• Helge Niemann added an answer:
    Can someone help me about the formation of gas hydrate ?

    hi, can you helpe me about the formation of gaz hydrate ? 

    Helge Niemann · University of Basel, 

    Tracking gas (assuming methane or other light hydrocarbons) in paleo systems is quite tricky. One way is as Bernie suggested, another one is to look at remnants of organisms that were involved in cycling of the gas (eg. methanotrophs/methanogens) or looking for geological structures related to the gas (chimneys, carbonate precipitates). However, that mostly depends on whether some of the gas in question has been produced/transformed in the stratum you're looking at.  

  • Marlina Elburg added an answer:
    Can someone recommend some articles about the influence of oxygen fugacity on arc mamgma and its relation to the formation of porphyry deposits?

    I want to learn about the influence of oxygen fugacity on arc mamgma and its relation to the formation of porphyry deposits. Can someone recommend some articles on this topic to me. Thanks a lot.

    Marlina Elburg · University of Johannesburg

    I find the work that has been done recently by Chiaradia (e.g. quite interesting when it comes to copper porphyries; that may be another starting point, for a somewhat different view on their genesis.

  • Jooly Jaiswal added an answer:
    What are the main points during Speleothem sampling?

    Can somebody tell me the proper site for speleothem sampling?

    I am little bit confused whether is taken from the location where it is equilibrium with external atmosphere or deep from the cave where humidity is near about 100. Some one told me the sample collected near from the cave entrance are most significant for the climatic study because it records the diurnal variation of the atmosphere. but here the kinetic fractionation also goverened the precipitation process please tell me the exact things.

    Jooly Jaiswal · Wadia Institute of Himalayan Geology

    Thank you so much Mr. Silviu Costantin for your answer. Now I am understand the point of consideration during the speleothem sampling.

  • Syed Haroon Ali added an answer:
    What is the Sequence Stratigraphy, High Resolution Stratigraphy and Cyclicity of Mixed Carbonate-Clastic Successions?

    Hi all,

    While working with Mixed Carbonate-Clastic successions, how do we mark Sequences and High Resolution Stratigraphy? Any recommendation of reference or research paper will be appreciated.



    Syed Haroon Ali · King Fahd University of Petroleum and Minerals

    Thanks Sir for sharing your experience and research!

  • Levent Artüz added an answer:
    Will anyone be able to identify the foraminifera?
    Image is attached.
  • Aaron Lim added an answer:
    Could you recommend me a software for creating stratigraphic column (for Mac)?

    I've googled and I've found a bunch I was just wondering if anyone had used any that they particularly enjoyed.

    Aaron Lim · University College Cork

    Sedlog (link attached) is really useful and quick to learn. It works for mac users also.

    See here

  • Paul Aharon added an answer:
    Can somebody help me about the trace element incorporation in speleothem in Lesser Himalayan Region?

    In general Mg incarporation in speleothem is temperature dependent and Sr and ba is not dependent on Temperature. Their incarporation in Spoeleothem is depend on soil dust activity. Can some body  tell how trace element  incarporated, the source and the governing factor of their concentration,the relation  between them.What can be other trace element other than Mg,Sr,Ba,U, Na,P  incarporated in speleothem and the importance?

    Paul Aharon · University of Alabama

    Interpretation of trace element ratios (typically E/Ca)  in speleothems in terms of climate is complicated by their partitioning in the epikarst. There are a number of papers dealing with the subject, some suggested by other responders.

    Additionally check the papers by Dan Sinclair who dealt with trace element partitioning in the epikarst.

  • M.Cemal Göncüoglu added an answer:
    Are there any recent publications on Silurian and/or Devonian "Orthoceras Limestones" in NE Gondwana?
    We are compiling a correlation and would appreciate any (published/unpublished) data with reliable ages.
    M.Cemal Göncüoglu · Middle East Technical University

    Danke Mike

    alles Gute


  • Ioannis T. Alexandridis added an answer:
    What kind of structure is this?
    I found this suspicious structure in fragments of Iron ore (magnetite). Its original structure is difficult to me. The main belt is a metamorphic volcano-sedimentary environment with relative proposed age of Neoproterozoic to lower Paleozoic.
    It resembles some volcanic structure, sedimentary structure or even fossil or stromatolite?
    Ioannis T. Alexandridis · Aristotle University of Thessaloniki

    You could also check the case of having "fold rodding lineation" (crenulation lineation). The specific sample, could easily be a remnant of fold limp, so the parallel structures could be the aformentioned structure.

