The Franklin plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
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Partly cloudy; warmer
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76° on Nov. 11, 2020, the hottest reading for this week of the year since 1840. Next is 74° in 2009.
Franklin’s center stands about 570 ft above sea level. Within three miles the land runs from 500 ft to 1,350 ft, a difference of 850 ft: hilly country. The highest named summit within 15 miles is Bear Mountain, about 1,600 ft, 14 miles west-southwest.
Under the town center the state geologic map shows Gettysburg Formation (siltstone-mudstone, shale), from the Triassic, 202 to 252 million years old.
The section below crosses 8 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 16×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Siltstone-mudstone, shale. Age: Triassic, 202 to 252 million years old. About 8 mi of the line.
Age: Precambrian. About 4 mi of the line.
Basalt. Age: Jurassic, 145 to 202 million years old. About 4 mi of the line.
Quartzite. Age: Cambrian, 487 to 542 million years old. About 3 mi of the line.
Dolostone. Age: Cambrian, 487 to 542 million years old. About 2 mi of the line.
Shale. Age: Triassic, 202 to 252 million years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 2 smaller units along the line are not listed.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Franklin reaches Chesapeake Bay and the Atlantic Ocean by way of North Branch Bermudian Creek, Bermudian Creek, Conewago Creek and the Susquehanna: about 100 river miles.
Lake on the way: Lake Aldred.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Franklin; river miles along the main stem, rounded.
Franklin has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 21° in January. A normal year brings about 28 inches of snow; with the rain, that comes to about 48 inches of water.
Normals 1991–2020 and records since 1840 at Carlisle Water Plant, 12 miles north-northwest, 140 ft lower. NOAA, through RCC-ACIS.
