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Hello, I am a PhD student in sedimentology and biostratigraphy, and I have a fossil leaf specimen from a Jurassic-Cretaceous deposit. I would like to receive recommendations on fossil plants used in stratigraphy, especially the upper jurrasic and lower cretaceous. Additionally, if possible, could someone help me find specialists or relevant articles on Jurassic and Cretaceous fossil plants?
Thank you very much for your assistance!
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Dear László Attila Horváth, thank you very much for all this valuable information.
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Hi,
we are looking for potential tectonic structures around the Faroe Islands on seismic data and are looking for papers detailing the stratigraphy there (especially west and southwest of the Faroes) and/or for collaborators that may give us an overview of the stratigraphy and geology there. We are notably working with 2D seismic survey OF95RE11.
All the best,
Jean-Baptiste
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Try David Jolley at the University of Aberdeen. Mention that I suggested you should contact him. If he is not working there himself, he'll likely know someone who is.
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Hi everyone.
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?
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Sorry for late response: I've only just seen this post. As others have noted, the preservation of these specimens is not great, so it is difficult to say much about them. However, here are some suggestions (...guesses!):
1. Probably not a rudist: the compressed, elongate triangular ('jamon')shape suggests a pinnid (maybe this is the one Christian commented on?). The lithology looks quite suitable for pinnids.
2. A nice view...
3. I agree with Diego: the cavity left by complete dissolution of the shell has been filled by sparry calcite growing into it from the opposing internal and external mould walls, hence the concentric seam where the prisms have met in the middle. I doubt it's a rudist, as I would have expected to have seen at least a vestige of the calcitic outer shell layer, which tends to remain when the aragonitic inner shell is dissolved, but none is shown. Possibly the thick umbonal tip of another, costulate pinnid, preserved implanted in the sediment?
4. No rudists here - just some burrowing bivalves, including a probable costulate trigonioid.
5. Seems to be an elongate internal mould of a slightly tapering cylindrical shell of some kind (hinted at by the poorly preserved pale lines on either side), but of what I cannot say. I see nothing strictly diagnostic for rudists.
All I can really say is keep looking - y buena suerte!
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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.
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I am not so familiar with the area you are researching. 27 years before I had to leave the profession... But since then I've been working in my former profession as a hobby... You should pay attention to what Ralph Thomas Becker said : 'The famous outcrop of Ouidane Chebbi and other Kem-Kem outcrops show a medium-scale hill and valley Devonian-Carboniferous topography transgressed by flat lying Cretaceous beds. So it seems that there was no alpine-style mountain range left in the Jurassic.'! Very logical!
If you look at his work he made paleontological study near the East of Anti-Atlas Range: Dra Walley... That is why you can use as prove his works... Regardless of that, without doing any research there - there is no possibility to do - my opinion was that the area worked as continental medium in Jurassic... You don't have an easy job... You need to do research in East (West Algeria, There has to exist drilling's Data! and seismic 3D surveys, 2D seismic sections) . In principle, you should be thinking about what the Moroccan Anti-Atlas would have looked like in the Early Jurassic nearly as it looks now... Only its West, North-West Area had other features. you have to determine correctly, why? I cannot say more about Hungary from here... It is clear what you have to do.
Regards,
Laszlo
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I am trying out with strater 5 and Sedlog 3.
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I have not used coral draw for such purpose but you can check YouTube.
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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.
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A good program that is also free to user for noncommercial uses is found at:
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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!
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Hi! I have some examples of grave vertical stratigraphy performed with modern recording techniques. I hope these help.
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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.
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I want to believe that the discussion raised seeks to emphasize the need for erecting precise criteria to serve as marker units or stratigraphic horizons based on the abundance of complete absence of certain taxa; and therefore find usefulness in regional correlation schemes. Such criteria should be based on peculiarity of the tools used, if they are fossils markers, are they having the characteristics of guide fossils; if they are geochemical marker, could they be tied to known global geochemical perturbations eg the layer of iridium across the K-T boundary, suggests some control to the hypothesis of the extraterrestrial asteroid impact on the earth that led to the demise of the dinosaurs, etc. I suspect discussions along these lines and their suitability for application is the intent of this discussion raised.
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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
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Thank you very much indeed for your response with appreciation.
