Layering is the most obvious feature of sedimentary rocks. The layers are piled one on top of the other.

Sedimentary rocks have layers because of different depositions of sediments (small broken pieces of rocks) over time. These are your “sediments”. You get a large clear boc, and dump in all of your dirt.

Chemical sedimentary rocks can be found in many places, from the ocean to deserts to caves. For instance, most limestone forms at the bottom of the ocean from the precipitation of calcium carbonate and the remains of marine animals with shells.

Sedimentary rocks are laid down in layers called beds or strata. A bed is defined as a layer of rock that has a uniform lithology and texture. Beds form by the deposition of layers of sediment on top of each other.

The principle of cross-cutting relationships states that a fault or intrusion is younger than the rocks that it cuts through. The fault cuts through all three sedimentary rock layers (A, B, and C) and also the intrusion (D). So the fault must be the youngest feature.

igneous rocks

Sedimentary rocks are formed particle by particle and bed by bed, and the layers are piled one on top of the other. This Law of Superposition is fundamental to the interpretation of Earth history, because at any one location it indicates the relative ages of rock layers and the fossils in them.

There are three kinds of rock: igneous, sedimentary, and metamorphic. Igneous rocks form when molten rock (magma or lava) cools and solidifies. Sedimentary rocks originate when particles settle out of water or air, or by precipitation of minerals from water.

1. A horizontal layer of material, especially one of several parallel layers arranged one on top of another. 2. Geology A bed or layer of sedimentary rock that is visually distinguishable from adjacent beds or layers.

Bedding. Bedding is often the most obvious feature of a sedimentary rock and consists of lines called bedding planes, which mark the boundaries of different layers of sediment. Most sediments were deposited along a flat surface that was roughly parallel with the depositional surface.

Sedimentary rocks can be formed only where sediments are deposited long enough to become compacted and cemented into hard beds or strata. They are the most common rocks exposed on the Earth’s surface but are only a minor constituent of the entire crust. Their defining characteristic is that they are formed in layers.

Ripple marks and mud cracks are the common features of sedimentary rocks. Also, most of sedimentary rocks contains fossils.

For the most part the colors of sediment and sedimentary rock fall within two spectra: green-gray to red and olive-gray to black (Figure C70).

The most common sedimentary rocks – including shale, sandstone, and conglomerate – form from siliciclastic sediments. Other, less common, kinds of sedimentary rocks consist of carbonates (in limestones), iron oxides and hydroxides (such as hematite or goethite), or other minerals.