Villas Del Campo Diego Perello Ian Beltrand Christian Diaz Nelson Muñoz

1. Group#4
Diego Perello
Ian Beltrand
Christian Diaz
Nelson Muñoz

2. Sedimentary
Sedimentary rocks are formed from particles of sand, shells, pebbles, and other fragments of material.
Together, all these particles are called sediment. Gradually, the sediment accumulates in layers and over a long
period of time hardens into rock. Generally, sedimentary rock is fairly soft and may break apart or crumble
easily. You can often see sand, pebbles, or stones in the rock, and it is usually the only type that contains fossils.
Examples of this rock type include conglomerate and limestone.
Metamorphic
Metamorphic rocks are formed under the surface of the earth from the metamorphosis (change) that occurs
due to intense heat and pressure (squeezing). The rocks that result from these processes often have ribbonlike
layers and may have shiny crystals, formed by minerals growing slowly over time, on their surface.
Examples of this rock type include gneiss and marble.
Igneous
Igneous rocks are formed when magma (molten rock deep within the earth) cools and hardens. Sometimes the
magma cools inside the earth, and other times it erupts onto the surface from volcanoes (in this case, it is called
lava). When lava cools very quickly, no crystals form and the rock looks shiny and glasslike. Sometimes gas
bubbles are trapped in the rock during the cooling process, leaving tiny holes and spaces in the rock.

3. Like most Earth materials, rocks are created and
destroyed in cycles. The rock cycle is a model that
describes the formation, breakdown, and reformation of
a rock as a result of sedimentary, igneous, and
metamorphic processes. All rocks are made up of
minerals. A mineral is defined as a naturally occurring,
crystalline solid of definite chemical composition and a
characteristic crystal structure. A rock is any naturally
formed, nonliving, firm, and coherent aggregate mass of
solid matter that constitutes part of a planet.

4. 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.
Image displaying the Rock Cycle. Please have someone assist you with this.
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.
On Earth's surface, wind and water can break rock into pieces. They can also carry rock pieces to another place. 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.
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 300 to 700 degrees Celsius.
When Earth's tectonic plates move around, they produce heat. When they collide, they build mountains and
metamorphose (met-ah-MORE-foes) 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.

5. The original concept of the rock cycle is usually attributed to
James Hutton, from the eighteenth century Father of
Geology. The rock cycle was a part of Hutton's
uniformitarianism and his famous quote: no vestige of a
beginning, and no prospect of an end, applied in particular to
the rock cycle and the envisioned cyclical nature of geologic
processes. This concept of a repetitive non-evolutionary rock
cycle remained dominant until the plate tectonics revolution
of the 1960s. With the developing understanding of the
driving engine of plate tectonics, the rock cycle changed from
endlessly repetitive to a gradually evolving process. The
Wilson cycle (a plate tectonics based rock cycle) was
developed by J. Tuzo Wilson during the 1950s and 1960s.

6. The rock cycle is an illustration that is used to explain how the three rock
types are related to each other and how Earth processes change a rock
from one type to another through geologic time. Plate tectonic movement
is responsible for the recycling of rock materials and is the driving force of
the rock cycle.