Fault size attributes such as length, displacement and spacing depend on each other. There are different sampling biases and geological reasons that have varied impacts on fault size cumulative relations/distributions. There are considerable publications that highlighted this aspect (e.g. references listed below). The main factors/reasons that influenced the fault size distribution remain uncertain in many cases/researches. However, differences in the fault scale ranges of the fault size dataset could have the most significant impact on how these fault attributes distribute!
So, the question is that do you support this statement?
Schultz, R. A., Soliva, R., Okubo, H., and Mège, D., 2010, Fault populations, inWatters, T. R., and Schultz, R. A., eds., Planetary Tectonics: New York, Cambridge University Press.
Torabi, A., and Berg, S. S., 2011, Scaling of fault attributes: A review: Marine and Petroleum Geology, v. 28, no. 8, p. 1444-1460.
Nicol, A., Walsh, J. J., Watterson, J., and Gillespie, P. A., 1996a, Fault size distributions -- are they really power-law?: Journal of Structural Geology, v. 18, no. 2-3, p. 191-197
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Since histograms can be applied in many different field in Hydrogeology is it possible to use it for predicting aquifer type.
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yes very nice question. lets see how hydrogeologist think over it.
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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.
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You have to be very careful with the material you use because of potential diagenetic effects. It is best to use skeletal material originally precipitated as low-magnesium calcite, such as oysters for example. Even with low-Mg calcite material you need to be careful to make sure it is pristine. There are a number of petrographic and geochemical steps that can be done to assure you are using unaltered samples. There are numerous papers out there. Here's a paper you can look at to get an idea of the steps done to get good Sr dates. Ortega-Ariza, D., Franseen,E.K., Santos-Mercado, Ramirez-Martinez, W.R., and Core-Suarez, E.E., 2015, Strontium-isotope stratigraphy for Oligocene-Miocene carbonate systems in Puerto Rico and The Dominican Republic: Implications for Caribbean processes affecting depositional history: The Journal of Geology, v. 123, p. 539-560.
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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
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Martin Bohle As a recommendation: You may wish to visit the website of the Subcommission on Devonian Stratigraphy at:
See the newsletters where you could find answers to your question about the working methods of an organism.
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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
Jens Metschurat
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I don't have good knowledge in this area but a research colleague is quite. I will probably contact him and get back to you sir.
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I would be much indebted if you refer to some references on using nanotechnology in the field of paleontology!! I also would like to have your feedback on this field of research
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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
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Yes, you can download it via
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Dear Researchers,
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.
Thanks,
Soheil.
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Just the outline is visiable in the image. It looks like spongia (?) sclerite.
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Which software is able to create stratigraphy based on drilling logs and CPTs, beside Geo5?
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Hi, you can use Rockworks software.
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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"?
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Well, I'd say that, generally, quartzites do not represent unconformities. However, on a global evolutionary scale, it could be that before terrestrial plants evolved, one could imagine land surface as exposed igneous/metamorphic rocks with no vegetation to trap the finer particles on-land. Therefore, much of the surface (at this time) could have been composed of SiO2 aeolian dunes. If this were the case, your argument might hold up for quartzites older than terrestiral plants (700 Ma) and directly overly basement.
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Do you have any formal explantion of that term? The characteristic features, method for establishing? Relation to the lithostratigraphy? Any published sources?
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A svita in Russian usage is broadly comparable to a formation (and is often translated as such) However, while a formation is formally defined as a mappable unit within a hierarchy of Supergroup-Group-Formation-Member-Bed, there is no formal definition of a svita. It is just a general stratigraphic term for a "middle-sized" mappable/correlatable stratigraphic unit.
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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.
Sincerely,
Soheil.
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It looks like broken "shark" tooth.
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I need this paper. This paper is very important for my research.
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SEE : Volume No. 127 REVISED STRATIGRAPHY OF PAKISTAN
BY M. SADIQ MALKANI ZAFAR MAHMOOD
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Dear Researchers,
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.
Sincerely,
Soheil.
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Hi,
this the "stem" of the bryozoan genus Archimedes, the genus was called this due to its resemblance to Archimedes' screw.
Regards,
Kevin
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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?
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Dear Sumit Bhowmick,
You have interesting questions that make people think of our origin.
You had excellent answers so far. In short, sodium comes from weathering (of plagioclase, etc), chlorine from volcanoes.
K comes from weathering of orthoclase. Plagioclase is more abundant than orthoclase, thus maybe there was less in the seawater and the body fluids that were incorporated into the first living forms (our ancestors).
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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.
