Talk:Stratigraphy

Archaeological
Maybe move and merge Archaeological stratigraphy into Stratification (archeology) which basically covers the same content. With a see also link here. -Vsmith 16:25, 15 Nov 2004 (UTC)


 * I strongly disagree. Archaeologists, in the US, anyway, commonly use the word "stratigraphy" to refer to the process of recording and interpreting strata, as well as using it colloquially as a noun to refer to both the physical phenomena being interpreted and the data resulting from that interpretation Where "stratification" is used, it is more likely to refer to the processes by which soil layers are deposited, and archaeological sites are formed.  I am more inclined to rework portions of the article to make it clear that "stratigraphy" is as key a concept to archaeology as it is to historical geology.  It should be possible to do that without diminishing the value of the article to students of the lithosphere.--Digthepast (talk) 22:08, 27 November 2009 (UTC)


 * Seems to be a sloow discussion - or should I wait five years to respond? Seems things have changed a bit since then, but the archeology bit hardly at all. Vsmith (talk) 22:34, 27 November 2009 (UTC)

Wrong definition of Lithostratigraphy
Similar as in the actual wikipedia article about lithostratigraphy the article fails to define lithostratigraphy correctly. See the definition of the International Stratigraphy Guide: "A lithostratigraphic unit may consist of sedimentary, or igneous, or metamorphic rocks. Lithostratigraphic units are defined and recognized by observable physical features and not by their inferred age, the time span they represent, inferred geologic history, or manner of formation. The geographic extent of a lithostratigraphic unit is controlled entirely by the continuity and extent of its diagnostic lithologic features." (...) "Lithostratigraphic units are bodies of rocks, bedded or unbedded, that are defined and characterized on the basis of their lithologic properties and their stratigraphic relations. Lithostratigraphic units are the basic units of geologic mapping." A lithostratigraphic unit needs not to describe stratified rocks, nor do younger rocks need to be structurally above older rocks, nor must the rocks have been laid down horizontally, nor must the rocks be sediments at all. I would recommend either to include the "lithostratigraphy" article in here (with a correct definition) or to link here to a separate article "lithostratigraphy".

Cheers GeoJojo (talk) 08:58, 10 October 2018 (UTC)

Magnetostratigraphy?
No mention here of magnetostratigraphy? See http://www.stratigraphy.org/magn.htm and Polarity chron. 165.189.91.148 20:50, 3 April 2006 (UTC)

"Correction" on superposition removed from article
Removed the following for discussion:
 * Correction. Superposition is a principle affirmed by Nicolas Stenon, not a law. It has been challenged as such by the experiments of Guy Berthaul published in Lithological and Mineral Resources a journal of the Russian Academy of Sciences’ Institute of Geology. For details see www.sedimentology.fr.

Maybe so, but we don't mess up the article with it. If the Law is to be changed to Principle - then we'll just change it. Discuss? Vsmith 23:47, 4 March 2007 (UTC)

Also see: Talk:Law of superposition for a discussion of this, and that is the proper place for further discussion. Vsmith 23:55, 4 March 2007 (UTC)

The following copied from my talk for broader discussion. Vsmith 23:30, 5 March 2007 (UTC)

Sir,

The object is not to replace the term "law" by principle" but to draw attention to the historical situation whereby what was proposed as the "law" of Superposition (or more correctly as a principle) has been challenged by peer-reviewed scientific experiments in sedimentology published in the scientfic literature.

What was proposed as a principle of stratigraphy has been questioned by the scientific method. Should this fact not be reported?

