batuan sediment

8/3/2019 Batuan Sediment

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Batuan Sediment :

1. Breccia

Breccia is a term most often used for clastic sedimentary rocks that are

composed of large angular fragments (over two millimeters in diameter). The

spaces between the large angular fragments can be filled with a matrix of smaller

particles or a mineral cement that binds the rock together.

Breccia has many compositions. Its composition is mainly determined by

the rock and mineral material that the angular fragments were produced from.

The climate of the source area can also influence composition. Most breccias are

a mix of rock fragments and mineral grains. The type of rock that the fragments

were produced from is often used as an adjective when referring to the rock.

Some examples: sandstone breccia, limestone breccia, granite breccia, chert

breccia, basalt breccia and others. Often a breccia will contain many types of

angular rock fragments. These are known as polymict breccias or polymictic

breccias.

Breccia can be any color. The color of the matrix or cement along with the

color of the angular rock fragments determine its color. Breccia can be a very

colorful rock as shown in the photo at the top of this page.

Breksi:

Breksi terbentuk karena pengaruh temperatur sehingga termasuk batuan

sedimen klastik. Beberapa breksi mengalami pelapukan yang kemudian

ditransfortasikan dan selanjutnya mengendap. Breksi banyak jenisnya sari mulai

limestone breksi, basal breksi, sandstone breksi, granit breksi dan sebagainya.

Warna breksi sangat bermacam macam.


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2. Chert

Chert is a microcrystalline or cryptocrystalline sedimentary rock material

composed of silicon dioxide (SiO2). It occurs as nodules, concretionary masses

and as layered deposits. Chert breaks with a conchoidal fracture, often producing

very sharp edges. Early people took advantage of how chert breaks and used it

to fashion cutting tools and weapons. Dark varieties of chert are common and

are often called "flint".

Chert: This specimen of chert is about two inches (five centimeters) across. It

displays conchoidal fracture and has broken to produce sharp edges.

Most chert forms when microcrystals of silicon dioxide grow within soft

sediments that will become limestone or chalk. In these sediments, enormous

numbers of silicon dioxide microcrystals grow into irregularly-shaped nodules orconcretions as dissolved silica is transported to the formation site by the

movement of ground water. If the nodules or concretions are numerous they can

enlarge and merge with one another to form a nearly continuous layer of chert

within the sediment mass. Chert formed in this manner is a chemical sedimentary

rock.

Some of the silicon dioxide in chert is thought to have a biological origin.

In some oceans and shallow seas large numbers of diatoms and radiolarians live

in the water. These organisms have a glassy silica skeleton. Some sponges also

produce "spicules" that are composed of silica. When these organisms die their

silica skeletons fall to the bottom, dissolve, recrystallize and might become part of

a chert nodule or chert layer. Chert formed in this way could be considered a

biological sedimentary rock.


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Chert occurs in a wide variety of colors. Continuous color gradients exist

between white and black or between cream and brown. Green, yellow and red

cherts are also common. The darker colors can result from inclusions of sediment

or organic matter. The name "flint" is often used in reference to the darker colors

of chert. Red to reddish-brown cherts receive their color from included iron oxide.

The name "jasper" is frequently used for these reddish cherts.

Chert has very few uses today; however, it was a very important tool-

making material in the past. Chert has two properties that made it especially

useful: 1) it breaks with a conchoidal fracture to form very sharp edges, and, 2) it

is very hard (7 on the Mohs Scale). The edges of broken chert are sharp and

tend to retain their sharpness because chert is a very hard and very durable rock.

Thousands of years ago people discovered these properties of chert and learned

how to intentionally break it to produce cutting tools such as knife blades,

arrowheads, scrapers, and ax heads. Tons of chert fragments have been found

at locations where these objects were produced in what was one of the earliest

manufacturing activities of people.

Kuarsa:Kuarsa merupakan mikrokristalin batuan sedimen yang memiliki komposisi

senyawa (SiO2). Pecahan nya termasuk ke dalam konkoidal sedangkan

belahannya tidak ada. Warna batuan kuarsa bervariasi antara putih dan hitam,

antara krem dan coklat atau kuning dan merah. Kuarsa memiliki tingkat

kekerasan 7 pada skala mosh. Batuan ini pula termasuk jenis batuan asam.


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3. Conglomerate

Conglomerate is a clastic sedimentary rock that contains large (greater than two

millimeters in diameter) rounded clasts. The space between the clasts is

generally filled with smaller particles and/or a chemical cement that binds the

rock together.

Conglomerate can have a variety of compositions. As a clastic

sedimentary rock it can contain clasts of any rock material or weathering product

that is washed downstream or down current. The rounded clasts of conglomerate

can be mineral particles such as quartz or they can be sedimentary, metamorphic

or igneous rock fragments. The matrix that binds the large clasts together can be

a mixture of sand, mud and chemical cement.

Konglomerat:

Konglomerat adalah asalh satu batuan sedimen non klastik yang memiliki

diameter butirnya 2mm. Proses pembentukannya hampir sama dengan batuan

sedimen yang lainnya. Batuan memiliki struktur berupa jejak dan ukuran butirnya

termasuk dalam kerakal.


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4. Iron Ore

Earth's most important iron ore deposits are found in sedimentary rocks. They

formed from chemical reactions that combined iron and oxygen in marine and

fresh waters. The two most important minerals in these deposits are iron oxides:

hematite (Fe2O3) and magnetite (Fe3O4). These iron ores have been mined to

produce almost every iron and steel object that we use today - from paper clips to

automobiles to the steel beams in skyscrapers.

Iron Ore: A specimen of oolitic hematite iron ore. The specimen shown is about

two inches (five centimeters) across

Bijih besi:

Di bumi ini sangat beragam bijih besi yang termasuk dalam batuan sedimen.

Dimana dintaranya ada 2 bijih besi yang dapat bereaksi dengan oksigen, yaitu

hematite (Fe2O3) dan magnetite (Fe3O4). Diameter ukuran butirnya sekitar 5 cm.


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5. Shale

Shale is a clastic sedimentary rock that is made up of clay-size (less then 1/256

millimeter in diameter) weathering debris. It typically breaks into thin flat pieces.

Shale: The specimen shown is about two inches (five centimeters) across.

Serpih:

Serpih adalah salah astu batuan sedimen klastik yang terbuat dari lempung yang

diameternya lebih kecil dari 1/256 mm.

batuan sediment

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