Faith mentions: "No I am NOT confusing those things. I am dealing with what the length of the period itself is supposed to be, not the age of the rock. The whole range of possibilities has been adequately covered for the rate of sedimentation within that period as well. Please do not confuse this thread at this point. It's confused enough with eight or ten posters already."
I may be able to clarify this a little better as I've had some experience with fossils and geology. The time periods in the Geologic Time Scale were originally designed to give us the relative age of fossil assemblages. No dates were attached to them in any way. Divisions in the time scale were based solely on the appearance and/or dissappearance (extinction) of fossil groups and assemblages. It had very little to do with deposition and only gave us relative information on dates (this fossil containing rock/formation is older than that fossil containing rock/formation), usually based on the simple Principle of Superposition along with overlapping correlations proximally exposed strata. This continued until the 1960's and along came TIMS, SIMS and multile ICP-MS techniques. Now geochemists had some new great tools to get into the game with. They've tested the majority of the geologic rock record and found that the old paleontologists did a pretty darn good job in putting all of these fossils in order. In fact, if you ask me, this affirmation of the relative time scale with radiometric (absolute) dating techniques is not only the bedrock of modern geology, but also extends into chemistry, evolutionary biology and many other fields.
This message has been edited by Chuckdarwin1809, 03-11-2006 11:25 PM
"All gods were immortal" Zina G.
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