Hydropedology (Stratigraphy & Geomorphology) of Salinity and Evaporites
.
RATIONALE
DISSOLUTION, TRANSPORT, AND ACCUMULATION OF IONIC CONSTITUENTS OCCURS FREQUENTLY AND BY SPECIFIC GEOMORPHIC AND CHEMICAL FLOW PRINCIPLES.
THE ACCUMULATION OF SALTS RESULT IN LOSS OF PLANT PRODUCTIVITY AND IS ONE FORM OF DESERTIFICATION.
SALINITY AND SODICITY, THEREFORE, IMPACT SOIL PRODUCTIVITY, QUALITY, AND BEHAVIOR, WHICH IN TURN IMPACTS SOIL SURVEY CONSTRUCTION AND INTERPRETATION.
5/4/20121 - module 18
OBJECTIVES
• Participants will explain and diagram natural salinization based landscape features and saturated, matric, and osmotic water flow conditions.
• Participants will be able to diagrammically sequence salinization using the Hardie-Eugster Closed Basin Brine Model.
2
ARTESIAN FLOW
Black HillsRECHARGE
LincolnDISCHARGE
Ground Surface
Dakota Sandstone
360 MILES
DAKOTA SANDSTONE is a Cretaceous aged marine sediment.Like nearly all marine sediments, NaCl is present. Source of soil salts frequently is the parent material.
Soluble salts are translocated by saturated flow to discharge sitesand concentrated (accumulate) by matric flow (capillarity). Plantdamage is by osmotic flow or lack of flow to plant cells.
g
m
Evapotranspiration
Precipitation& Infiltration
THROUGHFLOW
Grand Forks
3
Gosselin DC, HF Edwin, and CO Frost. 2001; Gerla, P.J. 2004
MATRIC FLOW (Capillarity)
SOIL HORIZONS Calcic Horizon BkgMATRIC FLOW (Capillarity)
SOIL HORIZONS Calcic Horizon Bkg
MollisolCalciaquoll
ET>I
Bk Calcic Horizon
BkgGley-calcic
Mollic SurfaceDRY
m g
windEVAPOTRANSPIRATION
Dry
Wet
m
4
Moisture Profile
Root Zone
Water Table
Critical Depth
Water Table BELOW Critical DepthC
atio
ns
An
ion
s
Capillary Fringe
Salt Profile
NONSALINE
5
Capillary Fringe
Root Zone
Water Table Critical Depth
Cations Anions
Water Table above Critical Depth
BAD NEWS
Bkyzg
6
Salt ProfileMoisture Profile
Personal comm.A. Maianu
SeepAquifer coal seam
Recharge
Coal Seam Seep
JAROSITE - a bright yellow mineral KFe3(III)(SO4)2(OH)6
often occurs at reflow sites (seeps). Forms in acid sulfateconditions - pH levels below 4.0. Occurs in acid minedrainage in large amounts called “yellow boy”.
BE ALERT FOR JAROSITE NEAR BLACK SHALES!
Sulfate SulfideLow pH High pH 7
OCCURS IN WETLANDS WITHWET AND DRY CONDITIONS
Aquitard underclay
Hydrostatic Pressure Hydrostatic Pressure SeepSeep
Hydrostatic Pressure Hydrostatic Pressure SeepSeep
SALINE &SODIC SALINE
SODIC
AQUIFER
SHALE LANGDON, ND LANDSCAPE550m
8
sand lens
Till
piezometer
piezometric surface
RechargePothole
FlowthroughPothole
Seep
Seep
DischargePothole
TILLHigher Hydraulic Conductivity
Near the Soil Surface
Glacial Depression Glacial Depression Seeps inSeeps in
Sub-humid & Semi-aridSub-humid & Semi-aridClimatesClimates
9
After Lissey 1971
LANDSCAPE SALINITYLANDSCAPE SALINITYLANDSCAPE SALINITYLANDSCAPE SALINITY
PONDS AND CAPILLARY Or MATRIC FLOW
SALTS (precipitates)
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SALTS ARE PRECIPITATED IN SALTS ARE PRECIPITATED IN SEQUENCE FROM LEAST TO SEQUENCE FROM LEAST TO
MOST SOLUBLEMOST SOLUBLE• Calcite forms.Calcite forms.
• If Ca > carbonate, gypsum forms;If Ca > carbonate, gypsum forms;• If Ca < carbonate then pH exceeds If Ca < carbonate then pH exceeds
8.5, usually. And sodium carbonate 8.5, usually. And sodium carbonate minerals form; proto-dolomite has minerals form; proto-dolomite has been reported. been reported. (Ca>1Mg<1)(CO(Ca>1Mg<1)(CO33))22
• In gypsum sequence, sulfate salts are In gypsum sequence, sulfate salts are most common in saline soils.most common in saline soils. 11
Eugster – Hardie model 1970
CHEMICAL DIVIDESCHEMICAL DIVIDES
CaSO4
SO4Ca
CaCO3
Proto-dolomite (Ca>1Mg<1)(CO(Ca>1Mg<1)(CO33))22
High pH SodaSalts
12
HIGH CA HIGH CARBONATE
CHEMICAL DIVIDESCHEMICAL DIVIDEStypical Ground Water Effects typical Ground Water Effects
for North Dakota Ca<SOfor North Dakota Ca<SO44
CHEMICAL DIVIDESCHEMICAL DIVIDEStypical Ground Water Effects typical Ground Water Effects
for North Dakota Ca<SOfor North Dakota Ca<SO44
Conc.Mmols/L
EC(dS/m)
Sulfatic Water SOSO44
Ca SOCa SO4 4 pptppt
Arndt & Richardson 1989
CaCa
413
CHEMICAL DIVIDESCHEMICAL DIVIDEStypical Ground Water Effects typical Ground Water Effects
for North Dakota Ca<SOfor North Dakota Ca<SO44
CaCa
NaNaMgMg
Conc.Mmols/L
EC(dS/m)
Sulfatic Water
Arndt & Richardson 1989414
CHEMICAL DIVIDESCHEMICAL DIVIDES
CaCa
COCO33
RelativeAmount
EC mmols/cmEC mmols/cm15
Dessication
CONCLUSIONSCONCLUSIONS
• Even in landscapes with ground water Even in landscapes with ground water throughflow, the Hardie-Eugster throughflow, the Hardie-Eugster chemical divides system explains the chemical divides system explains the evaporite sequence and ion solution evaporite sequence and ion solution concentration.concentration.
