Answer:
C. Faults are younger than the youngest layer they cut through.
Explanation:
<em> A. Intrusive rock is older than the surrounding rock layers. </em>WRONG. The intrusive rocks are those that solidify underground and always form after the ones around them. So they are younger than the surrounding rocks.
<em>B. A fold is older than the oldest rock layer it contains. </em>WRONG. First, layers are set, and then, it occurs the folding. The folding is always younger than the involved layers.
<em>C. Faults are younger than the youngest layer they cut through.</em> RIGHT. A fault is a cut through different layers that occurs when the sedimentary rock breaks transversally. It occurs always after the sedimentary rock is already formed. So the fault is always younger than all the layers it cuts through.
D. Rock layers that have been overturned are oldest from the base to the surface. WRONG. If <u>overturned</u>, according to the superposition low, layers are oldest from the surface to the base. Superposition law states that during the sedimentary rock formation, the oldest layer is always that one at the bottom, while the younger layer is the higher one.
The main function of environmental policy is protecting a society's natural resources. These policies provide necessary measures to make sure all the resources remain available to everyone. The main function of environmental policy is protecting a society's natural resources.
<u>Answer:</u>
Cyanobacteria start producing pure oxygen around 200 million years ago.
<u>Explanation:</u>
Many scientists believed that Earth did not have any oxygen. Cyanobacteria or the blue green algae are the microbes which produced oxygen for the first time with the help of photosynthesis. This was around 4.5 billion years ago: after Hadean eon.
They were very simple, but they produced oxygen in the early earth’s atmosphere. So, they brought evolution on earth. This “blue-green algae” exists in salt water, rocks and soils and play a major role in maintaining the ecosystem.
Melting and crystallization
Intrusive slow igneous fast
Limestone mudstone
It weathers
They need to be buried and cemented
Yes over time and through the cycle
Lava extreme heating
Granite
Basalt
Marble slate
