How the geo strata are identified as time periods

I hope I am not being too pushy by providing you one example out of thousands for purposes of potential further discussion.In the paper Geology and Coal Resources of the Upper Cretaceous Fruitland Formation, San Juan Basin, New Mexico and Colorado by James E. Fassett, several methods are used to date a sequence of formations immediately near and including the Fruitland Formation in Northwest New Mexico. These methods include: correlation to type fossils, particularly ammonites; radiometric dating on included ash beds using the 40Ar/39Ar method; magnetic polarity reversal data, and rates of sediment accumulation/subsidence (although in this last case, not as a precise determinant of age but rather as examined rates that make sense under the model presented). Please pay particular attention to the section on "Summary of Chronostratigraphy."Sorry if the paper is technical in nature but geology is after all, a physical science that takes years to completely absorb (I somewhat know). Perhaps if you look at the paper, it may lead to questions that myself or others here may help answering.I hope that in answering this request, I am not attempting to move the thread too quickly.PS-There are more ways to date geologic formations than have been mentioned up to this point, but the above may be information overload enough for now as per admin. suggestion. Link to paper cited added by AdminJarEdited by AdminJar, : add link to cite

I'm sorry, I didn't know this thread was about your feelings. Please consider proposing a new topic about yourself.

You asked about wanting to see something about a geologic formation that was dated by multiple methods, if I understood correctly. I sought to show you an example of a geologic formation that was dated by multiple methods.I simply tried to answer your question because, as a librarian, it is my nature and my job to answer questions I feel I may be able to answer. I only asked that you try to read that one part of the paper which showed how a formation was dated by multiple means, not that you undertake a degree program, although you may want to have a dictionary of geologic terms handy in order to fully comprehend that one part of that one article.Although I do have a BS in geological engineering, I am no expert as I do not work in that field. Unfortunately, despiite the fact that it was 26 years ago, I may be still be too close to such esoteric knowledge to fully appreciate the difficulty a novice may have.For that reason, I will not contribute further to this thread unless requested.Edited by anglagard, : speling