Questions related to Geodynamics
If a rigid plate is bounded by two transform faults and the plate is moving, with the translatory motion of the plate will there be oscillatory motion as well? If not, why and if there is an oscillatory motion then what will be the mechanism of it?
I am looking for recommendations of any open source geodynamic modelling software that could help me model how the style of subduction initiation impacts the geometry of the resulting slab?
By "style of subduction initiation", I mean spontaneous (e.g. mantle plume, passive margin or transform collapse) or induced (transference or polarity reversal). So theoretically, I want to input the characteristics of these styles and see the geometry of the slab produced.
Image from Stern and Gerya (2018)
How can we relate the abundance and composition of granitoids to the geodynamic context in which they formed?
Why the granitoids are abundant in the Hercynian belt in the Western Europe?
Why the granitoids are scarce in the Calcedonian and Alpine Orogenies?
This topic has been open for a wide range of researchers here and outside of RG, as open access to write and read comments related.
I encourage researchers with a deterministic view on earthquake nature for being proactive by trying to use resources of this space as much as possible in a way of understanding this phenomena by challenging their forecast models through forecast tests.
On forecast, I would like to find the method, data and time window for forecast, with magnitude range and probability of occurence. If the location of future event is possible, please specify. It's a test, and additional option to write about our successful forecasts and our correct models.
Also, please be concise, as possible.
In addition, I suggest to make references to own research, or other sources, for keeping the transparency on sensitive questions such as autor rights, originality and other aspect. For this, in case of not published yet ideas, I suggest to publish and come down in the comments with reference to official open to public source - article.
N.B. Regarding the forecasts based on statistical methods, and random nature of the EQ phenomenon view, are also welcomed.
Paleomagnetic studies show that the South China block was moving northward continuously from 300 to 260 Ma and has experienced an overall ∼27° clockwise rotation since then (Huang et al., 2018) ,and assuming a stationary Emeishan mantle plume, so if I want to do a numerical simulation of the geodynamics of the Emeishan mantle plume based on the above conditions. How can I do it?
Plate tectonics is a theory that states that plates on the Earth's surface move as rigid bodies. GPS is a system that is working independently on the theoretical motions of these theoretical plates, which means that the motions of plates must be visible when studied by passive GPS receivers (if you don't think so, tell us). Some studies work with the so called plate-fixed (net rotation) reference frames, such as e.g. NAD83, that use GPS data, but state that the frame is plate-fixed - no plate motion is visible. My question is: Is it possible that one creates a plate-fixed frame for GPS? If you think so, please, describe the process. I repeat that GPS does not care about the reason why the passive receiver changed its position - so how can you fix your data to a theoretical motion of a plate?
My question is about occurred geodynamic events related to alkaline magmatism between Ordovician-Silurian periods in Central Iran tectonomagmatic zone or near adjacent zones.
Furthermore, the effective geodynamic events within the Gondwana at 500-400 Ma is very important to sole my problems.
I am looking for explanatory model for the of REE - Nb - U mineralisation in Siwana Ring Complex, Rajasthan, India with reference to its magmatic evolution, tectonic implication, and geodynamic history.
Dear all, I'd like to open here a sort of forum for understanding how the geodesists community is moving in view of the X-band SAR satellite constellation. The new constellation will offer new "free, near real-time SAR data" with the "latest information about any spot on the planet within the hour". This will open completely new horizons for InSAR monitoring of ground deformation especially for rapid phenomena such as eruptions and seismic crises. The huge amount of so frequent data acquisitions will open also new needs for rapid and automatic processing. My question are: who knows more? Are you planning a routine use of these data? How?
I am interested in sesmic tomography data (such as pictures) of the Dzhungarian basin, Tarim and Eastern Kazakhstan. The purpose is to undestand the geodynamic and tetonic processes at the collision, subduction zones.
