The Cies Islands were formed by tectonic plate movements that caused mountains to form and later sink below sea level, creating the islands. The islands feature geological formations such as lagoons, beaches, caves, cliffs, tombolos, dunes, and bays that were shaped by erosion, transportation, and sedimentation of materials. Physical, chemical, and biological weathering also contribute to changing the landscape of the Cies Islands over time.

1. Geology of Cies Islands
By Francisco, Mateo and Pedro

2. Formation
• Cies islands were formed because the
movements of tectonic plates, (forming
mountains) and with the de-glaciation, those
mountains were sunk. Atlantic islands and the
“rias” were formed like this.

3. Lagoa dos nenos
• What is a lagoon?
A lagoon is an area of shallow water separated
from the sea by sandy dunes or coral reefs.

4. Rodas beach
• What is a beach?
An area of sand along a shore.

5. Caves
• What is a cave?
A cave is a hollow place in the earth.

6. Cliffs
• What is a cliff?
A high, steep rock face precipice

7. Tombolo
• What is a tombolo?
A tombolo is a sedimentary landform, which is a
narrow spit of land between an island or a
large rock away from the coast.

8. Dunes
• What is a dune?
A sand hill ridge formed by the wind, usually in
deserts or near oceans

9. Bay
• Input sea coast, wide and fairly large, but
smaller than the Gulf

10. Examples of erosion, transportation
and sedimentation in cies.
Transportation
(waves, wind…)
Erosion
Sedimentation

11. Physical wethering in cies
• Takes place when rocks get fragmentated by
physical processes, and it doesn´t changes its
composition

12. Chemical wethering in Cies
• Takes place when the rock is chemically
disolved or altered

13. Biologic wethering in Cies
• Takes plave when a biologic agent brakes or
alters the rock

14. The End
Thank you!