TerraBrain

How do Panhandle Ogallala and loess soils affect foundations?

Reviewed by Preston, Oklahoma foundation repair consultant · Updated 2026-10-14

In short: The Oklahoma Panhandle sits on the High Plains, where the ground is made of Ogallala river deposits capped by wind-blown silt (loess) and sand. Soils here are dry most of the year, often contain calcium carbonate layers, and range from silty and loamy to clayey. Foundation movement tends to follow sudden changes in moisture rather than long wet seasons.

What layers lie under the Panhandle?

Ogallala Formation

USDA soil descriptions identify the Ogallala Formation as calcareous, loamy alluvium (river-laid sediment) of Miocene-Pliocene age 1. The Potter soil, which formed in this material, occurs in the Southern High Plains and Breaks of western Texas, eastern New Mexico and northwestern Oklahoma, on draws, escarpments and valley sides 1. Potter soils have calcic horizons, layers enriched in calcium carbonate, with strongly cemented carbonate nodules and calcrete fragments 1.

Loess

Loess is silt that was blown in by wind and settled over the land surface. Two High Plains soils formed in it:

Wind-blown sand and younger eolian deposits

Eolian means wind-deposited. Dalhart soils formed in loamy eolian sediments of Holocene age on interdunes and sand sheets in the Southern High Plains of Kansas, Oklahoma and Texas 4. Mansker soils formed in calcareous, loamy eolian deposits of the Pleistocene Blackwater Draw Formation in Texas, New Mexico and Oklahoma 5.

How do Panhandle soils compare?

Series Parent material Texture class Mean annual precipitation
Richfield Loess 2 Fine, smectitic 2 13–22 in (33–56 cm) 2
Ulysses Loess 3 Fine-silty 3 14–24 in 3
Dalhart Eolian sediments 4 Fine-loamy 4 15–23 in 4
Potter Ogallala alluvium 1 Loamy-skeletal, carbonatic 1 16–22 in 1

What do these soils mean for foundations?

Low rainfall, dry soil

Every series above has a mean annual precipitation of roughly 13 to 24 inches 1234. Ulysses notes that most rain falls in high-intensity thunderstorms from late spring through early autumn 3. Soils that stay dry most of the year can change markedly when they are suddenly wetted by a leak, a downspout or ponding. See hydrocollapse and collapsible and loess soils for how some low-density, dry soils lose volume when first soaked.

Clay where present

Richfield's subsoil is classed as fine and smectitic 2, meaning it has a clay-rich subsoil dominated by swelling clay minerals. Soil scientists rate shrink-swell by linear extensibility, with 3 to 6 percent rated moderate and 6 to 9 percent high 6. Lot-specific values are listed in the USDA Web Soil Survey. See perimeter drying settlement.

Carbonate layers

Secondary carbonates in Richfield begin at about 10 to 24 inches (25 to 61 cm) 2, and calcic horizons in Potter and Mansker begin within roughly the upper 2 to 15 inches 15. These hard, limy layers can affect digging for footings and piers.

Cold

Required footing depth for frost is set locally and differs across Oklahoma. See freeze-thaw and frost depth and frost heave.

Free, plain-English answers. It asks a few questions and walks you to the repair that fits.

Common questions

What is loess?

Loess is silt that was carried and dropped by wind. In the Oklahoma Panhandle, soils such as Richfield formed in loess on high tablelands.

What is the Ogallala Formation?

It is a Miocene-Pliocene deposit laid down by rivers. USDA describes soils such as Potter as formed in calcareous, loamy alluvium from the Ogallala Formation in the Southern High Plains, including northwestern Oklahoma.

Do Panhandle soils swell like central Oklahoma clay?

Some do. Richfield has a smectitic clay subsoil, while Dalhart is loamy. Low rainfall means the soils are often dry, so a sudden wetting from a leak or poor drainage can be a bigger change than in wetter parts of the state.

What is caliche?

Caliche is a layer of soil cemented or enriched with calcium carbonate. Panhandle soils commonly have carbonate accumulations that start within a few inches to a couple of feet of the surface.

Sources

  1. Official Soil Series Description: POTTER Series USDA Natural Resources Conservation Service
  2. Official Soil Series Description: RICHFIELD Series USDA Natural Resources Conservation Service
  3. Official Soil Series Description: ULYSSES Series USDA Natural Resources Conservation Service
  4. Official Soil Series Description: DALHART Series USDA Natural Resources Conservation Service
  5. Official Soil Series Description: MANSKER Series USDA Natural Resources Conservation Service
  6. Linear Extensibility (definition and shrink-swell classes, after NRCS National Soil Survey Handbook) UC Davis California Soil Resource Lab

Was this page helpful?