Biostratigraphy - Science topic

Keller 1982: http://mmtk.ginras.ru/pdf/keller1982.pdf

I will suggest you contact the GEOLOGICAL agencies in your country. Better still oil companies on exploration and exploitation. They will be the best to provide your need s. Best of luck

Hi Marcos. This is an eternal issue for palynologists and other biostratigraphers. My general opinion is that reworked taxa should be shown in charts, and properly annotated (usually Rw). But if the reworked taxa are irrelevant to your study, you may want to exclude them from the charts, but should in any case refer to them when describing the assemblages in the text.

It depends on your objective and what you want to show with your data.

All the best

Gil

Hi Dear Margherita

Barremian and Aptian limes contain abundant amounts of orbitolina and this is a good idea.But you have to make sure about the taphonomic effect of ostracoda on the chemical composition.

Hi Maqsood,

Take a look at this:

Cheers,

Nadir

With an example: in Agnini et al 2014, the LAD of Discoaster lodoensis was calibrated at 48.37Ma on the 1995 GPTS. It is thus between the bottom of C21n (47.906Ma) and the top of C22n (49.037Ma). On the 2020 GPTS, those chron boundaries are at 47.760 and 48.878Ma respectively. The mapped age of the LAD of Discoaster lodoensis on the 2020 GPTS is thus (by linear interpolation): 47.760 + (48.37-47.906)*(47.906-47.760)/(49.037-48.878) = 48.18606Ma. Note that we normally have a page on the NSB website allowing this kind of conversion but it is currently buggy since we updated the website last month and i m currently busy correcting it to allow this type of conversions again).

@ BIO-SEQUENCE STRATIGRAPHIC UTILITY OF SHE DIVERSITY ANALYSIS Wakefield, 2003

Hi Vicenzo,

just three remarks from my side:

1. Urgonina = subaxial section of Orbitolinopsis kiliani Silvestri

2. Paracoskinolina cf. reicheli = transverse section f an orbitolinid with pillars and one intercalary beam (right side)..such type of sections can be found among various taxa (e.g. P. reicheli, P. sunnilandensis, D. walnutensis etc.)...without axial sections that show the arrangement of the pillars (aligned or alternating) and the presence/absence of rafters in the marginal zone, generic and specific determination is almost impossible.

3. The presence of Orbitolinopsis kiliani challenges your upper Aptian age.

Hope this helps a little bit...more thin-sections = more specimens = more and better determinations = more and better stratigraphy : - )))

Saluti

Felix

Samples from IODP are usually given in the range of 10cc for foraminifera and 5cc for nannoplankton. I usually use half of the 10cc and save the rest in case of need and/or for eventual nannoplankton analyses. Then I weight the dry sediment before washing and the single fractions after washing. Then you split your fractionto have around 300 specimens and you count the single species relative abundances (and you count the number of splits as well). If you need to have foraminifera x gram of sediments, you consider sediment weight and split numbers.

First Appearance Data of Protohertzina might be constrained to 545–540 Ma according to SSFs (including Protoherzina and other protocodonts) reported from Ust’-Yudoma Formation, Russia. see the ref below:

Zhu M , Zhuravlev A Y , Wood R A , et al. A deep root for the Cambrian explosion: Implications of new bio- and chemostratigraphy from the Siberian Platform. Geology, 2017, 45(5):459-462.

Dear Majed,

This paper may be of interest to you:

Vavrek MJ. 2016. A comparison of clustering methods for biogeography with fossil datasets. PeerJ 4:e1720 https://doi.org/10.7717/peerj.1720

It concerns biogeographic data but its conclusions are interesting for fossil datasets.

All the best.

Leonid Shumlyanskyy

There are of course ,as follows:

（1）Zhu Zhi-Yong,Jiang Shao-Yong,Liu Guang-Xin,et al. Precise dating of the Middle Permian: Zircon U–Pb geochronology from volcanic ash beds in the basal Gufeng Formation, Yangtze region, South China[J]. Gondwana Research, 2013, 23: 1599-1606.