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Also sea level is belonging to Tides, Volcanic eruptions
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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?
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First, you have to consider the fact that not every organic molecule destabilizes under similar chemical conditions. To find a oraganic chemical trace of a fossil is rare, but provides informations on the morphology of the organism with graet fidelty.
After deposition/burial, the organic molecules (especially the least stable ones like protein, carbohydrates) gets degraded due to aerobic (and gradually anaerobic) bacterias. Proteolysis, or protein degradation is a set of processes that result in the hydrolysis of one or more of the peptide bonds in a protein, either through catalysis by proteolytic enzymes called proteases or nonenzymatically, for example at very low or high pH, T etc.
To preserve any animal Fossil, you need an environment with least "problems" like degradation, deformation etc. When the conditions are conducive, most of the soft parts gets leached into the soil/rock underneath and the "vacant" parts gets filled up with stable minerals (like pyrite, calcite, silica). Sometimes, the conditions get favourable for soft parts to get preserved also.
Now, Aromatic steranes are another group of biomarker compounds that are highly resistant to biodegradation and can be used for oil-to-oil correlation and oil source tracking. This can be seen for Cryogenian sponges.
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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. 
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Dear Prof Qasim Jan, Nusrat K Siddiqui and Munazzam Mehar,
My PhD work related to the spatio-temporal evolution of Kohat Potwar fold-thrust belts of Pakistan, I have collected samples from the entire Salt Range (Khewra, Karoli, Pail, Sakesar, Nammal, Zaluch, and Daud Khail sections) and Kohat. I used Apatite Helium and Fission track dating methods to document cooling ages. Interestingly Precambrian Samples gave similar AFT ages like Permain Samples around between 200-250 Ma. The ages are obviously partially reset but having similar ages was not expected. We conducted extensive thermal modeling of data and every model showed a cooling event in Late Paleozoic. We concluded that the Late Paleozoic rifting event reported In Kashmir, Zanskar and Peshawar effected the Salt Range. In my opinion, the trap is most probably related to Late Paleozoic rifting episode considering similar age magmatism in Kashmir.
I collected a small Khewra trap sample that is still sitting at my desk, It was not tempting to be tried for apatite. If Munazzam is interested i could try to separate zircons that will be no more than 3 days job, I would be free to do in December. The paper is in the final phase of review in Terra Nova, we are expecting a reply this week. If positive I will send you a copy. However, my thesis will be available online soon as I am defending thesis on 20th November.
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What is the conceptual difference between Geological Map and Stratigraphic Map?
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The geological map shows the distribution of the formations and their contact ( different kinds of rocks and faults).
There are three major types of maps they use: topographic, cross-sectional, and structural.
A structural map shows the geologic features of an area. Its appearance is similar to that of a topographic map, but a topographic map displays elevations of the Earth's surface and a structure map displays the elevation of a particular rock layer, generally beneath the surface. a geologic map shows the distribution of geologic features, including different kinds of rocks and faults.Rock units or geologic strata are shown by color or symbols to indicate where they are exposed at the surface. Isopach maps detail the variations in thickness of stratigraphic units.
A cross-sectional map shows the cross-section from the side.
So you can't talk about stratigraphic maps, but rather structural maps at different stratigraphic levels,
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I would like to know the fast and easiest way to differentiate aeolian and fluvial silt by looking at the samples itself.
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- Aeolian silt and sand grains have frosted surfaces due to the the abrasion that they suffered when impacted to each other's.
- Aeolian silt might be better sorted than fluvial silts, while fluvial silts tend to be mixed with fine sand and clays and often have organic matter content.
-In a fluvial system, silts and finer sediments are related to flooding plains, so when the river level grows up and cover the plains around the river, after the energy decreases, the silts, clays and organic matter particles deposit on the flooding plain. Silts also occur in abandoned channels in meandering river systems.
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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?
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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
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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.
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Dear Mr. Turra,
there exists a wealth of papers on volcaniclastic facies. But nevertheless I would direct your view to the textbook of Fisher and Schmincke, because it makes you acquainted not only with the outward appearance of the pyroclastic deposits at outcrop but also with the processes and physical laws behind all that.
Kind regards H.G.Dill
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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.
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See diapir influence on Cambrian reefs in Geological setting of the Moorowie Formation, lower Cambrian ...
and the chapter on the Frome Diapir minibasin (adjacent to Moorowie) in:
Sedimentology, Provenance, and Salt-Sediment Interaction in the Ediacaran Pound Subgroup, Flinders Ranges, South Australia
John Waldon Counts B.Sc., M.Sc.
