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Sedimentology - Science topic

Sedimentology encompasses the study of modern sediments such as sand, mud (silt), and clay, and the processes that result in their deposition.
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I am working in the lake sediment system and I have both radiocarbon and osl ages. In order to build a full chronology of the lake is Bayesian age depth model a good option? If not could you please suggest me the alternatives? Thanking in advance.
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Thank you for your suggestion. The radiocarbon dates focus on bulk organic matter, i.e. total organic carbon content( TOC) while the OSL dates focus on the quartz grains for luminescence study. As the area lies on plain land there are no hydrothermal influences
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I am aiming to generate 3D profile of subsurface formation using VES techniques . I have DDR3 Electrical Resistivity meter (http://www.indiamart.com/proddetail/ddr-3-resistivity-meters-3894683488.html) to carry out this studies. Is it possible ? 
If it is only software dependent, which software can be suitable for interpretation and 3D profile generation ? 
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Dear Colleague,
It is very possible to use DDR 3 for manual acquisition of 3D resistivity data but however requires intensive labour, prolonged duration on the field, more financial expenditure as the survey may spill into the following day if not completed.
The smartest way to embark on the acquisition, is by designing a spreadsheet that accepts all field parameters and automatically computes the apparent resistivity for effective monitoring of data trend.
It therefore advisable to input all recordings on a smart phone or tab when using DDR 3 for 3D acquisition.
Regards,
Alaka.
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Dear all,
The geological meaning of Cao* seems not to allow the occurrence of negative cases, but in the face of the high content of P2O5 (close to Cao), resulting in caO-P2O5 * 10/3 of the result is negative, how should I deal with this situation, what may be the geological reasons?
Looking forward to your kind suggestions in this regard!
Thanks & regards,
Yanhua Xu
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The calculation you are doing is to account for (exclude) the presence of apatite (Ca5[PO4]3(OH, F, Cl), in which (ideally) there are 5 moles of CaO and 1.5 moles of P2O5. So, for every mole of P2O5 you need to subtract 3.33 (10/3) moles of CaO assuming it is all in apatite, then see how much CaO is left over.
However, depending on the rock type, not all the P2O5 (or indeed any of it) needs to be in apatite. For example, in metapelites, it might be in monazite. You should also check that you have converted your bulk compositions to molecular rather than weight percent values. Lastly, all analyses are associated with uncertainties that need to be accounted for.
What negative values are you getting?
Good luck.
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I am working on the Triassic period and particularly sedimentology, petrography, porosity, fracture and Diagenesis.
who worked at this period and has related paper.
I appreciate it.
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You may have a look at the website "Triassic Stratigraphy"
or "The European Keuper: Stratigraphy and Facies"
Best regards
K.-P. Kelber
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I have analyzed few marine samples on the Mastersizer software for the grain size analysis. I calculated the mean grain size, and median data from it but i don't know how to calculate the sorting data from it. I would really appreciate it if somebody guide me how to calculate the grain sorting from this data.
Thanks
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Hello Muhammad Sarim - the pag file contains the information for the report, for example the layout. There should be a special folder where there files are stored,, similar to the way this is handled in the Zetasizer software.
If this does not help, reach out to the help desk https://www.materials-talks.com/help-for-my-instrument-one-step-away/
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In the volcanic-sedimentary sequence (teschenite association, Outer Western Carpathians), layers of very fine-grained sediment with an extremely high microcline content (up to 80%, the rest is calcite) were found in shales in close contact with the effusive volcanic (highly altered mygdaloidal trachybasalt?). Feldspar is up to 5 μm in size, hypidiomorphic to idiomorphic. The rock lies clearly outside the volcanic body, but is also finely amygdaloidal.
Is it possible that it is a sediment from hydrothermal activity or what is it about ??? Is there any literature on similar rocks?
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Dear Dr. Matysek,
It is always a bit difficult to hand down a remote-controlled expertise.
1. I was first pondering over the so-called keratophyre issue which also forms fine-grained ash tuff ?
It is in my opinion not a normal petrogenic but hydrothermal alteration process which brought about 80 % K feldspar together with calcite
2. is the XX shape in the last SEM image pointing to adularia XX? High K-feldspar contents may occur in the low sulfidation-type alteration (?)
3. I know abnormally high sanidine contents from hotspot volcanism taking place in the Mongolian plateau during the Tertiary and Quaternary. This vast eruptive igneous activity brought about mainly alkaline basanites and olivine basalts. There , sanidine formed instead of leucite. The rocks also are accountable for placers enriched in sanidine, olivine (“peridot”), garnet (enriched in pyrope) and last-but-least sparked the discovery of 50 micro-diamonds. The K2O/Na2O ratio is below 5 and did not qualify the area as highly prospective for diamond-bearing "lamproites". What is yours?
