Questions related to Biostratigraphy
Traverse's 2007 Paleopalynology (2nd Ed.) contains a chapter solely dedicated to reworked palynomorphs. If I understood correctly, spores or pollen found in rocks of older age can be released and subsequently redeposited in younger rocks. One major hint is that they can be more thermally mature/carbonised than the assemblage, and may not be as well-preserved.
However, when dealing with such scenarios, determining the last appearance of a certain morphotaxa becomes tricky. This issue is further complicated by the fact that it can be hard to distinguish reworked taxa from background levels of rare morphotaxa that may persist over time. In one core that I am analysing there is even a secondary acme of a morphospecies in strata that are almost a million years apart!
Should these potentially reworked specimens therefore be included in a biostratigraphic range chart, ignored, or singled out?
I want to use orbitolinids for the biostratigraphy of a Barremiam/Aptian carbonate platform, to support my chemostratigraphy data. I have used related publications for descriptions and pictures trying to identify the different species, but I would like to have the opinion of an expert to confirm my classification.
I am working on the biostratigraphy of Pleistocene sediments from the high latitude region in south-east Indian ocean sediments. Kindly suggest me any book or articles in which the above-mentioned foraminifera are discussed. The articles on the zonation will more be appreciated.
How can we interpolate the age of marker microfossils according to new time scale.
Eg. if the previous research papers or standard zonation charts has used older timescale then how can we use that particular microfossil in the new time scale.
When we are working with multiple microfossils then we try to follow a single timescale (the most recent one) so this is required.
Hi Cretaceous experts!
I'm trying to determinate these orbitolinids from the Lower Cretaceous of Sicily (Southern Italy). I would like to identify the species, but their systematics is rather difficult for me. I suppose they could belong to the genus Paracoskinolina and/or Urgonina and the assemblage seems to suggest a late Aptian/early Albian age. Any suggestions are appreciated and will be helpful.
How many grams (weight) is recommended for Planktonic foraminifera Analysis?. The samples are from Ocean Drilling Cores.
Most authors agree that the oldest paraconodonts like Protohertzina derive from the "Anabarites trisulcatus - Protohertzina anabarica Zone". According to the geological time-scale 2016 (Ogg et al. 2016), this would yield a minimum age of about 532.7 Ma. Of course, Protohertzina already occurs at the base of this zone, so my question would be are there any earlier "First Appearance Data of Protohertzina" or other early protoconodonts which are bounded below radiometric age or can be reasonable correlate to an interval below 532.7Ma. Your help would be greatly appreciated.
I am bit confused about which clustering method to use? I have collected sediment samples from an outcrop from old to young (constrained), my samples are hand picked specimens. I wan to run cluster analysis on the foraminifera and thecamoebians , but not sure which cluster method to use, I am between Ward's and Coniss and 'Euclidean' ?
I knew that (correct me if am wrong) Ward's usually used for clustering lateral samples, but what about coniss? in my case I have vertical section where I collected my samples from bottom to top!
The relationship between the origin of the bedded cherts which have volcanic ash beds from the Gufeng Formation and the onset of the Middle Permian Emeishan large igneous province eruptions.
I have completed the indirect dating methods like foraminiferal biostratigraphy and nannoplankton stratigraphy of Quaternary marine core sample.For direct dating of 1000 yr - 2.5 Ma marine core samples which method will be suitable?
I found this ammonite in the Oxfordian Ammonitico Rosso from the Balearic Islands, Spain.
I would like to know the genus and the species if possible. I'm doubting between Phylloceras and Trimarginites.
Following up with the previous questions, I found these specimens in the Oxfordian Ammonitico Rossos facies from the Balearic Islands, Spain. I would like to get some help identifying the genus and species of these 3 specimens.
I suspect that the second specimen, the one with primary and secondary ribs, could be a Taramelliceras.
What is the best method for measuring the age of clastic rocks which has no fossils ? Your advice is highly appreciated.
I am looking for a reliable method for dating azoic sediments (conglomerates, sandstones and mudstones). they are triassic-Jurassic red sediments separated by the CAMP.
Just wondering what the view in industry is for displaying *interpreted* biostrat data (biozones, chronostrat etc.) on charts. Some companies prefer a "top defines base" principle where the top of any underlying unit automatically defines the base of the overlying unit. Others prefer a "sample defines base" principle where the base of an overlying unit is drawn down to the sample *immediately above* the sample which defines the top of the underlying unit (if that all makes sense!). Or maybe there are even other alternatives?
I'm guessing there's a mix of preferences but it would be interesting to see what people think and reasons for choosing the method they use.
I'm looking for every reference could be useful. In addition I'm looking for the two following specific references that I cant download
1) Larger foraminiferal biostratigraphy of the upper Cretaceous (Campanian) to Paleogene (Lutetian) sedimentary rocks in the Haymana and Black Sea regions, Turkey Kuniteru Matsumaru. Micropaleontology Volume 62, No. 1 pp. 1-68 - online 07 Jun 2016
2) Larger Foraminifera from the Philippine Archipelago PART 1: Late Cretaceous to Middle Eocene Kuniteru Matsumaru. Micropaleontology Volume 63, No. 2-4 pp. 77-148 - online 31 Dec 2017
Moreover, if someone got an update email of Prof. Kuniteru Matsumaru I will be glad to receive this useful information.