Please tell me where oceanic crust is very thick and why? Is it related to the plume? I hope to listen a diffrent answer(one place which has thick oceanic crust, but the reason is uncertain)
Most crucial ground and borehole geophysical data are on the hands of oil and gas companies. They are not free for students, young researchers and for those who can not pay the quest or can not get access to data. In my opinion, these limits the effort of several researchers in their further work to understand the earth, its resources and estimating serval reservoir parameters.
- How can we get open sources or low coast reliable geophysical data? I want to ask geophysicists and geoscientists, who are using available open sources or low cost reliable geophysical data. What do you recommend or suggest ?. Any recommended data may be useful for detail geological / reservoir interpretation, geodynamics studies or earth resources exploration at large scale, detailed and small scale, or even at laboratory scale. Can those data be processed and interpreted to be published in highly -ranked journals?
I have got the first-hand paleocurrent data in the field by measuring the oriented
pepples and crossing beds. And now, except making the stratigraphic rotation,
what else should I do next ? Should I consider the roation of the block according
to the paleomagnetic data? and what I should do if none?
Is there any relation between the shape of the elliptical earth and the prediction of the epicenter of earthquakes?
There are many causes of earthquakes. Tectonics plates and geodynamic conditions control the earthquake occurrence in active regions. Thus monitoring the subsurface conditions clearly help us to predict an earthquake epicenter. It is well known that the energy explodes in weak regions, fractured area or the most easiest break up part of earth.
To my knowledge, during this Archean, the crust experienced a marked change in composition from sodic TTG assemblages to medium- and high-potassium calc-alkaline granite-granodiorite suites and sanukitoids . The specific timing of this change varies from craton to craton and is accompanied by significant changes in geodynamic settings associated with crustal thickening and reworking that contributed to the ﬁnal stabilization of the cratons.
I have some samples that synchronous TTG gneisses and potassic granitoids in the given region? anybody know studies about this ?Many thanks in advance for sending me messages about this.
Any one please give some comments on the problem given below:
In Geosoft Oasis Montaj ,while calculating the radial power spectrum in MAGMAP,the power spectrum is radially averaged, as a result if larger grid is available , the smoother the power spectrum will be.
The file scripted in Geosoft Oasis montaj contains 5 fields - the wave number increament, no. of samples averaged, the logarithmic of averaged wave no. and a 3 and 5 point depth estimate provides the result automatically(PDF 2-ENERGY SPECTRUM).
While dealing with real field data, ln (power) vs wavenumber K and depth estimate vs wave number K problem occurs with their data values and units in given fig 1 (POWER SPECTRUM),please give some interpretary comments? is it problem with the data collected?
Is there any other way which is reliable for calculating depth estimate of potential field data using Power Spectrum?
Linear magnetic anomalies are observed in the seafloor spreading. If we are having 10 transects in an ocean basin then for a particular magnetic Chron, amplitude of magnetic anomalies (normal or reverse) along all the profiles can vary (due to the thickness of oceanic crust). But how much magnetic anomaly variation, we can expect, for a particular magnetic Chron in all the transects.
I am presently working on local geoid model determination using gravimetric-geometric method. To obtain the gravity anomalies of chosen points, the points absolute gravity and their respective theoretical gravity must be obtained. Someone should please help me, I want to know if it is ideal to compute the theoretical/latitude gravity on WGS84 ellipsoid or it must be computed on the local ellipsoid adopted for geodetic computation in the area of study.
I'm going to process an embankment dam with geostudio SIGMA/W module. want to know how can I consider the effect of time in my processing? In other words, 10 or 15 years after dam construction has finished, how to predict the behavior of dam such as displacement in X or Y directions, total stress and so on?
All the best
I am looking for papers that show crustal extension estimates during the formation of a conjugate pair of continental rifted margins (I am happy with any pair of rifted margins).
Please, could you point me out towards literature about this?
I have information about temperature, pressure, normal and shear stresses, viscosity, conductivity, density, heat capacity and adiabatic heating for a particular area of mantle in the form of 2D matrices. I want to show phase relation for this region of mantle. Is there an equation (group of equations) which relates phase relation for mantle with these properties?