Berthault


 * Hi, I am reviewing the papers you linked to. Seems to me we are off a notch or two though. The details of sedimentology do not in my experience invalidate Steno's laws. We are talking of two different things here, and must consider the historical frame in which Steno and the early workers developed their concepts. The Law of Superposition still is valid in the large picture. Of course when we look at cross bedding and channel deposition in detail we may see presumed inconsistencies, however, the laws of Steno apply in the over-all picture for strata at the large scale and I see no reason to propose that the relative age dating developed using the old principles is in any way invalidated simply because of local scour and fill and cross-bedding within a single stratum. I haven't finished reviewing your papers though, and may return to the subject later. Vsmith 16:40, 5 March 2007 (UTC)

Thank you for your comment of March 5 and I am glad you are reviewing the link I sent. As you will see the research combines laboratory experiments and paleohydraulic analyses in the field. So we are looking at the whole picture not a single stratum.

A law applies universally. One cannot refer to experimental facts as “inconsistencies”. The facts are founded on empirical data and one has to distinguish objectively where the law applies and where it doesn’t.

No one witnessed the stratification of rocks. Stratigraphic principles are founded on the rocks’ appearances. But Stenon’s reference was not to rocks; he wrote: “strata owe their existence to sediments in a fluid”. It was these words which led me do the laboratory experiments. I worked alone at first, and then with qualified engineers, using flumes in which sediments transported by a current at varying velocities could be observed. In the deposit, all the characters of stratification could be seen; graded bedding, surface erosion, crusty surfaces and bedding planes due to desiccation. The stratification consisting of superposed strata prograded in the direction of the current. In such circumstances there was no question of the principles applying, nor was there any element of “inconsistencies”.

The question was to know how these experimental results could be applied to sedimentary rocks. It should be recalled that the results were coherent with Walther’s law, i.e. with modern sequential stratigraphy where the “systems tracts” are recognized as diachronic. Therefore, the results could be applied to transgressive and regressive phases in a series.

You will see on the website, I give as an example the Tonto Group (Lithology and Mineral Resources October 2004) using Rubin’s data concerning the relation between velocity of current and size of particles. The determination of the paleohydraulic conditions upon which sedimentary cinematic and time of deposit depend requires ascertaining experimentally the erosion of rocks in a powerful current. For this purpose I have just signed an experimental research contract with the Russian Institute of Hydraulics in St Petersburg. The results will enable a team of Russian sedimentologists with whom I operate to determine with greater accuracy the paleohydraulic conditions.

The problem has been that Stenon interpreted his observations to fit what he saw. Not having the laboratory equipment he was unable to test them and they looked so eminently reasonable that nobody else did either.

Guy Berthault (March 16, 2007)


 * Hi - sorry for the delay in responding - partly got sidetracked and partly waiting for someone else to join the discussion. Anyway:
 * First, your research seems to more properly apply to sedimentology than to stratigraphy. The details of fluvial transport are sedimentary processes as evidenced by the reference page you listed.
 * Steno's principles or laws, whichever, are still valid for the large picture for which they were developed. Steno's work must be considered in view of the timeframe in which he worked - and to criticise based on our understanding a couple hundred years later seems a bit off track.
 * The law or principle of superposition is still valid and I see nothing in your work that invalidates it. Younger sediments are deposited on top of older sediments, no question that I see. Structural events such as the development of landslide deposits and turbidites don't change that and neither do minor fluvial current features.
 * The principle of horizontality also remains valid for the large scale of geologic formations. Any geologist also knows that on the more detailed scale of fluvial, deltaic and wind deposits; crossbedding and other current features show a relatively small scale departure from horizontality. However, for the usage and context the principle was developed it remains valid and most larger scale departures from horizontality are structurally controlled (such as deposition in a subsiding basin).
 * In sum, I find your work interesting, but don't see it as a valid refutation of Steno's laws or particularly relevant to the stratigraphy article. Also please note that Wikipedia is an encyclopedia and not the place to "publish" your ongoing research. Vsmith 22:13, 18 March 2007 (UTC)

Thank you for your response. You say my work applies to sedimentology, but as our experiments are all concerned with the formation of strata I am unable to agree with you: 1.	they show that lamination is a mechanical property of heterogranular mixtures instead of successive layers. 2.	The experiments in Colorado show that variation of current velocity is responsible for stratified beds which prograde in the direction of the current; they do not succeed each other. 3.	Temporary variations of velocity create erosion surfaces. 4.	Desiccation produces bed plane partings.

