The Avondale 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.
Avondale’s center stands about 2,450 ft above sea level. Within three miles the land runs from 1,010 ft to 3,150 ft, a difference of 2,140 ft: mountain country. The highest named summit within 15 miles is Montezuma Peak, about 4,200 ft, 12 miles southeast.
Under the town center the state geologic map shows Early Proterozoic metamorphic rocks (metasedimentary, metavolcanic, gneiss), from the Paleoproterozoic, 1.6 to 1.8 billion years old.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 5×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Metasedimentary, metavolcanic, gneiss. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 13 mi of the line.
Metasedimentary, schist. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 3 mi of the line.
Granite, granodiorite, tonalite. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 3 mi of the line.
Gravel, sand. Age: Pleistocene, less than 0.8 million years old. About 3 mi of the line.
Sand, gravel. Age: Holocene, less than 10,000 years old. About 3 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
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 Avondale reaches the Gulf of California by way of the Gila and the Colorado: about 330 river miles.
210 miles of the trip are on the Gila.
Often dry. About 70% of the way is mapped as streams that run only after rain or snowmelt; the water makes the whole trip in floods.
Seldom reaches the sea. Dams and canals now take nearly all of the Colorado before its old delta in Mexico.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Avondale; river miles along the main stem, rounded.