My name is Boris Kapochkin. I wrote several monographs on the geodynamics of hydrogeology and the forecast of earthquakes. I consider it important to study the landslide process called slow earthquakes and changes in groundwater level. I have determined that hydrogeology can be the cause of rainfall and not vice versa. I understand that this information is known to you.
Perhaps this question does not leave many Geologists and Geophysicists perplexed that Plate Tectonics is the engine of change, but the existence of passive and active margins as we know today, it has not always been the same.
This question is somewhat disconcerting for the Geophysicists even today. The best theories offer a range of possibilities: lateral buoyancy contrast (Niu et al, 2003); the role of water (van der Lee et al., 2008); ductile deformation of passive margins (Goren et al., 2008); geodynamic forces such as rifting and plume ascent (Burov and Cloetingh, 2010); higher Moho temperature (Nikolaeva et al., 2011) from numerical models.
Today, there are two mechanisms recognized: induced and spontaneous.
Do you have some article or research to share?
Best wishes, Mario E. Sigismondi
Some researchers (Sablukov; Buslovich) predict that there are mezosoic kimberlites on East European Craton (EEC). Is there any evidence?
The only reason is the presence of KIM's in mezosoic sediments of the north-eastern part of Mezen syneclise (northern part of EEC). It looks unreliable to me because Devonian kimberlites are located on the north of Mezen syneclise.
A-type granitoids are important geodynamic markers. It is therefore crucial to know the age of the oldest A-type granitoids (both A1 and A2 type) of the World.
Please suggest me how to calculate stress accumulation and strain using gps displacements for understanding the occurrence of failure (earthquakes).....
Is Geodynamics have any direct or indirect relation with Ecology, preferably Agriculture? or Geodynamics have any direct or indirect impact on Agriculture? if so, what?
Fundamentally, we can address the key initial parameters in planetary formation, dynamics, and evolution as being astrophysical in nature. These astrophysical parameters lead to specific geologic and atmospheric conditions of every planet or moon. In a search for the most fundamental quantities that determine the characteristics of a planetary surface and atmosphere, I have devised the attached categories and list of parameters. My question is, which of these are the most fundamental and influential to the evolution of a planet or moon? Has the magnitude of importance of these fundamental quantities been tested? Most importantly: what mostly dictates how a planet become its unique set of conditions? Some qualities are guaranteed to be more imprint in some scenarios than in others, but which are the most common, and how do they manifest together into a unique planetary body? For example: changes in what parameters lead to what different planetary outcomes?
I am looking for a reference paper which exploit the factor of anisotropy which obtained by applying a geoelectrical survey over an area. The factor of anisotropy (lambda) is usually calculated from Dar-Zarrouk Parameters ( the transverse resistivity and longitudinal resistivity). What iam looking for is a research paper dealing with a direct useful application for lambda 2D maps in detecting subsurface heterogeneity for a specific objectives.
Semail ophiolite in Oman obducted on southeastern margin of Arabian plate is more or less at the boundary between the Arabian, Eurasian and Indian plate. I want to know if the obduction and post obduction history of ophiolite can be related to regional tectonic frame work of this region. whether the obduction itself is resulted by tectonic uplift, exhumation of Zagros orogeny? or what else? ideas and data? suggestions?
Yes this is a bit broader question but I want to know which processes play their role in movement of magma. If one wants to model magma intrusion in rocks, which processes should one not miss at all and which equations discuss these processes?. As a starter I can that we can use Navier Stokes equations for velocity fields, continuity equation for pressure distribution etc.
We would like to pick zircons from a fine-grained sedimentary rock which has much amount of pyrite. Without any chemical treatment, we want to get rid of pyrite. I checked their densities and magnetic susceptibilities, but they are not so different. What do you recommend me? Are there some heavy liquids or other physical process to seperate pyrite?
The continental drift is a reality now, supported by the dynamics of plate tectonics and seafloor spreading. Continuous convergence (collision) and divergence (separation) of continental and oceanic plates from each other has been reshaping our Earth since the initiation of the process. Therefore, the absolute location (latitudinal and longitudinal) of places has been changing with the change of associated biotic and abiotic environments (tropics shift to equator, or polar regions being shifted to mid latitudes for example).
