espanolEn el sur del Valle de Aburra aflora una secuencia de rocas de metamorfismo barroviano cuyas facies varian en sentido W-E desde esquisto verde, zonas de biotita y granate, a facies anfibolita, zonas de estaurolita y sillimanita. Se reportan por primera vez in situ los esquistos con granate y estaurolita que habian sido identificados unicamente como rodados en las quebradas La Romera y La Miel (Caldas), una franja de cuarcitas micaceas en la cuenca de la quebrada La Ayura y la presencia de sillimanita (fibrolita) en los porfidoblastos de andalucita de los esquistos cuarzo micaceos con grafito que afloran en la parte baja de la quebrada La Doctora (Sabaneta). El protolito corresponde a una secuencia pelitica con material igneo intercalado que fue sometida a un metamorfismo de tipo barico de media presion seguido por uno de baja presion, definidos ambos en metapelitas, el primero por la presencia de granate (posiblemente almandino) y estaurolita, y el segundo, por la de andalucita y biotita. Luego hubo una fase tectonica posterior a la cristalizacion de la andalucita y de la ultima biotita, la cual produjo una esquistosidad de crenulacion. Los eventos metamorficos probablemente ocurrieron durante la orogenia permo-triasica segun las dataciones disponibles, aunque no se pueden descartar eventos mas antiguos. EnglishA continuous sequence in which the metamorphic grade increases eastward from low to medium grade to the east of the town of Caldas and the Ancon Sur, to high grade in La Ayura creek, was identified in the southern part of the Aburra Valley, where the city of Medellin is located. This sequence follows a Barrovian zonation scheme from west to east, from greenschist facies, biotite and garnet zones, to amphibolite facies, staurolite and sillimanite zones. Garnet - staurolite micaschists traditionally reported as pebbles in La Romera and La Miel (Caldas) creeks were found in situ for the first time during the development of this work. Also reported for the first time is a mica-quartzite unit in the La Ayura basin and the presence of fibrolite within andalusite porphyroblasts in graphite-bearing micaschists in the lower basin of La Doctora creek. The metamorphic sequence has both medium and low pressure characteristics, such as the presence in the metapelites of staurolite and garnet, probably almandine, and andalusite, respectively. The protolith of these rocks is interpreted as a sedimentary sequence with interbedded mafic igneous material which underwent medium- pressure metamorphism and then a superimposed low-pressure metamorphism. After crystallization of andalusite porphyrobasts and part of the biotite, another tectonic phase took place, producing a crenulation cleavage. According to available radiometric ages, these metamorphic events may have taken place during a Permo-Triassic orogeny, but older events cannot be discarded.