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Dear all,
I am working on the biostratigraphy of Pleistocene sediments from the high latitude region in south-east Indian ocean sediments. Kindly suggest me any book or articles in which the above-mentioned foraminifera are discussed. The articles on the zonation will more be appreciated.
Thank You
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Dear colleagues,
I struggle to identify these sediments, which I suspect to be fluvio-glacials deposits alluvial from melting glaciers in Eemian.
The area where this conglomerate is exposed have a bed from recent Riss and located 500 km from the Alps (eastern France)...
I'm not expert, so I would be grateful for anyhelp.
In the geological map, I cercled in violet the light yellow area (Recent Riss).
Thank you !
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The paleoenvironment of this deposit should be studied according to the facies associations. But according to you, and as well as the roundness of the grains, it is probably a glaciofluvial deposit.
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Please help me in the identification of this well preserved fossil plant found in Tufa . Thank you in advance !
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Jean-Jacques Châteauneuf Thnak you very much for your comment. Best regards.
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In my studies of pre-Illinoian glacial deposits in Indiana it would be very useful to easily differentiate glacial materials with Bruhes normal and Matuyama reversed polarity. It is my understanding that Schlumberger's Susceptibility Measurement Tool (SUMT) is currently used in petroleum exploration (https://petrowiki.org/Downhole_magnetic_surveys). Is anyone aware of it's use in glacial studies?
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I am not
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36Cl is often used to date limestone, moraine, young lava flow, halite and groundwater. Somebody told me that 36Cl is also used to date young sediments, including continental sediments (mudstone). Can 36Cl be used for dating sedimentary age of young sediments?
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In theory, it should be possible to use Cl-36 in depth profiles as is done with Be-10. In this case, you focus in the post-sedimentary production of the cosmogenic nuclice and the decrease of production with depth. However, there are not so many labs using Be-10 in this context (a few though) and there is generally less people working with Cl-36. The problem might be that this isotope is found in chemically less stable material (carbnonates) and in groundwaterm so there might be problems with contamination and mobilaistion. This may explain why I have not found a single paper on this topic during my quick search (does not mean no papers exists).
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Are there any article about paleogene unconsolidated lime-mud state? for example DSDP sites? I'm interested in the question till what time can be marine micritic lime-mud stay in unconsolidated condition.
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Hi Viktor, have you looked at reports from the Ocean Drilling Program (ODP)? They sample many marine recent sediments around the world. Mudstones get lithified relatively quickly. I have personally seen drill core from Oligocene and Miocene from offshore Brazil, in which the sandstone was almost entirely unconsolidated, but the mudstones and marls were quite consolidated. Of course it depends on the pressure and temperature, so subsidence rates and local variations to geothermal gradients will affect the consolidation state.
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What are the links between regolith science and Quaternary geology?
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Dear Dr. Dembele:
The terminology as coined by Merril (1897) and described above is correct, but it will no longer be used in a way like that in practice or during field work. To be outspoken it is more a geo-philosophical term which is neither be used  by geomorphologists nor by sedimentologists anymore in this sense. The so-called mobile regolith is a clastic sediment sensu lato. No geologist dealing with fluvial drainage systems or unconsolidated lacustrine sediments will use the term “mobile regolith” but describe precisely what it is as a sediment.  What has been left is the in-situ alteration of a fresh unaltered parent rock from saprock, through saprolite into different types of soil which may be called by a more general term as “regolith”. Whenever I have more detailed information I am going to denominate the various layers from the fresh parent rock to the topsoil in more detail and try and avoid the term regolith. It is also correct that Quaternary geology is a discipline confined to the youngest period of time of geological history. Regolithisation, meaning the formation of an interface between fresh air and fresh rock is neither a fixed state nor a steady-state and started as early as an atmosphere got in touch with hard rocks (paleo-regolithisation). In this case it may be a function of time and up to the specialist of the Permian or Cretaceous to deal with and no longer part of Quaternary geology.