Then, how the shape of the earth arises due to the continuous movement of the continents and oceans is impacting the global climate? Does it also impact the paleoclimatic records which are being considered to understand the climate of the past?
I am looking for standard curves specialized for faults detection by using the (HEP) Horizontal Electrical Profiling technique in a ground resistivity survey. Please inform with a reference or file related to this technique.
Dr. Wadhah M. Shakir
Sanukitoids are granitoids showing enrichment of both large-ion lithophile elements (K, Ba, Sr) and mafic elements (Mg, Cr and Ni) at the level of their SiO2 contents. It is generally thought that these granitoids, with high Mg#, were produced from a mantle source (supplying Mg, Cr and Ni) fluxed with a crust-derived fluid or melt carrying K, Ba, Sr, LREE and Th. A likely tectonic setting is a mantle wedge overlying a subducted oceanic slab undergoing dehydration or melting. Therefore, many authors consider presence of sanukitoids as a strong indicator of subduction, especially in the late Archaean. Can such rocks form in tectonic settings unrelated to subduction?
Any suggestions on how to measure the thickness of the interlayer between the "brucite-like" layers in hydrotalcite minerals? Are these types of measurements being made, or do we need to do calculations? I have a rough idea of the spacing, as carbonate ions and water fit in, but could the spacing be more? I need to figure out what can fit in there, and maybe chemical engineers can help (I am a geologist)?
Thanks in advance!
Hello everybody. I am interested on studies about the use of GPS/GNSS stations on geodynamics. Someone could sugest me some bibliography? Thanks in advance!
I have a segmented CT image of a pore geometry. I can compute the skeleton on the geometry no problem and get an estimated hydraulic radius at each location along the skeleton by interpolating the Euclidean distance transform. This method gives the distance between the pore centerline and the closest pore edge, essentially a measure of the radius of the inscribed sphere within a pore geometry. This is adequate for semi-cylindrical pores, but for irregular pores, the effective hydraulic radius is larger.
Is there a modified distance map transform that gives a better estimate of the effective hydraulic radius of a pore from a CT image?
Any suggestion for geochemical discrimination diagrams for granitoids of various tectonic settings?
Chusi Li et al., 2015, ("Trace element indiscrimination diagrams"-Lithos 232) showed that many of the geochemical discrimination diagrams based on incompatible trace elements are not useful in distuishing basalts from various tectonic environments. With this in mind, I guess the distinction between granitoids of different tectonic settings would be even more tricky. Any suggestions regarding some useful discriminants for granitoids?
What is the most convinscing theory that discusses the generation of Earths magnetic field?
Many Geophysical references referred to magmatic currents which are rich in iron content and located at the lower mantle and outer core composes the main source of magnetic field. Iwould like to know if there are any new theories or any other references that discuss this subject.
I saw some of research articles reported micro-seismicity using linear array with close inter-station space. Also these studies reported more error in depth. How can we reduce this error. Is there any method for this type of work and can we apply that method for linear array with more inter-station spacing (~20-30 km).
This microfabric is observed in a chrnockite (igneous origin) and here shown as a BSE photog. The slight gray crystals are oxpyroxenes while the black gray ones are felsic minerals. Anybody konw what implications this fabric has in relation to petrogenesis and how it growed?I have appended the BSE photo below.
Hi to all!
I have some difficulties to find this:
Deibis, S., Futyan, A.R.I., Ince, D.M., Morley, R.J., Seymour,
W.P. and Thompson, S., 1986. The stratigraphic framework
of the Nile Delta and its implications with respect to the
regions hydrocarbon potential. Proc. 8th Explor. Conf.,
Can anyone help me?
Is it possible to integrate online conversion from ellipsoidal heights to orthometric heights using, for example, GRACE gravity data and other prior knowledge?
