No. 90 Cross-cutting relationships and inverted topography

Last known location: Geneseo, NY

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This block features a stratified sequence of cherry, green poplar, purpleheart, and maple that is cut by a number of geologic structures, including normal faults, reverse faults, thrust faults, and dikes. Resolving the order of cross-cutting relationships in this block is a fun challenge for even the most seasoned scientist! This sequence was then capped by a basalt lava flow made from black walnut that erupted out of the base of a small cinder cone. The flow shielded underlying rocks from erosion that eventually resulted in the development of an inverted topography.

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