IDENTIFIERS

Current Taxon Name (Soil Name): Ojinaga

OSD

Series Extent

User Site ID: S2004-TX377-001

User Pedon ID: S2004-TX377-001

Vegetation Plot ID: S04TX377001

User Site Association ID: Presidio TAMU SCL PedonsTX377-022 Pedons

Lab Information:

Certified Lab Pedon Description - yes

Lab Source ID - TAMU

Lab Pedon # - S04TX377001

NCSS Pedon Lab Data NASIS Record ID - 45558

Print Date: 2/16/2025

LOCATION

Location In Web Soil Survey

AOI is roughly a square mile and pedon is marked in the center.

Location in SoilWeb

Location in Google Maps

Std. Latitude: 29.7099056

Std. Longitude: -104.3860931

Datum: WGS84

Location Description: Presidio County, Texas; from the intersection of US Highway 67 and RM 170 north of Presidio, 8.6 miles north on US Highway 67 to intersection with ranch road, 1.8 miles west on ranch road, then 250 feet north in range.

Map Unit: 22—Ojinaga very gravelly loam, 1 to 8 percent slopes

Country: US—United States

State: Texas

County: TX377—Presidio

MLRA: 42—Southern Desertic Basins, Plains, and Mountains

MLRA Soil Survey Area: SW-MAF—Marfa, Texas

Non-MLRA Soil Survey Area: TX377—Presidio County, Texas

7.5 Minute USGS Quad: 29104-F4—Arroyo Melado, Texas

PEDON

Describers Name: Lynn Loomis, Jim Clausen, Derek Milner, and Tom Hallmark

Current Taxonomic Class: Loamy-skeletal, mixed, superactive, hyperthermic, shallow Calcic Petrocalcids

Current Taxon Kind: series

Pedon Type: OSD pedon

Pedon Purpose: full pedon description

Pedon Record Orgin: NASIS

Correlated Information:

Soil Name - Ojinaga (flagged as OSD)

PSC - 0 to 30 cm.

Classificaton Date - 7/19/2015

Classifier - Lynn Loomis

Soil Taxonomic Edition - twelfth edition

Moisture Class - aridic (torric)

Moisture Subclass - typic

Sampled As Information:

Soil Name - Ojinaga-OSD

Classificaton Date - 1/5/2004

Dynamic Soil Properties:

Pedoderm Loose Cover Indicator - no

Hydric: no

Certification Status: certified

QC Status: level 1

SITE

Parent Material: alluvium derived from mixed

Landscape: semi-bolson

Landform: fan piedmont

Slope Complexity: complex

Slope Shape Across: linear

Slope Shape Down: linear

Drainage Pattern: dendritic

Runoff: negligible

Drainage Class: well

Flooding: none flooding

Geology: Qao formation.

Surface Fragments: 90.00 percent nonflat subangular indurated 2- to 75-millimeter igneous, unspecified,

Benchmark Soil?: no

VEGETATION

SITE OBSERVATION

Observation Date: 1/5/2004 (actual site observation date)

Surface Cover Properties:

Site Obs. Cover Kind 1 - shrub cover

Site Obs. Cover Kind 2 - rangeland, shrubby

Pedoderm Loose Cover Indicator - no

Drained? - no

Bedded Soil? - no

Forest Plantation? - no

Vegetation Plot Plants
Plant Symbol	Scientific Name	National Vernacular Name	Plant Type Group	Canopy Cover %	Vegetation Stata Level
ACCOC CROTO ECEN2 FOSP2 JADI OPIM OPMA8 TIGR LATR2	Acacia constricta var. constricta Croton Echinocereus enneacanthus Fouquieria splendens Jatropha dioica Opuntia imbricata Opuntia macrocentra Tiquilia greggii Larrea tridentata	whitethorn acacia croton pitaya ocotillo leatherstem tree cholla purple pricklypear plumed crinklemat creosote bush	— — — — — — — — —	— — — — — — — — —	— — — — — — — — —

Pedon Restrictions
Kind	Hardness	Restriction Depth L-H	Restriction Thickness L-RV-H
		cm
petrocalcic petrocalcic	strongly coherent moderately coherent	30 - 41 41 - 56	— —

Pedon Diagnostic Features
Feature Kind	Feature Depth L-H	Feature Thickness L-RV-H
	cm
ochric epipedon calcic horizon petrocalcic horizon	0—14 14—30 30—56	—- —- —-