4. A reworking has to be excluded due to the fine grain-size (?). Are there agglomerates or breccias?
These are some thoughts which are still rather un-oriented in one or the other direction.
At the moment I would go along with points 3 and 4.
HGD
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As we know, it is a very difficult task to differentiate tsunami deposits from storm deposits. Sedimentological (grain size, grain sorting, sedimentary structure and sedimentary fabric), palaeontological, geochemistry and geophysical analysis are the most common methods to identify and characterise the tsunami deposits. Recently, X-ray computed tomography is being used in grain size, sedimentary structures and fabric analysis. Can we consider X-ray computed tomography as a unique tool that could discriminate between storm and tsunami deposits?
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The criteria that can be used to distinguish between tsunami deposits and storm deposits includes: the frequency of the deposits, the nature of neighbouring Facies associations and the sedimentary structure associations
The frequency of storm deposits is greater in a sedimentary series than those of tsunamis, to the point that sometimes we can have a succession of several hundred meters consisting almost essentially of storm facies as is the case for the Ordovician series of Morocco
Storm action is recorded from land to distal offshore so storm deposits must be associated with other shallow deposits: foreshore, shoreface, offshore or delta deposits. While tsunami deposits can occur in various environments ranging from the coast to the deep sea.
Storm deposits generally exhibit a wider variety of sedimentary facies than tsunami deposits.
Tsunami deposits may include sedimentary structures that reflect the combination of oscillatory currents and turbulent unidirectional currents. For example tsunami deposits of the Oligo Miocene of the NW Rif (Morocco) include layers of constant thickness displaying hummocky cross-stratification or Micro-hummocky cross stratification and large flute casts and groove casts at their base
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I am studying clays diffraction (air dried, treatment with etilenglycol and heat treatments).
Maybe other mineral association could help? Presence of other minerals (i. e. alunite)? I don´t need to be 100% sure but I would like to know how to predict the predominance of one of them. 
Thank you very much
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Hello,
distinguishing kaolinite and dickite by XRD is not that complicated. It is necessary to prepare the least structured preparation (cuvette filled from above or behind, powdered preparation, preparation mixed with plastic binder etc.) and possibly use the Rietveld method with the insertion of models of both minerals. The positions of relatively weak non-basal lines are decisive.
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During an examination of outcrops around Wadi Halfa North Sudan we found a discoidal shape grain of Barite Concretions or Sand Barite.
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Dear Mr. Daoud,
just this type was investigated in the cited paper:
DILL, H.G., BERNER, Z., KAUFHOLD, S., WEBER, B. and METZ, U. (2013) Facies-related baryte mineralization bearing Cu-Zn sulfides in Miocene estuarine deposits of the upper Rhein Graben (Wetterau, Central Germany).- Sedimentary Geology, 296: 55-71.
Abstract: Abstract
Baryte with or without base metal sulfides is quite common in sediments deposited in open marine environments or in continental sedimentary basins. Its precipitation is caused by hydrothermal processes, related to diagenesis, and frequently mediated by biogenic processes. The current study is focused on siliciclastic sandstones of Miocene (Aquitanian) age in an estuarine environment in the Wetterau region of the Rhein Graben, central Germany. In the estuarine environment only the central basin and the landward delta are host to a diagenetic and subsequent hydrothermal mineralization.
Diagenesis took place under near-ambient ( T ≈ 25°C) conditions and resulted in strong pyritization (-0.75 <Eh < +0.25, pH >5) in the central basin. Diagenesis is more landward represented by a pervasive silicification (pH < 12) in deltaic sandstones.
Epigenetic mineralization (100°-130°C) with pyrite in the central basins was succeeded by Cu-Zn-(Sb) minerals (0.75 < Eh < 0 / 5 < pH < 11), silicification and kaolinisation (2< pH < 9.5) and eventually by the formation of gibbsite (3 <pH<8). At the transition from the delta to the estuarine funnel, baryte is of very widespread occurrence. Its variegated texture and crystal morphology allow for a precise determination of the hydraulic system as marine phreatic, freshwater phreatic, and freshwater vadose. The narrow size of the rift graben and its sealing against the open sea fostered concentration of Ba and enhanced the redox processes. Hypogene brines along with Miocene volcanic activity provided the metals, and marine ingressions in this transitional environment supplied the sulfur. Sulfides were concentrated in the finer-grained rocks because of their enrichment in organic material, while sulfates accumulated in the more permeable coarser sandstones.
