Questions related to Stratigraphy
I'm studying an upper Aptian carbonate succession of NE Spain which has traditionally been considered to be devoid of rudists due to paleoenvironmental stress. I'm not at all familiar with this group, as indeed I haven't come across a single specimen in 4 years of field research.
However, these pictures of one of my reference outcrops, sent to me by a local, show some strangely shaped fossils which I cannot for the life of me identify. All pics are of the same stratigraphic level, which corresponds to a regional discontinuity surface which could have been subaerially exposed for prolonged amounts of time.
What do you see in these pics?
This question is for an updated paleogeographical reconstruction of the Atlas Gulf and assiociated landmasses in the Early Jurassic (Early Toarcian)
We know that this Paleozoic montane rangue was exposed on the EJ (Frizon de Lamotte et al., 2008), that was being pushed by two rift systems (the Tethyan Atlas rift in the north and the Atlantic rift in the west) and that there was an ongoing exhumation, that cutaround 7.5–10.5 km of crustal rocks by the end of the Middle Jurassic (Gouiza et al., 2017). As well there is evidence it was a source for siliclastic materials in the Early Jurassic Atlas Gulf (Krencker et al. 2020).
But, is there any suggested reconstrucion of it´s appperance? Or a suggestion of what it may have looked like?
-Frizon de Lamotte, D., Zizi, M., Missenard, Y., Hafid, M., Azzouzi, M. E., Maury, R. C., ... & Michard, A. (2008). The atlas system. Continental Evolution: The Geology of Morocco: Structure, Stratigraphy, and Tectonics of the Africa-Atlantic-Mediterranean Triple Junction, 133-202.
-Gouiza, M., Charton, R., Bertotti, G., Andriessen, P., & Storms, J. E. A. (2017). Post-Variscan evolution of the Anti-Atlas belt of Morocco constrained from low-temperature geochronology. International Journal of Earth Sciences, 106, 593-616.
-Krencker, F. N., Fantasia, A., Danisch, J., Martindale, R., Kabiri, L., El Ouali, M., & Bodin, S. (2020). Two-phased collapse of the shallow-water carbonate factory during the late Pliensbachian–Toarcian driven by changing climate and enhanced continental weathering in the Northwestern Gondwana Margin. Earth-Science Reviews, 208, 103254.
The data I have to incorporate in the stratigraphy section will include lithologies such as metamorphic rock (basement), granite (intrusive), shales of variable thickness and colors, Ages of each lithology, andesite and granite (extrusive), and unconformities.
Cemeteries often remain in use over many generations, and may represent several hundred or even thousands of years of burial tradition. Some cemeteries in cities contain tens of thousands of burials. With many graves inter-cutting each other, patterns of stratigraphic relationships can be quite complicated. The cemetery ground might be envisaged as a 3-dimensional stratigraphic structure of some complexity. But while it is common to see plans of the spatial layout of graves on a horizontal plane, it is actually quite rare to see good profiles or cross-sections through cemetery ground showing the vertical stratigraphy. With modern recording techniques and computer analysis, it should be possible to generate such cross-sections from data gathered during excavation. If anyone can point to good examples, that would be much appreciated!
A good number of Palaeocene-Eocene LBF taxa are reported mostly from the East-Coast sedimentary basins as well as Rajasthan Basins in India. Many of these genera / species have considerable index marker value in the stratigraphy and need to be defined on precise quantitative criteria in order to limit their morphological variation, thus making them more useful for finer stratigraphy. This will also open-up understanding their phylogenetic relationship through geological time. Initially genera like Laffetina, Lockhartia, Sakesaria, Ranikothalia and others may be taken up for the studies.
Is the power low relation of fault size based on the range of the data set? So, the full range of data will deviate from power low cumulative distribution regardless of other related factors such as data scale, sampling biases, mechanical stratigraphy, fault linkage, etc
Since histograms can be applied in many different field in Hydrogeology is it possible to use it for predicting aquifer type.
Is this coral limestone suitable for Sr isotope stratigraphic study to deremine its depositional age? The limestone underlies a turbidite sequece yielding Late Miocene planktonic foraminifera and calcareous nannofossils, and rare Oligocene-Miocene larger benthic foraminifera are obseved in the thin section of the limestone.
I look in context of a study about working modes of scientific bodies for publications that describe / analyse the working modes that are inherent to the practices of the International Union of Geological Sciences (IUGS) respectively the International Commission on Stratigraphy (ICS). Can anybody point me to publications, please? - best regards, Martin
Hi, dose anyone know tuff- layer or volcanic ash layers at northern germany from lower and middel Coniacium ?
