Dear Dr. Al-Ajmi,

I admonish you to cause unnecessary confusion by re-naming a formation owing to the thickness variation relative to the type locality. It makes no sense at all. Even if there are lithological changes or indications of a lateral facies change, e.g., from a continental facies through a shelf facies to a deep-water facies a well-entrenched stratigraphic term should be maintained in my opinion. Stratigraphy is aimed at correlating contemporaneous strata which can be different in thickness and composition. If we flood the local stratigraphy with a huge amount of local terms we once upon time are only forced to carry out a huge clean-up operation. The paper production is increased, the scientific profit certainly not.

My question what is the net-result and benefit of your renaming? A new paper will not be greeted with love and appreciated.

Keep hands off this action, it makes no sense neither stratigraphically nor scientifically at all. I recommend rather to investigate why such thickness changes, in particular, and lateral facies changes, in general, take place in this series.

Trust an “old dog” in field geology

H.G.Dill

Dear Dr. Al-Ajmi,

I admonish you to cause unnecessary confusion by re-naming a formation owing to the thickness variation relative to the type locality. It makes no sense at all. Even if there are lithological changes or indications of a lateral facies change, e.g., from a continental facies through a shelf facies to a deep-water facies a well-entrenched stratigraphic term should be maintained in my opinion. Stratigraphy is aimed at correlating contemporaneous strata which can be different in thickness and composition. If we flood the local stratigraphy with a huge amount of local terms we once upon time are only forced to carry out a huge clean-up operation. The paper production is increased, the scientific profit certainly not.

My question what is the net-result and benefit of your renaming? A new paper will not be greeted with love and appreciated.

Keep hands off this action, it makes no sense neither stratigraphically nor scientifically at all. I recommend rather to investigate why such thickness changes, in particular, and lateral facies changes, in general, take place in this series.

Trust an “old dog” in field geology

H.G.Dill

Based on the North American Stratigraphic Code (article 23), here in the US we would revise (the boundaries) and redescribe (the contents) based on the new information, but keep the definition of the formation (and its name) intact. The goal is to account for the new discovery while having the least possible impact on the existing body of literature and nomenclature.

Dear Dr. Al-Ajmi

There is indeed no point in changing a formation name, just because the unit is thicker elsewhere. It will merely create confusion. Rather than introducing new formation names, geologists should focus on integrating new observations in robust and well-established stratigraphic frameworks.

Dear Dr. Ai-Ajmi,

Field geologists commonly face this problem. Since a formation is defined (‘International Stratigraphic Guide’) by lithic characteristics, mappability (on scale practiced in the area/region/country) and stratigraphic position, so long as these properties are maintained, the name assigned at the stratotype is to be retained. If a distant section is connected with the stratotype by lithological continuity, thickness variation commonly occurs. However, greater thickness is not a criterion for designating a new formation. If the increase of thickness in the new section is due to additional lithology which is not present in the stratotype or which causes a marked change in the definition of the formation then a different name may be proposed, but its rank will depend on other criteria including mappability. If the two sections are lithologically disconnected, but stratigraphic position remaining same, it is desirable to tackle the problem with lateral lithofacies variation. It is also to be adjudged if the formation laterally qualifies for a group.

Best wishes.

No need to change formation name if the thickness varies at different places

Well i would like to thank all of you since you help me by giving you answers to this problem, and share me your experience.

Thank you

Dr. Hussain Fahad Al Ajmi

Research Center

Riyadh, Saudi Arabia.

[email protected]

+966506662263

No need to change the published/accepted name of Formation.

Dear

Laterally the formation(s) change in thickness and lithology , some formations have thickness range from meters to hundred of meters .

thanks

I see no need for a new formation name. If thickness mattered we would have a plethora of formation names, bringing in a great deal of confusion..

I agree with all colleagues in their opinion.

Since the formation is the same it is baseless to change its name on the basis of thickess or depth of burial.

It is a very good and impressive question to be answered.

I think there must be a way to update the old nomenclature of the old rock units.

If you have new data, e.g., new biostratigraphic finds, you can ponder over a re-naming of a stratigraphic unit but not in this case. It would nothing but to blow up the lists of publication and, in principal, violate what stratigraphy is all about.

H.G.Dill

Dear Hussain, I think changing the name of formation just based on thickness would not be of any importance to the readers. However, it can be divided into different units such as Upper, Middle, and Lower Section with variable lithological composition and thicknesses, further, it can be correlated with the formations of the same age in either onshore or offshore and vice versa. New names should be proposed only when there is a clear need for them. Every field geologist, before taking steps to establish and name a new unit, should carefully examine whether adding another name will, in fact, improve the understanding to the community or not? If the only thickness is concerned, I believe, it will not be a big addition. For further details, please refer to " Field Geologist's Guide to Lithostratigraphic Nomenclature in Australia by H. R. E. Staines" , although it is the only applicabale to Australian regime, however, you may get some insights for the criteria. Hope it works. Other professional geologists may put their valuable comments.

Regards

Majid

I think this is not important and it’s better to leave it like that

Dear Sir

In case we want to change a formation name, it is provided that 1) if the base and or top of the former name is not clear or unexposed, 2) if there is conglomerate bed has wide geographic distribution. In the above cases we can change the formation name. But the chage in thickness from one area to another we prefere the old name without change in name.

Best regards

M.A.KHALIFA, MEONFIA UNIVERSITY, eGYPT

I agree fully with Carl Stock: "I see no need for a new formation name. If thickness mattered we would have a plethora of formation names, bringing in a great deal of confusion.. "

I agree, no need for a new formation name. Formations commonly vary in thickness from place to place.

Useful to note somewhere that the formation can be thicker than measured at the Type Section. However it was never the case that formations are named where they are thickest...unless by happy accident that is the best "Type".

Dear Dr. Hussain Fahhad Al-Ajmi

I completely agree with Dr. Harald G. Dill. Lateral changes in the thickness of formations are normal in sedimentary basins. Because the process of sedimentation is not the same in all sedimentary basins at one time. Due to the confusion in future study, renaming is not suggested.

Thanks for your question

Best wishes

Mohammadsadegh

I think there would be a country based committee or commission with authority on name change and name allotment. You should submit your suggestion to that committee and let them decide. Assigning names by yourself will create much problem in literature.

Thanks

In Pakistan, it is done by Stratigraphy Committee of Pakistan