This was the first mention in the log of any sort of conflict, so I did a little research. I could not find a single source that tied things together, but here's what I found based on pieces of information from several sources.H.B.M.S Garnet made signal, "Hostilities has ceased for twelve hours" from last night which gives hopes of peace, but all hands below 60 are called to arms.
Argentina became independent from Spain in 1810 and was in a civil war from then until 1880, fighting over what form of government Argentina should have. A battle was fought in Buenos Aires in June, 1880 that ended on June 23 with the result that Buenos Aires became the capitol of Argentina.