    About the network of fractures I agree with Michael.


    Ioannis Alexandridis

  • M.Cemal Göncüoglu added an answer:
    Can someone advise on the sample preparation techniques of isotope dating of dolerite?
    I have collected some dolerite samples from Proterozoic sedimentary sequence. I want to know about the sample preparation techniques of isotope dating of dolerite.
    M.Cemal Göncüoglu · Middle East Technical University

    Do you have the thin-section view of the rock?

    Are there any unaltered primary minerals?

  • Valentina Yanko added an answer:
    Who is interested in collaborating on a project on quaternary freshwater and brackish water ostracods of the Lower Volga and Caspian region?
    We have samples from several boreholes and outcrops. Please contact me if interested.
    Valentina Yanko · Odessa National University

    Dear Guzel,

    We would be intresetd in collaborating with  you on the project. We have enormous data bank on forams and ostracods of the Ponto-Caspian region used for Quaternary stratigraphy and paleogeographic reconstrauctions.

    Best wishes,

    Prof. Dr. Valentina Yanko
    Head of the Department of Physical and Marine Geology
    Geological-Geographical Faculty
    Odessa I.I.Mechnikov National University
    2, Shampansky Per.
    Odessa, Ukraine 65058
    Tel: +380 (482) 63-33-17, +380 (48) 723-02-08

  • Kenneth M Towe added an answer:
    Is there a simple method to differentiate coal from charcoal?
    Maybe at the petrographic microscope there are some details like fractures that indicate burning.
  • André Klicpera added an answer:
    Can anyone help with lithological patterns to draw a stratigraphic column in Corel Draw?
    Particularly I need sedimentary rocks patterns.
  • Kenneth M Towe added an answer:
    What is the best estimate for the duration of the Cambrian Explosion?
    Which animal and protistan phyla appear simultaneously (within the resolution of chronostratigraphy)?
  • Martin H. Trauth added an answer:
    Which perspective of age-depth modeling is better, regression analysis or interpolation?
    Two perspectives of age-depth modeling prevail: (1) regression analysis, which represents a statistical expression of the data; (2) Interpolation, which reveals a deterministic relationship of the data. Which one is better?
    Martin H. Trauth · Universität Potsdam
    The problem with the Bayesian-based methods such the one of Marten Blaauw and Chris Bronk Ramsey is that they don't have a good algorithm to detect abrupt variations in the sedimentation rates including episodes of no deposition (hiatus). Chris told me that he can include hiatuses if one tells him where they are. In fact the use a memory factor to smooth the age-depth model to avoid abrupt variations in the sed rates, which is great if you expect a relatively linear age model. If you don't have that because you have a great mix of sediment types from clays to sands, maybe volcanic ashes and diatomits, you should try the method I published in:

    Trauth, M.H. (2014) A new probabilitistic technique to build an age model for complex stratigraphic sequences. Quaternary Geochronology, 22C, 65-61.