I recommend avoiding this term whenever you can and provide full particulars to the rock section under question so as to carry out a classification or denomination based on technical terms from modern-day geomorphology, sedimentology and soil sciences.
Good luck !
H.G.Dill  
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Besoin pour le partage académique:
Je commence un travail de recherche et je besoin de la base de données ICRG, quelqu'un peut me partager cette base (pour H revenus, les revenus, les revenus UM LM) Merci beaucoup?
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I advise you to translate (french to english) your question for more visibilty on researchgate
This is the translation :  
Need for academic sharing:
I start a research task and I want the ICRG database, someone can share me this database (for H income, income, income UM LM)
Thank you very much?
I wish you good luck
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Algae/fungi/bacterial? Are there dominant multi-species?
Dependence on rural/urban areas.... etc.
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Thank you for your answer @Thomas Petzold!
So diatoms are typically found in the unsaturated zone below...Do you also know of typical species at the surface of river bank sediments (0-30cm depth) or the Infiltration zone? Maybe you can recommend a key publication which would be very helpful as well!
Best KS 
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We have seen many salt strucutre in normal or reverse fault system, but how about the salt related strike-slip fault?
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Quite surprised to get so many answers for my question. Thanks again. All recommended papers I will read carefully.  Hoping to get more answers! 
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Recently in reading the The Salt Tectonics Short Course in Universidade Fernando Pessoa. Some basic knowledge can be learned in this course.  Pretty Good!
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The following article focuses entirely on that topic; mechanical relationship between strike-slip faults and salt diapirs. It gives examples from the Zagros Fold-and-Thrust belt, where, as Christopher Talbot mentions in his comment above, salt diapirs are interpreted to rise in pull-apart basins formed at the intersection of pre-existing thrusts and basement strike-slip faults. 
Koyi, H. A., Ghassemi, A., Hessami, Kh., and Dietl, C., 2008. The mechanical relationship between strike-slip faults and salt diapirs in the Zagros fold–thrust belt. Journal of the Geological Society of London, 165, 1031-1044.
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Further, a profile showing a distance-water depth profile between the shore line and my core site (red dot; GeoB12605-3) will be perfect.
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Dear Claudemir Vasconcelos,
Thanks for your help, it looks very nice!
I will try to use the Geomapapp to get it.
Cheers,
Xiting
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I have ~5mm thick potsherds which are of archaeological importance. I want to date them using OSL. What steps should I follow during sample preparations and after sample preparation should I target feldspar or quartz or polymineral? 
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A few things to note are :-
1) The sherd thickness is near the minimum to achieve a completely internal beta microdosimetry.For this the outer 2-3 mm would normally be removed, and both dose and dose rate measurements performed on the interior portions.
2) If this is not already too late the sherds should be double bagged and sealed, unwashed, from the excavation site, together with detailed records (photographs and sketches) of the materials within 30-50 cm of the find location. Subsamples of the materials in the categories should be retained. The reason for this is to allow reconstruction of the external gamma dose rates applicable to the excavation site. Typically this might account for about 30% of the total dose rate. If it is too late, then some information will be needed of the local hydrology to enable reasonable reconstruction of water content history.
3) Also note the geographical coordinates (longitude, latitude, altitude and overburden depth to surface) so that cosmic ray dose rates can be modelled
4) I agree that TL has some advantages for heated materials such as ceramics, but under appropriate conditions OSL may also be useful. There are OSL signal components which can be readily reset by thermal zeroing, providing the mineralogy is suitable.
5) Perhaps the most important step of all is to articulate the archaeological question and discuss it with the laboratory prior to initiating work. It is important to consider the levels of precision and accuracy which are realistically attainable from individual samples, or groups of samples,  and to work out how best to address the most important underlying questions.  
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Can someone explain me how exactly should I adapt quaternary sections (age+genesis) built according to USSR Quaternary Commission requirements to international scientific publication or just give me a link to comprehensive example?
The section is attached below.