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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?
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Dear Mr. Web,
to unequivocally interpret this section as a turbidite it is too small an insight into the entire lithological unit. If it were part of it, it would be the subfacies of a section cutting the BOUMA subsequences B (parallel laminated sandstone representing the upper flow regime) passing into subsection C (ripple-cross laminated sandstone representing the lower-flow regime). The relative amounts of the subsections shown in this outcrop, however, are not very much convincing me to direct my thoughts in this direction. I recommend mapping the area on a smaller scale and on the other hand looking for sole marks, cut-and-fill structures and reaction surfaces. I do not have doubt in the sedimentary stratification but for a precise analysis of the depositional environment and the up and down of the sequence I have not enough evidence.
With kind regards H.G.Dill
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I mean, "best, affordable and easy-to-use"!
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There are several interesting possibilities. You can even merge the available tools to achieve the desired result. I consider software inkscape (draw vector) and qtreejs plugin in qgis program as two accessible allies, because they are free softwares, and easy to handle for non-complex tasks. Another solution and the generation of layers by interpolations of geological contact points, equally possible in qgis, but depends on the data available to perform the task. See if you are encouraged to use these alternatives, we are here to collaborate in what you need.
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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.
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Dear Dr. Idries
These fine-grained sandstones show a rock parting on a different scale and intensity which allows the infiltration of (meteoric) fluids to a different extent and leave behind a residue of Fe-oxide hydrates (“limonite”). The latter “mineral” gives rise to the concentric structures resembling the contour lines of topographic map which reflect the different altitudes. It is a near-surface (supergene) process.
With kind regards
H.G.Dill
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seismic stratigraphy
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Following
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Hi,
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.
Thanks.
Edouard
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This facies belong to upper Cretaceous in the Azarbailan, NW Iran. this is a lime sandstone or sandy limestone that deposited in marine environments. I need more discusstons about this facies with references .
Photos take by 4 and 10 lens of microscope.
Tanks
Mobin
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Dear Mr. Nejad,
your attempt to interpret the carbonate (micro) facies is very ambitious and is in my opinion not the correct way because the term facies is a far-reaching one to discuss the origin of a rock unit, in this case a sedimentary one where all available features of different scales need to be considered. The late Professor Walliser from Göttingen University once showed us a hand specimen and said: “ You should not create a new orogeny using only one hand specimen”. With kind regards H.G.Dill
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Seimic Stratigraphy
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It is due to the differences in density between the oil and gas environments. Generally, gas is less dense than oil. Consequently, when the mechanical waves attempts to pass through the gas environment, it encounters less resistance compared to the oil environment where they encounter much resistance. Therefore in the gas environment, the amplitude of the penetrating mechanical wave will be higher than in the adjoining environments thus making the direct detection of gas possible..
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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.
Cheers
Finn
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It is thought that A. afarensis was ancestral to both the genus Australopithecus and the genus Homo.
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Hello,
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.
Simon
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Simple trigonometry and direction cosines.
The z-coordinate of your sample = z(collar) - depth(sample)*sin(DHdip), where
depth(sample) = halfway point between top and bottom of sampling interval and
DHdip = drillhole inclination angle from horizontal.
Sample x (Easting) and y (Northing) are given by:
x = x(collar) + depth(sample)*cos(DHdip)*sin(DHazi)
y = y(collar) + depth(sample)*cos(DHdip)*cos(DHazi)
As you know, I guess, you have to express the angles in radians for the trigonometric functions in Excel, so divide angles in degrees by 180 and multiply by pi.
You can correct for DH deviation using one of the common correction formulas. I have made an Excel spreadsheet that does that using the minimum curvature algorithm. I can send you a copy when I get back to my office computer on Monday. Haven’t checked the link William sent you above, but I guess you should find your answer there too.
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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
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Thanks dear Mario, Jorge and Irving for These helpful answers
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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?.
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I still think improved version of Markov Chain I.e. partial independence or quasi independence method are very useful in analysing cyclicity in the sequence.The only thing that matters was the collection of data and I personally used these methods in the borehole data given by the agencies working on the coal reserves. It is very good and one can get result within no time.If it is correlated with Harper's binomial method than nothing beats it's usefulness.I do not think it is outdated.For your information there is another method which correlate the borehole sequence in space is cross association method.One can look my paper with Prof Tewari appeared in Jour.Asian Geology in 2009.
