Aitor, Aritz & Irantzu

How old are the oldest rocks in the Bask Country? How got they

formed?

From 248 to 230 My (Lower Triassic): The stretching stress created down-faulted trenchesthat were filled with siliciclastic sediments brought in by rivers.

Why most rocks in the Bask Country are of under sea

origin?

Because it have been actively exploited in the past in many localities of the Basque Country.

What is the origin of the volcanic rocks in Gipuzkoa and Bizkaia seasides? What was going on

then?

This was a very special interval in the evolution of the Basque-Cantabrian basin, characterized by a high-rate tectonic stretching, a moderate sea-level rise and a tropical or near-tropical climate.This is called the “Flysch trough”, because sediments reaching it accumulated in a conspicuous vertical alternation of resistant and soft beds.

What is the Cretaceous-Triasic (C-T) boundary? Why is it so

important in the Bask Country?

A high-rate tectonic stretching, a moderate sea-level rise and a tropical or near-tropical climate. Because create some of the most espectacular scenaries of the Basque-Cantabrian basin, and are also of great economic value

How got The Bask Country come out from the sea? When did it

occur?

Uplifted terranes were subjected to erosion, and a fair proportion of the resulting detritus were transferred to the deep trough, and accumulated as flysch sequences. These are beautifully exposed, in the coast of the Gipuzkoa and Biscay provinces, From 83 to 33 My.