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I suppose you can find everything you need in the ICS Quaternary charts. I am not sure what I see on your drawing since there is no legend. Everything you need is there I suppose:
I see 6 or more division for former USSR, here http://quaternary.stratigraphy.org/regionaldivisions/
Pick precisely your area and you will obtain a correlation chart.
I am fairly sure Phil Gibbard can also help you if you are really stuck (but come with more information).
Good luck,
Julien
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What are the typical criteria to identify glacial or fuvio-glacial deposits in core samples as old as Permian?
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Dear Sir,
Surface texture studies will also throw light on such differentiation.
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I am looking for alternative methods for the preservation of permafrost, especially in ice-rich discontinuous regions. I have reviewed the studies for woods chips, however, I am looking for results of different materials (i.e., geotextiles, vegetation mats, sod, etc.) or new technologies. I appreciate any direction or research that can will be cited.
Thanks!
Michelle
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By no means a scientific answer but one of observation coming from a cold climate , plain old ordinary saw dust seems to be one of the best mechanisms to maintain a permafrost situation .  I have no data but have experienced it first hand , as a side note when old time ice saving techniques were used in the northern US and all of Canada sawdust was the choice insulation so much so that it ice was packed onto to ships and surrounded by sawdust and sent to the Caribbean islands fully intact
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I am looking for data especially for limestones that occur as drift in quaternary depositions (moraines) in NE Germany. Uranium concentrations would be best.
Ty in advance!
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Sehr geehrter Herr Buse,
you should direct your inquiries into literature towards the limestone geology at the western edge of the Baltic shield. There is a lot of work done by geologists in Lithuania and Latvia which is underlain prevalently by dolomites. Uranium is not an element which got strongly enriched in limestones. There are only a few sites with abundant U in limestones, such as the Jurassic Todilto Limestone in New Mexico or some sites in Jordan. May be REE are a better set of marker elements.
Glückauf !
H.G.Dill
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I would like to get age constraints on the deposition of fluvial sediments in a river deposit in the Kenya Rift. Age estimates are Mid to Late Pleistocene. The sources are mostly basaltic, trachytic and phonolitic lava flows. Quarz content is fairly low, so I'm guessing OSL won't be the method of choice. Any ideas?
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I would suggest post-IR IRSL K-feldspar dating: worked fine for the Middle to Late Pleistocene Rhine in The Netherlands. 
More info on the technique can also be found at: https://www.researchgate.net/profile/Jakob_Wallinga
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I'm working on geological model of an alluvial fan in the Red Sea. I found one and half sequence in the upper 90 meters of a fan. I have one sample from each meter in depth.
Is that Quaternary? or it contain a portion of Pliocene?
At the upper most, should I have highstand tracts?
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Dear Ahmed
personally, I think it is difficult to apply sequence stratigraphy on alluvial fans. Alluvial fans in the Levant and at the Arabian Peninsula are nice archives, but often used only because for their terrestrial record.
But answering your questions:
You can expect a lot of facies changes in such a system. Not only triggered by HST and LST, but also by climate driven erosion independent from sea level change, and in that region more important, geomorphological gradients driven by tectonics independent from climatic or transgressional factors, too. Where exactly are you working?
To define the age absolutely, you can use some of the methods Smaine suggested, if you find the material you need for dating and they are not effected by taphonomy or diagenesis (I did not expect you will find useful material in a core, but maybe some fossil corals). If you are lucky you will find some artifacts, which can give you a maximal indirect age, or some soil horizons you can maybe correlate with major climatic shifts in your working area. Without that, it could be anything in the fan: Holocene, Pleistocene, Pliocene. Be a bit more specific with the area you are working in, and others con be more specific with their answers.
There are some useful sedimentological studies from southern Jordan and from the Gulf of Elat, and also papers about the pleistocene  reefs of egypt. From the other countries the scientific record is sparse and sometimes not very reliable (as far as I know).