• Soil salinity in the mid-continent should Soil salinity in the mid-continent should be explained in terms of such an be explained in terms of such an evaporite sequence if possible.evaporite sequence if possible.
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CHEMICAL DIVIDESCHEMICAL DIVIDES22ndnd Step Sandy Soils in ND Step Sandy Soils in ND
and in Warm Climates Ca<COand in Warm Climates Ca<CO33
Horizon Depth pH Clay CO3 EC(cm) % Clay % dS/m
A 0-21 8.3 16 2 2Btn 21-43 8.9 47 42 6Bk 43-75 9.0 40 39 7Cg 75-150 9.1 8 6 5.8
*Bk is proto-dolomite (Ca>1Mg<1)(CO(Ca>1Mg<1)(CO33))2217
Humdinger data
? QUESTIONS
1. Diagram and explain translocation and accumulation of soluble salts by water flow characteristics.
2. Diagram and explain the Hardie & Eugster evaporite sequence.
3. Diagram and explain the profile salt accumulation of secondary salinization.
18This is part of the Humdinger Exam ..
EBtn pH 9.1
Bk50% clay
THE STUDENT WILL DESCRIBE AND EXPLAIN THE DEVELOPMENT OF THIS SOIL, ESPECIALLY FOCUS ON THE WATER DYNAMICS.STIRUM: COARSE-LOAMY, MIXED, SUPERACTIVE, FRIGID TYPIC NATRAQUOLL
2Cg 94% sand
OUTWASH TERRACE; HIGH WATER TABLE EVERY SPRING; OUTWASH TERRACE; HIGH WATER TABLE EVERY SPRING; 94% SAND OR COARSER, HIGH SODIUM & pH; white Bk is 94% SAND OR COARSER, HIGH SODIUM & pH; white Bk is
Protodolomite; note the Btn horizon. Protodolomite; note the Btn horizon.
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SODICITY SODICITY
• 1. Add SODIUM
• 2. SOIL AGGREGATES harden dry.They are stronger dry than Ca types.
• 3. Soils expand more with sodium ions wet.They are more plastic and weaker wet than Ca exchange ions.
• 4. Erodibility and crusting are increase with sodium ions. Tilth of the soil is remarkable poor.
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CHEMICAL REACTIONSCHEMICAL REACTIONS SODIUM EXCHANGE SODIUM EXCHANGE
RECLAMATION RECLAMATION
CHEMICAL REACTIONSCHEMICAL REACTIONS SODIUM EXCHANGE SODIUM EXCHANGE
RECLAMATION RECLAMATION
Na2SO4 + Ca
+ CaSO4
Na Na
CaCl2 +
Na Na Ca+ 2NaCl
SODIUM EXCHANGESODIUM EXCHANGE
RECLAMATIONRECLAMATION21
END TO FACE END TO FACE FLOCCULATIONFLOCCULATIONEND TO FACE END TO FACE
FLOCCULATIONFLOCCULATION
++
++
++++----------- --------------------
NEGATIVE
POSITIVE
OPEN AGGREGATION
Non-Dispersed22
Dispersed ClaysDispersed ClaysFACE to FACEFACE to FACE
Loose SLICK Packing Wet (Weak)Dense Packing Dry (Strong)
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REFERENCES USED
• Arndt, J.L. and J.L. Richardson. 1989. Geochemical development of hydric soil salinity in a North Dakota prairie-pothole wetland system. Soil Sci. Soc. Am. J. 53:848-855.
• Hardie, L.A. and H.P. Eugster.1970. The evolution of closed-basin brines. Mineral Soc. Am. Spec. Pap. 3:273-290.
• Keller, L. P., G. J. McCarthy, and J. L. Richardson. 1986. Mineralogy and stability of soil evaporites in North Dakota. Soil Sci. Soc. Am. J. 50:1069-1071.
• Knuteson, J. A., J. L. Richardson, D. D. Patterson, and L. Prunty. 1989. Pedogenic carbonates in a Calciaquoll associated with a recharge wetland. Soil Sci. Soc. Am. J. 53:495-499.
• Maianu, A., J.L. Richardson, and P.G. Held. 1987. Salt accumulation in the groundwaters of North Dakota. ND Farm Research 45(2):12-18.
• Richardson, J.L. 2005. Soluble salts: Translocation and accumulation, pp 1664-1665. in Lal, R. (ed.) Encyclopedia of Soil Science, 2nd Edition, Volume 2. Taylor & Francis, NY.
• Skarie, R. L., J. L. Richardson, A. Maianu, and G. K. Clambey. 1986. Soil and groundwater salinity along drainage ditches in eastern North Dakota. J. Environ. Qual. 15:334-340.
• Steinwand, A.L. and J.L. Richardson. 1989. Gypsum occurrence in soils on the margin of semipermanent prairie pothole wetlands. Soil Sci. Soc. Am. J. 53:836-842.
• Timpson, M. E. and J. L. Richardson. 1986. Ionic composition and distribution in saline seeps of southwestern North Dakota, USA. Geoderma 25:295-305.
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