LOCATION POZUELO PR
Tentative Series
ASR/AMA
04/2026
POZUELO SERIES
MLRA(s)--273
Depth Class--Very deep
Drainage Class--Subaqueous drainage
Water depth range--0 to 400 centimeters
Saturated hydraulic conductivity--Moderately low to high
Parent Material--Fine estuarine deposits
Geomorphic location--Mainland coves
Slope--0 to 1 percent
Mean Annual Air Temperature--26 degrees C (79 degrees F)
Mean Annual Water Temperature--28 degrees C (82 degrees F)
TAXONOMIC CLASS: Fine, mixed, subactive, nonacid, isohyperthermic Grossic Hydrowassents
TYPICAL PEDON: Pozuelo silt loam in a mainland cove in Jobos Bay main lagoon (Colors are for moist soil unless otherwise stated).
Aseg--0 to 15 centimeters; very dark greenish gray (10Y 3/1), silt loam; 5 percent shell fragments; structureless, massive; moderately sticky, moderately plastic; very fluid; color change with 3 percent hydrogen peroxide; strong effervescence to 30 percent hydrogen peroxide; strongly alkaline (pH 8.5), moderately alkaline (pH 8.2) oxidized pH; clear boundary.
Cseg1--15 to 39 centimeters; dark greenish gray (10GY 4/1), silty clay; structureless, massive; very sticky, moderately plastic; moderately fluid; no color change with 3 percent hydrogen peroxide; slight effervescence with 30 percent hydrogen peroxide; strongly alkaline (pH 8.7), strongly alkaline (pH 8.5) oxidized pH; clear boundary.
Cseg2--39 to 85 centimeters; very dark greenish gray (10Y 3/1), silty clay loam; structureless, massive; moderately sticky, moderately plastic; very fluid; no color change with 3 percent hydrogen peroxide; slight effervescence with 30 percent hydrogen peroxide; strongly alkaline (pH 8.9), moderately alkaline (pH 8.4) oxidized pH; clear boundary.
Cseg3--85 to 126 centimeters; very dark greenish gray (10Y 3/1), silty clay; structureless, massive; very sticky, moderately plastic; moderately fluid; slight sulfurous odor; no color change with 3 percent hydrogen peroxide; slight effervescence with 30 percent hydrogen peroxide; moderately alkaline (pH 8.4), moderately alkaline (pH 8.0) oxidized pH; diffuse boundary.
Cseg4--126 to 190 centimeters; very dark greenish gray (10Y 3/1), silty clay; structureless, massive; moderately sticky, moderately plastic; moderately fluid; no color change with 3 percent hydrogen peroxide; slight effervescence with 30 percent hydrogen peroxide; strongly alkaline (pH 8.5), moderately alkaline (pH 8.4) oxidized pH.
TYPE LOCATION: Guayama municipality, Puerto Rico. Las Mareas Lagoon, at Jobos Bay National Estuarine Research Reserve property. Approximately 3.4 kilometers (2.1 miles) southeast from the Jobos Bay Reserve headquarters office building and approximately 3.75 kilometers (2.3 miles) northeast of Cayo Caribe southernmost shore point.
Latitude--17.9475850
Longitude-- -66.1920680
Datum--WGS84
Coordinate source--Manually entered from GPS
RANGE IN CHARACTERISTICS:
Depth to bedrock--Greater than 200 centimeters
Depth of organic material (where present)--0 to 27 centimeters
Manner of failure--Slightly to very fluid throughout
Shell fragments--0 to 35 percent or less by volume from 0 to 100 centimeters Reaction throughout--Moderately to strongly alkaline (pH 7.9 to 9.0)
Oxidized reaction--Moderately to strongly alkaline (pH 7.9 to 9.0)
Sulfurous odor--None to strong throughout and intensity decreases with depth
Electrical conductivity (1:5 soil-water)--4.0 to 10.0 dS/m throughout
Oase horizon (where present):
Hue--10Y or N
Value--2.5
Chroma--0 to 1
Texture--muck
von Post Humification--H7 to H10
Aseg horizon:
Hue--10, 10Y, 5Y, or N
Value--2.5 to 4
Chroma--0 to 1
Texture--loam, silt loam, silty clay loam, silt loam, or silty clay with their mucky analogs
Cseg horizons:
Hue--5Y, 10Y, 5GY, 10GY, N
Value--2.5 to 4
Chroma--0 to 1
Texture--silty clay, silty clay loam, clay
Cg horizon (where present):
Hue--10Y
Value--4
Chroma--1
Texture--sandy clay
COMPETING SERIES: There are no competing series in the same family.
GEOGRAPHIC SETTING:
Parent Material--Fine estuarine deposits
Landscape--Coastal lagoons in semiarid coastal plain, Puerto Rico
Landform--Mainland coves
Mean Annual Air Temperature--22 to 31 degrees C (72 to 88 degrees F)
Mean Annual Precipitation--508 to 1,145 millimeters (20 to 45 inches)
Mean Annual Water Temperature--26 to 32 degrees C (79 to 90 degrees F)
Water salinity range--28 to 43 parts per thousand
GEOGRAPHICALLY ASSOCIATED SOILS:
These are the
Majaguas,
Ostiones, and
Placeres soils.
Majaguas soils--are in the lower lagoon bottom further from the mangrove margin and has a fine-loamy control section.
Ostiones soils--occur on slightly higher submerged mainland beaches and have coarser textured horizons
Placeres soils--have a skeletal control section and occur in estuarine tidal creeks and streams close to the mangrove margin where more clams and mussels provide shells for the substrate.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--Subaqueous (permanently submersed)
Saturated hydraulic conductivity--Moderately low to high
Soil moisture regime--Peraquic
Soil is continuously inundated by saline and brackish water
USE AND VEGETATION:
Major Uses--Used for wildlife habitat, recreational boating, fishing, swimming, marinas, mooring fields, and commercial shellfish habitat. These soils provide improved water quality and flood / storm surge water storage.
Dominant Vegetation--Turtle grass (Thalasia testudinum) and paddle grass (Halofila decipiens).
DISTRIBUTION AND EXTENT:
General area--Coastal lagoons along the southern coastal plain of Puerto Rico.
Land Resource Region--Z - Caribbean Region
MLRA--273 - Semiarid Coastal Plains
Extent--Small
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Special Projects Office
SERIES ESTABLISHED: Humacao Area, Puerto Rico Eastern Part (PR689); Guayama Municipality, Puerto Rico; 2024. The name is from the Pozuelo peninsula in Guayama which borders a great part of the Jobos Bay lagoon, where it was originally recognized. The word Pozuelo can be translated as a small water hole used to collect water.
REMARKS: This subaqueous series is mapped in areas previously published as water in Puerto Rico Soil Survey publications.
Diagnostic horizons and features recognized in this pedon--
Peraquic soil moisture regime--Positive soil water potential (permanently submerged) at the soil surface. (under 0 to 4 meters of salt water)
Ocrhic epipedon--the zone 0 to 15 centimeters (0 to 6 inches).
Oxidized pH values--the shell fragments and Halimeda materials that occur throughout this soil buffer the oxidized pH preventing potential sulfidic materials from developing
High n-value--slightly to very fluid throughout
ADDITIONAL DATA:
OSD pedon: 2024PR057701
Supporting pedons: 2024PR057416, 2024PR057417
_____________________________________________________________________
National Cooperative Soil Survey
U.S.A.