The Millbrook 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.
Mostly sunny
Sunny; warmer
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Partly cloudy
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3° on Nov. 17, 1959, the coldest reading for this week of the year since 1911. Next is 4° in 1933.
Millbrook’s center stands about 630 ft above sea level. Within three miles the land runs from 550 ft to 760 ft, a difference of 210 ft: rolling country.
Under the town center the state geologic map shows Ancell Group (sandstone, limestone, dolostone), from the Middle Ordovician to Late Ordovician, 454 to 468 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 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, limestone, dolostone. Age: Middle Ordovician to Late Ordovician, 454 to 468 million years old. About 9 mi of the line.
Shale, limestone. Age: Late Ordovician, 445 to 454 million years old. About 6 mi of the line.
Dolostone, limestone. Age: Late Ordovician, 447 to 459 million years old. About 4 mi of the line.
Dolostone, limestone. Age: Late Ordovician, 454 to 459 million years old. About 2 mi of the line.
Shale, sandstone, coal. Age: Middle Pennsylvanian to Late Pennsylvanian, 304 to 315 million years old. About 2 mi of the line.
Dolostone, limestone. Age: Silurian, 422 to 445 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 Millbrook reaches the Gulf of America by way of the Fox River, the Illinois and the Mississippi: about 1,460 river miles.
Lake on the way: Peoria Lake.
1,190 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Millbrook; river miles along the main stem, rounded.
Millbrook has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 16° in January. A normal year brings about 25 inches of snow; with the rain, that comes to about 39 inches of water.
On November 14 Millbrook normally reaches 50° and falls to 32°. The record high is 74°, in 1999; the record low 5°, in 1996. The most rain on this date, 1.30 in, fell in 1926.
Normals 1991–2020 and records since 1911 at Morris 1 NW, 17 miles south-southeast, 110 ft lower. NOAA, through RCC-ACIS.
