SANTO DOMINGO– Although both are part of the Dominican Republic's coastline, the beaches of Baní and Boca Chica have a distinguishing characteristic: the composition of their sand. Their differences lie not only in color and texture, but also in the origin of the materials that reach their shores and the natural processes involved in their formation.
According to research by the Technological Institute of Santo Domingo (INTEC), published on June 28, 2026, 88% of the sand on eight major Dominican tourist beaches is of biological origin, meaning it comes from the remains of marine organisms such as corals, red algae, and mollusks. The study was led by Dr. Melvin Arias, a specialist in Physical Chemistry, along with researcher Yolenny Mabel Cruz Salazar and specialists from other national and international universities.
Punta Salinas: a sand marked by the minerals of the mountains
However, Punta Salinas, in the province of Peravia, has a unique composition. According to results published by INTEC, its sand contains fragments of volcanic rocks, including quartz and magnetite, transported from the mountains by the Ocoa, Baní, and Nizao rivers. These terrestrial materials influence the physical and mineral characteristics of the sand, differentiating it from other beaches in the country.
Boca Chica: a sand of mainly marine origin
On the other hand, according to the technical study Geomorphology and Beach Regeneration in the Dominican Republic," prepared by specialists affiliated with the National Geographic Institute, Boca Chica beach is primarily composed of biogenic sediments produced by the reefs and marine communities that inhabit its surroundings. The document also explains that its reef lagoon creates low-energy water conditions, favoring the accumulation of fine sediments such as sand, silt, and clay.
Coral reefs and human intervention also play a role
The study also indicates that the composition of Boca Chica can vary due to the artificial introduction of materials and human interventions in the area. Its natural components include fragments of calcareous algae, mollusks, and other marine organisms, which are responsible for much of its sedimentary characteristics.
INTEC's research also highlights that river mouths can significantly alter the composition of beaches, while reef activity contributes to producing and renewing marine sediments.
Two beaches, two geological histories
Thus, the differences between Baní and Boca Chica have a scientific explanation: while Punta Salinas receives a significant influence of mineral materials transported from the mountains, Boca Chica has a greater influence of sediments generated by marine ecosystems.
A curious fact that demonstrates that the sand on our beaches has its own natural history and that, behind its colors and textures, there is a whole geological and biological process that is part of the natural wealth of the Dominican Republic.
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