Mottureaux et Gilgais

Verger, Fernand

doi:10.3406/geo.1964.16655

Cited by 10 publications

(3 citation statements)

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“…Motts, 1970), (ii) differential expansion and contraction associated with wetting and drying (gilgai) (e.g. Hallsworth et al, 1955;Verger, 1964), or (iii) ephemeral ground ice (e.g. Tufnell, 1975;Mackay, 1980).…”

Section: Sigm~cance Of Zonation and Environments Of The Carbonate Sedmentioning

confidence: 99%

Morphology, distribution, and preservation potential of microbial mats in the hydromagnesite-magnesite playas of the Cariboo Plateau, British Columbia, Canada

Renaut

1993

Hydrobiologia

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Benthic microbial mats are common in the alkaline hydromagnesite-magnesite playa lakes of Interior British Columbia. Four main zones are recognized based on mat morphology that can be related to the type and duration of wetting. From the basin margin toward the playa centre they are: (i) vegetated hummocky ground; (ii) polygonal hummocky ground; (iii) low-domal and stratiform mats, and (iv) laterally continuous and pustular mats. Mats in peripheral mudflats are commonly mineralized by hydromagnesite, mostly precipitated by capillary evaporation of shallow groundwaters. Mats forming in the ephemeral lake tend to have lower carbonate content.Although widespread, the mats are poorly preserved in the Holocene sedimentary record. Underlying sediments are commonly weakly bedded, disturbed or massive. Desiccation, dehydration, wettingdrying cycles, and grazing by invertebrates cause fragmentation of mats at the surface, facilitating erosion. Cryogranulation, interstitial mineral precipitation, vesiculation, bioturbation, compaction, and volume changes associated with diagenesis, disrupt and destroy lamination in the upper few centimetres. Most surviving organic matter is lost by early microbial degradation.

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Section: Sigm~cance Of Zonation and Environments Of The Carbonate Sedmentioning

confidence: 99%

Morphology, distribution, and preservation potential of microbial mats in the hydromagnesite-magnesite playas of the Cariboo Plateau, British Columbia, Canada

Renaut

1993

Hydrobiologia

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“…Differential swelling acts in the same way as differential frost heaving: dilation of the trench during rewetting acts like a 'soil' wedge while desiccation of the prism promotes its domeshaping by shrinking. Thus, it is normal to find phenomena known as gilgay (Jaillard & Cabidoche, 1984;Knight, 1980;Verger, 1964) and desiccation macropolygons (Butzer, 1971) in both tropical or temperate swelling clays. The geometry of the stresses are similar ( Figure 5).…”

Section: Differential Frost Heave and Differential Swellingmentioning

confidence: 99%

Differential frost heave, load casting and convection: Converging mechanisms; a discussion of the origin of cryoturbations

Vliët-Lanoé

1991

Permafrost & Periglacial

126

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This paper reviews and discusses the main mechanisms involved in cryoturbation processes and patterned ground. The arguments are based upon field, thermal, moisture and micromorphological data in relation to cryogenic fabric stability and local hydraulic conditions. Differential frost heaving appears to be the main mechanism of cryoturbation, but its action can be helped by cryostatic pressures, by differential swelling and probably also by load casting in poorly drained sites. Differential frost heaving can be emphasized if organics are present. Frost‐susceptibility gradients provide an understanding of the geometry of deformations.

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“…The Gilgai microrelief includes 3 distinct groups based on their morphology according to Verger (1964) and Khitrov (2016b). Shapes can be termed isometric, elongated, or strongly elongated.…”

Section: Methodsmentioning

confidence: 99%

Gilgai Microrelief Morphology in the Caicó – Rn Region

Lira

Reis

Lopes

et al. 2022

IJSA

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The Gilgai microrelief is characterized as a succession of alternating micromounds and depressions, in soils rich in expansive clays (2:1). Its genesis is related to successive cycles of wetting and drying, especially pronounced under conditions of imperfectly or poorly drained soils. There are still many gaps in the literature on the genesis, evolution and dynamics of the processes involved in areas with Gilgais in Brazil, so studies aimed at understanding their patterns of occurrence are necessary. Thus, the aim of this study is a morphological characterization of Gilgais, in the Potiguar semi-arid region, to verify the hypothesis of homogeneity of its patterns of regional occurrence. The analyzed data refer to two sampling sites, where a total of 120 micro-reliefs were measured, in relation to their height, width and distance between micromounds. Descriptive statistical analysis and ANOVA analysis of variance were applied to the data, seeking to understand the patterns of occurrence of microreliefs. The Gilgai microreliefs observed in the two sampling sites present morphological patterns specific to each site, and differ in some aspects. In both places studied, the micro-reliefs were classified as isometric shapes with no defined orientation. However, in terms of height, width and distance between micromounds, the two sampling sites present statistically significant differences, demonstrated through the analysis of variance of the ANOVA statistical test. This indicates that despite having similar shapes, the size proportions and spacing patterns of the micro-reliefs found in each location are different, ruling out the hypothesis of homogeneous patterns of regional occurrence.

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Mottureaux et Gilgais

Cited by 10 publications

References 0 publications

Morphology, distribution, and preservation potential of microbial mats in the hydromagnesite-magnesite playas of the Cariboo Plateau, British Columbia, Canada

Morphology, distribution, and preservation potential of microbial mats in the hydromagnesite-magnesite playas of the Cariboo Plateau, British Columbia, Canada

Differential frost heave, load casting and convection: Converging mechanisms; a discussion of the origin of cryoturbations

Gilgai Microrelief Morphology in the Caicó – Rn Region

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