Sections

Ecological Land Types within LTA 191.

ELT 191a

Elevation Range
Minimum: 
868 m
Minimum in ft: 
2847 ft
Maximum: 
981 m
Maximum in ft: 
3218 ft
Median: 
925 m
Median in ft: 
3035 ft
Soil Summary: 
soils include very and extremely gravelly loams shallow to a caliche hardpan and very deep, very gravelly sandy loam to sand surface soils over gravelly, very gravelly and extremely gravelly sandy loam to sand subsurface layers, soils are limy throughout, moderate to strong development (lime accumulation and cementation); other soils are moderately deep to a lime cemented hardpan and have very cobbly loam surfaces over very cobbly clay loam and clay, lime deeper in the soil profile, and strong development (clay accumulation and cementation); other soils are very deep; very gravelly clay loam, gravelly sandy loam, and very gravelly sandy loam surface layers over gravelly, very gravelly and extremely gravelly sandy loam, gravelly and very gravelly sandy clay loam subsurface layers; lime depth ranges from the surface to more than a foot below the soil surface; no to modest development (lime and clay accumulation); this ELT is dominated by Pima County map units 67 (Redo very gravelly sand, 15 to 50 percent slopes), 22 (Delnorte-Stagecoach complex, 0 to 20 percent slopes), 50 (Nahda very cobbly loam, 2 to 8 percent slopes) and 61 (Pinaleno-Stagecoach-Palos Verdes complex, 10 to 35 percent slopes) which comprise 37%, 28%, 17% and 15% of the ELT, respectively
Geologic Materials: 
alluvium and residuum associated with sandstone, siltstone, and conglomerate, undivided (QTs); early Pleistocene piedmont deposits (Qo); and (KJb) which comprise 70%, 13% and 13% of the unit, respectively
Landforms: 
moderately dissected, moderately to deeply incised fan and pediment surfaces

ELT 191b

Elevation Range
Minimum: 
885 m
Minimum in ft: 
2902 ft
Maximum: 
965 m
Maximum in ft: 
3167 ft
Median: 
927 m
Median in ft: 
3041 ft
Soil Summary: 
very deep, very gravelly sandy loam to sand surface soils over gravelly, very gravelly and extremely gravelly sandy loam to sand subsurface layers, soils are limy throughout, moderate to strong development (lime accumulation and cementation); other soils associated with draws and washes are very deep, very gravelly fine sands over extremely gravelly sands, limy throughout, little or no development (relatively recent alluvium); this unit is dominated by Pima County map units 67 (Redo very gravelly sand, 15 to 50 percent slopes) and 5 (Arizo-Riverwash complex, 0 to 3 percent slopes) which comprise 72% and 20% of the ELT, respectively
Geologic Materials: 
alluvium and residuum associated with sandstone, siltstone, and conglomerate, undivided (QTs); Holocene piedmont alluvium, undivided (Qy); and middle to late Pleistocene piedmont alluvium, undivided (Qi) which comprise 71%, 19% and 7% of the unit, respectively
Landforms: 
moderately dissected, deeply incised fan and pediment surfaces

ELT 191c

Elevation Range
Minimum: 
934 m
Minimum in ft: 
3064 ft
Maximum: 
1077 m
Maximum in ft: 
3534 ft
Median: 
993 m
Median in ft: 
3258 ft
Soil Summary: 
very deep, very gravelly sandy loam to sand surface soils over gravelly, very gravelly and extremely gravelly sandy loam to sand subsurface layers, soils are limy throughout, moderate to strong development (lime accumulation); other soils are finer textured and very deep, typically silt loam surfaces over silty clay and clay subsurface layers, lime and gypsum concentrations occur throughout, moderate to strong development (lime and gypsum accumulation, clay accumulation); this unit is dominated by Cochise County, Northwestern Part map unit 15 (Calcigypsids-Contention-Redo complex, Sonoran, 5 to 45 percent slopes) which comprises 88% of the ELT
Geologic Materials: 
alluvium and residuum associated with conglomerate, older than Quiburis Formation, San Manuel? (Tcg); unnamed (Tq); and late Holocene alluvium (Qy2) which comprise 71%, 13% and 11% of the unit, respectively
Landforms: 
finely dissected, moderately to deeply incised fan and pediment surfaces