H.G.D.
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Dear collegues,
I am looking for papers in the field of sedimentology using the line count method for componentry measurements. The line count consist in using a 1m long tape (or longer sometimes) and measure the intersection length of clasts/particules found along the tape.
Thanks,
Ben
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Hi Everyone,
Please find our new Geosphere paper on this topic: Precision and accuracy of modal analysis methods for clastic deposits and rocks: A statistical and numerical modeling approach.
This one is now avaliable online.
Best regards,
Benjamin
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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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Hi everybody! Does anyone may suggest me some useful references (papers, books) for the interpretation of the signals emitted from the organic matter preserved in the sediments? Can be great to find a sort of table reporting the different kinds of organic matter (e.g., algal, terrestrial) and their response under specific emission filters.
Thanks in advance,
Luca
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Dear Mr. Pellegrino,
We have studied sedimentary basins across the world since many years backed by coal petrographic analyses under different wave length.
The publications below are all available on request for download from the RG server:
DILL, H. G., KOCH, J., TESCHNER, M. and WEHNER, H. (1991) Coalification and organic geochemistry of the Permo-Carboniferous beds in the Stockheim Basin, NE-Bavaria (F.R. Germany).- Erdöl and Kohle, 44: 97-105.
DILL, H.G., KOCH, J., SCHEEDER G., WEHNER, H., and STRAHL, J. (2003) Lithology, palynology and organic geochemistry of carbonaceous rocks in fluvial-lacustrine series of Tertiary to Quaternary age (Kathmandu Basin, Nepal).- Neues Jahrbuchfür Geologie und Paläontologie Abhandlungen, 227: 1-38.
DILL, H.G., WEHNER, H., KUS, J., BOTZ, R., BERNER, Z., STÜBEN, D. and AL-SAYIGH A. (2007) The Eocene Rusayl Formation, Oman, carbonaceous rocks in calcareous shelf sediments: environment of deposition, alteration and hydrocarbon potential.- International Journal of Coal Geology 72: 89-123.
DILL, H.G., KUS, J., DOHRMANN, R. and TSOY, Y. (2008) Supergene and hypogene alteration in the dual-use kaolin-bearing coal deposit Angren, SE Uzbekistan.- International Journal of Coal Geology, 75: 225-240.
DILL, H.G., KUS J., ABED., A.M., SACHSENHOFER R.F.and ABUL KHAIR H. (2009) Diagenetic and epigenetic alteration of Cretaceous to Paleogene organic-rich sedimentary successions typical of the western margin of the Arabian Plate, northwestern Jordan.- GeoArabia, 14: 101-140.
DILL, H.G., BECHTEL, A., KUS, J., GRATZER, R. and ABU HAMAD, A. M. B. (2010) Deposition and alteration of carbonaceous series within a Neotethyan rift at the western boundary of the Arabian Plate: The Late Permian Um Irna Formation, NW Jordan, a petroleum system.- International Journal of Coal Geology, 81: 1-24.
DILL, H.G. , BECHTEL, A., BERNER, Z., BOTZ, R., KUS, J., HEUNISCH, C. and ABU HAMAD, A. M. B. (2012) The evaporite-coal transition: Chemical, mineralogical and organic composition of the Late Triassic Abu RuweisFormation, NW Jordan - reference type of the “Arabian Keuper”.- Chemical Geology, 298-299: 20-40.
DILL, H.G., TECHMER, A. and KUS, J (2013) Evolution of an old mining district between 725 and 1630 AD at the boundary between Thüringen and Bayern, SE Germany, using mineralogical and chemical markers, radio-carbon dating and coal petrography of slags.- Archaeological and Anthropological Sciences, 5: 215-233.
DILL, H.G., KUS, J., KAUFHOLD, S., RAMMLMAIR, D., and TECHMER, A. (2017) Oligo-Miocene coal in a microtidal environment reworked under Quaternary periglacial conditions (Western Falkland Islands/Isla Gran Malvina). – Coal formation and natural sand processing.- International Journal of Coal Geology 174: 8-22.
