The first Blizzard-made maps were like this. The average starting location had 1 regular gas geyser and about 9 regular mineral fields. There were some expansions that followed this suit, but then there were others that had some variation. Some expansions had slightly fewer minerals than normal (1 geyser and about 6 fields). Other expansions had nothing but minerals (usually about 12 fields). Others had nothing but gas (1 or even 2 geysers). And finally, there were some expansions that followed one of those examples but had the fields and geysers separated significantly further apart than normal.
This variation was eventually done away with for the sake of balanced map gameplay. A great example of a map with such variation is the classic, Blizzard-made, 256x256, 8-player map
Killing Fields:
http://classic.battle.net/images/bat...c/lp/8/lkf.jpg
http://classic.battle.net/images/bat...c/lp/8/bkf.jpg