Synthesis of the geological events in Catalonia

The objective of this page is to present, in a graphic form, the succession of geological events of which there exists, in Catalonia, a written record in the rocks. The vertical scale is in million years, the unit of time measurement in geology.

The sedimentary record is indicated in a synthetic way in the stratigraphical column. The thickness of the sediments is not the real one, but refers to time. The sedimentary rocks which are more representative of each epoch and the main unconformities are indicated. In order to facilitate the reading, a column which is indicative of the predominant sedimentary environment, marine or continental, is included.

The magmatic processes, extrusive or intrusive, are represented in the next column; in this the coloured boxes indicate the time range of the volcanic activity or of the placement of the intrusive rocks. The volcanic rocks are intercalated between the sedimentary record, but the intrusive rocks are placed in depth, and for this reason, the levels of placement have been indicated, that is to say, into which sedimentary rocks the intrusive complexes intrude.

In relation to the intrusive rocks, aureoles of contact metamorphism are formed, and these are indicated in the column by a tracing of red lines, just as it is represented in the Geological Map of Catalonia 1:50 000. The contact metamorphism can affect any sedimentary or volcanic rock of ages between the Neoproterozoic and the Carboniferous pre-Westphalian. The rocks formed by metamorphic contact are represented in the lithological column in a simplified way.

The processes related to the regional metamorphism are indicated in the next column. The part marked with blue lines represents the extension of these processes, as it are also represented in the Geological Map of Catalonia 1:50 000. Beside this, the rocks formed by regional metamorphism are indicated in the lithological column.

The orogenic cycles are represented in the corresponding column; for each of them the epochs with extensive context (blue boxes and arrows) have been distinguished from the compressive context (red boxes and arrows).

To complete the picture, a summary of the biosphere evolution has been included in which are indicated, in parallel to the rest of the geological events, the appearances and the radiations of the most representative groups, as well as the major reductions and extinctions.