DILL, H.G., KUS J., BUZATU A., BALABAN S.-I. ,KAUFHOLD S., and BORREGO A. G. (2021) Organic debris and allochthonous coal in Quaternary landforms within a periglacial setting (Longyearbyen Mining District, Norway) - A multi-disciplinary study (coal geology-geomorphology-sedimentology).- International Journal of Coal Geology (on-line)
With kind regards
H.G.Dill
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Hello, i have a sandstone in thin section with 15% matrix from marine deposition and i am confused with this mineral appearance in xpl it has gold colour and in ppl it has brownish yellowish colour but i can't identified it's name. I think it's calcite or lamonite but i doubt it. If you know it please help me
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Primarily, it is likely to be an Fe-bearing calcite or Fe-bearing dolomite which under the influence of oxygen has been altered as to the valence state of Fe. Since trivalent Fe cannot be accommodated into the lattice of carbonate minerals it is expelled from the structure and concentrated as a mixture of Fe oxide hydrates which suitably are denominated as "limonite" (rareky pure goethite). You are on the right track with your assumption.
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Sedimentology, Geology 
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May be it's too late but the answer is you need to create the chart so that one of the axes is of probability scale. You can do it by calculating z-scores for your cumulative distribution function, which is calculated by NORM.S.INV function in Excel. Put z scores on one axis and the random variable (whatever it is) on the other. The random variable's axis should be of logarithmic scale. That's how you obtain a log-probability chart.
In log-probability chart, they say that a straight line is formed if the random variable is log-normally distributed, and the standard deviation is equal to the the ratio of the values of random variables at CDF= 84.1% and 50%.
My question is where 84.1% comes from.
Also, I wrote an Excel VBA routine that uses Gradient algorithm and iteratively finds the mean and the standard deviation of a log-normally distributed sample once the random variable and corresponding cumulative probabilities are given. I need that 84.1% issue to be solved before I conclude my software and publish it.
Any help is appreciated.
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Hello, I am currently working on the design of a device that measures thermal conductivity of sediments and I am not sure if i estimated heat losses and heat flux in the correct way. The device is a 0,0034 cubic meters (200 cubic inches aprox) box with a resistor (curved alloy wire) in contact with one face of the sample, connected to a power supply. The resistor is in the middle of one face of the sample and a heavy insulator, like glass wool (i am not sure if this is the proper term for the material).
This is not my work area, i'm a geologist, but given my current research i am in the need to resolve this issue
Please feel free to answer any of this questions, also any comment will be helpful.
My questions are:
  • If it is ok to estimate heat losses considering an estimation of the temperature at a middle point in the box and thickness and the thermal conductivity at the five walls that surround the internal sample considering that one side of the device is in contact with the surrounding air
  • If using a common insulator (say 0,02 to 0,04 W/m.C°) will yield an aproximate heat loss of less than 1W, considering 0,1 m wall thickness (4 inches aprox).
  • If the sample will reach a quasi steady-state heat flux or will be far from it, considering the room temperature stays aproximately constant.
  • How much heat will disipate the wire if the power output of the power supply is, say 6W. In other words what will be the heat flow at the resistor, through the first face of the sample near the resistor, given that supplied power.
Regards
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Hello Matias
Now I think that I understand what you are trying to do.
I think you can obtain a quasi-steady-state in your sample but you must wait some time to obtain it. As you have an insulator (your box) under the resistor you may have a problem with increasing temperature in that wall of the box and an increase of heat flowing in your sample.
You can obtain the heat lost through the walls of the box measuring temperature differences between inner and outer surfaces of the box P(lost) = (0,04) (Tin - Tout)/ 0,1. You can also have an idea about the heat lost through lateral sides using several termocouples in the upper surface of your sample located from the center to the lateral part of the samle.
The values obtained will depend on the sample you want to study. In principle if you are studying rock sediments you will obtain low thermal conductivity values (compared with common rock values ) but higher values than 0,04 and you will have heat flowing predominantely in the vertical direction.
Try to not use high temperature values in your experiment. Thermocouples are very good to use in this type of experiments because its volume is very small and they have a rapid answer.
As I said in my first message you are using Joule's effect in your experiment and the power dissipated is P= R I2 . The value o I depends on the value of R. You must know the ddp (voltage) at the ends of your resistor ((V=RI).
I think I unswer to your questions but if you have some question more you can contact me.
Best regards
Maria Rosa Duque
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Does anybody know a free software to draw a sedimentological log with comments and sample locations? I tried installing Sedlog but does not work on my PC. Thanks
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Hi Zeinab,
SedLog is fine but I'll recommend to use a vector illustration software like Adobe Illustrator or CorelDraw. Making an illustration will always give more opportunities than the parameters defined by a software like SedLog.