（2） Wu Q,Ramezani J,Zhang H, et al. Calibrating the Guadalupian Series (middle Permian) of South China[J]. Palaeogeogr. Palaeoclimatol. Palaeoecol., 2017, 466: 361-372.

However,did the volcanic ash beds souce from the Emeishan large igneous province(ELIP) eruptions and whether the bedded cherts of Gufeng Formation were affected by ELIP?

According to your summary of the minerals involved, I can only recommend to direct your thoughts to the K-bearing mica and make use of K/Ar or Ar/Ar dating techniques.

Kind regards

H.G.Dill

Maybe Holcophylloceras mediterraneum?

I am not an expert of Oxfordian ammonites, but according to the subcircular section in the very internal towers, then oval and finally subrectangular to subquadratic elevattion , I guess it belongs to Peltoceratoides, probably it's

( Gregoryceras pervinquieri (Spath,1913) )

Good luck

As I understood you have clastic rocks. The clastic rocks have mineral constituents derived from more than one source, each mineral gives the age of its source rock " assuming a state or radioactive secular equilibrium exists". So, it is impossible to have a true age dating for clastic rocks by simple method of dating as we do for hard rocks. You will then have mixed ages. You can use 87Sr/86Sr stratigraphy if you have chemically formed sediments such as limestone but since you have clastic sediments you will have minerals with different 87Sr/86Sr ratios. People try to use Thermoluminescence dating (TL dating) for clastics and age of sedimentation but with high uncertainty.

TL dating is the determination, by means of measuring the accumulated radiation dose, of the time elapsed since material containing minerals was either heated (lava, ceramics) or exposed to sunlight (sediments).

Dear Mr. Afenzar: You have to investigate in more detail your red bed sediments and clearly distinguish between cement minerals, which are autochthonous and amenable to radiometric dating given they contain K, U, Th, and Rb such as some micaceous phyllosilicates, cryptomelane or uranyl-bearing supergene minerals. The majority of mineral phases might be of detrital origin which have only some implications on the lithological processes in the provenance area and give you a maximum age of formation which has very little meaning for your problem. Lithostratigraphic correlation with other strata of a defined age of sedimentation is possible but needs a lot of experience because you have to take into consideration lateral facies changes between the two.

I wish you much success

H.G.Dill

Mike,

It is important I think to honour the sample spacing and therefore follow your sample defines base approach. This means there will be unzoned intervals where there are no studied samples; this is fine as it means if additional samples become available in the gap that the zonal boundaries can be adjusted to fit any new data which may be in the new sample.

There is also another approach whereby regional knowledge allows you to know that a formation boundary, which may fall between biostratigraphic sample points allows you to say that the overlying biozone definitely has to fall above that formational (and associated wireline log) boundary. So to take the top defines base principle in these circumstances is something you may know has to be wrong.

I hope this helps.

Phil

Hi Patrick,

nice! Many thanks for you very detailed list of references. I will go through them in order to find more on upper K forams.

Best,

Lorenzo

Ghulam:

Kindly see this link for useful insights.

Best

Syed

Thanks a lot Luc,

It's a pleasure to have some news of you. Yes I know, It's very damage because this surface (probably a condensed surface) is plenty of belemnites and ammonites, even large specimen of 20 cm. Unfortunately the dolomitization and the bad preservation give us bad material... You which work on the area, did you have some publication on Upper Jurassic of the area of Saint-Vallier du Thiez?

Thanks a lot,

Cheers

Majed:

Have a look at this link for essential insights about Ammonite biostratigraphy of Cretaceous. How Bentonite is related to this theme remains unclear to me.

Best

Syed

 https://www.researchgate.net/publication/281108040_Ammonite_Biostratigraphy_of_the_Cretaceous-An_Overview

Use a low speed diamond saw with dual blades and a 2mm spacer. It will cut out a wafer which can be broken into samples. The drill was a good idea too.

Abdalla:

Specimen documented by Rzger does not match the species: Insculptospora maxima . Have a look at the documented form in this link:

 http://www.academia.edu/11957312/Climate-controlled_palynofacies_and_miospore_stratigraphy_of_the_Jauf_Formation_Lower_Devonian_northern_Saudi_Arabia

Best

Syed

Daniel:

Attached links would offer helpful insights:

Best

Syed

Taghi:

Strong affinity is suggested with Globotruncana arca (Cushman) of Late Campanian age. 