Good luck
Johannes
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We measured this Raman spectrum on a secondary mineral speleothem of a lava tube (https://www.researchgate.net/publication/265952424_RAMAN_STUDY_OF_SECONDARY_MINERALS_IN_A_RECENT_LAVA_TUBE). The main body was Thenardite and additionaly this spectrum appears occasionaly. Do you know it ?
Thanks for your help.
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Did you run the pattern through CrystalSleuth against the RRUFF database ? If you send me a copy of the spectrum data in CSV format I can run it against a RRUFF extract that is both cleaner and more extensive than the one released with CrystalSleuth from the RRUFF website.
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I have found some grains in the Middle Triassic carbonates (Lower Anisian, Aegean, Lower Muschelkalk) and I'm trying to identify them - please see the attached pictures.
Are they calcispheres of algal origin (e.g., Globochaete alpina) ?
Is it possible to identity them in a range of genus, species?
Does anyone have any experience with such objects?
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Dear Monika,
Because your question was formulated: “Middle Triassic calcispheres?” I answered in this connection. On closer examination of attached photos, I turned my attention to the pictures 4 and 7. They resemble the sections of the species Gemeridella minuta Borza & Misik. I hope that for you in this case could be useful following articles:
1. Borza, K., Misik, M. 1975. Gemeridella minuta n. gen., n. sp. aus der oberen Trias der Westkarpaten. Geol. Zb., 26; 77-81.
2. Misik, M., Borza, K., 1978. Gemeridella, Didemnoides, Didemnum und Korperchen ahnlicher Gestalt aus dem Mesozoikum der Westkarpaten. Geol. Zb.– Geologica Carpathica, 29; 307–326.
Good luck!
Daria
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We are looking for a multidisciplinary team to carry out geological, chronological and environmental studies on stratigraphical sequences reaching at least 20 m deep. Our initial evaluations suggest that the deposits may present a continuous chronostratigraphical sequence dating from around 1.5 Myrs. The two volcanic structures are in a closed depression context linked to soil subsidence at the base of their lava emission centers. This situation is due either to the collapse of the craters under the weight of the lava or to the retraction of the lava during its cooling phase. These depression structures functioned as sediment traps which have yielded archaeological surface remains attributable to the Middle Pleistocene and through to the Holocene. They are located in the south of France, in the Baumes volcanic complex (communes of Caux, Nizas, Pézenas, Lezignan-la-Cebe ...). Exceptional sediment traps, the exhaustive study of these infillings would be a major asset for the paleoenvironmental restitution of the sector and more broadly of Western Europe since 1.5 Ma.
Please contact me if you are interested and I will be able to provide you with more information.
Je cherche une équipe pluri-disciplinaire pour l'étude géologique, chronologique et environnementale sur des séquences stratigraphiques de minimum 20 m de profondeur susceptibles de recouvrir une chronologie continue depuis 1,5 Ma. Il s'agit de deux structures volcaniques en dépression fermées dues à l’affaissement de sol à l’aplomb de centres d’émission de lave soit liées à un effondrement des structures du cratère sous le poids de la lave soit à la rétractation de la matière lors du refroidissement de la lave. Ces structures dépressionnaires ont fonctionné comme des pièges sédimentaires et livrent des éléments archéologiques en surface depuis le pléistocène moyen jusqu’à l’holocène. Elles sont localisées dans le sud de la France, dans le complexe volcanique des Baumes (communes de Caux, Nizas, Pézenas, Lézignan-La-Cèbe ...). Pièges sédimentaires exceptionnels, l’étude exhaustive de leur remplissage serait un atout majeur pour la restitution paléo-environnementale de ce secteur et plus largement de l’Europe de l’ouest depuis 1.5 Ma.
Merci de me contacter pour de plus amples renseignements.
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Chere Laurence,
j'ai travaille un peu plus au Sud and le pleistocene ancien dans des sequences volcaniques de l'Escandorgue et avec une approche multidisciplinaire. Je serais tres heureuse de reprendre des travaux sur ce sujet avec votre equipe. Dans mon equipe a Londres nous pouvons faire de la geologie, stratigraphie, palynologie et macrorestes. Toutefois nous n'avons pas la possibilite de faire du paleomagnetisme et de datations, mais je pourrais facilement revigorer mes anciens contactes.
