Thorium is found in small amounts in most rocks and soils; it is three times more abundant than tin in the Earth's crust and is about as common as lead. Soil commonly contains an average of around 12 parts per million (ppm) of thorium.
Thorium is several times more abundant in Earth's crust than all isotopes of uranium combined and thorium-232 is several hundred times more abundant than uranium-235.http://en.wikipedia.org/wiki/Thorium
I have previously done calculations based on the chemistry (relative natural occurrences) to get a 120x number. U238 having a certain occurrence, u235 being a percentage of that, and thorium being more abundant than either.http://www.world-nuclear.org/info/default.aspx?id=448&terms=thorium
" it is about three times more abundant than uranium.
The 2009 IAEA-NEA "Red Book" lists 3.6 million tonnes of known and estimated resources as reported, but points out that this excludes data from much of the world, and estimates about 6 million tonnes overall."http://www.world-nuclear.org/info/inf75.html
uranium-238 (99.28% natural abundance), uranium-235 (0.71%)
So Thorium is 3x U238 and U238 is 139.8x more abundant than U235 so a total of more than 419x.