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hi, can you helpe me about the formation of gaz hydrate ? 
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Keep in mind that H2S and CO2 are very different from non-polar hydrate formers. H2S has a dipole moment that results in an average outward positive "sky" facing an average inward negatice "sky" from waters in the lattice. See for instance:
Kvamme, B.; Førrisdahl, O.K.: "Polar guest-molecules in natural gas hydrates." Fluid Phase Equilibria, 83, 1993, 427
CO2 have the opposite average Coulumbic effetct
CO2 is also fairly large so will destabilize water lattice by roughyl 1 kJ/mole as compared to an approximate rigid lattice. But CO2 has strong attractions to lattice waters so still a good hydrate former. For the destabilization effect see:
Kvamme, B., Tanaka, H.: "Thermodynamic stability of hydrates for ethylene, ethane and carbon dioxide". J.Phys.Chem., 99, 7114, 1995
See also papers in the thesis:
PhD Khuram Baig. "Nano to micro scale modeling of hydrate phase transition kinetics". Funded by industry and RCN. Graduated May 2017
and the paper
Bjørn Kvamme, Eirik Iden, Jørgen Tveit, Veronica Veland, Mojdeh Zarifi, Khadijeh Qorbani, Effect of H2S content on thermodynamic stability of hydrate formed from CO2/N2 mixtures, J. Chem. Eng. Data, 2017, 62. 1645-1658
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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!
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Shahid:
The Patala Formation is of Late Palaeocene-Early Eocene age. The entire western sector of Indo-Pakistan region lacks marine strata of Danian age.
There is no ambiguity about this.
Best
Syed
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Dear all,
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.
Best regards,
Ashok
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heavy and clay minerals are good indicators...
For example
Chemical analysis of sediment and ratios like Ca/Fe, Sr values, K/Al will give provinances
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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.
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For topographic maps, you can refer to Basic Map & GPS Skills, a National Geographic publication.
For lithostratigraphy, you shpuld study stratigraphy plus the lithology of each individual straigraphic unit
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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?
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Christopher:
There is no straightforward answer to your question as the subject needs to be explained in detail. However, this link would provide you with basic and useful insights:
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Syed
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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.
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Dear Mr. Pdah,
your question finds an answer in the unmetamoprhosed lithological setting as well.
A granite intrusion into country rocks,  effusive rocks overlying basement rocks or dykes and sills are younger than the enclosing country rocks.
With kind regards
H.G.Dill
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Usually in the Neoproterozoic Katangan Supergroup, the diamictite is following respectively by the deposition of the laminated shale and the carbonate rocks. In this context, Can I call these carbonate rocks as the cap carbonate?
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Dear Rzgar,
Your answer far from the Pascal's question. He is talking about cap carbonate after glaciation age, while you are talking about sealing cap carbonate in reservoir. Pascal, you can read some papers about dolomite cap carbonate in Scotland, Death Valley, Namibia. Here are some references:
Anderson, Ross P., et al. "Microstructures in metasedimentary rocks from the Neoproterozoic Bonahaven Formation, Scotland: Microconcretions, impact spherules, or microfossils?." Precambrian Research 233 (2013): 59-72.
Brasier, M. D., and G. Shields. "Neoproterozoic chemostratigraphy and correlation of the Port Askaig glaciation, Dalradian Supergroup of Scotland." Journal of the Geological Society 157.5 (2000): 909-914.
Shields, Graham A., et al. "Barite-bearing cap dolostones of the Taoudéni Basin, northwest Africa: sedimentary and isotopic evidence for methane seepage after a Neoproterozoic glaciation." Precambrian Research 153.3 (2007): 209-235.
Prave, A. R. "Two diamictites, two cap carbonates, two δ13C excursions, two rifts: the Neoproterozoic Kingston Peak Formation, Death Valley, California." Geology 27.4 (1999): 339-342.
Corsetti, Frank A., and John P. Grotzinger. "Origin and significance of tube structures in Neoproterozoic post-glacial cap carbonates: example from Noonday Dolomite, Death Valley, United States." Palaios 20.4 (2005): 348-362.
Bosak, T., et al. "Agglutinated tests in post-Sturtian cap carbonates of Namibia and Mongolia." Earth and Planetary Science Letters 308.1 (2011): 29-40.
