Sierra Ballena Shear Zone or SBSZ is a sinistral strike-slip shear zone running across the Uruguayan Shield in eastern Uruguay and the Brazilian state of Rio Grande do Sul.
[2][3] The system was last active in the Precambrian.
[2]
Shear zones and terranes in Uruguay after Gaucher
et al.
., 2008.
[
1
]
Sierra Ballena Shear Zone is marked as "SBSZ". To the west
Sarandí del Yí Shear Zone
is marked as "SYSZ".