Best,
Adrián
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Palynological/ Sedimentological/ Facies interpretations
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Dear Mr. Akhtar,
sequence stratigraphy methods are widely used in correlation and study of facies distribution in hydrocarbon exploration . I recommend startimg with the classical studies of Wilgus et al. 1988, Emery & Myers 1996, Miall 1997, Posamentier & Allen 1999, and Catuneanu 2003.
With kind regards
H.G.Dill
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We want to model shoreline change and morphological changes there.
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Delft 3D is a good choice
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In a delta front context, How can we discriminate between sands deposited by river floods & sands deposited in wave dominated deltas
esp when we don't have any sedimentary structures observed except few horizontal lamination, no bioturbation. 4 to 5 meters of structurless/massive fine sandstone with abundance of mud clasts and few convoluted bedding (attached some core photos)?
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The question whether it is a fluvial-dominated or wave-dominated delta cannot be decided based upon the data available and should be done by investigating the vertical/ lithologs and also in plain view (e.g. "birdfoot delta" = fluvial) .
Often it is not a true end-member type but a mixture of wave- and fluvial-dominated processes. That is why I tried to convince you to look at this transitional landform between land and sea in a 3-D view to get a full-blown and true picture. It is certainly not an easy task.
H.G.Dill
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The samples were collected from aquifer with the following lithology:
- Conglomerates, calcareous limestones sand red and green clays 
- Marls, clays and white limestones
- Clays and gypsum;
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use this paper for more
Significance of saturation index of certain clay minerals in shallow coastal groundwater, in and around Kalpakkam, Tamil Nadu, India
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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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I am looking for a master's degree in a good university specializing in sedimentology and diagenesis of carbonate rocks. Could you guide me?
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Thank you Sergio Rodriguez. The problem at Erlangen University is the language, many courses are in Dutch.
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Many time people use HCL before granulometry analysis of sediment and how it affect the overall size of the original material. If we are in deeper environment, then the main source of material is biogenic apart from terrestrial input, because the material derived to this environment is mainly pelagic sources (Benthic, Siliceous, Planktonic forms).
What is the best practice to do the analysis without affecting the originality of the material. Please provide your opinion so that i could clear my understanding about the procedures involved behind it.
Thanks
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biogenic sediment are made up of carbonate and arogonite. It consist of small voids/ gaps inside. If we will remove these biogenic content from the sediment. Geotechnical properties of sediment will automatically improve.
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I have performed d 13C carbonate in Cenomanian-Turonian core samples and got negative values, I need an explanation from sedimentology and petrology point of view.
the target to detect the positive excursion of OAE2
**you will find plotting to the values attached
Thanks in advance
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CHEMOSTRATIGRAPHY OF CENOMANIAN–TURONIAN CARBONATES OF THE SARVAK FORMATION, SOUTHERN IRAN
E. Hajikazemi I.S. Al‐Aasm M. Coniglio
Journal of Petroleum Geology, Vol. 35(2), April 2012, pp 187-206
Abstract
Stable‐isotope and trace‐element analyses from five surface and subsurface sections of the mid‐Cretaceous Sarvak Formation in southern and offshore Iran confirm the presence of the regional‐scale Turonian unconformity and of a more local Cenomanian–Turonian unconformity. The geochemical results indicate the presence of previously unrecognized and/or undifferentiated subaerial exposure surfaces. Sarvak Formation carbonates at or near palaeo‐exposure surfaces show varying degrees of diagenetic modification, and more extensive alteration is associated with longer periods of exposure. The subaerial exposure and associated diagenetic processes greatly influenced reservoir quality and amplified karstification and evolution of porosity in the Upper Sarvak Formation.
The palaeo‐exposure surfaces are identified by their negative δ13C values (as low as – 6.4%) and negative δ18O values (as low as –9.4%), together with low Sr concentrations and relatively high 87Sr/86Sr ratios. These geochemical characteristics are interpreted to be the result of the interaction of the Sarvak Formation carbonates with meteoric waters charged with atmospheric CO2. The meteoric waters also caused karstification and soil formation which in some places extends a few metres below the exposure surfaces. Depleted carbon values were not recorded in areas where palaeosols are not well developed or where the uppermost layers of the Sarvak Formation have been removed by erosion.
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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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Petrology is a branch of geology concerned with the study of rocks. As we know, that the rocks are of three types, igneous, sedimentary and metamorphic. So, Sedimentary Petrology is the study dealing with sedimentary rocks: their origin, occurrence, composition, texture, etc. Now, another term used for the study of sedimentary rocks is Sedimentology which largely overlaps the former. With no sharp demarcation between the two, they appear to be interchangeable. Are they synonyms?