ELT 191d

Elevation Range
Minimum: 
901 m
Minimum in ft: 
2956 ft
Maximum: 
1101 m
Maximum in ft: 
3612 ft
Median: 
972 m
Median in ft: 
3189 ft
Soil Summary: 
very deep, very gravelly fine sand over stratified sands, fine sands, gravelly coarse sands, etc., mixed limy and non-limy layers, little or no development; other soils are shallow or very shallow to conglomerate bedrock, sandy loams throughout, limy, little or no development; this unit is dominated by Cochise County, Northwestern Part map unit 68 (Redington-Ripsey-Rock outcrop association, 15 to 70 percent slopes) which comprises 95% of the ELT
Geologic Materials: 
alluvium and residuum associated with conglomerate, older than Quiburis Formation, San Manuel? (Tcg) and unnamed (Tcg) which comprise 67% and 18% of the unit, respectively
Landforms: 
moderately to finely dissected, moderately to deeply incised fan and pediment surfaces

ELT 191e

Elevation Range
Minimum: 
886 m
Minimum in ft: 
2908 ft
Maximum: 
976 m
Maximum in ft: 
3201 ft
Median: 
923 m
Median in ft: 
3028 ft
Soil Summary: 
very deep, very gravelly sandy loam to sand surface soils over gravelly, very gravelly and extremely gravelly sandy loam to sand subsurface layers, soils are limy throughout, moderate to strong development (lime accumulation and cementation); other soils associated with draws and washes are very deep, sandy loams over fine sandy loams, sandy loams, and very gravelly sandy loams, limy throughout, little or no development (relatively recent alluvium); this unit is dominated by Pima County map units 67 (Redo very gravelly sand, 15 to 50 percent slopes and 3 (Anthony fine sandy loam, 0 to 3 percent slopes) which comprise 76% and 21% of the ELT, respectively
Geologic Materials: 
alluvium and residuum associated with sandstone, siltstone, and conglomerate, undivided (QTs); Holocene piedmont alluvium, undivided (Qy); and middle to late Pleistocene piedmont alluvium, undivided (Qi) which comprise 70%, 23% and 7% of the unit, respectively
Landforms: 
coarsely dissected, weakly to moderately incised fan and pediment surfaces

ELT 191f

Elevation Range
Minimum: 
852 m
Minimum in ft: 
2794 ft
Maximum: 
942 m
Maximum in ft: 
3089 ft
Median: 
904 m
Median in ft: 
2966 ft
Soil Summary: 
soils include very and extremely gravelly loams shallow to a caliche hardpan and very deep, very gravelly sandy loam to sand surface soils over gravelly, very gravelly and extremely gravelly sandy loam to sand subsurface layers, soils are limy throughout, moderate to strong development (lime accumulation and cementation); other soils are moderately deep to a lime cemented hardpan and have very cobbly loam surfaces over very cobbly clay loam and clay, lime deeper in the soil profile, and strong development (clay accumulation and cementation); other soils are very deep; very gravelly clay loam, gravelly sandy loam, and very gravelly sandy loam surface layers over gravelly, very gravelly and extremely gravelly sandy loam, gravelly and very gravelly sandy clay loam subsurface layers; lime depth ranges from the surface to more than a foot below the soil surface; no to modest development (lime and clay accumulation); this unit is dominated by Pima County map units 67 (Redo very gravelly sand, 15 to 50 percent slopes), 50 (Nahda very cobbly loam, 2 to 8 percent slopes), 61 (Pinaleno-Stagecoach-Palos Verdes complex, 10 to 35 percent slopes), and 22 (Delnorte-Stagecoach complex, 0 to 20 percent slopes), which comprise 37%, 26%, 17% and 14% of the ELT, respectively
Geologic Materials: 
alluvium and residuum associated with middle to late Pleistocene piedmont alluvium, undivided (Qi); early Pleistocene piedmont deposits (Qo); and (KJb) which comprise 55%, 31% and 7% of the unit, respectively
Landforms: 
coarsely to moderately dissected, moderately to deeply incised fan and pediment surfaces

Catalina