I can only find:
MUTTERLOSE J., HISS M., LINNERT C., MUELLER M. (2014): Lithologie und Stratigraphie einer sedimentären Großrinne aus der Oberkreide (Coniacium) von Soest; Geol. Paläont. Westf. 86, S. 19 – 36, 4 Abb. 1 Tab. 1 Taf; Münster Juni 2014.
They say there are no tuff layer in Soest at lower Coniacium sedimentary rocks. But this are cannel sediments.
Dose anyone have a reading recommendation ?
Thank you and Glück Auf
I am looking for new research on facies models, similar to those published quite some time ago in the book "Volcanic Successions, Modern and Ancient" and in the book "Pyroclastic Density Currents and the Sedimentation of Ignimbrites".
I am interested in the state of progress of this line of research and its potential use in volcanic stratigraphy.
I am looking for an electronic version of:
King, C., Gale, A.S., Barry, T.L. 2016. A revised correlation of Tertiary rocks in the British Isles and adjacent areas of NW Europe. Geological Society of London, London, 724 pp.
I realize that large parts are available via GoogleBooks but many passages are missing there. I am especially interested in the chapters including non-marine deposits, such as those dealing with the North Sea, London and Hampshire basins.
Best regards, Thomas Neubauer
I found it from Permian limestone strata in Julfa province (North-West of the Iran country).
It should be mentioned, this microfossil extracted from samples collected of the Stratigraphy and bio-event studies of the Guadalupian -Lopingian boundary in the northern margin of Sanandaj-Sirjan Zone, Central Iran and North-West of Iran.
In some stratigraphic section, quartzites represents the UNCONFORMITY LEVEL or basement.
Could anyone recommend me some "reference studies/review papers" that explain "why quartzites represent the unconformities"?
Do you have any formal explantion of that term? The characteristic features, method for establishing? Relation to the lithostratigraphy? Any published sources?
Dear Researchers, I found it from Middle to Upper Permian limestone strata in Julfa NW Iran country. This microfossil extracted form sequences that belong to the Stratigraphy and bio-event studies of the Guadalupian -Lopingian boundary in Sanandaj-Sirjan Zone and northwest of Iran project.
I need this paper. This paper is very important for my research.
Anybody knows what is this microscopic fossil from the Middle to Upper Permian limestone strata?
I found it from the Middle to Upper Permian limestone strata in Julfa NW Iran country. This microfossil extracted form sequences that belong to the Stratigraphy and bioevent studies of the Guadalupian -Lopingian boundary in Sanandaj-Sirjan Zone and northwest of Iran project. Perhaps Identifying it, will be beneficial for the aim of the project.
What are the possible bio-geological and mineralogical sources of Na+ and Cl- ions in seawater ?(which minerals and geological event like major weathering events in Precambrian and Phanerozoic, excluding glaciation-deglaciation fluctuation). What had been concentration of soluble species in seawater at geologic past ?(e.g. iron and nickel concentration dropped after great oxygenation at early proterozoic)
P.S:Upon reading some early replies, I add
- Cl is not very much abundant element in universe or solar system, so why there is so much chlorine on earth? what caused cl to be caught into molten earth when the planet was forming?
- Feldspar contains K and Ca also. Ca may be precipitable in suitable pH, but why there is so much less K in seawater compared to Na? Is this because all known life form maintain K concentration higher an Na concentration lower in cell than intracellular fluid? Why did that happen in the first place?
Sea level fluctuation is caused by several factors. The major factors affecting sea level are the shape and volume of the basin of deposition, volume of the water contained therein, and tectonic uplift and subsidence. Depending upon their magnitude, their duration and affected area also varies. Some of them are of global influence whereas others are regional or localized. Sea level fluctuations greatly affect sedimentation process in the basin. This is ultimately reflected in the stratigraphic setting of the region.
What are the Geo-physico-chemical steps and mechanisms to form animal and (rare) fungal fossils? how some organic chemical signature from the species (like Sterane from Cryogenian sponge) remain in rock record while body does not remain?