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Please compare the terminology of the terms "sedimentology" and "sedimentary petrology" given by the Glossary of Geology, Second Edition, Robert L. Bates and Julia A. Jackson, Editors (1980), and please decide for yourself what the similarities and differences are:
"sedimentology" (quotation): "The scientific study of sedimentary rocks and of the processes by which they were formed; the description, classification, origin, and interpretation of sediments. Sometimes miscalled 'sedimentation'."
"sedimentary petrology" (quotation): "The study of the composition, characteristics, and origin of sediments and sedimentary rocks. Often miscalled 'sedimentation'."
Best regards,
Guenter Grundmann
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In deltaic system; Very fine to fine grained compact sandstones with planar laminations and no bioturbation. could we consider this a wave or fluvial dominated delta front?
* some intervals of fluid mud (Non bioturbated shales)are observed within the prodelta facies
* only a half HCS observed
* sand intervals are very clean and can form 4 to 5 meters of sandtones
* Some sediment gravity flow and dewatering structures were also observed
Wave dominated or River dominated delta front ???
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Dear Colleagues,
to distinguish the three end-member types of deltas (wave-. fluvial-.tide-dominated) should not be done based upon the description of some textures and structures. The delta front is the subaqueous part of the delta which is mainly built up under the influence of marine high energy processes, such as longhshore drift, wave and tidal actions. There may be discordant beds which have derived from fluvial reworking but they have not been mentioned in your record. You excluded a strong tidal impact which could have been indentified by the overall stacking of bedsets. So I assume you are studying currently a wave-dominated part. My general recommendation is try and investigate the entire delta (I do not know how much of it you have insight into ?) plot it and collect all data. The risk to over-interpret one part while others are ignored is high.
With kind regards
H.G.Dill
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I agree with Dr Dill it is mostly Liesegang structures.
We recorded it from Late Jurassic and Cretaceous formations in Kurdistan.
Some of them are very rich with organic matter and others are rich with iron oxide.
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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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just wondering if there is any published material on how the stereochemistry of environmentally important biomarkers could be affected by the paleo-strain the rocks in a sedimentary basin were subjected to (e.g. folding).
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Thank you so much. Will check that.
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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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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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Please, i'm looking for a copy of a Book : "Principles of Alluvial Fan Morphology ( Dan Bowman )", can you help me to find it ??
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Your email
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Dear colleagues Good day. Can I ask if any one have ever seen such hexagonal cracks (about 1 t0 2 cm in diameter) in marine marlstones. I will be very much grateful if any reference or interpretation is provided. Regards, Sincerely yours Issa Makhlouf Prof. of Sedimentology Hashemite University Jordan
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Isotropic contraction cracks, in this case most probably dessication cracks.
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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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Clay samples are heated at 950 degree centigrade (LOI method) before XRF analysis. Due to which Fe percentage increases in the XRF results. It is due to the oxidation of samples during fusion. Is there any procedure to correct the Fe value within the results?
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Hi Jorge
I agree it's certainly possible. However, since XRF only detects the Fe content not the O content, the meaured Fe content will not change as a result of its oxidation state: this was the point I was aiming to make.
Kindest Regards
Paul.
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These microfacies belang to Cretaceous plagic limeston in the Azerbaijan (NW Iran). I cant identify plancton microfossils.
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No oolite at all, but calcispheres (= calciodinoflagellate cysts) -@ Som Nath Kundal -
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I am working on the Archean Quartzite rocks from the western Dharwar Craton. I am need to use tectonic discrimination diagram using trace element. I have already used some diagram by major elements. So I am expecting the experts in the field of Sedimentology to suggest me some tectonic discrimination diagram for my manuscript.
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Dear Rajamanickam,
Perhaps you can use trace element discriminant diagrams given by Pearce et al 1984 if you have analyzed those trace elements. You can try to discriminate between granitic sources of quartz in your quartzite, being aware that quartz from all sources are now mixed together. In case, if the source area of quartz was dominant in one of those granite types, you may end up in a good conclusion.
Best Wishes!
LRK
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These deposits were from mud caps of sediment gravity flow deposits. These mud caps are homogenous and no trace fossils can be identified. Can any one help me identify these aggregates? Thank you very much! The SEM images are attached.
