Just As I Thought

Hard as a rock

Arlington County has a whole host of maps available, from property plats to geological maps, there’s a fun time to be had by all. My co-worker Tim and I probably spent the better part of our day learning what kind of geology underlies our homes. Some of the geological descriptions sound downright sexual…

Potomac Formation, undivided (Early Cretaceous) — Varicolored clay and silt interbedded with pebbly to cobbly sand in fairly well bedded, interfingering fluvial deposits. Unit forms a southeastward-thickening prism of sediment up to 600 ft (180 m) thick. Unconformably overlies saprolite on Piedmont crystalline rocks.

There are also such phrases as:

  • clay has high shrink-swell characteristics.
  • Probably derived from fluvial overbank deposits.
  • Thickness is irregular.
  • Rock is typically well foliated and in many places has a strong quartz-rod lineation.
  • Much of the phyllonite had a migmatite protolith as relict leucosome can be seen in many outcrops.
  • Thickness varies from a few feet up to 30 feet, with the thickest deposits found at the toe of slopes.

Or am I just sexually frustrated, do you think?

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