Form of weathering caused by the activities of living organisms for example, the growth of roots or the burrowing of animals. Tree roots are probably the most significant agents of biological weathering as they are capable of prising apart rocks by growing into cracks and joints. Plants also give off organic acids that help to break down rocks chemically (see chemical weathering).
Yellow represents the golden land of South America. Blue stands for the ocean separating the country from Spain. Red symbolizes the blood and courage of the people resisting the tyrants. Effective date: 26 November 1861.