Prior to their Alpine overprinting, most of the pre-Mesozoic basement
areas in Alpine orogenic structures shared a complex evolution, starting
with Neoproterozoic sediments that are thought to have received detrital
input from both West and East Gondwanan cratonic sources. A subsequent
Neoproterozoic-Cambrian active margin setting at the Gondwana margin was
followed by a Cambrian-Ordovician rifting period, including an
Ordovician cordillera-like active margin setting. During the Late
Ordovician and Silurian periods, the future Alpine domains recorded
crustal extension along the Gondwana margin, announcing the future
opening of the Paleotethys oceanic domain. Most areas then underwent
Variscan orogenic events, including continental subduction and
collisions with Avalonian-type basement areas along Laurussia and the
juxtaposition and the duplication of terrane assemblages during strike
slip, accompanied by contemporaneous crustal shortening and the
subduction of Paleotethys under Laurussia. Thereafter, the final Pangea
assemblage underwent Triassic and Jurassic extension, followed by
Tertiary shortening, and leading to the buildup of the Alpine mountain
chain.
Recent plate-tectonic reconstructions place the Alpine domains in their
supposed initial Cambrian-Ordovician positions in the eastern part of
the Gondwana margin, where a stronger interference with the Chinese
blocks is proposed, at least from the Ordovician onward. For the Visean
time of the Variscan continental collision, the distinction of the
former tectonic lower-plate situation is traceable but becomes blurred
through the subsequent oblique subduction of Paleotethys under Laurussia
accompanied by large-scale strike slip.
Since the Pennsylvanian, this global collisional scenario has been
replaced by subsequent and ongoing shortening and strike slip under
rising geothermal conditions, and all of this occurred before all these
puzzle elements underwent the complex Alpine reorganization.