How does molten rock change the landscape

 · V olcanoes occur when cracks in the Earth’s surface allow hot molten rock to rise up from below the crust. A volcanic eruption can change the shape of a mountain by blowing parts of it away, but volcanic eruptions can also build up the land around a volcano when lava flows out and hardens on the surface. Lava flows, however, can bury homes and agricultural land under tens of meters of hardened black rock; landmarks and property lines become obscured by a vast, new hummocky landscape. People are rarely able to use land buried by lava flows or sell it for more than a small fraction of its previous worth.  · Sedimentary and igneous rocks began as something other than rock. Sedimentary rocks were originally sediments, which were compacted under high pressure. Igneous rocks formed when liquid magma or lava—magma that has emerged onto the surface of the Earth—cooled and hardened. A metamorphic rock, on the other hand, began as a rock—either a sedimentary, igneous, or even a Estimated Reading Time: 4 mins.

If so, an eruption begins, and the molten rock may pour from the vent as non-explosive lava flows, or if may shoot violently into the air as dense clouds of lava fragments. Larger fragments fall back around the vent, and accumulations of fall-back fragments may move downslope as ash flows under the force of gravity.

Some of the finer ejected materiaIs may be carried by the wind only to fall to the ground many miles away. The finest ash particles may be injected miles into the atmosphere and carried many times around the world by stratospheric winds before settling out.

Fountaining lava and volcanic debris during the Kilauea Iki eruption of Kilauea Volcano, Hawaii. M olten rock below the surface of the Earth that rises in volcanic vents is known as magma , but after it erupts from a volcano it is called lava. Originating many tens of miles beneath the ground, the ascending magma commonly contains some crystals, fragments of surrounding unmelted rocks, and dissolved gases, but it is primarily a liquid composed principally of oxygen, silicon, aluminum, iron, magnesium, calcium, sodium, potassium, titanium, and manganese.

Magmas also contain many other chemical elements in trace quantities. Upon cooling, the liquid magma may precipitate crystals of various minerals until solidification is complete to form an igneous or magmatic rock. T he diagram below shows that heat concentrated in the Earth's upper mantle raises temperatures sufficiently to melt the rock locally by fusing the materials with the lowest melting temperatures, resulting in small, isolated blobs of magma.

These blobs then collect, rise through conduits and fractures, and some ultimately may re-collect in larger pockets or reservoirs "holding tanks" a few miles beneath the Earth's surface. Mounting pressure within the reservoir may drive the magma further upward through structurally weak zones to erupt as lava at the surface.

In a continental environment, magmas are generated in the Earth's crust as well as at varying depths in the upper mantle. In this Module, you will encounter a LOT of sandstone.

Sandstone is a sedimentary rock that is highly resistant to weathering. Other sedimentary rocks you will encounter are mudstone and siltstone. These are soft and easily weathered lots in the Painted Desert. Yet another sedimentary rock you will see is limestone. Limestone is composed of calcium carbonate, which is water soluble it dissolves in water. Therefore, the limestone you find in a dry area will remain a rock a lot longer than limestone you find in a MOIST area.

Regarding metamorphic rocks, there really aren't many of these on the Colorado Plateau.. So, good thing for you, we are really not going to cover this rock type in this Module. You will see a few igneous rocks in this Module You see granite intrusive igneous and basalt extrusive igneous. The granite you will see is high up in the La Sal Mountains and the basalt you will see sits as cap rocks on top of softer, underlying sediments.

A cap rock is a comparatively more resistant rock that protects the rocks beneath it from weathering and eroding. The key to understanding rock weathering is to realize that rocks weather at different rates and into different forms based on their chemical composition and based on what weathering processes dominate the area.

For WAY more information on rocks than you are required to know for this Module, visit the following links:. Jump to igneous Jump to metamorphic Jump to sedimentary. Weathering breaking down rock and erosion transporting rock material at or near the earth's surface breaks down rocks into small and smaller pieces. These smaller pieces of rock such as sand, silt, or mud can be deposited as sediments that, after hardening, or lithifying, become sedimentary rocks.

