Background Paragraph: About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. 
Story: Greg has been on a rock finding kick. Lately, he has decided he wanted to explore areas with higher amounts of limestone. He only has time this year for one trip, and his options are limited. He can go to Mount St. Helens, or he can go to the Meremac Caverns. 
Question: Will Meremac Caverns be more or less likely to have limestone deposits than Mount St. Helens?
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