture will break across the sand grains rather than around them. The purple samples come from the Brazos River. I have broken each pebble, Quartzite has almost no commercial use. Put quartzite rock into Google to see examples.

Metamorphism due to pressure and temperature

17. SHALE - Texas or Pennsylvania

Shale is a sedimentary rock that is made up of very small clay and silt particles. Put shale. photomicrograph into Google and see the fine structure in shale. Black shale also contains abundant organic matter, which can be a source for hydrocarbons if buried deeply and heated to the right temperature.

18. SLATE - Maine

Heat and pressure will convert (metamorphose) shale into slate. The metamorphism creates mica flakes perpendicular to the pressure applied to the rock. The slate splits easily along the mica, A common use for slate is flooring or roofing for houses. See slate uses to find other uses.

Metamorphism due to pressure and temperature

19 LIMESTONE — Texas

Limestone is a sedimentary rock that is primarily composed of calcium carbonate. Frequently the calcium carbonate is the skeletons of microscopic animals. This rock will fizz in 5% hydrochloric acid. Put limestone photomicrograph into Google and see the fine structure of limestone. Limestone is often quarried for gravel, building stone and thinner "flags" for walkways and building facings. Many Texas state government buildings arc faced with a fossiliferous white limestone quarried near Austin. Texas.

20 MARBLE - Georgia

Heat and pressure will convert (metamorphose) limestone into marble. Marble is commonly used for flooring and the external panels for buildings. Put metamorphic rock marble into Google for more info.

IIgneous Environments

• Extrusive - Magma (molten rock) rises toward service and EXit the earth. It cools quickly. Lava flows, Ash plumes
• HGMS 27 basalt
• HGMS 29 Rhyolite
• HGMS 25 Scoria
• HGMS 24 Pumice
• Intrusive - Magma rises near surface and stays INside the earth. Batholith, Dike, Sill.
• HGMS 23 Granite - small crystals

Igneous Environments

• Extrusive - Magma (molten rock) rises toward service and EXit the earth. It cools quickly. Lava flows, Ash plumes

27. BASALT - Lahitas, Texas

Basalt is a common extrusive igneous rock that is rich in magnesium, calcium, and iron. Most of the oceanic crust is basalt. This rock cooled from a lava flow at the surface of the earth. Put igneous. rock basalt into Google.

29. RHYOLITE - Davis Mountains, Texas

Rhyolite is a common extrusive igneous rock that is low in iron, calcium, and magnesium. Look closely with a microscope (10x) and you will see the tiny, glassy, blocky crystals, which are a high temperature, early crystallizing sanidine, a potassium felspar. These crystals form at some depth before the lava spilled out on the surface. There are also bubbles, which formed as the lava reached the surface and the dissolved gasses came out. Still later, some of these bubbles & cracks were filled by low temperature minerals (clay, calcite, zeolites, quartz and agate) as water moved through the cooling lava. (Web - Put rhyolite rock into Google)

25. SCORIA - New Mexico

When basalt lava with a lot of gas included reaches the surface of the earth, the dissolved gas bubbles out as the rock cools, leading to this characteristic porous texture. Iron minerals in the lava can oxidize and color the surface red. Put igneous rock scoria into Google

24. PUMICE - California

When lava is very viscous and full of gas, it will cool into what is essentially foam. This rock floats! Try it. You should store the pumice dry to keep it from gradually adsorbing water and sinking. Put

igneous rock pumice into Google. Pumice is used in as an abrasive for cleaning porcelain and in personal care products for callus removal.

• Intrusive - Magma rises near surface and stays INside the earth. Batholith, Dike, Sill.

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23. GRANITE - Texas, New Hampshire, Colorado

The pink crystals are microcline feldspar. The gray areas are quartz, The black spots are biotite mica, magnetite and pyroxenes. The continents are floating on a granite basement in a sea of basalt. The central part of the Texas Hill Country, where this granite is found, is an exposed PreCambrian landscape uncovered by the uplift of the Rocky Mountains in New Mexico. They are the oldest rocks in Texas.

Vocabulary

• Weathering - the breaking down of exposure rock by water, ice, and wind into small grains and soil.
• Transportation - the movement for material across the earth’s surface by water, wind, ice, and gravity.
• Deposition - the process creating landforms and land masses from soil, sediments, and rocks.
• Sediments - solid material that is transported and deposited to a new location.
• Lithosphere - the rigid outer part of the earth consisting of the crust and upper mantle
• Lithification - buried sediments are converted to rock by pressure and cementation
• Sedimentary rock
• Metamorphism - Further heat and pressure coverts the sedimentary rock.
• Metamorphic rock
• Magma - extremely hot liquid and semi-liquid rock
• Uplifting - rising of portions of the earth surface
• Crystallization - the process of liquid rock freezing into solid rock
• Intrusive Igneous rock is formed when magma is trapped deep in the earth and solidifies slowly (granite, pegmatite, Diorite). Larger crystals.
• Extrusive igneous rock is formed when magma erupts to the surface from volcanoes or fissures and solidifies almost instantly (basalt, tuff, pumice). Small crystals.

Rocks & Minerals

Rock Cycle - Geological processes the form rocks

Karl Schleicher 3/23/2023