Setting and Climate
Slope	Slope Length USLE	Upslope Length	Elev.	Corr. Elev	Aspect	MAP	REAP	FFD	MAAT	MSAT	MWAT	MAST	MSST	MWST	MFFP	PE Index	Climate Station ID	Climate Station Name	Climate Station Type
%	m				degrees	mm	mm		C						mm
1.5	—	—	1000	—		275	—	262	21.6	30.3	12.1	—	—	—	—	—	TX7262	Presidio	US Official

A—0 to 14 centimeters (0.0 to 5.5 inches); brown (10YR 5/3), brown (10YR 4/3), moist; very gravelly sandy loam; 62 percent sand; 24 percent silt; 14 percent clay; weak coarse subangular blocky parts to weak medium subangular blocky parts to weak fine subangular blocky, and weak medium platy structure; slightly hard, very friable, slightly sticky, slightly plastic; very high excavation difficulty; 4.0 very fine roots throughout; 10 percent distinct white (10YR 8/1), dry, carbonate coats on all faces of peds and 35 percent distinct white (10YR 8/1), dry, carbonate coats on rock fragments; 45 percent by volume nonflat subangular indurated 2-?-75 millimeter igneous, unspecified fragments; grv-l of Field estimated texture class; violent effervescence, by hcl, 1n; strongly alkaline, pH 8.5, pH meter; gradual smooth boundary. Lab sample # TAMU6837; slightly moist when described; observed in trench. Platy stucture is located in upper 2.5 cm of horizon.; discontinuous - phpvsfiid 254391; continuous - phpvsfiid 254392; discontinuous - phpvsfiid 254391; continuous - phpvsfiid 254392

Bk—14 to 30 centimeters (5.5 to 11.8 inches); pale brown (10YR 6/3), brown (10YR 4/3), moist; very gravelly coarse sandy loam; 65 percent sand; 22 percent silt; 13 percent clay; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; very high excavation difficulty; 6.0 very fine roots throughout; 50 percent distinct white (10YR 8/1), dry, carbonate coats on rock fragments; 25 percent by volume nonflat subangular indurated 2-?-75 millimeter igneous, unspecified fragments and 30 percent by volume nonflat subangular indurated 2-?-75 millimeter petrocalcic fragments fragments; grv-l of Field estimated texture class; violent effervescence, by hcl, 1n; moderately alkaline, pH 8.2, pH meter; very abrupt smooth boundary. Lab sample # TAMU6838; dry when described; observed in trench. Layer of calcrete fragments at 20 cm depth nearly continuously cemented and have a strongly cemented laminar cap 1 mm thick.; continuous - phpvsfiid 254385; continuous - phpvsfiid 254385

Bkkm1—30 to 41 centimeters (11.8 to 16.1 inches); white (10YR 8/1), light gray (10YR 7/2), moist; cemented material; structureless massive; strongly coherent by carbonates; very high excavation difficulty; 4.0 very fine roots top of horizon; 15 percent by volume subrounded 2-?-75 millimeter igneous, unspecified fragments; violent effervescence, by hcl, 1n, pH meter; gradual smooth boundary. Lab sample # TAMU6839; dry when described; observed in trench. Indurated laminar cap 2-3 mm thick.

Bkkm2—41 to 56 centimeters (16.1 to 22.0 inches); white (10YR 8/1), very pale brown (10YR 7/3), moist; cemented material; structureless massive; moderately coherent by carbonates; very high excavation difficulty; 0.2 fine roots in cracks; 12 percent distinct white (10YR 8/1), dry, carbonate coats on rock fragments; 25 percent by volume subangular 2-?-75 millimeter igneous, unspecified fragments; strong effervescence, by hcl, 1n, pH meter; gradual smooth boundary. Lab sample # TAMU6840; dry when described; observed in trench. continuous - phpvsfiid 254393; continuous - phpvsfiid 254393

BCk1—56 to 87 centimeters (22.0 to 34.3 inches); light gray (10YR 7/2), dark yellowish brown (10YR 4/4), moist; extremely gravelly loamy coarse sand; 79 percent sand; 16 percent silt; 5 percent clay; structureless single grain; loose, loose, nonsticky, nonplastic; very high excavation difficulty; 1.5 very fine roots throughout; 50 percent distinct white (10YR 8/1), dry, carbonate coats on rock fragments; 35 percent extremely coarse irregular noncoherent cemented white (10YR 8/1), dry, carbonate masses throughout; 65 percent by volume nonflat subangular indurated 2-?-75 millimeter igneous, unspecified fragments; grx-lcos of Field estimated texture class; violent effervescence, by hcl, 1n; strongly alkaline, pH 8.5, pH meter; gradual smooth boundary. Lab sample # TAMU6841; dry when described; observed in trench. continuous - phpvsfiid 254386; continuous - phpvsfiid 254386

