where did geologists base their interpretation of the earth's crust?

Answer 1

That's a rather vague question, but mountaingym and gwenilynd are correct.

The earth's crust is anywhere from 50 to 200 km thick, and our deepest drill holes are only a few km below surface so we use indirect sources of data.

Most of the information we know about the earth's internal structure comes from geophysics. We know the mass of the earth from calculating the distance from the sun and its orbiting speed, and we know there are layers in the earth from seismic data. Combining these data with surficial data we have a pretty good idea of the very complex structure within the earth.

For example, we know that the average density of the entire earth is about 5.5, but the earth's crust is only about 2.7. Therefore, density (or specific gravity) of the core of the earth must be greater than 5.5.

We also know that part of the earth's interior must be liquid, because certain types of seismic waves (earthquakes) do not travel through the liquid mantle.

The chemistry of the earth's interior has been determined partly from eclogites and stony meteorites.

And if you want to see a geologic column, look no further than the Grand Canyon.

Answer 2

In addition to seismic wave data geologists have determined the middle crust not to be rigid, since no earthquakes originate there. Also, xenoliths from upper mantle volcanoes (called kimberlite pipes) give us another window into the lower crust. There is no information on the structure of the Earth's crust in the Bible and the Gilgamesh Epic has nothing to do with Geology, unless you accept Mesopotamian Mythology as your explanation to Science, like some nuts do.

Answer 3

The Geologic Column. Charles Lyell, with the help of others, decided to make a timescale and give it index fossils. The problem is they just made the whole thing up. There is no Geologic Column anywhere in the world aside from the textbooks. If there is one it would be over one-hundred miles thick. I don't know of anybody digging that deep. It is true that there are layers in the earth. You won't have to dig too deep to find that out. Those layers were formed by a global flood. Just look anywhere that a flood has taken place and you will find all sorts of damage. Then imagine an entire planet suffering from a flood. That is why there are sedimentary layers, fossils, mountain ranges, faults, volcanoes, canyons, you name it!
Geologists will try to tell you that a certain layer is a certain age. However, they date the layers by the fossils found, and then date the fossils by which layer they find them in. Circular reasoning.
Try some experiments with dirt and water. Put some in a jar and shake it up. Mix some up and send it down a plume. Have fun playing in the mud but remember to wipe your feet before entering the house...

Answer 4

Are you asking how we know what the inside of the earth looks like? Are you asking about tectonic plates?

We know what the inside of the Earth looks like mostly from seismic data. Scientists measure the waves that travel through the Earth. The waves travel all the way into the Earth and bounce back. How long it takes gives a lot of information about what is there. It works along the same idea as SONAR.

If you're asking about tectonic plates or something else let me know and I'll edit my answer.