SOS 5705C Field Assignment

1. SOS 5705C Field Assignment Jake Sneider April 3rd 2008

2. Pit Locations in Mojave Desert 1 2

3. The Mojave or Mohave Desert occupies a significant portion of Southern California and parts of Utah, Nevada, and Arizona. Named after the Mohave Native Americans it occupies over 22,000 square miles in a typical Basin and Range topography.

4. Soil One Location & Geomorphic Description Location: Jawbone Canyon OHV Area • Horse Canyon, California • Mojave Desert Area, Northwest Part, California • Map Unit: 5205 -- SCODIE-GRANDORA ASSOCIATION, 15 TO 60 PERCENT SLOPES Geomorphic Description • Parent Material: colluvium and residuum derived from granite • Bedrock Kind: granite; Bedrock Depth: 88.0 cm • Geomorphic Setting: on backslope of mountain flank • Upslope Shape: linear; Cross Slope Shape: concave • Slope: 63.0 %; Aspect: 345 (deg) • Elevation: 4829 feet, 1,472.0 m • Mean Annual Precip: 18 cm • Drainage Class: somewhat excessively drained

5. Soil One Landform:Backslope of Mountainside

6. Landscape and Vegetation Photos

9. Interesting Stuff in Jawbone

11. A: 0 – 14 cm C1: 14 – 41 cm C2: 41 – 88 cm R: 88 cm Soil 1

12. A: 0 – 14 cm A Horizon A--0 to 6 inches, (0 to 14 cm); gravelly coarse sand, dark yellowish brown (10YR 3/4) moist; weak medium subangular blocky structure, soft, very friable, nonsticky, nonplastic; common fine, medium, and coarse roots and many very fine roots; common very fine interstitial pores; 2 percent medium and coarse gravel and 13 percent fine gravel; neutral, pH 7.0 by Phenol red; abrupt wavy boundary.

13. C1: 14 – 41 cm C1 Horizon C1--6 to 16 inches, (14 to 41 cm); yellowish brown (10YR 5/4) very gravelly loamy coarse sand, dark yellowish brown (10YR 3/4) moist; weak medium subangular blocky structure parting to massive, soft, very friable, nonsticky, nonplastic; common fine, medium, and very fine roots; common very fine interstitial pores; 5 percent cobbles, 10 percent medium and coarse gravel and 20 percent fine gravel; neutral, pH 7.2 by Phenol red; clear smooth boundary.

14. C2: 41 – 88 cm C2 Horizon C2--16 to 35 inches, (41 to 88 cm); dark yellowish brown (10YR 4/4) very gravelly loamy coarse sand, dark yellowish brown (10YR 3/4) moist; massive, soft, very friable, nonsticky, nonplastic; common fine roots and few very fine roots; common very fine interstitial pores; 5 percent medium and coarse gravel, 10 percent cobbles, and 15 percent fine gravel; slightly alkaline, pH 7.4 by Phenol red; abrupt smooth boundary.

15. R: 88 cm R Horizon R – 35 inches, (88cm); indurated, slightly fractured granite bedrock

16. Soil One Scorecard

17. Interpretations and Classification Full Classification: Sandy, mixed superactive, mesic Xeric Torriorthents Series Info: Very close to Grandora series (mixed, mesic Xeric Torripsamments

18. Soil TwoLocation & Geomorphic Description Location: Joshua Tree National Park Geomorphic Description • Parent Material: alluvium derived from granite • Geomorphic Setting: backslope of fan remnant on fan piedmont • Upslope Shape: convex; Cross Slope Shape: linear • Slope: 6.0 %; Aspect: 243 (deg) • Elevation: 1,450.0 m • Mean Annual Precipitation: 12.5 cm • Drainage Class: well drained

19. Soil 2 Landform: Backslope of Fan Remnant

21. Landscape and Vegetation Photos

24. Interesting Stuff in Joshua Tree

26. Soil 2 A: 0 – 7 cm Bw: 7 – 18 cm Bt: 18 – 110 cm Btk: 110 – 150 cm

27. A Horizon: 0 – 7 cm A--0 to 3 inches, (0 to 7 cm); yellowish brown (10YR 5/4) gravelly loamy sand, dark yellowish brown (10YR 3/4) moist; weak medium subangular blocky structure, soft, very friable, nonsticky, nonplastic; many very fine roots throughout; common very fine interstitial and tubular pores; 5 percent medium and coarse gravel and 10 percent fine gravel; neutral, pH 7.2 by Phenol red ; abrupt smooth boundary.

28. Bw: 7 – 18 cm Bw Horizon • 3 to 7 inches, (7 to 18 cm); brown (10YR 5/3) loamy sand, brown (10YR 4/3) moist; weak medium subangular blocky structure, soft, very friable, nonsticky, nonplastic; common fine and very fine roots throughout; common very fine interstitial pores; 2 percent medium and coarse gravel and 8 percent fine gravel; neutral, pH 7.0 by Phenol red ; clear smooth boundary.

29. Bt Horizon 7 to 43 inches, (18 to 110 cm); yellowish brown (10YR 5/4) sandy loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure, slightly hard, very friable, slightly sticky, nonplastic; few fine and medium roots throughout; common fine and medium tubular pores; 10 percent continuous faint clay films between sand grains; 2 percent medium and coarse gravel and 8 percent fine gravel; neutral, pH 7.2 by Phenol red ; clear smooth boundary. Bt: 18 – 110 cm

30. Btk Horizon • 43 to 59 inches, (110 to 150 cm); brown (7.5YR 5/4) sandy loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure, slightly hard, very friable, slightly sticky, slightly plastic; 10 percent continuous distinct strong brown (7.5YR 5/6), dry, clay films on surfaces along root channels and 10 percent continuous distinct clay films on rock fragments and between sand grains; 5 percent fine carbonate masses in matrix; 2 percent medium and coarse gravel and 8 percent fine gravel; slightly alkaline, pH 7.6 by Phenol red. Btk: 110 – 150 cm

31. Soil 2 Scorecard

32. Interpretations and Classification Classification: Coarse-loamy, mixed, superactive, thermic Typic Haplargids Series Info: Tentatively classified as Goldpeak

33. Which of the five Soil Forming Factors led to the genetic differences of these two soils? • Climate? • Organic Matter • Relief? • Parent Material? • Time?

34. The climate in each location is very similar. • There is very little organic matter in the desert. • The rock source for each soil’s parent material is granite.

35. The Main Factors for Genetic Difference Are: 1.Relief Landform, landscape and slope are the main differences that led to development of the two soils. 2. Time Due the landform and slope of each site, soil 2 was in a much more stable position and thus had more time to develop an argillic horizon.

36. Questions?