The classical stratigraphic sequence of the Salt Range contains thin flows of an ultrapotassic rock at its base. Commonly known as Khewra trap, it occurs at the top of the very late Proterozoic to Early Cambrian rocks consisting of marly anhydrite/gypsum, and oil shalis overlying evaporites. The trap is an unusual rock consisting of euhedral to skeletal, spinifex, stellate phenocrysts
in a very fine-grained to cryptocrystalline, locally glassy, matrix. The phenocrysts (up to 3 cm long) are considered to be Mg-rich enstatite now complliely pseudomorphed by a mineral aggregate principally made up of talc with subordinate amoun'ts of Mg-rich clays and, locally, quartz. The matrix is unaltered and almost entirely made up of Na-Ca-poor and
Mg-Fe-rich K-Feldspar (sanidine-orthoclase), with granules, specks and dendroids of Fe-Oxide. Talc, Mg-rich clays, quartz, dolomite, and Fe-oxide constitute the amygdules.
Chemical analyses ofthe rock samples from the trap are remarkably similar in composition except for some variation in iron oxide due, probably, to leaching during alteration. The rocks consist approximately of 60 wt% SiO2, 0.7VoTtOy ll%o Al2O3,2-5% FeO, 10% MgO, 0.4% CaO, O.5% Na2O, 9% K2O, and 0.04% P2O5, Normatively the rocks are eisentially made up of orthoclase and orthofyroxene.
I would like to know the fast and easiest way to differentiate aeolian and fluvial silt by looking at the samples itself.
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 am looking for publications demonstrating the sedimentation VS subsidence rates in minibasin settings and the controlling factors. Sedimentation type and architecture would be helpful as well.
I have an image of a metasedimentary outcrop from a Proterozoic continental rift-fill sequence (attached).
The middle layer has a pelitic composition and contains abundant cordierite porphyroblasts (visible as weathered depressions). The layers above and below this layer are more psammitic. The lower layer appears to display inclined cross bedding, whereas the top layer seems to be more massive. I suspect that this outcrop preserves a 'fining upwards' sequence with the psammitic layers representing the coarser (high-energy) deposition and the cordierite-rich layer representing a finer (low-energy) depositional phase.
What I'm not sure of is which way this outcrop is younging. Are the cross bedded layers deposited on top of the pelitic layer (i.e. the image is 'upside-down')?
Or, was the pelitic layer deposited on top of the cross beds?
These photos taken at Sandstone layer . Please can somebody help me in the identification of these concentric and parralel laminations ? And which is the origin of this process ? NB : outcrops located on the coast influenced by marrine erosion.
Do you have any examples of basinal sedimentary section (black shales) where TOC correlates with calcite content? If yes which interpretations are given to these results knowing that we usually observe negative correlation between these two proxies.
Hi, nice meeting and talking to you in Quebec. I cannot find your e-mail address anywhere so I try here. Your new generic name for D. habilis? I can't remember it. What is it? and could you also provide me with a reference?
I am finishing a very big MS with a revision of the Jurassic stratigraphy of East Greenland and D. habichi occurs scattered in the paper. It would be useful with a more up-to-date name.
I am working on stratigraphy and lithogeochemistry of a VMS-hosting sequence of Paleoproterozoic volcanic rocks and would like to plot drillcore samples that I collected into IoGas and Geoscience Analyst. I only have the collar location, drillhole orientation and sample depth, however both softwares require the ZYX coordinates to display the sample accurately. I know these calculation can easily be done with Gocad, Target or other 3D mining softwares, but I am wondering if there is another (cheaper) option where I could process small batch of data on a need basis. It does not have to be something that takes into account all the drillhole deviation, I am not looking for that kind of precision. Thank you.
I am wondering if it possible to find a reef over pleo island, which formed by one of the horst block in a graben, and also is there any study case using seismic stratigraphy technic could be recommended similar to this situation?
Thanks in advace
Most of papers/researchers regarding cyclicity using Markov Chains are from 1970's to 1990's. However, in the recent literature only a few papers deals with this method. To what extent the use of Markovian processes can control or explain cyclothems or coarsening-, and fining-upward cylces?. Analysis of cyclicity in recent literature is restricted to use astronomical forcing cycles (Milankovitch bands) of known periodicities by using spectral or fourier analysis, so then, we can assume that these are the today-acepted methods for assess cyclicity?, what do you think about it?.
According to my knowledge and as per the established stratigraphy, the Patala Formation is not Danian. It is Thanetian-Ypresian as is the Pabdeh Formation. I suggest a correction. Many even doubt the assistance of Danian strata in the Salt Range and Kohat - Potwar, but that is a separate debate. The Patala Formation is Late Paleocene without any doubt, whereas Danian represents Early Paleocene. Cheers!