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Dear Mr. Shan,
with some caveats, your spectra point to gypsum/anhydrite and kaolinite-group minerals, both of which herald a secondary acidic environment and oxidizing conditions. It is a local alteration spot. There a relics of mica and feldspar still present
Kind regards
H.G.Dill
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I have been searching for some articles which may address the problem mentioned above. I could find some excellent papers dealing with origin of red beds in sand dunes but hardly any dealing with fluvial deposits of Holocene or Late Pleistocene.
Any help in this regard is welcomed.
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Dr Jérôme Juilleret additions to the photo nicely highlight the depositional and post-depositional events of this sequence. Although the oxidation can be caused by several processes, in profiles such as this, it has been my experience in the western U.S., southern Italy, Jordan and Iran, that they occur under conditions of fluctuating water table, and their location in a profile is often linked to zones of lateral movement of ground water across a sedimentary profile due to the presence of zones of increased grain size. These more permeable units allow more rapid movement ground water. When these units occur at the top of the ground water table, oxidation also commonly occurs. The variable occurrence of these units in your profile more than likely record different levels of your water table
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Works on adhesion warts have shown that these surface features are usually originated by the adhesion of windblown sand on a wet surface. My question is:
Is it possible for wind-blown mud particles to form adhesion warts? Or the different particle size and kinetic energy preclude the formation of these surface structures?
Many thanks for the help!
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I am looking for the causes that produce a HREE depletion in sedimentary phosphatic chalks of Late Cretaceous.
Thank you for yours answers,
Damien
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Dear Damien,
One of the reasons could be the sistematic difference of oxidation potential between the REE, which leads to different grades of adsorption of these elements into iron oxyhydroxides, organic matter and phopsphates particles present on the sea water. For more details you can check the work of Sholkovitz et al. (1994) - Ocean particle chemistry: the fractionation of rare earth elements between suspended particles and seawater. Geochimica et Cosmochimica Acta.
Other reasons could be related to post reworking processes, such as taphonomic process: Auer et al. (2017) - The impact of transport processes on rare earth element patterns in marine authigenic and biogenic phosphates. Geochimica et Cosmochimica Acta.
Best regards,
Emilio
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I wish to do grain size analysis of sand. What experimental set up should I follow for it and how should I analyse the data. Please provide some references on this topic.
Thanks.
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For an overview of various methods, see:
February 9th, 2012 Size and shape characterization in soils and sediments
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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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Dear all,
I have calculated Fine content (Silt+Clay), Liquid Limit, Plastic Limit, Plasticity Index, Mean grain size, SPT value for soil samples. I need to obtain Clay % for my study. Kindly suggest a suitable empirical formula to calculate clay % from the above available parameters.
Thanks you.
Ashok
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No such empirical formula exits to obtain Clay % from Fine content (silt+clay). The A-line in the plasticity chart enables you to see if the majority of (silt+clay) fraction is clay if it plots above the A-line and silt if it plots below the A-line. However, it could be organic soils as well!
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Slump structure
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Gentlemen - I believe you will find this document of great interest:
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such as homogeneity particle size index.
Especially for sandstone and limestone.
And how they can be calculated (With math calculations).
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sajad
grain size , arrangement and cementation and matrix, diagnises , fossils.
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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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Dear all,
I have collected soil samples up to a depth of 50m from surface during drilling. I need to interpret alternate cycles of dry and wet climate on the basis of soil types. What are the criteria to classify soils into Entisol, Vertisol, Alfisol, Oxisol etc. ? I would like to know the parameters like texture, color, amount of organic matter, presence of particular minerals, cation exchange capacity, and pH values to characterise the soil types. It would be really helpful if you kindly provide me the list or document where the parameters range are given to classify the soils.
Thanks & regards,
Ashok
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Please have a look at enclosed PDF..
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Dear Colleague,
this is not a question. I want only share the following paper with you:
In this paper you can find the description of physical features of a S. spinulosa reef in the Mediterrenean area.
Sincerely
Massimo
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Dear Massimo, thank you very much.
Regards
Alessandro
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Miller (1996) suggested that based on its original definition, the term "diamictite" should be restricted to the matrix-supported diamictite. However, other authors such as Schultz (1984) and Eyles et al. (1983) used the term clast-supported diamictite. What do you suggest?
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Yes, exactly, the exact definitions are still not available and the terms are used in slightly different meaning, depending on the author. I find the classification of Moncrieff (1989) the best so far and it is commonly used in glacial geology, which is my playground. Hope, this was helpful.
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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:
Best
Syed
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carbonate sedimentology - petroleum geology- diagenesis- sequence stratigraphy
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Jamal:
Have a look at this link for essential insights:
Best
Syed
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I am studying facies sequence of Tertiary rock in Bengal basin.