The Zr melt concentrations in the Laacher See Magma Reservoir have been estimated by Hans Schmincke and coworkers to be in the range of hundreds of ppm (ULST), O(1000ppm) (MLST) and around 3000 ppm (LST) for the lower H20-undersaturated, middle, and upper H20-saturated compositionally zoned magma chamber respectively.
I wonder how this may relate to Zircon saturation curves. Such curves have occasionnally been constrained experimentally for certain magma compositions (work by Mark Harrison, Bruce Watson and coworkers) but I am finding it difficult to translate how this may relate to the case of the Laacher See magmas.
Zircon solubility appears to be related to Zr concentration, Temperature and magma composition including SiO2 and TiO2 concentrations and the alkali/alumina index (eg. Harrison et al 2007) and one may also expect that it also depends on the amount of dissolved volatiles (eg. water) in the melt.
I cannot find relevant papers which would enable to assess for what conditions Zircon saturation may be reached for the 3 end-member compositions of the zoned Laacher See magma chamber (or in a presumed basanite parent magma at LSE).
What intrigues me is that Zr contents seem to me to be very high at Laacher, yet Zircon occurrence seems to be "rare" and restricted to mostly very small zircon crystals in LST pumices and to some rare occurrences of sometimes larger crystals (typically mm-sized xtals) in some cumulate nodules from LLST and MLST (eg. Schmitt 2006).
Is it that a large melt H20 content suppresses Zircon crystallisation ?
Or that Zircon crystallization rates are too low in general in the LSE magma conditions ?
I would be grateful for any insights into Zircon saturation and Zircon crystallization rates and what may control them at Laacher See (P: 115-200 MPa; H20: 2.5-5.7 vol% or so), or in basanite-tephrite magmas under crustal conditions.
I am also interested in any insights for Thorite crystallization in LSE magma conditions or in basanite-tephrite magmas under crustal conditions.
Thank you in advance for any suggestions or insights.
Happy New Year and Best Wishes,
I would like to dialogue with someone familiar with programming in XOJO (formerly RealBasic). I am an old VisualBasic programmer, and need some help with code to read external files (common delimited variable lists) and write external files (also common delimited variable lists). Some sample code would be great! I've attached a program (zipped archive) that I've written to help with some paleomagnetic research. I need to write a batch version of this program.
Why such a long gap in the ages of same rock sample? Can anyone please suggest any good paper I can look into?
In my project area the Bastard reef is not continuous and rather grades into a melanorite. The chrome stringer is still seen at the bottom contact of the melanorite which makes people acknowledge the unit as a Bastard pyroxenite.
In most of my samples stretching lineations are subparallel to the dip of c-planes. However,I have some samples where pucker axis lineations within mylonitic metapelites are stretched in a direction which is sub-parallel to the strike of mylonitic c-planes giving rise to very prominent stretching lineations. In the latter case, can I suspect greater involvement of pure shear which produced the stretching lineations and c-planes both at the same time??
Why should we put the early marine strata unit in the foreland basin system (peripheral foreland basin)? I am wonder when a basin can be named foreland basin, before the final collision or after? If it is post-collision, what is the difference between the marine strata bearing forleand basin and the remnant oceanic basin?
If we want to develop an analogue or numerical material for the simulation of coupled fault & fracture processes during brittle geological deformation on outcrop or structural scale what is the minimum set of rock parameters required to characterise material rheology?
Fundamental parameters: density, Poisson ratio
For fault processes: internal "peak" friction, stable and dynamic friction, cohesion, shear strength
For fracture processes: Young modulus, tensile strength, compressive strength
Would these parameters be sufficient to properly scale or define analogue/numerical materials to define the key characteristics for coupled fault-fracture processes in natural rocks? What else is required or not?
Please share you ideas.
Can we use a euler pole estimated using ITRF2000 to transform another set of velocities defined in ITRF2008?
Is Euler pole independent of the ITRF used during processing stage?