I have done XRD analyses of modern fluvial unconsolidated sediments (soil- clay, silt and sand) to identify the mineralogy and their proportions. I require to select the best minerals to interpret the provenance & paleoclimate of the modern fluvial sediments. Do I need to select different mineral group for provenance & Paleoclimatic interpretation? I would be extremely grateful if you kindly help me in this regard.
an someone explain how to understand topographic map better before we going to field work such as about their contour, their expected lithology, drainage pattern?
and how do we know an expected geology structure such as fold and fault through topographic map?
lastly, how to create or do lithostratigraphy?
thank you everyone.
I am endeavouring to reassess some Australian palynostratigraphic zones for the Mesozoic, which no one has done (that I know of) since before the release of the latest geologic time scale (2012). Am I correct in saying that palynostratigraphic zones are determined by their stratigraphic placement in the rock record? So if the timing changes (e.g. the Middle-Late Triassic boundary shift from 229 to 237 Ma), the palynozones would become older like the stratigraphy and not remain where they are relative to the chronologic ages?
If the metamorphosed igneous body is younger to the metasediments, then I would expect to observed the following points in the field:-
1. Presence of dykes, sills, tongues or apophyses within the metasediments.
2. Presence of metasediments as xenoliths within the igneous body.
Friends, please help me with some more points. Your contributions to this question will have a crucial impact in my research work. Thank you in advance.
I have been looking for the detailed information about the vindhyan basin evolution, its stratigraphy and also its prosectivity for shale gas exploration. I found some links online but are not accessible. Can anyone provide the links from where I can directly download? Thank you in advance.
Because i think that i have sand dikes injected in a sandstone, but i can observe or identificate the unit source for where came from
Hi, can anyone help me to identify this vertical trace fossil? I really appreciate it. Info: it was found in an Early Jurassic (Sinemurian-Pleinsbachian) marginal marine setting and it was located in siltstones. The first photo (a) corresponds to a cross-section view, whereas the second photo (b) is a lateral view. Scale is 2 mm.
Thank very much in advanced!
Would you like to help in identification of attached SEM image Ostracoda. I am suspecting it Cytherella sp. The associated larger benthic foraminifer pointing Palaeocene age and shallow marine ramp setting environment of deposition. Image scale bar =μm
could you answer me what could cause such deformations in Pleistocene glaciolacustrine deposits like on attached photos? There are mostly slightly folded layers and many overturned folds, didn't find any faults.
What methods do you propose to examine and analyze such deposits?
Can any body tell me or guide me. What will be the possible and correct interpretation when whole rock plot below the plagioclase in Sm-Nd isochron plot and high MSWD about 2.8( Basalt). There are some possible reason for this i.e Alteration and Contamination but here in my case these both possible reasons are not affected so much. There are some intergrowth present in these rock(basalt) may be the reasons for this. Give me your valuable suggestions and some good paper which is related to this kind of issues
It is a common experience that from seismic sections one can identify mostly the first order unconformity surfaces and if the data quality is too good, second order events can also be detected. However, when in the same area, well log data is studied, we start getting third order and sometimes still higher order unconformities. I just want to know the practical significance of studying multi-order sequence stratigraphy and ultimately where should we stop.
I HAVE NOW RECEIVED A PDF FROM CHRIS CLEAL. THANKS TO EVERYONE WHO ANSWERED!
Anyone have the volumes from the Moscow ICC congress in 1975. I do not know what volume, pagination, or even the exact year! of Richard Leary's publication, but this is the citation information I have:
Leary, 1979??. Namurian paleogeography of the western margin of the Eastern Interior (Illinois) Basin. Compte Rendu 8th International Congress on Stratigraphy and Geology of the Carboniferous, Moscow, 1975. Seems to be on around page 49 or so, and may or may not have associated plates/figures.
Need some literature on 2D resistivity surveys done on alluvial plains to reconstruct sub-surface stratigraphy or palaeochannel drainage network.
I'm in need of a stratigraphic column of Holy cross mountains in Poland. I want to have a lithostrat column that displays all rock units in Kielce and Lysogory regions. There are some papers but I could not compile column of each region separately.
I would be grateful if someone give me a link or a paper or a map that I can get what I'm looking for.
Thanks for your concerns.
Greeting agglutinated salt marsh foram's researchers,
I have encountered in southern California salt marsh the following live&dead species in surface samples. Test flattened, ovoid in outline, planispirally enrolled and its wall is very coarsely agglutinated. I thought it might be Ammobaculites labvthnangensis (Loeblich and Tappan, 1988) but I'm not sure. I would appreciate your advice on that- see SEM images. Thanks:)