Hoffmann, K-H., et al. "U-Pb zircon date from the Neoproterozoic Ghaub Formation, Namibia: constraints on Marinoan glaciation." Geology 32.9 (2004): 817-820.
Best regards,
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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.
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Vindyan basin has low maturity and type II prone. It may be better for shale oil rather than shale gas.
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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
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Thanks for the answer Mr. Dill.
I've been working with fluvial deposits and saw several injectites like that case in the picture. In one thick sandstone layer (mayor channel) saw a few sand dikes injected but i can´t find the source of the material. I inferred that the layer suffers liquefaction and fluidization and the injection happens in the same layer. Is an assumption, but i´m not sure.
(Apologies for my english)
Regards
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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!
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This trace impression showing :
1 -Rate of sedimentation with respect to time.
2-In upper and lower part decreasing and increasing size of width of digging materials
That happens when change in facies. Basically this type of structure occurs in sandy shore zone of marine environment where .That fossil can be skolithos or glassifungites.
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Dear colleague!
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
Thanks
Regards
SANJAY
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 Thank you so much   Dr.  Hakima Belkhattab  for your  input.
 Regards
 Sanjay
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Good morning,
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?
Thank you!
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Dear Mateusz
The deformation of glacilacustrine sediments could be due to many processes, both syn- and post-depositional (fluidisation, density-driven deformation, glacier overriding; etc.). Looking at the photographs, I do not see any clinching evidence for glacitectonics (but this does not mean that this can be excluded, as the strain signature may vary both vertically and laterally, as someone else pointed out).
In some ways this reminds me of work that we did in Waterville, Ireland (Evans et al., JOURNAL OF QUATERNARY SCIENCE (2012) 27(1) 51–63).
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Thin section from uppermost Cretaceous mudstone (P. hariaensis zone) Haymana Basin-Central Anatolia.
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Most probably part of a fish..
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Alveolina and Nummulite from Early Ypressian in Egypt, I need your kind help to identify them specifically and their precise age assignment. Also, if you can recommend me Professor of Larger Foraminifera for contact about that issue?
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Alveolina is an extinct genus of foraminifera that are spherical or elliptical chambers are formed by transversely subdivided into Cambreta
alveolina: Upper Paleocene - middle Eocene
scientific classification
domain : Eukaryota
United : Eukaryota
Superfílum : Reta
class : Polythalamea
order : Miliolida
superfamily : Alveolinacea
Genre : alveolina †
go through the book Foraminifera By J.R. Haynes
A nummulite is a large lenticular fossil, characterized by its numerous coils, subdivided by septa into chambers. These are common in Eocene to Miocene marine rocks, particularly around southwest Asia and the Mediterranean (e.g. Eocene limestones from Egypt). 
Nummulites
Temporal range: Tertiary
Scientific classification
Domain:EukaryotaKingdom = Protozoa
(unranked):SAR
(unranked):Rhizaria
Superphylum:Retaria
Phylum:Foraminifera
Order:Rotaliida
Superfamily:Nummulitacea
Family:Nummulitidae
Genus:NummulitesLamarck, 1801
Dr. Arun Deo Singh
Professor, Ph. D. (BHU)
Contact Information:
Tel.+91-542-2366070,Fax: +91-542-2368390
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I want to know the key importance and reference of Cretaceous in geological time-scale. 
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Abelardo:
What makes you feel that the question posed by a young Scientist Ijaz is foolish? Oil production is important but there are a host of other academic and applied aspects which need to be understood for this unique period.
Best
Syed 
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I take this photosa from thin sections of Carboniferous carbonats in Iran. Who can identify these microfossils?
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All what you have in the pictures are typical fossils in Carboniferous limestones. Most of them are fragments of molusc shells. Some of them may be regarded as bivalves. Basically all bioclasts that show long recrystallised shells.Some others are gastropods, including that reagrded by somebody as a pinus pollen (the pinus pollen has an organic wall and the fragment shown in your picture is calcitic, recrystallised from aragonite). With those pictures we can not be sure on more precise identification of the bivalves and gastropods. I do not think that the gastropods belong to the group of Pteropods, becasue they are really rare in the fossil record (most of them lack mineralised Shell). You have also some ostracods (for instance in the picture 3). They usually show a better preserved shell than most moluscs, because they are mainly calcitic, not aragonitic. Some of them show a brown shell in this case.  