Best

Syed

Dear Taghi,

 Stable isotope studies you can study in many institute/universities around the world. It wont cost you much. If you have good no. of micro fossil that will be well enough.

mainly use G.rubber, G. bulloide etc.

Hope the following papers will help you for further analysis.  Check the methodological part.

all the best

Sorry, it is not my speciality

Luoyang:

You may find this link interesting:

Best

Syed

Well, if you're talking about gas/oil plays in the Devonian-Mississippian black shales, not much.  Conodonts form the biostratigraphic framework for them.

Suman:

For Palaeogene, again the  facies is important. One should not loose sight of the fact that calcareous nannofossils being much smaller than planktonic foraminifera, yield far more specimens per unit volume of sample. Also the age of the samples could be determined in minutes by calcareous nannofossils, whereas for planktonic foraminifera it may take hours to days. In marginal marine facies, if the biozonation yielded by these two groups are integrated, a much finer resolution could be obtained (Eocene of Kutch, India). But in Palaeogene Flysch facies of Andaman island, for example, you may not get any trace of these two groups, which are otherwise present in Flysch of other regions, like European Flysch. So depending upon region, tectonics, facies and state of preservation, you may choose either of two or both.

Best

Syed

Dear Syed,

I am giving you an up vote on your answer. Best wishes, Paul.

Zailiang:

You have a choice when you are working with outcrop sections whether marine or of non-marine facies. You have a choice of only palynofossils when working with exploratory borewell material (well cuttings or cores). In certain marine outcrop sections like Jurassic, ammonites are better as they offer much higher resolution than accompanying calcareous nannofossils.

Best

Syed

Thanks for the refreshing contribution of Zaiiang, Kenneth and Marcelo. I quiete liked the following Aeon video:

You might be interested in the very last contribution of Guex and Galster

"A simple technique to establish sequences of datums and to highlight transgressive–regressive cycles"

Dear Paul and others. I think this is not a question of either, or. Species are always both: both are intrinsic to species; it strongly depends on the spatial and temporal scales you are looking at how useful the organism/species is for your stratigraphic or environmental purposes.

We live in a deterministic system where every moment is unique and never exactly repeats any previous moment. Furthermore, organisms interact with, and are part of this environment. Both evolution (by natural selection) and ecology are thus interwoven and two sides of a coin - one does not work without the other. Thus, at every given moment in time you have a unique configuration of life forms. Furthermore, each species has a unique set of parameters with respect to its niche (role in the ecosystem) and period of occurrence. I agree with everybody that both can only be elucidated through detailed, study of the organisms in space and time. Mostly, this is a lot of work.

Interestingly, for short time intervals, it is unlikely to see species getting extinct or new species appearing. All you see is changing (relative) abundances and they reflect the changing environment (Think e.g. of reconstruction changes in the order of millennia and shorter periods; like environmental change over the last 200 yrs). Organisms that appear or disappear from your (local) record in such situations are likely to do so because of a changing local environment and haven't become globally extinct or newly evolved.

With an increasing time window, species turnover (extinction and emergence of species) plays an increasingly important role. For environmental reconstruction this is a complicating issue since it interrupts the continuity of the system. You have to find out the ecology of the newcomers and to find a way to deal the loss of information due to extinction.

Despite these complications, each species has a first appearance, and as such is a marker for a given time interval. This interval may be entirely in the past or continue into the future. As such each species is also a biostratigraphic indicator.

Thanks for comments, interesting, approach you shortly.

following the link above, then find out your answer

Dear Shaddha

you check link below 

Regards

Massih

Hello Hans-Volker,

Are you certain? Ammonoid beaks (lowr jaw-parts) (aptychae) are either divided in two parts (aptychus-type with varous subtypes used for an elaborate parataxonomy) or a single part (anaptycus-type). (good examples are here at researchgate in this publication: https://www.researchgate.net/figure/263301051_fig4_Figure-1-3-D-reconstruction-of-four-ammonoid-jaw-morphotypes-%28viewed-from-the-left

This mold looks like it consists of 4 parts. Even if the upper jaw beak is preserved in ammonites (which happens less often than jin lower jaws due to their different thickness etc.) it has a single point not divided by  a deep fold so the resulting mold would have 3 part and not 4 as in this fossil.

