Saturday, February 12, 2011



Tectonism is the change of position of Earth’s shell that is caused by endogenic power with directions of horizontal and vertical.

According to its moving velocity, tectonism is separated into two parts, as follows:

1. Epirogenesa
Epirogenesa is the change of position of Earth’s shell the motion of which is slow in a wide area. Epirogenesa process consists of two kinds, are:

a. Positive Epirogenesa is the phenomenon of falling of land so as if the sea water increases. Example: Sinking of Atlantis terrestrial.
b. Negative Epirogenesa is the phenomenon of rise of terrestrial so as if the sea water decreases. Example: The rise of Scandinavia beach.

2. Orogenesis Motion
Orogenesis motion is an endogenci power motion that is relatively fast and covers relatively short region. It means the formation of mountain (oros=mountain, genesus=birth) and fold happen.
Example: The formation of folding of circum pacific young mountain.

Friday, February 11, 2011

Sedimentary Rock

Sedimentary Rock

Igneous rock that is uncovered to the Earth’s surface will undergo destruction (erosion) by the influence of weather, then it is transported by natural power such as water, winds or glaciers and it got sediment in another places, so sedimentary rocks formed.

According to the formation process, sedimentary rocks are separated into:

a. Clastic or Mechanic Rock.
It is formed from the clump of larger rock that is carried from the slope of mountain, through the rain water then it is carried by river flow and then it is got sediment in a downstream region in the form of sand the chemical composition of which is still same with original rock. It means the sedimentation does not undergo a chemical process, but only a mechanical process.

The example of clastic rock are: brexi rock, conglomerate rock, sand and clay.

b. Chemical Rock.
chemical rock
It is formed through a chemical process, such as it undergone by a limestone in the cove’s roof. The limestone is permeated by the rainwater that contains carbondioxide will dissolve in the form of lime water solution. Some solution drop from cave’s roof and fall to the dry base of cave, the rest stick on the ceiling of the cave, so it is formed a limestone sediment as the remain of vaporization of lime water when that solution drops. Stalactite and stalagmite are formed, which are one of process produced by chemical rocks.

c. Organic Rock.
It is formed from the accumulations of animal and plant remains.

Thursday, February 10, 2011

Metamorphic Rock

Metamorphic Rock

Metamorphic rocks are rocks produced from the conversion of the original rocks as a result of a metamorphic process, that is a process in which is undergone by the original rocks as a result of the pressure and temperature which are higher simultaneously.

Metamorphic rocks can be classified as follows:

1. Termic metamorphic rock
Termic metamorphic rock is a rock formed because of the rise of temperature. For example, lime stone formed because the influence of a high temperature so it becomes liquid, then after undergoing cooling process that lime stone changes to be marble stone.

2. Dynamic metamorphic rock
Dynamic metamorphic rock is a rock formed as the result of pressure from the layer above it in a long time. This dynamic metamorphic rock is called kinetic metamorphic rock. For example, writing stone that comes from clays, that get pressure from the layer above it.

3. pneumolici contact metamorphic rock
pneumolici contact metamorphic rock is a rock formed as the result of rise of temperature followed the insertion of elements of another rocks (another substances).
For example: quartz in its metamorphic process is inserted borium element, will produce an kind of pearl stone called tourmaline, while if the additive element is fluorium, will produce topaz, a kind of pearl that has yellow color.

Tuesday, February 08, 2011

Igneous Rock

Igneous Rock

It happens from magma (molten rock) that undergoes a cooling process, then freezes. Based on the freezing process, igneous rocks are divided into three kinds, those are:

1. Inner Igneous Rock

The freezing happens inside, very deep under the Earth’s surface. Its cooling process is very slow. This causes the formation of big, perfect, and compact mineral crystals. The structure of mineral like that is called plutonic structure or granite (holocrystaline). Inner igneous rock is called also abisis rock. For example: granite rock, diorite, synite, and gabro.

2. Igneous Rock or Hypabyssal Rock

The remain of magma permeates into the upper layer and intrudes to the cracks of volcanic tunnels, then it becomes cool and freezes. The freezing process is relatively faster, so crystals that happen are not as compact as inner igneous rock. The structure of this igneous rock is called porphyry structure. For example: granite, diorite porphyry, syenite porphyry, and porphyry.

3. Outer igneous rock or effusive igneous rock

Igneous rock of this kind happens from magma that reaches the Earth’s surface, then it freezes. Its freezing process is rapid, so crystal can be formed. For example, in porphyry texture.

Monday, February 07, 2011

Formation Process of Rock

Formation Process of Rock
Respectively, the formation of rock on Earth can you see in the following cycle of rock.


1. Magma as the host of all rocks that form lithosphere.
2. because of the cooling process in the internal of Earth, in Earth’s surface, it happens the freezing process of magma inner igneous roc and the outer.
3. Through the process of destruction without the changing of chemical composition from origin rock, classical sediment rock is formed.
4. For sedimentation through a chemical process, the product is a chemical sediment and the sedimentation done by organism, the product is an organic sediment.
5. The change caused by the rise in temperature produces contact metamorphic rocks; by the pressure produces dynamic metamorphic rocks, and by the addition of another substance produces pneumatholitic contact metamorphic rocks.
6. Finally, whatever rocks that have been in contact with magma will undergo the change of form first, if a condition is possible, they will enter again into magma.

Sunday, February 06, 2011

Helium Method and Black Tin Method

Black Tin Method and Helium Method

Black Tin Method

Uranium and thorium change to be tin through a radioactive process. The change can be determined, that is from 1,000 kg of uranium and 0,0001 gram of black tin. In one year, uranium 238 changes through levels to be black tin 206 and thorium 232 to be black tin 208.

Helium Method

In that change it is also formed the elements of helium. Based on the amount of helium elements formed, it can be known the period of radioactive process happens. According to calculation of A. Holmes in 1946-1947. The age of Earth’s shell since Cambrian age is at least 3,350 million years. Commonly it can be accepted the age of Earth is 4,5 million years, while the age of galaxy is more than 10 billion years.