Extreme pressure from burial, increasing temperature at depth, and a lot of time, can alter any rock type to form a metamorphic rock. If the newly formed metamorphic rock continues to heat, it can eventually melt and become molten magma. When the molten rock cools it forms an igneous rock. Metamorphic rocks can form from either sedimentary or igneous rocks. The sedimentary particles from which a sedimentary rock is formed can be derived from a metamorphic, an igneous, or another sedimentary rock.

All three rock types can be melted to form a magma. Thus, the cycle has continued over the ages, constantly forming new rocks, breaking those down in various ways, and forming still younger rocks. Rocks at the surface of the earth range in age from over three billion years old to a few hundred years old.

Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic rock can change into igneous or sedimentary rock.

Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. Igneous rock can form underground, where the magma cools slowly. Or, igneous rock can form above ground, where the magma cools quickly. Notice how many time "weathering" and "erosion" green arrows appear in the above diagram? When it pours out on Earth's surface, magma is called lava.

Yes, the same liquid rock matter that you see coming out of volcanoes. Igneous rock that pours out onto the Earth's surface is called igneous extrusive , whereas igneous rock that cools beneath the surface is called igneous intrusive. On Earth's surface, wind and water can break rock into pieces weathering! They can also carry rock pieces to another place erosion!. Usually, the rock pieces, called sediments, drop from the wind or water to make a layer.

The layer can be buried under other layers of sediments. After a long time the sediments can be cemented together to make sedimentary rock. In this way, igneous rock can become sedimentary rock. All rock can be heated. But where does the heat come from? Inside Earth there is heat from pressure push your hands together very hard and feel the heat. There is heat from friction rub your hands together and feel the heat.

There is also heat from radioactive decay the process that gives us nuclear power plants that make electricity. So, what does the heat do to the rock? It bakes the rock. Remember, all rocks are made up of mineral crystals, or pieces of other rocks made up of crystals. Baked rock does not melt, but it does change.

It forms crystals. If it has crystals already, it forms larger crystals. Because this rock changes, it is called metamorphic. Remember that a caterpillar changes to become a butterfly. That change is called metamorphosis. Metamorphosis can occur in rock when they are heated to to degrees Celsius. When Earth's tectonic plates move around, they produce heat.

When they collide, they build mountains and metamorphose the rock. The rock cycle continues. Mountains made of metamorphic rocks can be broken up and washed away by streams. New sediments from these mountains can make new sedimentary rock. The rock cycle never stops.

Igneous Rocks : Igneous rocks are a type of rock formed from extremely hot 2, degrees F molten masses known as magma. Generally, magma lies about 90 miles below the surface. In certain places, such as Yellowstone National Park, the magma is as close as 40 miles below the surface. Hardening magma is only one way that rock forms. A second type of rock forms from layers of small particles, called sediments.

Most sediments consist of tiny bits of rock. The loose fragments come from larger, older rocks. Although solid rocks may seem never-changing, tiny rock fragments come off all the time. Sometimes rain loosens the surface of a rock. Sometimes water that freezes, then thaws, cracks open rocks and loosens particles. The tiny fragments may fall down slopes and settle. Running water and wind may also carry particles away.

This process, known as weathering, takes place everywhere on Earth. Over millions of years, rivers can create canyons by eroding layer upon layer of rock. These particles may be carried great distances. They may end up in a sea, a lakebed, or even on dry land. There, the sediments settle layer after layer. Everyday, the Mississippi River deposits thousands of tons of sediments when it reaches the Gulf of Mexico. Sediments also come from other sources, such as organic matter.

In seawater, countless tiny shells and skeletons may form layers on the bottom. In swamps, decaying plants slowly build up. Certain minerals dissolved in a body of water can form sediments, too. The process starts as the water slowly evaporates.

Over time, less and less water remains to mix with the minerals. The excess minerals start grouping together to form crystals. These crystals slowly build up. Evaporation caused Gypsum like this to crystallize in large, thick mineral beds. Whatever the sediment, its deposits form thousands upon thousands of layers.

As new layers settle on top, they bury lower layers deeper down in the earth. The weight of the upper layers squeezes the lower layers together.