Explanation:
Here is the explanation about these layers.
Limestone: This rock is formed from sediments that gather on the river floor over time & Limestone is mostly found in rivers, caves, etc. This resource is made from natural activity, for example, sediments travelling through the river & the water causing it to settle.
Banded-iron formations: This rock, or resource, is thought to be made in the seawater millions of years ago and is the result of oxygen production from a particular type of photosynthetic cyanobacteria. The oxygen, combined with dissolved iron makes this resource.
A metamorphic rock with fine grains: I cannot explain how this rock is made from, please find someone who can.
Red Beds: "Red beds may form during diagenesis. The key to this mechanism is the intrastriatal alteration of ferromagnesian silicates by oxygenated groundwaters during burial. " - Wikipedia
Chert Layers: Chert can form when microcrystals of silicon dioxide grow within soft sediments that will become limestone or chalk.
I hope this has helped you to learn about these rocks.
The answer to this question is Salinization that was a very easy question
Answer:
A, D Is your answer
Explanation
Researching bones, animals, and DNA can tell you a lot about the
colonial history of a region. Even clothing, vehicle parts, and
plant life can tell how people lived in colonial times.
Precious metals are rare, naturally occurring metallic chemical elements. They tend to be less reactive than most elements, are usually ductile and have a high lustre. Precious metals have high economic value. Examples are: gold,silver and platinum. Gems on the other hand are minerals or rocks that can be cut, shaped, and polished into beautiful stones. Examples include emerald, ruby and sapphire.
Both precious metals and gems are rare and valuable.