N'hesitez pas a me contacter: suzanne.leroy@brunel.ac.uk
Quelques references utiles
Leroy S.A.G., Arpe K. and Mikolajewicz U., 2011. Vegetation context and climatic limits of the Early Pleistocene hominin dispersal in Europe. Quaternary Science Reviews 30: 1448-1463.
Brugal J.-P., Ambert P., Bandet Y., Leroy S., Roiron P., Suc J.-P. et Vernet J.-L., 1990. Mammifères et végétaux du maar pliocène final de Nogaret (Escandorgue, Hérault, France). Géobios, 23, 2: 231-247.
Leroy S., Ambert P., and Suc J.-P., 1994. Pollen record of the Saint-Macaire maar (Hérault, southern France): a Lower Pleistocene glacial phase in the Languedoc coastal plain. Rev. Palaeobot. Palyn. 80: 149-157.
Leroy S.A.G. and Roiron P., 1996. Final Pliocene macro and micro floras of the paleovalley of Bernasso (Escandorgue, France). Review of Palaebot. and Palynol. 94: 295-328.
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I am wondering if mangrove environments have ever been considered in global carbonate budget calculations? How are these systems affected by climate/drainage change?
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Ashleigh Costelloe is working in the population dynamics of foraminifera in the Caroni Swamp, Trinidad.  As an adjunct to her work, I took a couple of push cores to examine and, below about 3 cm, found. . .  nothing.  Even the organic walled foraminifera had disappeared, never mind the  calcareous ones.  The same thing has been found in northern South America (see Debenay, J.-P., Guiral, D., Parra, M., 2004. Behaviour and taphonomic loss in foraminiferal assemblages of mangrove swamps of French Guiana. Marine Geology 208, 295-314). 
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The north Apennine (Italy) is characterized by the presence of numerous releasing/restraining bend related to sinistral "snake" strike-slip shear zones.
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Dear Abed, thanks for your answer. The "snake strike-slip" shear zones are pointed out by me in the Nord Apennines and in the East Variscan Shear Zone, one of the most long intra-continental shear zone running from Slovenia to Morocco. This shear zone has this frame in relation to the morphology of the Gondwana continent at Carboniferous-Permian time. And at present time I have a lot of data that allow me to write a new paper about the role of the pre-existing tectonic barriers and their relationships with incoming Wilson Cycle.
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The archaeological record is useful to look at in terms of palaeo hazards but has not been utilized that much yet.
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We sent two interesting cites on the subject:
Lario, Javier; Luque, Luis; Zazo, Cari; Goy, José Luis; Spencer, Chris; Cabero, Ana; Bardají, Teresa; Borja, Francisco; Dabrio, Cristino J.; Civis, Jorge; González-Delgado, J. Ángel; Borja, Tsunami vs. storm surge deposits: a review of the sedimentological and geomorphological records of extreme wave events (EWE) during the Holocene in the Gulf of Cadiz, Spain César; Alonso-Azcárate, Jacinto. Zeitschrift für Geomorphologie, Supplementary Issues, Volume 54, Number 3, July 2010, pp. 301-316(16)
M.A. Rodríguez-Pascua, R. Pérez-López, J.L. Giner-Robles, P.G. Silva, V.H. Garduño-Monroy, K. Reicherter. A comprehensive classification of Earthquake Archaeological Effects (EAE) in archaeoseismology: Application to ancient remains of Roman and Mesoamerican cultures. Quaternary International 242 (2011) 20-30.
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Is there empirical or modeling data showing how coastal aquifers respond to sea level changes (tens to hundred meters) during the Pleistocene?
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Here is a modeling study of the Floridan Platform, USA:
Hughes et al. (2009) Hydrogeology Journal, vol. 17, p. 793-815.