BCk2—87 to 124 centimeters (34.3 to 48.8 inches); light gray (10YR 7/2), dark yellowish brown (10YR 4/4), moist; extremely gravelly loamy coarse sand; 79 percent sand; 16 percent silt; 5 percent clay; structureless single grain; loose, loose, nonsticky, nonplastic; very high excavation difficulty; 3.0 very fine roots throughout and 1.0 fine roots throughout; 35 percent distinct white (10YR 8/1), dry, carbonate coats on rock fragments; 2 percent fine platy noncoherent cemented white (10YR 8/1), dry, carbonate masses throughout; 3 percent by volume nonflat subangular indurated 75-?-250 millimeter igneous, unspecified fragments and 62 percent by volume nonflat subangular indurated 2-?-75 millimeter igneous, unspecified fragments; grx-lcos of Field estimated texture class; violent effervescence, by hcl, 1n; strongly alkaline, pH 8.8, pH meter; clear smooth boundary. Lab sample # TAMU6842; dry when described; observed in trench. continuous - phpvsfiid 254390; continuous - phpvsfiid 254390

CBk1—124 to 145 centimeters (48.8 to 57.1 inches); light gray (10YR 7/2), dark yellowish brown (10YR 4/4), moist; extremely gravelly coarse sandy loam; 75 percent sand; 16 percent silt; 9 percent clay; structureless single grain; loose, loose, nonsticky, nonplastic; very high excavation difficulty; 4.0 very fine roots throughout; 10 percent distinct white (10YR 8/1), dry, carbonate coats on rock fragments; 1 percent fine irregular extremely weakly coherent cemented white (10YR 8/1), dry, carbonate masses on bottom of rock fragments; 5 percent by volume nonflat subangular indurated 75-?-250 millimeter igneous, unspecified fragments and 80 percent by volume nonflat subangular indurated 2-?-75 millimeter igneous, unspecified fragments; grx-lcos of Field estimated texture class; strong effervescence, by hcl, 1n; moderately alkaline, pH 8.0, pH meter; clear smooth boundary. Lab sample # TAMU6843; dry when described; observed in trench. discontinuous - phpvsfiid 254389; discontinuous - phpvsfiid 254389

CBk2—145 to 175 centimeters (57.1 to 68.9 inches); light gray (10YR 7/2), yellowish brown (10YR 5/4), moist; extremely gravelly coarse sandy loam; 75 percent sand; 19 percent silt; 7 percent clay; structureless single grain; loose, loose, nonsticky, nonplastic; very high excavation difficulty; 25 percent distinct white (10YR 8/1), dry, carbonate coats on rock fragments; 2 percent coarse irregular moderately coherent cemented white (10YR 8/1), dry, carbonate nodules on bottom of rock fragments; 25 percent by volume nonflat subangular indurated 2-?-75 millimeter igneous, unspecified fragments; grx-sl of Field estimated texture class; strong effervescence, by hcl, 1n; moderately alkaline, pH 8.0, pH meter; clear smooth boundary. Lab sample # TAMU6844; dry when described; observed in pit, small. discontinuous - phpvsfiid 254388; discontinuous - phpvsfiid 254388

C—175 to 200 centimeters (68.9 to 78.7 inches); brown (10YR 5/3), brown (10YR 4/3), moist; extremely gravelly loamy coarse sand; 88 percent sand; 5 percent silt; 7 percent clay; structureless single grain; loose, loose, nonsticky, nonplastic; very high excavation difficulty; 35 percent prominent white (10YR 8/1), dry, carbonate coats on rock fragments; 1 percent very coarse cylindrical noncoherent cemented very pale brown (10YR 8/2), dry, carbonate masses throughout; 65 percent by volume nonflat subangular indurated 2-?-75 millimeter igneous, unspecified fragments; grx-cos of Field estimated texture class; violent effervescence, by hcl, 1n; moderately alkaline, pH 8.1, pH meter. Lab sample # TAMU6845; dry when described; observed in pit, small. 5% of carbonate coats on cobbles, 20 of carbonate coats on pebbles. Evidence of fluvial stratification. Alternating beds of medium gravels with finer gravels. Trace amount of gypsum masses on tops of some medium gravels; discontinuous - phpvsfiid 254387; discontinuous - phpvsfiid 254387