Conventions in Stratigraphy

[stoodleypike]

Hi All,

 

Like many of you, no doubt, I like to keep detailed records of where all my fossils are from. One thing I'm not sure of, though, is in what order stratigraphic data should be written. Do you move from the largest units (groups) to the smaller ones (beds and horizons), or visa versa? And whereabouts should geographical information be placed, not to mention periods, dates, etc.

 

I'd be surprised if there isn't a convection about these sort of things. Can anyone tell me what it is?

[doushantuo]

hoping this might help

owenstratigreview10570_articles_article_file_1642.pdf

[doushantuo]

or this:

https://www.idigbio.org/wiki/images/7/7f/255-271_Murphy_.pdf

[doushantuo]

or this:

http://www.nwrc.usgs.gov/techrpt/sta08.pdf

[Ridgehiker]

Firstly the most important info is the specific location where a fossil is collected. This never changes.  Some type of physical or GPS description.

 

'Then' stratgraphic info.  The stratigraphic info can change.  What was once considered the 'a' member if the lower 'x' formation could be reassigned to something else.  But the actual location never changes.  And, the age can change...Upper Campanian to Middle Campanian, etc.

 

Then here is the accepted norm in a particular subset of paleontology.  Researchers describing Jurassic bivalves from the UK may use a different data set from someone describing Permian corals from Arctic Canada.  'Fomations'  and 'Members'  are not universal. Biostratgraphic zones may be used such as the 'abc organism zone' of the something or another Chalk.

 

Anyways, any system needs to be flexible and not try to squeeze different stratigraphic units into one model.  Units may correspond to each other but they can be apples and oranges.

 

You are fortunate if in the UK because stratigraphy is well established and the studies over the decades top notch in peer reviewed quality.  

[Raggedy Man]

Canada hit it dead on. Many of my finds in Southeast Minnesota were found in groups or formations that have over the years evolved into the joining of some or have been disassociated due to unknown information during the study. As Canada stated, the exact location of the find never changes. I typically just record the member and formation and geological age on the ID cards, but I also keep records of the locations in my database. Paleontology and Geology are a forever evolving science and should be treated as such.

[Troodon]

Cannot agree more with the previous two posts.  Location, location first it never changes .

[DPS Ammonite]

I would write out the stratigraphic units from smallest to largest when describing where a fossil come from. The fossil is from the A Bed of the B Member of the C Formation of the D Group. It is less writing than: the D Group which is part of the C Formation which is part of the B Bed etc.

 

I don't know if there is a best way to organize and place in order the other information that you mentioned.

[stoodleypike]

Thanks, guys, for all the useful info.

 

The conclusions I've come to after reading through all the literature you recommended are:

 

(1) There are a number of different types of stratigraphy (biostratigraphy, chronostratigraphy, lithostratigraphy, etc.) each with their own system of nomenclature. Don't get them mixed up and use terms from one set of units with terms from another set;

 

(2) Usage can be either formal or informal. Again, don't get them mixed up. As I'm not a professional stratigrapher, my descriptions will inevitably tend to be on the informal side. No harm in that. Accuracy is the main thing. Any type of description, providing it is consistenly applied, is probably sufficient for even the keenest of amateurs. I've always described strata from big to little, so I'll carry on doing it that way. No point in changing it as this stage. But if you've always gone from little to big - then, good luck to you. I can't see there's anything wrong with that.

[Wrangellian]

On 2016-10-13 at 11:24 AM, DPS Ammonite said:

I would write out the stratigraphic units from smallest to largest when describing where a fossil come from. The fossil is from the A Bed of the B Member of the C Formation of the D Group. It is less writing than: the D Group which is part of the C Formation which is part of the B Bed etc.

 

I don't know if there is a best way to organize and place in order the other information that you mentioned.

I'm a little tardy getting to this party, but I think you could just as easily write: "D Group, C Formation, B Member, A Bed" - as long as you mention Group, Formation, etc, there will be no confusion. Main thing for clarity is doing it in order from largest to smallest or smallest to largest, rather than mixing them up. (Maybe use abbreviations such as Gp, Fm, Mbr to save space)

[stoodleypike]

Thanks, Wrangellian.

 

I'm sure you're right (at least it makes sense): big to small, small to big - either way is OK, just so long as you include all the individual parts and get them in the right order.