The saldoneres of Sant Pere de Ribes: a tool for the interpretation of our
geological history
The town of Sant Pere de Ribes is located in a tectonic
depression in the Garraf Massif. This small basin, known as the Vilanova -
Sant Pere de Ribes depression, developed within the Mesozoic materials of the
Garraf Massif and became filled by Miocene and quaternary sediments. White fine
sands rich in quartz are common within the depression and have been
traditionally exploited for cement and glass and these are known locally as
saldoneres. The Garraf Massif is formed mostly of calcareous materials and the
similarity of the sands with the feldspars produced from the weathering of
granite leads to questions of their origin.
Sant Pere de Ribes Sílices Mestre quarry site - a permit is
required for a site visit
Geology Fieldwork
Miocene beds at Sant Pere de Ribes
Geology student tasks
1. Draw annotated/labelled sketches of the locations.
2. Construct a sedimentary log.
3. Draw annotated sketches of the different beds.
4. Analyse the sediments and their mineralogy, measuring pebble size, b-axis,
grain size, and the degree of sorting.
5. Measure the angle of dip.
6. Identify the fossils.
7. Analyse the fossil assemblage.
8. Comment on risk assessment and geoconservation.
Sant Pere de Ribes fossil assemblage
Interpretation of the geological history
Sant Pere de Ribes pebble beds
What is the mineral composition of the sands sediments? Is there a large or
small range?
Are the deposits textually and compositionally mature or immature?
What evidence exists for the direction of transportation and the environment
of deposition?
Are there calcareous sediments from the surrounding Garraf Massif within the
sands?
Are the fossils marine, freshwater or continental?
