But doesn't it strike you as so
obviously circular that someone would have realised? As I cited before, TalkOrigins have two exhaustive refutations of these kinds of arguments - whatever you may have heard, scientists really don't date things like that.
This is a rather common quotation, but sadly it's taken out of context from Ager's essay on his fustration of physicists taking most of the credit for palaeontological discoveries. His full quote is as follows:
"No palaeontologist worthy of the name would ever date his fossils by the strata in which they are found. It is almost the first thing I teach my first-year students. Ever since William Smith at the beginning of the 19th century, fossils have been and still are the best and most accurate method of dating and correlating the rocks in which they occur. Oil companies spend millions of pounds employing palaeontologists to date the sediments found in their boreholes. Palaeontology is many things, but its most practical application is in providing a dating service second to none.
As for having all the credit passed to physicists and the measurement of isotopic decay, the blood boils! Certainly such studies give dates in terms of millions of years, with huge margins of error, but this is an exceedingly crude instrument with which to measure our strata and I can think of no occasion when it has been put to immediate practical use. Apart from very "modern" examples, I can think of no cases of radioactive decay being used to date fossils. In fact, fossils such as small marine invertebrate and plant spores and pollen are constantly used as precision tools in dating the rocks. We are measuring in millimetres while the physicists are measuring kilometres. ..."
So not only is the quote out-of-context, and not only is the full quotation actually a rather unscientific rant against physicists, but the full quotation actually argues
against your claim, stating that palaeontologists
don't date fossil by the strata they're found in. Ager's whole spiel is his indignation at physicists dating fossils using radiometric dating rather than his idealised strata.
I fear you've succumb to another Creationist quote-mine. Here is the full quotation:
"
Even after the analyses are calculated as dates, they have no geologic significance until placed in the context of previous work on maps. Otherwise each analysis represents only its particular sample. Structure, metamorphism, sedimentary reworking, and other complications have to be considered. Radiometric dating would not have been feasible if the geologic column had not been erected first.
"The technique having passed its pragmatic test, some enthusiasts are already talking about its replacing stratigraphy entirely. They even say that radiometric dates calibrate stratigraphy" - Vita-Finzi, 1973 p. xi, p. 1-3.
So, when we look at the quote in context, we see that they're not actually making some secret claim about circular logic. Rather, they're pointing out the
historical importance of pre-radiometric stratigraphy in basically creating the whole field of dating strata. It's nothing more than a nod to the efforts of those scientists who went before.
A philosophical discourse, rather than a scientific publication. It is not so much a refutation of the veracity of stratigraphy, but rather a jumbled and confused diatribe. Nonetheless, O'Rourke is careful to write (however sloppily):
"The charge of circular reasoning in stratigraphy can be handled in several ways. it can be ignored, as not the proper concern of the public. It can be denied, by calling down the Law of Evolution. Fossil dates rocks, not vice-versa, and that's that. It can be admitted, as a common practice. The time scales of physics and astronomy are obtained by comparing one process with another. They can be compared with the geologic processes of sedimentation, organic evolution, and radioactivity. Or it can be avoided, by pragmatic reasoning.
The first step is to explain what is done in the field in simple terms that can be tested directly. The field man records his sense perceptions on isomorphic maps and sections, abstracts the more diagnostic rock features, and arranges them according to their vertical order. He compares this local sequence to the global column obtained from a great many man-years of work against his predecessors. As long as this cognitive process is acknowledged as the pragmatic basis of stratigraphy, both local and global sections can be treated as chronologies without reproach."
As should be clear, your quotation was both out-of-context and wholly misrepresentative of what he was
actually trying to say.
I'm now disinclined to give exhaustive refutations of further quotes, since, with all due respect, it's quite likely you haven't actually read any of these quotes beyond what Creationist sites have parroted. I can only recommend that you actually research the quotes you cite before you cite them (without sourcing the original Creationist site, which is tantamount to plagiarism).