[blackpacific]

You can’t be serious. How do you know it was sedimentary rock they drilled through?

I think the same calculation was done for the moon dust for the Apollo program. The feet of the LEM were designed to hold the craft up in feet of dust, like snowshoes. When they landed the dust was only about .25 inches thick. Did anyone go back through the calculations to readjust the age of the Moon?

[fso301]

You can’t be serious. How do you know it was sedimentary rock they drilled through?

LOL. Sand, salt and carbonates. For starters, the name of the formation "Lower Tertiary" should give a hint. Secondly, if you read my profile, you will see my family used to live in an out of the way part of South Louisiana. Guess what's big business it that part of the country?

You can read more about the formation here.

[Titanites]

How do you know it was sedimentary rock they drilled through?

There are several ways, including:

1. Cuttings: small pieces of the rock broken off by the drill bit during the drilling operation are returned to surface in the drilling mud being circulated.

2. Coring: a special bit and barrel are run into the ground to cut a piece of the rock for examination on surface.

3. Electrical Logging: special tools are run across the rock face and readings are taken of the rock properties and transmitted to surface for evaluation.