Can anyone explain why Reduction to pole(RTP) value of total magnetic field deviates after a certain limit of total magnetic field(very high magnetic anomaly) ..that is calculated from magnetic field calculator for determining inclination and declination which is used for RTP calculation ? RTP basically reduces the anomalies to those that would be observed at Magnetic north pole with a vertical remnant magnetization direction?? Explain the reasons in detail??
The source parameter of an earthquake ( like Moment (Mo), stress drop (sigma), source radius (r), Magnitude (Mw) etc.) can be derived simply from the corner frequency of the recorded seismogram.
1.) why corner frequency is so important in calculation of source parameters as compared to the strength (magnitude) of the frequency content of the seismogram?
2.) The seismogram records only a fraction of the energy released by an earthquake. Is it correct to estimate moment/magnitude/energy/source radius etc. from the recorded seismogram?
I want to learn about the influence of oxygen fugacity on arc mamgma and its relation to the formation of porphyry deposits. Can someone recommend some articles on this topic to me. Thanks a lot.
The research for PGE (Platinum Group Elements) in mafic ultramafic igneous bodies are properly done in thick (3000 to 4000 m) bodies. The question is: when you start to consider a thick sill as a possible reservoir of ultramafic cumulates? In the bibliographic research I've done, for instance, in sills with less than 300 metres some mineral fractionation may occur, but not to produce ultramafic cumulates.
I can only find publications on dykes of the single regions surrounding the North Atlantic, but not a map summarizing all dykes. Is there a good compilation in the literature? Something like in the link?
It seems that in a fossil orogenic belt, like the famous Sulu-Dabie orogenic belt, both orogenic delamination and slab breakoff have proposed to them. Which one is more plausible? How can we tell which process might have been responsible for a specific fossil orogenic belt if both HP-UHP metamorphic rocks and syn- and post-orogenic magmatic rocks occur there?
Working at the southern Central Andes we have found some interesting features. In the hinge zone of a broad (ca. 6 km) basement-cored anticline there are sub-vertical clastic dikes of breccia cutting the sequence. The basement is composed by Paleozoic metamorphic rocks and granites and is cropping out several km away from the dikes outcrop. It is covered by Jurassic volcanics of the syn-rift stage of the Neuquén basin. The dikes have between 1 and 3 meters wide and are not oriented in none particular strike. The breccia is composed by basement and syn-rift volcanics angular clasts and boulders ranging from 1 cm up to 50 cm. We are working with the structural data obtained from field work and are interested in any reference we can use to better understand their genesis. The timing of the intrusion is not clearly related with folding, it could be more related with a prior extensional stage in the region...
I am trying to reduce a wealth of crystallographically determined vorticity vector orientations from some sample suites, some of which are known to have been deformed in a triclinic system. For some of the samples (deformation geometry is not known for all of them), the vorticity vector does not lie in the foliation plane (I am inferring that the foliation approximates the flow plane, which may not be the case). I understand that is predicted (and observed) that vorticity vectors can be oblique to lineation orientations in triclinic deformation. However, is it permissible that the vorticity vector lie outside of the foliation plane in certain deformations?
I would like to distinguish these two lithologies to show a geochemical contrast between them in a figure. The figure presents a cross section through an oceanic core complex. The cross section is perpendicular to the ridge axis.
I am looking to find a code to compute the viscoelastic deformation of a beam over a fluid, in order to compute the time dependant flexure of the lithosphere under a load.
Can anyone suggest an easy way to do this? Is it possible to do it for a broken and an infinite beam (like in regional isostasy)? Is it posible to do it with variable Te?
Seamount subduction has been well studied especially since 2000 (Kodaira et al.). In some cases such as the 1946 Nankai earthquake (Mw 8.2), it has been suggested that seamounts act as a barrier and hence prevent earthquake rupture due to weak coupling. On the other hand Husen et al (2002), suggest that seamount acted as an asperity (and hence strong interplate coupling) in the 1990 Gulf of Nicoya earthquake (Mw 7). Is the debate still open or a conclusion has been reached on the role subducted seamounts play in earthquake generation?
The strain at depth will induced stress at subsequent shallower depth and this process will continue until it is released at the surface.