Talk:Geologic ages of earth history

Headings

Thomas, standard top-level headings are two equals signs; bold is not necessary. The reason it's two and not one is that single equals signs produce headings that are the same size as the title of the article --Larry Sanger 21:23, 15 April 2007 (CDT)

Hi Larry, Right. Caught that after I had switched them back. Thought it was my oversight. But I reverted them. All article headings start at double equals and work down from there. Thanks for the tip. - Thomas Simmons 14:33 18 April, 2007 (EPT)

Change title to 'Geologic time scale'?

Could we change the title of this article? To "Geologic time scale", I suggest. There are at least two reasons for this.

First, the description and classification of geologic time is usually found in Geologic time scales (what I also mean is that books about this topic are traditionally titled "Gologic time scale <year>", e.g., Gradstein F.M., Ogg J.G. and Smith A.G., 2004, A Geologic Time Scale 2004, Cambridge University Press).

Second, age has, in stratigraphy, a precise meaning. Strictly speaking, the article "Geologic ages of earth history" should thus be a list of ages.

This article is quite important for Earth Sciences. It might evolve into a description of the geologic time OR to a timeline of event in geologic time. I'll contribute soon (as soon as I can find the time). Thanks for starting it, for now! --Nereo Preto 01:57, 18 April 2007 (CDT)

The segmentation of time described, and the names of each segment, are not confined in their use only to geology. Biologists would also use many of these time classifications. Particularly within the study of Paleontology. Could this article be called the 'Classification of times'? Derek Harkness 04:53, 18 April 2007 (CDT)

Ok, let's do this: I'll take the time to collect some references and I'll post here soon some text about what could be this article about, and what should be its correct name in my view. I'll try to stick to authoritative sources. Then we'll discuss about it on the base of sources (of course, everyone who believes he has an argument is welcome to contribute! Don't take my step as something like "I'm the expert, shut up" please!)

The article of course can evolve under its current name for the moment. I suggest, however, to take a look at chronostratigraphy, where I posted a table with all divisions of geologic time. Related articles may be also useful (see links there). --Nereo Preto 11:17, 18 April 2007 (CDT)

The further the title gets from the actual topic, the more obscure it becomes and the less likely it will be spotted by the general public. The alternatives are semiotic artefacts of the sources which means if the reader is not familiar with the topic (one reason for coming here) they will miss these key words generated by very specialised literature. Redirects, however, are the best answer since they will fit a multitude of reader-contexts. If the literature shows a common use, then we simply put up a redirect. Piece of cake.

The limitations of the topic--in this case, geological--are the focus of the topic, but branching articles will of course make specific distinctions as would, say, palaeontology. The very names of the eras and other categories indicate a cross-disciplinary work--Phanerozoic, for example, refers not to rocks per se but about the evidence of life-- fossilised. Hence the conjunction of two disciplines in the study of the non-living and the living. If the title becomes too ambiguous it will literally loss meaning to all but those who read the books the editor has perused. Not an efficient way to communicate with the reader in my view.

I had this very problem with the article on the Eastern Orthodox Church. I listed synonyms and made redirects and Robert is Your Mothers's Brother. Thomas Simmons 17:07 19 April, 2007 (EPT)

Did the redirects. If you input Classification of times or Geologic time scale you will get to Geologic ages of earth history - Thomas Simmons 17:51 19 April, 2007 (EPT)

I believe this does it for now. Thanks Thomas. --Nereo Preto 10:05, 20 April 2007 (CDT)

What is this article about?

I read more carefully the article and I got confused about its function. What is this article about?

• If the article is about subdivisions of geologic time (without reference to absolute time, i.e., subdivisions which have a name regardless to their duration in millions of years), than we are talking about chronostratigraphic units
• If the topic is the numbers, i.e., how many million years ago a certain event occurred, then we are talking about geochronometry
• If this article is intended at the description of geologic time, both in terms of its subdivisions, absolute ages and definition of subdivision boundaries (e.g.: the Cretaceous-Tertiary boundary may be defined by the extinction of Dinosaurs), then the argument is the Geologic time scale.
• If instead the article is intended at a description of what happened through geologic time, then there is no name for it, but I suppose it would be something like "timeline of geologic time".

The reason I am so nitpicking -sorry about that- is the International Code of Stratigraphic Nomenclature (find it here, under "stratigraphic guide"). The existance of such a code implies that some concepts of stratigraphy (as the first two of the list above) have an official name that cannot be changed. In other words, if we refer to, e.g., chronostratigraphic units and call them the Geological ages of the earth, every expert will stigmatise our article as wrong (and there will be no room for discussion).

The meaning of "Geologic time scale" is not encoded, but it is implicit in expert's use. Check out: Gradstein F.M., Ogg J.G. and Smith A.G., 2004, A Geologic Time Scale 2004, Cambridge University Press, Cambridge, UK. This is the latest work about the topic, and is at present used as "the Bible" among researchers and students. Brief description of the work here.

I believe we must take a decision on which part, or concept(s), of stratigraphy we want to put in this article. Then it can be properly linked to other existing articles. Most important, we'll then be able to file it under a proper title. --Nereo Preto 10:53, 20 April 2007 (CDT)