Is there a term or expression in the geosciences (or any other field?) that means "to imagine how (a) hypothetic (geological) structure(s) of a specific age would look like at present after having been deformed by specific, known tectonic events"?
The idea is that there is no certainty that the hypothetical structures exist because they were never dated. The point is specifically to uncover them by imagining what they would look like at present had they existed at time T and been deformed subsequently by tectonic events X, Y, Z, etc. (events which we know/are confident occurred), thus allowing us to identify structures with suitable geometry during fieldwork.
Please let me know if you have heard of anything of the sort.
Thanks for your help!
If you analyze geological structures using seismic prospecting methods, then there are no strong differences. There may be differences in the permeability of the geological structure to deep fluids. But they are also insignificant.
I have not heard of such a thing. The types of structures typically associated with specific tectonic events (be it compressional, extensional, or oblique) are well documented. I suggest reviewing the textbook "Structural Geology" by Haakon Fossen to familiarize yourself with structures you may expect to encounter. However, while in the field, you don't want to necessarily expect what structure you are trying to map. Document all structural features (fault and fracture planes, foliation and bedding surfaces, axes of outcrop-scale folds), and record crosscutting relationships and mineralization associated with specific fault/fracture trends. If done methodically, the structures should be revealed by your mapping and noted relationships.
Short answer might be: a (conceptual) model ?
Anyway, I'm not sure to understand your point, if you're talking about an induced structure, as a fold, or the expected evolution of a passive marker, as a fossil.
In any case, the absolute elapsed time since its formation is probably of negligible importance. All that counts is the number and intensity of events that a given structure went through.
As Evan Strickland pointed out, the major structures and associated events are well known. As long as the total deformation/alteration path was not too complex it is possible to track the history back in time. However, small event, or events with opposite-effects can also be missed...
If your point is associated with a specific location with a known history, it is possible to predict the current shape of any structures of interest... and check for its consistency with the field analysis.
One problem that can emerge from your point (if I get it right) is a validation bias, where you "find" the structures that you imagined since you can add all the events you want to create them.
Hope it helps,
Oswald Malcles and Evan Strickland ,
you are (wrongly) assuming that we know all the events that affected a margin/area (e.g., Timanian Orogeny in Svalbard, which was known in Russia and northeasternmost Norway very early on, but was not known in Svalbard prior to 2008 when a Timanian age was obtained). The present question is specifically targeting known (or unknown) events, which we have not yet uncovered in specific areas/margins/terranes, but which we suspect. How do we decide which structures to sample in the field to date the event we suspect? To decide, we need to imagine how structures related to that suspected event would have looked like initially (strike, dip, attitude, etc.), how they would have been deformed by subsequent events, and, thus, how they would look like at present. The question is "Is there a name for such a reconstruction/imaginative/modelling process"?
Oswald Malcles , in the present case, there would be no validation bias if the age obtained for the structures formed during a suspected event yields an age overlapping with that of the event.
Thanks again for your help and for the discussion!
Dear Jean-Baptiste P. Koehl ,
The beofre made answers ( Borys Kapochkin , Evan Strickland , Oswald Malcles ) are relevant to your question:
I suggest you check out the stratigraphic courses that are based on geosynclinal theory... You will not be able to use the current global tectonics... Always be careful, try to think with a simple mind, because if you don't, you'll get confused.
Note that the Earth expanded and events that occurred after the Jurassic period. Don't forget to consider the theory of catastrophism (with well defined processes) and principle of actualism.
Regards,
Laszlo
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