Taphonomic analyses should be done previously to any paleobiogeographic or paleoecologic interpretation. Stratigraphic ranges are not paleobiologic ranges. That we have are taphoregisters. Vertical range does not correspond actually to temporal distribution of taxa, and preservation may be linked to taphonomic factors related to facies. Taphonomic processes such as necroplanctonic derivation, rejoining, or other biostratinomic displacements can also deeply modify geographic distribution of fossils, and some of the biostratinomic displacement mechanisms may be related to facies.

Thank you Massih for your help!

Best regards

Hi Sofie

Late Triassic Dinoflagellate literature is substantial, I can recall one important publication with which you can start searching/requesting for more:

W.A.S. Sarjeant (1963), Nature, 199, 353-354. Fossil Dinoflagellates from Upper Triassic Sediments.

Also look at : Jafar and Tripathi (2001): Late Triassic palynomorphs from the Andaman-Nicobar Basin, Andaman Sea India. Modern Geology, v. 24, 205-219.

Best. 

Hi Yoannis,

Although I am not palynologist, but am very interested in this subject. I have a procedure for Quaternary pollen and you may have a look to the attached file. Hope this will help you.

"Solva“ as a stratigraphic term refers to a lithostratigraphic unit generally referred to as the "Solva Group.“ To my knowledge no chronostratigraphic meaning has ever applied to this so that „Solva Stage“ is invalid. The name Solva is a reference to a rock unit exposed in Solva Harbour, Pembrokeshire, South Wales. The name has been introduced by Henry Hicks in 1881 (Hicks 1881, The classification of the Eozoic and Lower Palaeozoic rocks of the British Isles. Popular Science Review, new series 5). A relatively comprehensive discussion on the stratigraphy and the problems related to this can be found in Rushton (1974, The Cambrian of Wales and England. In: Holland, C.H., ed., Lower Palaeozoic rocks of the world. 2. Cambrian of the British Isles, Norden, and Spitsbergen. Wiley & Sons).

Thank you Sysfrizal for your answer, which does  not  essentially answer the question.However, it is very instructive so I am voting you heads up on your response.

For cyanobacteria (phosphate deposit forming cyanobacteria) it is documented that it is their post mortem alteration...same is true for shelly deposits generating phosphatic deposits.....It may be the same phenomenon in case of conodonts added with replacement of calcium carbonate by calcium phosphate. It has also been published (in Nature) that apatite crystallites grow over organic carbon nucleites.  

One important significance is the autoecology of the species. Most of the time, wide-stratigraphic-range species are opportunistic, eurytherm, euryhaline, etc. That is quite paleoenvironmental information on that. If it has extant relatives, or the species is extant, the application of the actualistic principle is more dependable. In fact, the wide-stratigraphic-range species are the one that are good proxys for paleoecology. The short stratigraphic range species are good for biostratigraphy.

If the taxon really changes or not in the geologic time, is another discussion. If there is no morphological differences, paleontologist will see them as the same species (taxon). But there is no more information available in the fossil record! So, that is what it is.

Thanks Haylay for coming back to my answer. It is quite difficult to find any published material on this topic. I worked in Triassic carbonates in Central Europe and from my experience it seems that bioclastic carbonates are the best material to find conodonts. These bioclastic carbonates are rich in invertebrate shell material, but also vertebrate remains such as teeth, bone fragments (fishes, marine reptiles) and it seems that these clastic layers, often related to storm events, yield the best material like in bone breccias.

I think you should use/apply the concept of acme zone, abundance zone, or peak zone.

In carribbean modern sediments, we found two dinoflagellate cyst species thought (up to now) extinct since Pliocene. That is discussed in :

« Organic-walled dinoflagellate cyst distribution in the Gulf of Mexico »

Limoges A., Londeix L., de Vernal A.. Marine Micropaleontology in a forthcoming issue (it has been accepted some weeks ago).