The Caledonian mountains and Appalachian mountains are recognised to be the roots of the same Palaeozoic orogenic belt. This has since been split in two with the opening of the Atlantic.

On the European side, two orogenies are recognised: the Caledonian and Variscan (or Hercynian). On the American side the Appalachians are also recognised to be made up of multiple orogenies, eg. the Taconic and Allegheny.

A parallel could be drawn with the present day Tethyan Belt - especially the Mediterranean length. Here we don't see one big mountain building episode but many as each sub-continent or large island is accreted onto Europe. Similarly, Pangaea was not formed in one big orogeny but multiple as sub-continents such as Avalonia were accreted on to what is now North America.

Can each orogenic episode on the European side be correlated with an orogenic episode on the North American side? I.e. having two names for the same orogeny?

Are correlations possible at a finer scale? For example the Caledonides in Scotland are marked by some very prominent ancient faults (Great Glen, Moine, and Highland Boundary Faults). The Appalachians also have some large fault systems. Can any of these be correlated across the Atlantic? Can specific sedimentary sequences be correlated? (I realise that big picture sequences in the late Palaeozoic are broadly similar, e.g. Permian Aeolian Sandstones, Carboniferous Deltaics & Coal, etc)

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    $\begingroup$ This article may be of interest earth.ox.ac.uk/~conallm/Caled.pdf $\endgroup$
    – user889
    Commented Oct 17, 2014 at 12:18
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    $\begingroup$ Thanks @Omen. Yes it does a good job of answering my question. If you want to write it up as an Answer, I can mark it as such. $\endgroup$
    – winwaed
    Commented Oct 17, 2014 at 20:13
  • $\begingroup$ There we go, I wrote in some summary of the article - the stratigraphic columns are brilliantly done. $\endgroup$
    – user889
    Commented Oct 17, 2014 at 20:29

1 Answer 1


The article The Caledonian Orogeny redefined (McKerrow et al. 2000) have done exactly that - correlating the stratigraphic and orogenic aspects of all of the orogenic movements (as you have listed) that they define as being orogenic phases comprising the Caledonian Orogeny.

An important distinction the McKerrow et al. make is to state that the term 'Caledonian Orogeny' is not a single event, but rather comprised of all the tectonic movements that occurred in the ~200 million year development and closing of the ancient Iapetus Ocean, through the Cambrian to Devonian.

With this framework, the authors were able to determine a continuous stratigraphy through deposits of the tectonic events of the Caledonian Orogeny in the present day North American and European continents.


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