I;m facing difficulty in identification of Nummulites, Assilinas, Ranikithalia, Lokhartia, operculina species as working on biostratigraphy and microfacies analysis of Early Eocene Formation from Nothern Himalayas, I needed relevant data,
thanking of anticipation..
It come from dolomitic limestone from South-East of France dated from Kimmeridgian (Late Jurassic) following the geological map. This specimen looks like to an Oppeliidae such as Streblites??
What is your opinion? And I know, it 's very poorly preserved, but it is the best specimen!
Can someone suggests to me some recent or not very old papers about these topics:
Biostratigraphy, Bentonite and ammonite Dating methods
Thank you in advance.
I have some Eocene samples characterized by planktonic foraminifera assemblages ( I.e.Clavigerinella colombiana, Clavigerinella akersi,and Pseudoglobigerinella bolivariana), which are better adapted to eutrotrophic cold water environments. At the same time in such samples I find increased abundance of calcareous nannofossil genus Chiasmolithos.
and where can I have my picked foraminiferas analysed? Also, any idea on the costs?
Thank you for you time.
I am working in a project which aimed to combine all the vegetation data with paleoenvironment, paleocology and paleoclimatology. Since pollens are vital elements for paleoenvironment reconstructions, we will use them as proxies. Recently, I found LPJ-GUESS software (Lund University, Sweden) and I started to look in its own database and models.
The attached image is the "Biomass" model for Azerbaijan as paleoclimate records. I want to understand how to interpret this image in the language of paleoenvironment.
In comparison, which proxy gives more accurate biostratigraphic data: nannoplankton or planktonic foraminifera?
What is the most suitable climate change modelling that can be coupled with biostratigraphy data for future climate change prediction?
Specifically, I'm interested in estimating absolute ages for nannofossil events (LADs, FADs, acmes, etc.), potentially using published calibrated ages to constrain certain events. The data is in the form of multiple wells with events associated with particular depths. I'm aware of four main methods: graphic correlation, constrained optimization, RASC, and unitary associations. Are there other methods? Any recommendations for software? Suggestions about the best method for this data set? Thanks in advance-
It would obviously take a lot of detailed knowledge of the species involved and its paleoenvironment and its biostratigraphy.
The enclosed photographs are from Upper Jurassic - Lower Cretaceous fluvial succession of Gondwana. I am of the opinion of their origin through biogenic activities, however, not very sure. The preservation of the structures is in light to dark gray clayey horizons having abundant leaf impressions of Pteridophytic to Gymnospermus remains. The clay units occur as interbedded horizons with siltstone or, lenicular/poketed occurrence in medium grained sandstone
First time in our lab we are attempting trace element analysis on speleothems. We are using JLs-1 as standard. For major elements we dissolved 6mg sample in 60 ml (10000 x dilution factor). Though major elements were easily measured, trace elements like U and Th went beyond detection limit. The standard used has 0.0287 ppm of Th. For calibration curve, further dilutions may reduce it to undetectable limits.
One of the most problematic age determination of rock units is referred to change in stratigraphic range of some foraminifer taxa as endemic species and facies change in Cretaceous of the Zagros shallow water facies, probably it is assigned to paleobathymetric change. I will appreciate that anyone interpret presence and extinction of shallow water foraminifer and provincialism and Cretaceous sub stage.
I am interested in biostratigraphic and taxonomic reports of Triassic dinoflagellate cysts, especially such records that are not easy to come by via libraries and on-line access. If you have any such reports that you can share, or knowledge of where I can get access to them, I'd be greatful.
Clarification: I am NOT looking for records of published Triassic dinocyst taxa. It is accounts of undescribed or obscure forms that I am after!
I am looking for a protocol to isolate and mount fossil pollen plates from coastal sediments. I have a little experience working with fresh plant material for pollen analysis.
I'm putting together a table of Lower to Middle Cambrian fauna and have been using the Palaeo database/fossil works as a reference. However When it comes to filing in regional Stage data, a lot are referred to this 'Solvan Stage'. I have only found one reference to it (in "Phosphate Deposits of the World" by Cook and Shergold), but no other ones. Can anyone point me in the right direction?
In the Pennsylvanian of Atlantic Maritime Canada this species has a restricted range. I am wondering if this species is a good index fossil.
Beside crystallite growth due to thermal overprint it seems that These crystallites also can be enlarged in different ways. Has anybody an idea?
To reflect on the limits of the application of actualism in paleoecology, I wonder about the significance of paleontological species that have a wide stratigraphic range.
Almost all marine sediments and sedimentary rocks are expected to hold some phosphatic fossil elements (Sweet, 1988). Based on some factors (including primary results) in the study area I found that going for conodont dating will be fruitful.
In the core I am studying right now, I divided it based on evidence to zone, sub-zone and know I have trouble to determine which prefix I should use for the division smaller than sub-zone? Is there any standard to use for smaller division?
The term "Lazarus Effect" gets used a lot in a theoretical sense, but I would like to find out what sort of durations the "outages" are for Lazarus taxa.