Dear Ahmed Morad ,

I am not sure if I understood well what you mean, but if we are talking about metamorphic phase transformations, what about AFM - AKF - ACF diagrams and - maybe - a petrogenetic grid showing the main reactions along the P-T-t path of these rocks?

Dear Samuele Papeschi

what i mean is like drawing a detailed Tectonic schematic cross section for a subducting slab focusing mainly on the transformation of shales and carbonates into greenschist facies schist and Thermal skarn overlying this slab ..

clearer now ? :)

Dear Dr. Morad:

You may find some evidence in the following publication a graphical abstract of which is attached below:

DILL, H.G. (2019) Coupling restites and mobilizates – Geological and litho-chemical investigations of paired belts of calcsilicate fels and quartzite (SE German Basement) - Quo vadis David London´s pegmatology ?.- Ore Geology Reviews 105: 636-662.

The paper is available on request fro download on the RG server.

With kind regards

H.G.Dill

Harald G. Dill

Thanks Prof. Dill

it is kind of you ^_^

Waiting for more if some colleagues can provide :)

You have an interesting proposition. In this age of videos and 3D representations one should be able to "create" the scenery of what is going on at this common phenomenon of subduction, that is everyone is talking about, but no one has ever seen it!

Well, there are many graphic artists around especially young in age who can start drawing a scenery of a "subductingplate" and you take it from there.

When I was teaching about rocks forming under mountain chains I had found a large slab of counter-top "granite" that I was showing my students to help them understand the probable conditions deep underneath a mountain.

Dear Ahmed Morad: I understand perfectly what is your proposal. The best way to show how marine sediments get into a subduction zone is to draw a detail of the hinge zone where the oceanic plate bends when foundering inside the mantle. In this hinge zone stretching occurs, and some expansive graben structures are formed (normal faults parallel to the trench), which trap sediments and lead them to subduction. Then those sediments are metamorphosed under high P/T conditions and become phyllites and schists, usually white schists, and even metacherts and fine grained marbles. There is a quite accesible outcrop in a main freeway near the city of Puerto Cabello (north-central Venezuela) of eclogite knockers inside a relatively monotonous micaschist. A close look at thin sections of this schist shows the presence of kyanite, garnet, white mica, and Mg-glaucophane, these are usually called white schists, since the glaucophane is almost colorless and retrogradly altered to talc! Some have carbonate too, and in nearby localities of this same high P terrane there are also metacherts and marbles. So, there's no doubt that some marine sediments are indeed subducted and transformed to high P metamorphic rocks in the subduction complex. Regards, Sebastian.