Do you think rocks are boring? Well, rocks and minerals are all around us! It is a natural substance composed of solid crystals of different minerals that have been fused into a solid lump. They help us to develop new technologies and are used in our everyday lives. Some of the uses of rocks and minerals include; building materials, cosmetics, cars, roads, and appliances. There are three basic types of rock: igneous, sedimentary, and metamorphic.
	 
	On Earth's surface, wind and water can break the 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 a sedimentary rock. The rock cycle continues and never stops. Mountains made of metamorphic rocks can be broken down and washed away by streams. New sediments from these mountains can make new sedimentary rocks.
	 
	Among the three types of rocks, sedimentary rocks are commonly called stratified rocks. Why is it so? This is because sedimentary rocks have a layered or stratified structure. This process is called stratification in which sedimentary rocks are arranged in layers due to crustal movement, displacement of soil, and distortion of terrain. The layers of stratified rocks differ from one another depending on the kind, size, and color of the sediments.
 
Stratification of Rocks
 
	The layers (strata) are formed from the accumulation, compaction, and cementation of sediments over a period. Most fossils are found in these layers. Young rock layers are found at the surface and older layers below. Geologist has been using these stratified rocks to reconstruct Earth’s history.
	 	When might the youngest layer in a set of sedimentary rock layers not be on top?	 
	   
  
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  Sedimentary rock layers contain information about the relative ages of events and objects in the Earth’s history. As you read earlier, sedimentary rocks form from the sediments that fall to the bottom of lakes, rivers, and seas. Over time, the sediments pile up to form horizontal layers of sedimentary rocks. The bottom layer of rock forms first, which means it is     the oldest. Each layer above that is younger, and the top layer is the youngest of all. This ordering is relative because you cannot be sure exactly when each layer formed, only that each layer is younger than the one below it. When horizontal layers of sedimentary rock are undisturbed, the youngest layer is always on top, as shown in the photograph on the left below. But over millions of years, the movement of tectonic plates can disturb rock layers. A whole set of layers can get turned on its side. Rock layers can get bent, or even folded over, like taco shells that begin as flat tortillas. If a set of rock layers has been disturbed, the youngest layer may no longer be on top. One way scientists determine the original order is to compare the disturbed rock layers with a similar but undisturbed stack of layers.	 
	The following geologic events contribute to the formation of stratified rocks.
	 
A.   Weathering- The bigger rocks break into smaller pieces by means of physical, chemical, biological and chemical weathering.
	 
B.    Erosion- The sediments will be moved by wind or water into the lower parts of the area.
	 
C.    Deposition- The sediments will settle on one particular area.
	 
D.   Compaction- The sediments will continuously be pressurized by the weight of other rocks at the top most layer that makes it lose its porosity.
	 
E.    Cementation- the sediments will be glued by different minerals from the water and it will produce different layers of rock.  use this to make a VBA code for PowerPoint presentation make a 8 slides