Message #153809

[lithicbeads]

Limestones formed adjacent to large expanses of flat land with low gradient streams and limestone formed in seas with large shallow expanses would be unlikely to be hard. Our coastal limestone here in the west were formed adjacent to volcanoes jutting out of deep ocean so they got lots of silica from deep water diatoms and much silica from the steep and quickly eroding volcanoes.
These island arcs docked against B.C. , Alaska , Washington , Oregon and California bringing their unique reef and back arc basin geology( sediment based) mixed with the sea bed geology that collided with them to make all  of the coastal west.