I "have the following sequence?" What does that mean? I have it on paper? I have drilled through level 5? What are you talking about? And why are you asking me? I don't claim to be a geologist.
You have drilled through to level 5 lets say.
Why date it at all? Why not just identify it as "Permian" by its characteristics? It is by its characteristics that you date it, of course, what else? But the dating is superfluous, the characteristics are what matter.
Because dating is very important. Much of what we extract today, in various forms of carbon, date in rocks with those specific ages. Often the date of the rock is extremely valuable. If you want to call a radioactive date a "characteristic" then go ahead.
Whatever you would hypothesize WITH it. You are assuming things I have not said. I've eliminated nothing from geology except the idea of old age. Everything else applies, all the observations of the strata and their fossil contents and their arrangements etc etc etc.
It is their arrangement with regards to identifying an ancient coastal landscape. It is also with regards to identifying deposits that are specifically created on land. Both of these require an OE to be true for me to infer any reasonable thing about Number 6.
I see no need to recognize a "transgressional/regressional sequence of a shoreline," simply a need to recognize that this particular sequence of rock is likely to be followed by a particular type commonly associated with coal, if that is indeed the case and if coal is what you are interested in, all based on previous experience that these strata are often found in this order. Those are the important things. The idea of the "depositional environment" is interpretation and superfluous to the actual facts needed.
Thats whats wrong!
It WONT likely be associated with coal in all cases. Only when I have identified it in the context of its depositional environment can I make that prediction. Without that I have no idea what number 6 will be. I have no basis because in another location it might be a totally different story.
I tried to respond point by point to the rest of your post but it is clear that you don't even understand what I am trying to say. I don't mean that as a attack. I just honestly and genuinely think you are ignorant about some of the most basic concepts in geology.
The example is simple but it is not just a matter of:
Simply recognizing that this particular sequence is commonly associated with what you are looking for is quite sufficient without any notion of land-based or marine-based anything
We know oil and coal are made from organic materials. In particular we know coal forms from peat which gets its start in swamps. Therefore we know what type of strata we need to look for to find these things and it is completely dependent on the depositional environment of our target area. Without that you are just drilling holes in rocks that look the same as the ones you hit paydirt in last time.
Oversimplifications such as:
Again, only a knowledge of the types of rocks and the configurations that tend to be associated with coal is needed.
only betrays a complete misunderstanding of the field. It is like telling a computer tech support person on the phone that you can't get your email because the g-wave flux capacitor in your computer is broken. It is a total indication of your lack of fundamental understanding of the principles being talked about. I hope this does not offend you but rather inspire you to branch out and study this if it interests you.
Well, 1) I'm not offering an explanation for the strata, merely recognizing that they are often found in some predictable patterns and configurations which are useful to know, and 2) the concept of a depositional environment is superfluous. I know you are convinced of its importance, but it seems to me that it's merely a fanciful handle on the strata, quite inessential. If it were essential, don't you think the oil explorers would emphasize these supposed environments? But they don't mention anything except the actual physical properties, the rocks and fossils etc, their hardness or softness and other characteristics, not a word about how or why they are that way.
1) First thing, no one ever said that this was a predictable pattern. The geologic history of a completely different location that still contains carbon elements may be utterly unique. But because of the skill of interpreting the geologic column a trained geologist can make accurate predictions as to the potential of a given drill site. This includes recognizing the depositional environment of the location and putting it into the context of an ancient past.
2)The reason you may not see geologists articulating the concept of a depositional environment is simply because it is part of the grammar of advanced geology. Like what was given before, civil engineers don't refer to Newtonian concepts when they do their job but they use those concepts in everything they do.
OE has no doubt motivated the investigations into the geo column that do have practical use in oil and other explorations, but OE itself (including the notion of depositional environments) has no utility in itself that I can see despite your allegiance to it.
It has nothing to do with allegiance. It has everything to do with the complete inability to make any sense of it any other way. You would know if you truly looked into it for yourself in any academic manner.
This message has been edited by Jazzns, 08-09-2005 10:43 PM
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