In a word...yes they can. I recently downloaded a custom soil report from the NRCS and it contained 34 pages on soils, and soil types. It clearly showed on it the gravel pits we have. Its like anything, they take a sampling, then use history and patterns to develop an idea what the soil is like in between the areas tested.
Here is what my Home Field has for soil as downloaded from the NRCS website:
3.5 Acres of 2E Soil
6% Slope
Soil:
MbB—Marlow fine sandy loam, 3 to 8 percent slopes
Marlow and similar soils: 83 percent
Description of Marlow Setting
Landform: Drumlinoid ridges
Down-slope shape: Convex
Across-slope shape: Convex
Parent material: Coarse-loamy lodgment till derived from granite and/or
coarse-loamy lodgment till derived from mica schist
Properties and qualities
Slope: 3 to 8 percent
Depth to restrictive feature: 20 to 36 inches to dense material
Drainage class: Well drained
Capacity of the most limiting layer to transmit water (Ksat): Moderately
low to moderately high (0.06 to 0.60 in/hr)
Depth to water table: About 18 to 26 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Low (about 3.4 inches)
Interpretive groups
Land capability (nonirrigated): 2e
Typical profile
0 to 6 inches: Fine sandy loam
6 to 24 inches: Fine sandy loam
24 to 60 inches: Fine sandy loam
I have yet to disprove the NRCS satellite testing via real-world soil tests. What it says via satellite is what we are seeing on the ground. Its pretty darn accurate in other words.
Its also pretty cool. I can literally check what I have fo soil type just outside my door and never leave my computer or my coffee. More astonishingly, you can too as 95% of the US has been tested.
You can check this out, and generate your own custom soil report by going to the NRCS Web Soil Service. The program is a bit goofy, and takes awhile to get used to as it is processing a lot of data, but it is useful. I get all my maps from that. Its great because I can pick out individual fields, then figure out how many acres, and how many miles of wire I need to fence them in.
Oh and yes EVERYTHING is free. At first I let the "add to Cart" and "Checkout" tab hold me back as I don't part from a dollar bill easily but its a misnomer. Its all free. As I said, it takes awhile to figure out, but its been a great resource for me.
Web Soil Service