Gypsic Features

Poch, Rosa M.; Artieda, Octavio; Лебедева, М. П.

doi:10.1016/b978-0-444-63522-8.00010-3

Cited by 21 publications

(17 citation statements)

References 87 publications

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“…Big gypsum crystals with an irregular shape are relic features. Soil solutions saturated with Ca 2+ and SO4 2-needed for their crystallization could circulate exclusively with the high stand of ground water [43] that was not the case after the Early Khvalynian time. After the cease of marine sedimentation, big gypsum crystals with jagged edges were formed in the process of local re-crystallization.…”

Section: Discussionmentioning

confidence: 98%

Landscape Dynamics in the Caspian Lowlands Since the Last Deglaciation Reconstructed From the Pedosedimentary Sequence of Srednaya Akhtuba, Southern Russia

et al. 2018

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Surface Kastanozem of the Lower Volga area was first studied as a part of the pedocomplex, with the lower part (148–160 cm) formed in Early Khvalynian Chocolate clays (13–15 ka), the middle part (100–148 cm) in a mixed clay-loess sediment sand, and the upper part (0–100 cm) in loess. This resulted from local aeolian transport, with the source material derived from the rewinding of marine sediments. They are enriched in aggregates of Chocolate clays and glauconitic grains of a fine sand-course silt size and have similar contents of clay minerals. The high salinity of similar types evidences marine genesis for both Chocolate clays and source material for loess sediments. Clay fragments of a sand and silt size are responsible for the heavy texture and high gypsum content of loess. The study of soils with the focus on micromorphology and clay mineralogy allows the identification of the complex character of a shift from marine to sub-areal sedimentation. This shift was accompanied by short breaks in sedimentation, allowing the development of synlithogenic soil horizons of Late Khvalynian, after-Khvanynian, and Boreal time. The features of shallowly buried soil horizons confirm increased aridity after the last deglaciation. Surface Calcic Kastanozem is a full Holocene soil reflecting the present environment. However, it is deeply influenced by shallow buried soil horizons and Chocolate clays.

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Section: Discussionmentioning

confidence: 98%

Landscape Dynamics in the Caspian Lowlands Since the Last Deglaciation Reconstructed From the Pedosedimentary Sequence of Srednaya Akhtuba, Southern Russia

et al. 2018

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“…At Çatalhöyük, the crystallization of secondary gypsum was more commonly observed in burials from the North Area, with lenticular gypsum formed in conditions of an alkaline pH, a high Ca:SO 4 ratio and in the presence of organic matter (Cody ; Kushnir ; Poch et al . ). This can clearly be linked to the localized fluctuations in relative humidity and temperature on diurnal and annual cycles and the additional problems created by sorptivity and hysteresis (Lingle and Lercari ).…”

Section: Discussionmentioning

confidence: 97%

‘Not All That Is White Is Lime’—White Substances from Archaeological Burial Contexts: Analyses and Interpretations

et al. 2019

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Archaeological burial contexts may include a variety of white substances, but few analyses have been published. This study reports on the physico-chemical characterization of such residues from seven archaeological sites. It is often assumed that white materials from burial contexts are lime. Our findings demonstrate that they can be gypsum, calcite (chalk), aragonite, brushite, degraded metal, natural (gum) resins or synthetic polymer-based products. These may be present as the result of diagenetic processes, funerary practices or modern contamination. This paper provides an analytical approach for the holistic investigation of white materials encountered in burial contexts.

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“…Based on crystal sizes of the pure gypsum silts measured by microscopy, they concluded that their origin is aeolian (gypsiferous loess). However, they did not take into account that these crystals may not be detrital but instead could have originated from post-sedimentary dissolution-precipitation processes from gypsum clasts from the sediment, or by precipitation from surface or subsurface waters with sulphate and calcium in solution, with modal sizes between 30-1000µm (Poch et al, 2018). Faraco (1975) studied "gypsiferous silts" from a geotechnical point of view and attributed their high gypsum contents to the colluvial or aeolian origin from gypsum sources.…”

Section: Review Of the Term "Gypsiferous Silts"mentioning

confidence: 99%

Silt-sized sediments and gypsum on surface formations in the Ebro valley. A disambiguation of the term gypsiferous silts

Poch¹,

Rodríguez‐Ochoa²,

Artieda³

et al. 2021

GeA

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Since the 60’s, many authors have reported the presence of common silt-sized materials in the Ebro valley, on surface formations and positions that have given rise to several interpretations, sometimes contradictory. According to the references, three main terms are used (gypsiferous silts, loess and flour-like gypsum) applied to silts and fine sands with gypsum accumulations. The two first terms are applied to materials with carbonate contents up to 40-50%, coarse silty to fine sandy textures, and located in different positions. Loess normally appears as thick outcrops on slopes leeward from the main wind direction, with a limited pedogenesis consisting of a partial carbonate mobilisation and gypsum contents between 0 and 30%. The third (gypsum-rich) type has a variable spatial distribution, appearing between limestone layers, along footslopes, outcropping as metric surface formations, or as generalized karstified subsurface accumulations. Their composition is almost 100% silt- to fine sand size lenticular gypsum. While some authors claim for an aeolian origin to all these materials, only part of them (loess) has a clear aeolian origin, while flour-like gypsum derives from on-site weathering of gyprock or by precipitation of calcium- and sulfate saturated watertables as it is reported to occur in many other arid regions; and the rest (gypsiferous silts sensu stricto) are mainly colluvial-alluvial. This distinction is necessary since they differ in their geotechnical behaviour and properties relevant for agricultural land uses, therefore they should be taken into account when carrying out geological mappings or soil surveys in this and similar arid regions.

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Gypsic Features

Cited by 21 publications

References 87 publications

Landscape Dynamics in the Caspian Lowlands Since the Last Deglaciation Reconstructed From the Pedosedimentary Sequence of Srednaya Akhtuba, Southern Russia

Landscape Dynamics in the Caspian Lowlands Since the Last Deglaciation Reconstructed From the Pedosedimentary Sequence of Srednaya Akhtuba, Southern Russia

‘Not All That Is White Is Lime’—White Substances from Archaeological Burial Contexts: Analyses and Interpretations

Silt-sized sediments and gypsum on surface formations in the Ebro valley. A disambiguation of the term gypsiferous silts

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