This seems like a simple question, but I can't find much information on the web about this, and I haven't studied Geology or Geophysics.
In Valparaíso there are a large number of "Cerros" ("= hills" - some locals say 42) around the bay, and they are really steep. From sea level, they rise to around 200m within around 300 or 400m from the "plan" (an area recovered from the sea where most of the city centre is). These hills all rise from the coast quite rapidly, and outside of Valparaiso, towards Santiago, the average elevation drops a little and then rises as it meets the pre-cordillera of the Andes at about 1000-1800m.
The sudden rise is so steep that there are several funicular railways that serve the local population to help them get up the first 60-100m or so. There are even staircases next to them which few people use unless they are walking down!
Valparaíso is part of the Pacific "Rim of Fire", and there is the Pacific subduction zone quite close offshore.
So would all these hills be formed by repeated uplift due to earthquakes, which are weathered down over time? There are no cliffs to speak of in the area, just a lot of hills.
Or would glacial processes have been involved? When the Andes was formed, I imagine the glaciers would have made their way toward the sea and dump loads of material near the coast which might have formed these hills?
Could someone help me with the answers, or point me towards scientific information about the Geological history of the area?