    I can send you the paper privately if you send me a message.
  • Om N. Bhargava added an answer:
    Does anyone have information about Ordovician diamictite in the Indian subcontinent?
    I'm referring to Gondwana sedimentary rocks.
    Om N. Bhargava · Geological Survey of India
    In Bhutan Nake Chu Fm was regarded as Ordovician, our work found that it rests below the Cambrian hence could not be Ordovician, it is Neoproterozoic equvalent of Blaini in the Himalaya and Nantuo in China.
  • Jahn Hornung added an answer:
    For a species is a stratigraphical range up to 140 Ma realistic ? (e.g. the dinocyst "Spiniferites ramosus" is mentioned from Valanginian to Present)
    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.
    It depends on how reliable you consider the morphological information preserved in the fossil record. Lungfish teeth from the Early Cretaceous of Australia have been considered to be identical to those of the living species Neoceratodus forsteri. This would give this species a range of 100 myr, the longest known for a vertebrate. However, we do not know whether the Cretaceous lungfish would not have been quite different in other body parts than the tooth-plates. However, if you have most of the animal preserved you can make better assumptions. The tadpole shrimp (Triops cancriformis) is known from morphological indistinguishable fossils dating back to the Late Triassic (220 Ma). Single-celled organisms may be prone to very slow evolution, there have been records of amoebae indistinguishable from extant species from Triassic and Cretaceous amber. They may also have extremely long individual lifes, as they are not subjected to cell death and may theoretically enjoy an eternal live, if they are not destroyed by predators or environment. There have been repeated reports of Permian, possibly even Cambrian, bacteria from rock salt deposits which went into stasis when their water environment dried up and they were encapsulated by a salt crystal. It was reported that it was possible to revive them in the lab, though these reports are somewhat disputed...
  • John M McArthur added an answer:
    Can anyone recommend a good text book or papers on the red colored, carbonate free paleosol? What are the physical features? How do you identify them in the field? What is their geochememistry?
    John M McArthur · University College London
    The second paper on the last-glacial-maximum palaeosol is attached.
  • John Jones added an answer:
    Why the Great Permian extinction happened?
    Nobody knows what happened, but my theory is that there was an impact by a comet in Siberia, which triggered the extinction.
    John Jones · Mississippi State University
    I agree with the view that more than one single event caused that and other mass extinctions. One cause which was not mentioned is the creation of Pangaea. That event would have caused the loss of a great deal of shallow marine habitat, and formed large deserts because of new mountain ranges and continental effects. While impacts and increased vulcanism may be factors, loss of habitat and climate change certainly figured in. Migrations often mean invasive species which can greatly upset the local ecosystems as well. After all, I don't think there is a strict boundary for the extinction(s). John Paul Jones
  • Romain Liard added an answer:
    Can anyone help with drawing logs with sedlog?
    I need new symbology as none is there for fluvial deposits. I tried to follow the steps provided in help, where svg/svgz files are to be imported. But the sedlog is not reading the files. Can someone help or suggest some other software? PS: I am using coral draw to draw the new symbols.
    Romain Liard · Mahasarakham University
    Personally I use the Gimp. It usually open SVG format with no problem even if layers are very often flattened by the transfer from a soft to another.
  • Massimo Zecchin added an answer:
    How possible is it to have several forced regression surfaces below and immediately above major sequence boundary?
    We are working on Cretaceous shallow marine to deltaic successions. The upper part of the shallow marine seems to have repetitive cycles of forced regressive units (identified by several levels of Glossifungites), the last of which is capped by a major sequence boundary. Temporally across the boundary are other repetitive cycles of forced regressive units (similar to lower units) before the normal deposition of coarsening upward deltaic successions.
    Massimo Zecchin · National Institute of Oceanography and Experimental Geophysics (OGS)
    The information provided is not sufficient to make a reliable interpretation. The description looks like that of multiple ravinement surfaces recording a high-frequency cyclicity.
  • Mobin Ebrahim Nejad added an answer:
    Who can help me with the identification of Oligo-Miocene forms?
    Im looking for collaborate for study of Oligo-Miocene deposits in the Iran. We sampled and made thin sections.
    Mobin Ebrahim Nejad · ........
    Dear Ouda
    Tanks a lot for your helps
    I've sampled and made thin sections. I can send you thin sections but can you send back them? Please my email:
    All the best
  • Hamou Djellit added an answer:
    How to ascertain the relationship between slump fold (or syndepositional fold) axis and palaeoslope dip?
    Is the axis of slump fold overturned downslope or upslope? Thanks a lot!
    Hamou Djellit · Center for Research in Astronomy and Astrophysics Geophysics
    Les plis de type slump sont associés à des instabilités de pente. Ils apparaissent isolés et de façon locale au sein d'un ensemble dont la déformation générale obéi à un mode et régime de déformation tout à fait différent. Lorsqu'on en est présence d'un slump la première des choses à vérifier et la compatibilité du pli (en terme de contrainte) avec la déformation globale de la série qui le contient.
  • M.Cemal Göncüoglu added an answer:
    Did the Late Ordovician ice sheet/glacial period reach southeastern Turkey-northern Arabian platform?
    Southeastern Turkey-generally Diyarbakır-Mardin area sediments a marker for the base of this topic?
    M.Cemal Göncüoglu · Middle East Technical University
    In Mid 1990's with H. Kozlu we had found out that the so called Silurian basal conglomerates in S Turkey actually correspond to Late Ordovician glacio-marine sediments (dropstones in G…oncuoglu, M.C. 1997. Distribution of Lower Paleozoic units in the Alpine Terranes of Turkey: paleogeographic constraints. In: Göncüoğlu, M.C. and Derman, A.S.(Eds), Lower Paleozoic Evolution in northwest Gondwana, Turkish Assoc. Petrol. Geol., Spec. Publ.No:3, 13-24, Ankara.). Monod et al (2003) and Ghienne et al (2010) then performed field work on these and have described the details of the Hirnantian glaciation. The most recent information is given in Kozlu, H. & Ghienne, J. F. (2012) Ordovician. In: Goncuoglu, M.C.& Bozdogan, N (Eds.) Paleozoic of Eastern Taurides-Guidebook . Gondwana and Its Petroleum Potential: A Field Workshop. Turk. Assoc. Petrol. Geologists. Spec. Publ. Nr. 7, 42-60.
  • P. K. Gautam added an answer:
    How good is to try interpolation methods to find the age of the sediments when reversal is encountered?
    Suppose we are doing 14-Carbon isotope dating of the bulk lacustrine sediments and we find some reversals i.e. older age in the younger sediments or the opposite result. Then, can we try interpolation methods to get rid off from the error? How reliable will be the interpolations method in it?
    P. K. Gautam · University of Hyderabad
    Many thanks Prof. Martin Trauth for your suggestion.
  • Akbar Heidari added an answer:
    How to correlate marine and continental Lower Triassic beds?
    A topic on problems of correlation with using of biostratigraphy and paleomagnetic data.
    Akbar Heidari · Shahid Chamran University of Ahvaz
    Using palynology could be useful because spore and pollen develop in continental environments and dinocysts develop in marine environments. So using them and their ages could very useful for correlation
  • Shandelle M Henson added an answer:
    Any experience with creating SVG graphics for SedLog?
    I can create an SVG file in Adobe Illustrator, but when I try to import it to SedLog as a symbol, I get the error "Unable to read this file:" Anyone know how to get past this?

