Can the appearance of a rock give clues to its origin?

Answer 1

they dont have an origin, they are in (the whole earth is) what is called the rock cycle

its like the chicken and the egg question to suggest the origins of rocks. their structure changes based on what minerals are present and temperatures and pressures are present at the time of formation in either the earths crust or mantle. there are 3 groups of rocks: Igneous: come form magma in earths mantle/crust (volcanic rock) Sedimentary: laid down in beds/layers from deposition of ancient seas and rivers Metamorphic: rocks that are subjected to immense pressure and temperature of different levels of the earth (deeper -the higher the pressure and temp)

Answer 2

"On the rocks" is an expression meaning "over ice." The origin of the phrase is rather cloudy but it is thought to have been born under the influence of pop culture as the phrase is used in many television shows and old movies.

Answer 3

Certainly. There are many properties of rocks that can help you identify how they came about.

Igneous rocks are formed from magma, but this can occur in different ways. For the sake of simplicity, let's take a look at three general kinds of igneous rocks: basalt, granite and obsidian.

- Basalt is generally a fine-grained dark and relatively heavy rock, it is classified as an extrusive igneous rock, as it forms on or near the surface of the crust. It has very small crystals (often not visible to the naked eye) due to its rapid cooling rate.

- Granite is a coarse-grained rock that is often a good deal lighter in both its color and its weight when compared to basalt. Granite is an intrusive igneous rock, which means that a pool of magma fills into a space inside the crust, where it then starts to cool slowly. The cooling rate is slower here than on the surface due to the lack of convection in the crust, and the warmer temperatures therein. This slower cooling period allows crystals more time to grow in size, which explains the coarse nature of granite.

- Obsidian is volcanic glass, and it technically has no crystalline structure. It is classified as an extrusive igneous rock, and is formed when lava expelled from a volcano is cooled so rapidly that there is no time for it to form crystals.

___________________________

Sedimentary rocks are quite a bit more complicated, and metamorphic rocks even moreso, so I'll just provide a general summary.

Sedimentary rocks are broken up into two classes (three if you're being very particular, but I'm not) clastic and chemical.

Clastic sedimentary rocks are composed of fragments of minerals and rocks that have formed and fused together, usually under pressure. Examples of these are sandstones and siltstones.

Chemical sedimentary rocks are formed from minerals which have precipitated out of water. Some examples are limestone, and dolomite.

Origins can be a little more difficult to determine in a hand sample of the rock, unless there are fossils present, but if you are able to see layers of different sedimentary rocks in a strata, you can actually piece together the general history of an area. By looking at the sequences, you can determine when an area was submerged (in geologically relevant time periods), which direction the water came from, how long it was submerged and when it receded. For more information on these, I suggest looking up 'upward coarsening' and 'upward fining sequences'.

Metamorphic rocks are igneous, sedimentary or even other metamorphic rocks that undergo a change of structure, most often by being exposed to heat and pressure. This can help determine the history of an area, as they indicate a process that might otherwise not be readily apparent from the conditions on the surface.

Answer 4

im pretty sure it means the construction or the landform of the rock HOPE I HELPED YOU!!!

Answer 5

rock paper scissors? 1/3

rock paper scissors lizard Spock? 0