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Who has been following the debate about the standardization (and renaming) of Sequence Stratigraphy? Since the paper by Catuneanu et al (2009) and earlier through his book Principles of Sequence Stratigraphy (2006) I have been largely on board with his groups vision (IWGSS). I still think several naming schemes and principles are under debate though and the discussion on SEPM Seq Strat between the groups is very interesting. The passion and vigour in which the two groups discuss the topics is quite interesting to say the most.

has anybody else been following this and have the new naming schemes (by Octavian Catuneanu and his group) been incorporated into your companies Seq Strat workflow and methods?

Would love to hear and maybe continue the discussion here.

Have heard of Catuneanu and read parts of his paper. Not really my discipline though, but that rant between Catuneanu and Embry is hilarious (the comments on the ISCC report and Embry's comment on Shoehorning).

I think I'm going to follow this a little. I remember when this Sequence Stratigrapy topic became hot when in University! Never knew it has become such a puzzling and unorganised discipline!

thanks for this!

I prefer the Catuneanu approach as it brings everything back to the basics. Still the points mentioned by Embry on the data driven approach may be more practical. I do believe however that nomenclature should be based on theory and sturdy principles. The practical user can than farm in on this naming scheme and mold it into a practical sense on a project-to-project specific manner.

Surfaces and sequences may not be present or visible in certain settings and may show characteristics not defined by Catuneanu, but a uniform theory based naming scheme will remove a lot of the confusion.

I a sense I have noticed that many of the debate resides around the more scientific population using sequence strat, rather than the petroleum professionals. They usually don't have to focus too deep into difficult coastal system details and can usually come away with assigning risk and uncertainty, rather than defining new theory. Usually interpretation is driven by data quality and availability anyways and typical outcrop resolution is not available. This basically forces them to stay away from very detailed description of variations on the normal sequence stratigraphic principles.

Given the importance of sequence stratigraphy for petroleum geology, I think it is important to debate the obvious differences between the pragmatic, material-based approach which I and others advocate and the theoretical, time-based approach of Catuneanu and Posamentier.

I have put online my recent handbook on Practical Sequence Stratigraphy at https://docs.google.com/leaf?id=0Bxwf7m ... MGFh&hl=en

Wow! Has dr. Embry entered the discussion.
Welcome!

Thanks for pointing us to your book. I remember reading parts of this a while back, but have not been that involved the last months. I'm printing it now and will give it a thorough read.

I have one question though after reading the intro, since you're now here...

Near the end of the introduction you state that:


I might be misinterpreting this and it may be tackled in later chapters, but can’t biostratigraphic interpretation indicate depositional environment and thus be a way to characterize a surface? Also periods of nondeposition can be observable through plant roots, certain pollen, oxidization of microfossils etc. And can’t chemical interpretation also indicate depositional environments (the CCD for instance) and periods of nondeposition like leaching of paleosols?

You might be refering to 'pure' biostratigraphy, which solely aims to date/correlate strata based on a particular fossil assemblage. However, most biostrat reports we recieve also include interpretation of the depositional environment. We include these interpretations in our GDE's, which ultimately help to characterize our sequences and feed into our sequence strat models.

Am I on the right track of what you're stating there?

Thanks again for joining and I hope we will be able to feed off of some of your wisdom.

Patjang, Sorry I am slow to reply but I was in Houston for the Final Four. There is no doubt that aspects of biostratigraphy can contribute to surface identification and you have noted some of the ways it can. depsotional environments and water depth interpretations are enhanced by biostratigraphic data. Importantly the existence of a time gap is often is revealed by biostratigraphic data.
The point I was making is, that although such data contribute to the the identification of a given boundary, the specific type of surface is determined by the defining criteria for that surface type. Thus if we see all the data we have, including some biostrat data, indicate we have a change in depositional trend from coarsening upward trend to a fining upward one, the strata are all marine and that there is no stratigraphic break, we would assign the surface to an MRS.
Basically, surface identification is the same as facies identification. It is just that geologists tend to get lots of training in facies identification and very little to none in surface identification. If you want to do sequence stratigraphy you have to be able to competently recognize the six material-based surfaces that are used in the discipline for correlation, and differentiate them from within-trend facies contacts.

Ashton, thank for your reply!

I too was out of office and apologize for my late response.
Your post does clear things up for me and I agree that surfaces/hiatus are often easily recognized due to the break/change in trend that catches the eye. But, what they actually implicate and what process caused them is a lot more difficult to assess, while this can have important affects on the measure of continuity or their geometry. Often I see that these breaks/changes in trend are almost blindly correlated over huge distances and I try to make an effort in addressing whether this is correct or what the geological grounds are for doing so.

Each type of sequence stratigraphic surface has a number of characteristic features which allow it to be differentiated from other types of sequence stratigraphic surfaces and WTFCs. I agree many people extend surfaces on faith rather than empirical observations and that is not the best way to explore. What we are often looking for is where the SR-U adjoins with the MRS and this locates the most basinward shoreline position where a thick. sandstone is often present.
Until sequence stratigraphy pulls away from the faith-based methods of Vail/Posamentier/Catuneanu and adopts skeptical empiricism and critical rationalism, it will remain a quagmire of nonsense and confusion.

Dear Dr. Ashton Embry,

Thanks a lot for sharing your doc to the community. I was reading your articles in series then there was a break because The Reservoir became limited to the members only.

But I am glad to have the complete series on my laptop.

Good Job!

Regards,

Farrukh

Dr. Embry,

Sequence stratigraphy has been interesting me both personally and professionally and I have been following your publishing and communications in the past. I came across this post through a google search and also found out about your facebook page with your articles on there (http://www.facebook.com/pages/Practical ... 803?ref=ts). I was wandering if there are any new developments in the standardization of sequence strat. Have you published new papers? The latest on facebook are from 2010.

Thanks,

Tumis