Spanish term (edited): registro

Although Asker hasn't given us this bit of context, the ST appears to come from Argentina.

With that in mind: Rosario es la ciudad cabecera del departamento Río Segundo en la provincia de Córdoba, Argentina. https://es.wikipedia.org/wiki/Villa_del_Rosario_(Córdoba)

The terminology in Argentina is "back to front" compared to other jurisdictions, as shown here:

www.revista-notariado.org.ar/cv_autor/bio/page/6/
"María Mercedes Córdoba. Abogada graduada de la Universidad Nacional de Rosario. Escribana titular del Registro 157 de Rosario desde 2005."

(It's a concidence that the escribana's surname is "Córdoba", the same as the name of the province where she has her office).

So, given that in Argentina, an "escribano" is (to all intents and purposes) equivalent to a public notary (in most English-language jurisdictions), the "registro" in Asker's ST is the "office of the public notary".

Then, the "Libro de Intervenciones" is the register of notarised acts held by the "escribano" (not Asker's "Notarial Registry").

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Note added at 3 hrs (2017-12-15 23:34:13 GMT)
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I apologise: Asker did tell us this was from Argentina. Mea culpa...