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I want to separate fluid inclusion which are trapped in speleothem.
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Here are some additional and related papers where you can read about the different methods and applications.
If you can't have access, please drop me an e-mail (demeny@geochem.hu),
Attila Demeny
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Lu-Hf analysis techniques and implication
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Springer just published an Encyclopedia of Scientific Dating Methods, covering all major techniques for the Earth Sciences. There is a search option and you possibly find all sorts of applications/limitations for Lu-Hf
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For my current research I am trying to find a map which includes the location of the Storegga Submarine Slide and both the Stuoragurra fault and the Parve fault. Does anyone whether a map like that exists?
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Thank you very much, I have since been offered one that I did used in my work, I am not sure how to remove the question now. But thank you and Kindest regards
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Does anyone know of any research into increased melt supply rates in volcanoes (preferably coastal or island arcs) as a result of sea level rise? Preferably with regard to the Early Holocene Sea Level Rise. I am trying to find further research to support the notion that mantle loading as a result of sea level rise and pressure increase can promote the ascension of fresh magma.
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At the mid oceanic spreading ridges, the magma rises in the rift to the
elevation of the equilibrium pressure, so a rise in ocean elevation will
mean a lower elevation of cooling and hardening of the magma in the
crack, and the opposite will be true if the ocean level falls.
The shape of the ocean floor is thus a geologic record of the
cyclical changes in the ocean elevations, and of its overall trend
toward a thinner ocean with a greater surface area.
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How can you calibrate pMC dates? e.g. what would be the calibration values for 130±2 pMC.
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pMC is percent modern carbon, with modern or present defined as 1950. Of course as calibration is needed anyway you could just apply the formula and give a negative radio carbon age of minus 2150 years bp, but that'd be rather confusing. Since the atmospheric atom bomb tests of the fifties and sixties atmospheric radio carbon values have gone haywire, although they're nearing normal again now. So for anything younger than 1850 AD or so laboratories often do not give an age but the raw radiocarbon measurement as percent of the standard. It is up to you to try and make sense of it in the context of sample.
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Symbols or a legend used in geomorphological mapping varies significantly from map to map and place to place and they are not consistent. The legend and mapping symbols in geomorphological maps are likely to be chosen on the basis of purpose of the output, and hence the legend is not pretty standard with compared to that in other maps like geological. I am planning to compile a geomorphological map in an area where is largely covered with alluvial fills and fluvial erosional landforms. Is there any standard protocol or guideline or any good article on geomorphological mapping that could be useful for reading?
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Dear Tilak,
I have worked a lot in this issue. I have compiled references since geomorphological mapping starts to be used in geomorphologic surveys, data collection and results presentation. I have some reviews but mostly were published in portuguese language. Indeed the last publication on this matter (I didn´t agree with all the ideas in the book) belongs to Jan Otto and Mike Smith (eds.) published by Elsevier "Geomorphological mapping: methods and applications".
But what I can say to you is that there are no standard symbols and legends apply by everybody. That was the aim of the Subcommission on Geomorphological Mapping of the IGU, that started its activity in 1962. Although the work done, namely the publication of the "Manual of Detailed Geomorphological Mapping", edited by Demek, in 1972, establish the modern concept of geomorphologic mapping and represents in our point of view a sort of revolution in the way how geomorphologic studies are done, the "Project of the Unified Key to the Detailed Geomorphological Map of the World" for maps at 1:25 000 and 1:50 000 scales, failed completely its pourpose. The Unified Key was not applied by the different country researcher and we can say that, nowadays, are the objectives of each work, the habits of each researcher and personal conotations about graphic symbols, that prevail.
In my opinion, we are quite far from the adoption of commum methodologies and legends in the survey of landforms, deposits and processes. On the contrary, it seems that the prevailing tendency it's for the diversification of legends and procedures.
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You will find a lot of different examples in this jounal : Archaeological Prospection. Fluxgate magnetic gradiometer is today the most common geophysical instrument for archaeology.
