Ecological Land Types within LTA 31.

ELT 31a

Elevation Range
Minimum: 
1076 m
Minimum in ft: 
3530 ft
Maximum: 
1348 m
Maximum in ft: 
4424 ft
Median: 
1185 m
Median in ft: 
3888 ft
Soil Summary: 
dominant soils are very deep, very gravelly fine sandy loam over very gravelly sandy clay loam subsoils, lime within a foot of the soil surface, moderate development (clay and lime accumulation), other soils are very gravelly loamy sand over gravelly sandy loam and are limy throughout, moderate development (lime accumulation); unit is dominated by Cochise County, Northwestern Part soil survey units 62 (Nolam-Stronghold complex, 5 to 30 percent slopes). This unit comprises 98% of the ELT
Geologic Materials: 
alluvium and residuum associated with Late Pliocene alluvium, widespread capping Quiburis basin (Tqf); middle Pleistocene alluvium (Qi2); and Johnny Lyon Granodiorite (Xgi) which comprise 39%, 29% and 15% of the unit, respectively
Landforms: 
coarsely to finely dissected, weakly incised fan and pediment surfaces

ELT 31b

Elevation Range
Minimum: 
1106 m
Minimum in ft: 
3630 ft
Maximum: 
1381 m
Maximum in ft: 
4530 ft
Median: 
1243 m
Median in ft: 
4078 ft
Soil Summary: 
dominant soils are very deep, very gravelly fine sandy loam over very gravelly sandy clay loam subsoils or very gravelly and gravelly sandy loam subsurface layers, lime within a foot of the soil surface or throughout, moderate development (clay and/or lime accumulation), other soils are very gravelly loamy sand over gravelly sandy loam and are limy throughout, moderate development (lime accumulation); unit is dominated by Cochise County, Northwestern Part soil survey units 62 (Nolam-Stronghold complex, 5 to 30 percent slopes) and 83 (Tombstone-Stronghold complex, 5 to 30 percent slopes). These units comprise 57% and 41% of the ELT, respectively
Geologic Materials: 
alluvium and residuum associated with Pliocene-Pleistocene basin fill conglomerates (QTc); biotite granitoids of Happy Valley area); and early Proterozoic Pinal Schist (Xp) which comprise 62%, 16% and 8% of the unit, respectively
Landforms: 
moderately to finely dissected, weakly to moderately incised fan and pediment surfaces