Question: what kind of boundary is offshore the andes mountains
Answer: The Boundary Treaty of 1881 ( Spanish : Tratado de Límites de 1881 ) between Argentina and Chile was signed on the 23 July 1881 in Buenos Aires by Bernardo de Irigoyen , on the part of Argentina , and Francisco de Borja Echeverría , on the part of Chile , with the aim to establish a precise and exact borderline between the two countries based on the uti possidetis juris principle .