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Dear colleague:
There is a wide range of marks and traces in the field of inorganic and organic sedimentology which have some implications on the paleobathymetry of sedimentary strata. The same holds true for the floral and faunal remains in paleontology. There are much more publications, items and species of assistance to address this issue than room available in this Q&A process on Researchgate.
I wish you much success
H.G.Dill
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I'm going to be coring in a terrestrial environment (ravines near a river). This area has experienced erosion from logging, then agriculture and now construction. I want to be able to tell which layers of sediment are from logging/agriculture/construction to gauge their impacts over time. I'm a grad student and the budget for this project won't be enough to send the samples to another lab for processing, so I'm trying to find out if our facilities will be adequate. 
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AAS cannot be used for measuring 210Pb! It can be measured by 3 methods. 1) Alpha Spectroscopy ; 2) Gamma spectrometry (as mentioned by Arribere) and 3) MC-ICP-MS. By Alpha Spectroscopy, 210Pb activities of sediments can be analyzed indirectly by measuring the activity of its granddaughter 210Po (half life=138.4 d) which is in radioactive equilibrium with 210Pb (half life=22.3 yr). A polonium tracer and chemistry is involved. You may read references. There is some good literature describing the method (e.g., Koide, M., Soutar, A., Goldberg, E.D., 1972. Marine sedimentology with
210Pb. Earth and Planetary Science Letters 14, 442–446. The experts believe that the sensitivity of this method is better than Gamma spectroscopy. But in Gamma, the advantage is the non-destructive technique and does not involve chemistry. You may read an attached paper where this technique is used. In any case, some of the experts suggest that 210Pb cannot be used as a single dating tool and should be used in combination with other methods (say 137Cs...).
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Source of the Sediments and the reason for its mottled texture
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Please check out this article:
About mottled texture, can you post a couple of detailed representative photos?
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Dear all, 
I have these plates which contain SEM images of Foraminifera from the Upper Cretaceous (Turonian) from the Ferron Sandstone Member, Utah, USA.
All the samples recovered from shales from this member, The Ferron Sandstone member belongs to the Mancos Shale formation.
This area range from shelf to deltaic environments. The preservation is poor in some samples but fairly good in others. 
I am just struggling in identifying them, so I kindly ask for your help!
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It is clear that a job of cleaning and using the 3D scanning technique would help a lot. However, looking briefly and apparently the first plates appear to be benthic foraminifera of the genus Textularia; The third plate reminds me of benthic foraminifera of the genus Ammonia and the last plate really needs to be more worked on in the cleaning and for me they are difficult to be identified.
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about Tethys Sea
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Are you referring to northern border of the Indian plate, or the present day political border of India? The latter is not easy to answer very simply. As you know, India is a large country and its geology shows considerable change from Assam to Kashmir. There are juxtaposed fold-thrust belts, suture zones, HP-UHP rocks, island arcs, Asiatic (formerly Gondwanic) blocks and of course the Siwaliks. 
You might like to contact Wadia Institute of Himalayan Gelogy, Dehradun, India, and Dept of Earth Sciences, Indian Institute of Technology, Roorkee, India. Their e-mails should e available on the internet.
Best, Qasim
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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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As part of a Ph.D study on Early Jurassic sedimentological, climatic and environmental changes, we are currently studying the significance of condensation and the deposition of phosphate-rich sediments in Switzerland. We are determining if this phenomenon is linked to global oceanographic-climatic changes or to the more regional tectonic constellation and the presence of local highs. Therefore, we would be glad if you could help us to inventory the distribution of condensation and phosphate enrichment during the Early Jurassic. We are especially interested in the occurrence of condensed phosphate-rich sediments in Europe but also welcome indications of sites in other parts of the world.
Schöllhorn Iris, Thierry Adatte and K. Föllmi (University of Lausanne)
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Image shows ammonites that occur on the top of upper Jurassic bed.
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oh Dr. your perfect hunting Great Extinction of end Jurassic ....in Pic . show small &young ammonite in highly biodiversity in global death .....
suture line is Nautoloid clearly .
and this fossils in hard ground because global climate change causses from catastrophic (Activity of volcanic )
congratulation 
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Dear Irfan,
I found the following thesis for you. I hope it helps.
SEDIMENTOLOGY OF SINJAR AND KHURMALA FORMATIONS (PALEOCENE-LOWER EOCENE) IN NORTHERN IRAQ
Regards
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inter my account ..the same paper from south iraq
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