Effects of Desiccation Cracks on Slope Reliability

The Bauru Basin (Upper Cretaceous) accumulated an essentially sandy continental sedimentary sequence. In a first desertic phase the basaltic substratum was covered by a widespread and homogeneous aeolian sand unit with minor loess intercalations. The substratum relief favored the formation of an endorheic drainage system under semi-arid climate, a process that started the development of the Araçatuba Paleoswamp. The palustrine deposits (Araçatuba Formation) comprise siltstone and tipically greenish gray narrow tabular strata of sandstone cemented by carbonate. Moulds and gypsite and dolomite pseudomorphs were identified. The moulds seem to be genetically associated with desiccation cracks, root marks and climbing ripple lamination levels, that, on the whole, indicate calm shallow saline waters undergoing phases of subaerial exposition. At the boundaries of the study area, sand units may exhibit sigmoidal features and convolute bedding structure, which is characteristic of marginal deltaic deposits. The Araçatuba Formation is enclosed in and later overlaid by the aeolian deposits of the Vale do Rio do Peixe Formation.

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Desiccation-crack-induced salinization in deep clay sediment

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-9-13155-2012 ◽

2012 ◽

Vol 9 (11) ◽

pp. 13155-13189

Author(s):

S. Baram ◽

Z. Ronen ◽

D. Kurtzman ◽

C. Küells ◽

O. Dahan

Keyword(s):

Isotopic Composition ◽

Conceptual Model ◽

Pore Water ◽

Vadose Zone ◽

Land Surface ◽

Water Infiltration ◽

Arid Environments ◽

Desiccation Cracks ◽

The Impact ◽

Desiccation Crack

Abstract. A study on water infiltration and solute transport in a clayey vadose zone underlying a dairy farm waste source was conducted to assess the impact of desiccation cracks on subsurface evaporation and salinization. The study is based on five years of continuous measurements of the temporal variation in the vadose zone water-content and on the chemical and isotopic composition of the sediment and pore-water in it. The isotopic composition of water stable isotopes (δ18O and δ2H) in water and sediment samples, from the area where desiccation crack networks prevail, indicated subsurface evaporation down to ∼3.5 m below land surface, and vertical and lateral preferential transport of water, following erratic preferential infiltration events. Chloride (Cl-) concentrations in the vadose zone pore water substantially increased with depth, evidence of deep subsurface evaporation and down flushing of concentrated solutions from the evaporation zones during preferential infiltration events. These observations led to development of a Desiccation-Crack-Induced Salinization (DCIS) conceptual model. DCIS suggests that thermally driven convective air flow in the desiccation cracks induces evaporation and salinization in relatively deep sections of the subsurface. This conceptual model supports previous conceptual models on vadose zone and groundwater salinization in fractured rock in arid environments and extends its validity to clayey soils in semi-arid environments.

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Effect of Depth of Desiccation Cracks on Earth Embankments

Geo-Congress 2013 ◽

10.1061/9780784412787.080 ◽

2013 ◽

Cited By ~ 1

Author(s):

Siddharth Khandelwal ◽

Marcelo Sanchez ◽

Zenon Medina-Cetina

Keyword(s):

Desiccation Cracks

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Palaeoenvironmental significance of storm coquinas in a Lower Cretaceous coastal lagoonal succession (Vectis Formation, Isle of Wight, southern England)

Geological Magazine ◽

10.1017/s0016756800003782 ◽

2000 ◽

Vol 137 (2) ◽

pp. 193-205 ◽

Cited By ~ 13

Author(s):

JONATHAN D. RADLEY ◽

MICHAEL J. BARKER

Keyword(s):

High Resolution ◽

Principal Components ◽

Lower Cretaceous ◽

Coastal Lagoons ◽

Trace Fossils ◽

Isle Of Wight ◽

Southern England ◽

Desiccation Cracks ◽

Stratigraphic Framework

Thin bioclastic limestone beds (‘coquinas’) in the Vectis Formation (Wealden Group, Lower Cretaceous) of the Isle of Wight, southern England, exhibit a range of biofabrics and internal stratigraphies. These features are attributed to both simple and complex storm deposition of allochthonous biogenic and siliciclastic materials in coastal lagoons and on adjacent mudflats. These modes of deposition facilitated preservation of dinosaur trackways, desiccation cracks, shallow-tier trace fossils and in situ bivalve colonies through rapid burial. The coquinas thus preserve a record of surficial muds, commonly lost through reworking. The principal components of the coquinas comprise dispersed elements from within the argillaceous ‘background’ facies. Some of these beds are laterally traceable for up to 27 km, providing the foundations for a high-resolution event-stratigraphic framework.

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Burrow casts from the Lystrosaurus-Procolophon Assemblage-zone, Karoo Sequence, South Africa

Koedoe ◽

10.4102/koedoe.v34i1.409 ◽

1991 ◽

Vol 34 (1) ◽

Cited By ~ 34

Author(s):

G.H. Groenewald

Keyword(s):

United States ◽

South Africa ◽

United States Of America ◽

The United States ◽

Climatic Conditions ◽

Desiccation Cracks ◽

Assemblage Zone

Five types of burrow casts from the Lystrosaurus- Procolophon Assemblage-zone (Palingkloof Member and Katberg Formation, Triassic, Karoo sequence. South Africa) are associated with casts of desiccation cracks and red mudstone. Vertebrate remains of Lystrosaurus sp. and Procolophon sp. indicate that these animals probably made the burrows during the Triassic. It is possible that burrowing was an adaptive advantage during periods of severe and unfavourable climatic conditions. Similar burrow casts were found in the Dicynodon-Theriognathus Assemblage-zone, suggesting a burrowing habit for fauna represented in this zone. In structure, the burrow casts resemble those of Scoyenia, Thalassinoides, Histioderma, Gyrolithes and Planolites reported from Germany, France, Asia, Ireland, Spain and the United States of America.

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