    Update: Running Windows 7 64-bit OS.
    Shandelle M Henson · Andrews University
    I finally figured out a way around the problem. I don't know if my solution will work for you. I'm running Windows 7, SedLog 3.0, and Inkscape 0.48. (1) Open the SedLog program folder that contains the SVG files: Computer > Local Disk > Program Files (x86) > SedLog 3.0 > patterns > lithology. Place your new svg files in here, where the original svgz files are kept. (2) Go up to SedLog 3.0 > data > lithology. Open the OTHER.DAT file with Notepad++. Enter the code for the new svg files, for example:

    Ripple-bdd Sand or Ss USGS 611
    patterns/lithology/Ripple-bdd Sand or Ss USGS 611.svg

    Now open the SedLog program and try to create a bedding layer with your new svg patterns. If it appears to work but you can't see anything but white where the pattern should be, then your pattern is "off the page". In Inkscape, Go back into Inkscape and adjust the pattern on the page. The coordinates should be, roughly, X=0, Y=1002, W=50, H=50 px. Save it as an svg file and repeat the directions above. I hope this works for you!
  • Madyan Alowady added an answer:
    How can use paleoclimatic to determine bauxite origin?
    How can use paleoclimatic to determine bauxite origin?
    Madyan Alowady · King Saud University
    Thanks a lot Dr.Zoltán Kern and Dr B. Singh
  • L. R. K. Perera added an answer:
    How does one see through uniformitarianism to extract evidence of evolution?
    The uniformitarian principle – present is the key to the past – apparently hinders our thoughts about evolution. This is simply because, if the past had been very similar to today, it casts doubts in our mind about evolution. Thus, how can one see through uniformiatarianism to extract evidence of evolution? One has to have a clear picture about things that evolved and things that did not evolve.
    L. R. K. Perera · University of Peradeniya
    Michael, thank you for the contribution. One cannot disregard the possibility that sometimes processes may have been actually different from one another (or the causes of a given process may have been different) in the past but their outcomes look the same because the latter were governed by the same chemical and physical laws. Then, if one interprets those outcomes as indicative of uniformitarianism it is misleading and is only an illusion.
  • K. K. Sinha asked a question:
    Can anyone help to identify the fossil appearing feature in the photograph?
    It is from Krol Formation, Nainital, India which is considered Terminal Proterozoic sequence

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