By: Jahaira Fernandez

Field Project

Sandstone

It’s a sedimentary rock

Made of tiny grains of quartz

Formed in Oceans, river, and lakes where tiny bits of rock and dirt settle to the bottom.

They can even be found in deserts

They come in many colors: bright white, red, yellow, orange, purple, and green.

They are buried under a lot of sand and dirt, which makes it turn into a solid rock.

They’re composed of fragments, particles of older rocks, or from existing solid matter. The cement binding these grain are silica, calcites and clays.

I found this sedimentary rock, which I

believe is called a sandstone rock in the

Sequoia Park . This rock is very big and

due to its enormous size, it caught my

attention right away. This rock is very

interesting because the colors that it

contains are very unique. This rock, is gray

and black and it has tiny dots, which look

like little black crystals all over it. There

was grass growing in some open spaces of

the rock. In some parts, it had black thin

lines. This rock was located in the right

side of road and what surrounded it, were

very tiny rock, weeds, and dirt. A couple

more steps away from it, there was tree

barks and above the rocks, there were

many trees, some were bigger than

others.

Sandstone

It’s a Metamorphic rock (fine-grained no foliated) and has no specific composition.

Hornfels is a rock that was "baked" while near a heat source such as magma, chamber, sill or dike.

The color of this rock is dark gray to black, dense and it’s a hard, compact, massive rock breaking with conchoidal fracture into sharp angular pieces.

Hornfel rocks are harder than glass and has a dull luster.

Form under high pressure and temperature regimes

This rock can form practically anywhere.

Hornfels

I found this rock in the Sequoia park as well. I believe that this rock is a hornfel. The color of this rock is almost black, but it looks mostly blue. It also has light blue in it and green. It has several small little cracks and in one side it’s lighter than the other. The rock was by this tree log. Around this tree log, as you can see there’s only grass, dirt, and some bushes. There weren’t that many rocks by this tree log, but what I did find was some small insects crawling on the log.

Siltstone This rock contains sediment grains

that are very small and they are larger than the size of clay.

These type of rocks, have a lot of clay and they’re classified as mudstone.

Siltstone is made from silt of course. Silt is another name for clay and is very fine grained.

Siltstones differ significantly from sandstones due to their smaller pores and higher propensity for containing a significant clay fraction.

This rock has a pale color and it also has some white in it as well. You can burly see the little holes it has and in some of the sides, it has black little dots. They look like small little sprinkles. I found this rock in the Santa Cruz Board walk. Next to the board walk, there was a small lake and that’s where I found it. There were any different sizes of rocks

Rhyolite

This is an igneous rock

Rhyolite is a light-colored, fine-grained rock that contains quartz and feldspar minerals. 

Usually light coloured; white, grey, greenish, reddish or brownish.

Rhyolite is typically found in continental settings where magmas have incorporated granitic rocks from the crust as they rise from the mantle. It tends to make lava domes when it erupts.

"rhyolite" means "flow stone" in scientific Greek.

This rock, which I believe is a Rhyolite, is has a very light brown color and I found it in my back yard patio. There’s no grass in the area where I found it because there’s only dirt. The ground where I found the rock, was sort of muddy and there were several cracks on the ground.

Amphibolites This is a Metamorphic rock.

Amphibolites is a rock composed mostly of amphibole minerals. Usually it's a hornblende schist like this as hornblende is the commonest amphibole. 

It’s a non-foliated metamorphic rock.

It forms through recrystallization under conditions of high viscosity and directed pressure.

It is composed primarily of amphibole and plagioclase only with very little quartz. 

This rock, which I believe is a Amphibolites, has two bright colors that are light

brown and small dark brown and black dots. The same dots also clear and

they sparkle a lot, especially in the sunlight. I found this rock in the Santa

Cruz Board Walk as well. This rock was by on the

ground by the parking lots and the area around it was surrounded by the beach water. There were several

benches as well around the area where I found it.

A FaultThis fault is going to

Interstate High Way 5. This is a strike-slip fault. Here, any earthquakes have passed several times. It’s surrounded by green grass and in some areas it’s just covered with dry grass.

Marine EnvironmentIn the Marine

Environment there’re many life creatures living under water. There’re fish, sharks, dolphins, whales, etc.  Marine organisms contribute significantly to the oxygen cycle. They help to regulate the Earth's climate.

Weathering Example # 1

This example is called Mechanical Weathering and this happens due to the break down of many rocks because of the exerted pressure they’re receiving.

Weathering Process #2This example is

called Chemical Weathering because it’s surrounded by abundant water. Chemical weathering only occurs in tropical climates .

A DamThis dam is near Fresno

and it’s gated for the safety of people. Some of the water that’s retained here, is from the sierra mountains that’s melting away. There’re rocks near the edges of the cement and the rest is just dirt and there’s also trees as well.