Task: Sentence Expansion
Input (English): South Caucasus , also referred to as Transcaucasia or Transcaucasus , is the southern area of the Caucasus region between Europe and Asia , going from the Greater Caucasus to the Turkish and Iranian borders , between the Black and Caspian Seas .
Output (English): Transcaucasia spans the southern portion of the Caucasus Mountains and their lowlands , straddling the border between the continents of Europe and Asia , and extending southwards from the southern part of the Greater Caucasus mountain range of southwestern Russia to the Turkish and Armenian borders , and from the Black Sea in the west to the Caspian Sea coast of Iran in the east .