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I'm a little confused about the inter-changeability of these terms in a marine sedimentation context. My understanding is as follows:
Glaciogenic sedimentation = sedimentation derived from glaciers (or ice-sheets)
Glacimarine sedimentation = sedimentation derived from glaciers (or ice-sheets) that calve directly into the marine environment.
If this is correct then glacimarine sedimentation is a subset of glaciogenic and either of the terms could be used when referring to an ice-sheet that extends into the sea.
Can anybody provide some clarification?
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I don't think you need any clarification, your succinct definition is right on the mark. In "Glacimarine Environments: Processes and Sediments," Dowdeswell and Scourse (1990) defined glacimarine as "all those areas where sediment is deposited in the sea after release from glacier ice (including tidewater ice fronts, floating glacier tongues, ice shelves and icebergs) or sea ice." Since marine basins are more highly represented in the geologic record, even though this can be indeed be considered a subset of glacigenic, it is an important area of study. The book "Climate Modes of the Phanerozoic" (Frakes, Francis, and Syktus, 1992) is full of references to using marine sediments with increases or decreases of ice-carried dropstones as a proxy for ice-volume change.
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I would like to know the Zr/Ti ratio present in mud flat sediments. Is there any world average or a range? I'm reading (from "Dellwig, O., Hinrichs, J., Hild, A., Brumsack, H.-J. (2000). Changing sedimentation in tidal flat sediments of the southern North Sea from the Holocene to the present: a geochemical approach. Journal of Sea Research, 44: 195-208") that this ratio is different for present and Holocene sediments of mud flats. The Zr/Ti ratio reported in this paper for recent sediments is 0.25 and for heavy minerals it is 0.48. We obtain a value of around 50 for recent sediments of east coast of India. I would like to clarify that. Any information on sea level fluctuations along east coast of India is also welcome.
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The ratio would depend on source area composition. For example, if the mudflat sediments are derived from felsic sources, the ratios would be different from those derived from mafic sources.
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I'm looking for the paper of Matsumoto (1924) in which the genus was established, the paper in which Palaeoloxodon raised up to rank of genus e and so on. Can you help me?
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Seiche in volcanic lake
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Rosanna,
I suggest that you compile historical earthquake data and recorded measurements of seiche waves on Lago di Bolsena for those events. Didn't some one note the seiche amplitude for the 1980 earthquake? If not, then perhaps historical photos will show the water line? This may be a question that is easiest to answer with a day or two spent in the library, followed by interviews with residents at the lake.
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I tried to understand the meaning of D(4,3) and D(0,5) values in grain size analysis, but everywhere it is written that these values are volume weighted mean and surface weighted mean. I do not understand what does it mean and what it reflects.
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You can find some explanations in attachments
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We have sediment cores from a lake and in the anoxic part (where we have varves), we have alternate carbonate and organic layers. In the same varve layers we do not have any tree pollen. Can anyone please suggest what could be the possible reason behind that?
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Anoxic conditions are generally good for pollen preservation. Pollen grains may show different degrees of deterioration depending on the thickness and type of exine. Therefore a selective deterioration may occur in highly calcareous or oxidative sediments, or when hydratation-dehydratation cycles occurred.
There are no reason to have a selective deterioration of pollen (gametophyte) based on the habitus of the sporophyte.
If a deterioration occurred in these samples, I think that it has not involved only pollen grains of trees, and that it was not related to the anoxic conditions.
If the deterioration has not occurred, possible explanations of the absence of trees may be that trees were truly few (open grassland?) and with low pollen productivity; some high-productive pollen therefore masked rare pollen grains.
I suggest to count more pollen grains or to prepare again the samples.
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dating of Pliocene fluvial sediments in Danube Basin, Central Europe
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The most important thing is collecting the most representative samples for the feature you are trying to date. You should consider origin, transportation, deposition and erosion/burial history of the sample. All of these factors will affect the age your sample yields. Detailed geomorphic documentation of the sample and its surrounding always helps.