Overall, the current is really the agent of stratification of aqueous deposits. This knowledge is a major tool in paleohydraulic analysis of sedimentary rocks and particularly in determining the time taken for them to form. To me as an experimenter, this provides a much more viable approach than chronostratigraphy.

My second Russian article explaining the formation of the Tonto Group shows the application of the experiments to the large picture and how they modify the standard stratigraphic interpretation. Insufficient data on erosion, however, prevented me from giving a more accurate interpretation of the boulders at the base of the Tapeats Sandstone eroded by a massive current.

I think Wikipedia readers will recognise that this research challenging the principles of superposition represents new knowledge and merits a place in an encyclopedia.

Guy Berthault

Hello,

It's now a month since I wrote. Your further coments would be appreciated - Guy Berthault


 * The larger context of Dr. Berthault’s “research” can be seen in


 * Berthault, G, 2009, Sedimentological Interpretation of the Tonto Group Stratigraphy (Grand Canyon Colorado Rover): Sedimentology of the Grand Stratigraphy, The Kolbe Center for the study of Creation.


 * The “Contact Us” web page states: “Kolbe Center Mission Statement - The Kolbe Center for the Study of Creation is a Roman Catholic lay apostolate dedicated to glorifying the Most Holy Trinity by proclaiming the truth.”


 * and Berthault, G, 1998, Genesis and historical geology A personal perspective. CEN Technical Journal. vol. 12, no. 2, pp. 213–217


 * Also, look at:


 * Henke, K. R., nd, Berthault's "Stratigraphy": Rediscovering What Geologists Already Know and Strawman Misrepresentations of Modern Applications of Steno's Principles. No Answers in Genesis!


 * MacAndrew, A., nd The Curious Case of the One-Man Band: The work of Guy Berthault: Revolutionary Geology or Extravagant Hubris? Alec’s Evolution Pages. 72.203.142.175 (talk) 02:24, 14 August 2013 (UTC)

Proposed References
I have added 29 possibly useful references mainly on books dealing with stratigraphy. They are sorted by Harvard (Name and Date) order at the end of the article in a section "Proposed References". Please, could you review and use these references by inserting them at the right place in the article. These references are already made with the "Cite book" template (see guideline in: WP:CITET) and will be correctly auto-formatted and also automatically recognised by Zotero (bibliographic extension of Firefox). In advance, many thanks. Shinkolobwe 23:27, 23 October 2007 (UTC)

List moved here for consideration - such a proposed list not appropriate in the article. Here for article improvement. Vsmith 00:01, 24 October 2007 (UTC)

References have been collected and added here. Please, could you review them and insert them at the appropriate place in the body of the text. Thanks


 * In my opinion, most of these are just various introductory (or advanced) textbooks, and unless something specific is referenced in the text of the article virtually all of them do not belong in the article as references. A few, such as No. 2, No. 25, No. 27, are either too advanced or too specialized to belong here, again unless there is information in them that is used specifically to support something (something specific) in the text. In such a case, citations to page numbers would probably be appropriate. Cheers Geologyguy 00:15, 24 October 2007 (UTC)

Tectonostratigraphy
Have added this under 'see also' but imagine it could have a section devoted to it on this page. cheers Geopersona (talk) 19:56, 19 October 2019 (UTC)

Using stratigraphic terminology
This 2009 paper, available via a department of the Government of West Australia, may be of use/interest - https://www.dmp.wa.gov.au/Documents/Geological-Survey/Stratigraphy_How_to_use_strat_terminology.pdf So too this 2013 one hosted by the European Association of Science Editors - https://ease.org.uk/wp-content/uploads/2-11.pdf Geopersona (talk) 08:20, 8 June 2024 (UTC)