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shell is minute with distinctive sculptures, however without a sharp boundary to distinguish the protoconch and teleconch.
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Luoyang:
You may find this link interesting:
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Syed
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The attached photos are from Upper Eocene rocks in the Northern Plateau of Bahariya Oasis, Egypt. This is about 0.5m thickness bed totally formed of fibrous calcite. can anyone help me to identify this facies and the reason why calcite appears in this form?
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Calcium carbonate (CaCO3) can occur in several mineral forms including as aragonite, formed through biological and physical processes, including precipitation from marine and freshwater environments. Aragonite's crystal lattice differs from that of calcite, resulting in a different crystal shape, an orthorhombic system with acicular crystals. Repeated twinning results in pseudo-hexagonal forms. Aragonite may be columnar or fibrous. 
This facies makes sense to me in the sequence you describe in layers with sandstone and shale, all three environments would be typical for marine and fresh water environments.
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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
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Dear Perera, If alkali feldspar is present in basalt what are the possible interpretations?? can you please through some highlight..
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Orbitolina larger foraminifera Paleo-ecology.
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Bencaabane:
You would find this link useful:
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Syed
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I mean doing stratigraphic correlation by Trace Fossils. Thanks.
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I imagine it would depend on the environment.  It would be easier in areas where the water depth and conditions change frequently.  If an area is in deepwater abyssal plain for long time, then the trace fossils and critters are probably very similar through time, so that would be the more difficult scenario.  If you could combine trace fossils with nanno fossils or benthic forams or pollens or chemical signatures, I think you could start to pull together a nice regional interpretation.  At a field level, there probably isn't enough heterogeneity to do more than what you could do with well logs.
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Both methodologies have limitations. Name some of them.
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Dear Syed,
I am giving you an up vote on your answer. Best wishes, Paul.
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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.
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I think that a good answer would be: it depends! In large scale exploration, it may be enough if you keep the sequence stratigraphical analysis in the lower frequency packages. But if you are working in a field development, you may need to go to higher frequencies to understand the facies distribution. In many cases, you may also find difficult to define the "end" of the stratigraphic approach (end of external controls as sea level or tectonics). In this case, you will be entering in the world of architectural element (facies associations) and sub-environment of deposition (architectural element association), "packages" that not necessarily have external control. I have a good summary of this question in the attached paper.
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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.
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I am showing my age, now, but I was actually there in Moscow in 1975!  I have made a pdf from my copy of the conference proceedings and will send you a copy. It was incidentally in Volume 5.
Chris
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Need some literature on 2D resistivity surveys done on alluvial plains to reconstruct sub-surface stratigraphy or palaeochannel drainage network. 
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Dear Imran, I work in a thick alluvial plain (the Po plain Italy). It's composed by gravel, sands and clay and the total thick above the marine sediment could be more than 500 metres. My personal experience with 2D resistivity is not good ! No possibility to detect in a correct way the boundary between different lithology and different kind of answer respect presence or not presence of water. So I suggest you to approch another survey methodology !!! Paolo
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Related to paleoecology and latidudanal controlled facies.
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 Dear Daniel,
The limitations of facies analysis in paleoclimatology include the absence of environmentally controlled biota. Flora and fauna could be so adapted  that their presence indicates the environment including climate. Such biota are called facies fossils.Cosmopolitan biota are not so tied, they are "all-weather" types and do not indicate any particular environment.Similarly, there are physical sedimentary structures that are climatically controlled as well as soils, eg, glacial tillite  and boulder-clay for glacial lands; dunes for hot deserts and so on. Absence of these environmental (including climatic) determinants limit facies analysis in palaeoclimatology or any other palaeo studies, since they are the "tell tales" of the environment.
Facies, after all, are the different aspects of the environment that may be existing at a particular time, which also is often the name- bearer.
All the best.
Obianuju P. Umeji
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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. 
Regards, 
Karwan
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Hello Karwan,
You may try:
Malec, J. (1993): Upper Silurian and Lower Devonian in the western Holy Cross Mts. Geological Quarterly 37 (4): 501-536.
Wójcik, K. (2015): The uppermost Emsian and lower Eifelian in the Kielce Region of the Holy Cross Mts. Part I: Lithostratigraphy. Acta Geologica Polonica 65 (2): 141-191.
or the more general overview in AAPG Memoir 84 published in 2006 ...
Best wishes, Mike
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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:)
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