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?