Micromorphology, clay mineralogy, and geochemistry of calcic-soils from western Thar Desert: Implications for origin of palygorskite and southwestern monsoonal fluctuations over the last 30 ka

Hameed, Abdul; Raja, P.; Ali, M.; Upreti, Neha; Kumar, Nitesh; Tripathi, Jayant K.; Srivastava, Pankaj

doi:10.1016/j.catena.2017.12.034

Cited by 15 publications

(8 citation statements)

References 55 publications

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“…The binding energies of both O 1s and Si 2p tend to shift to a relative higher energy with an increase of reaction temperature. The change from microcline (KAlSi 3 O 8 ) to calcium aluminum silicate (CaAl 2 SiO 6 ) and the formation of the Si-contained composites (in the form of Si–O connection) are both associated with the rearrangement of bindings between the oxygen atom and other atoms (i.e., Al, Ca) in the mineral matrix. , …”

Section: Results and Discussionmentioning

confidence: 99%

Clean Process to Utilize the Potassium-Containing Phosphorous Rock with Simultaneous HCl and KCl Production via the Steam-Mediated Reactions

Wang

Shi

et al. 2022

ACS Omega

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In this paper, a clean process based on the steam-mediated reactions for simultaneous HCl and KCl production using the potassium (K)-containing phosphorous rock as a precursor is proposed. Through hydrochloric acid (HCl) leaching, not only the generation of H 3 PO 4 and CaCl 2 (via further precipitation) were realized but also the acid-insoluble residue [phosphorous-rock slag (PS)] rich in elements, that is, K, Al, Si, and so on, in the form of microcline (KAlSi 3 O 8 ) and quartz (SiO 2 ) was obtained and became readily available for further HCl and KCl generation. Over 95% of the elements, that is, K, Al, and Si, come into the final products, and the overall acid consumption (based on HCl) is significantly reduced (90%) due to recovery of acids. The impacts of the key operational parameters such as temperature, duration, and reagent impregnate ratio were rigorously analyzed via a supervised machine learning approach, and the optimal conditions were determined [reaction temperature, X 1 , 850 °C; reaction duration, X 2 , 40 min; and impregnate ratio (PS over CaCl 2 ), X 3 , 2.5] with approximately ±10% uncertainties. Thermodynamic analysis indicates that the introduction of steam to PS + CaCl 2 not only enhances the chemical potential for the formation of HCl and KCl but also provides the transport advantage in continuously removing the generated products, that is, HCl and KCl, out of the system. Molecular simulation indicates that the presence of both steam and SiO 2 in the PS matrix plays critical roles in decomposing PS + CaCl 2 at high temperature. The shrinking core model shows that both the intrinsic kinetics and transport are influential with the activation energy being around 14.63 kJ/mol. The potential reaction pathway is postulated.

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Section: Results and Discussionmentioning

confidence: 99%

Clean Process to Utilize the Potassium-Containing Phosphorous Rock with Simultaneous HCl and KCl Production via the Steam-Mediated Reactions

Wang

Shi

et al. 2022

ACS Omega

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“…The relatively higher concentrations of vermiculite and the lesser amounts of palygorskite with short and broken fibres (Figs 8B, S5B) in the Btk horizons at Jimabad (Table 2) may be related to phases of higher moisture concomitant with wetter conditions reported by Hameed et al (2018) in the western Thar Desert in India and Karimi et al (2013) in southern Mashhad city in Iran.…”

Section: Osl Ages and Palaeoclimatic Implications Of The Soilsmentioning

confidence: 88%

“…The presence of spindle-shaped calcite precipitation clearly suggests that biogenic activity must have played an important role (Hameed et al 2018) during the formation of these two argillic calcic horizons, in conditions wetter than now. Micromorphological observations also confirm biogenic carbonate nodules as pedofeatures in the 2Btkb2 horizon (Fig.…”

Section: Osl Ages and Palaeoclimatic Implications Of The Soilsmentioning

confidence: 96%

Late Pleistocene–Holocene pedogenesis and palaeoclimate in western Asia from palaeosols of the Central Iranian Plateau

Rashidi

Karimi

Murray

et al. 2021

Boreas

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The Late Pleistocene and Holocene in western Asia is characterized by frequent, millennial-scale, high-amplitude environmental climatic changes. However, little is known about palaeoclimate conditions on the arid Central Iranian Plateau and knowledge of palaeosols and past phases of pedogenesis in relation to climatic events is scarce. Nevertheless, these palaeosols contain important information on the Last Glacial-Interglacial cycle and Holocene climate and environmental changes in the region. Three representative pedons with eight argillic horizons from the interior of the Central Iranian Plateau, namely Isfahan, Jimabad and Bajestan are selected for micromorphological, mineralogical and submicroscopic analyses. The ages of these palaeosols are constrained using the optically stimulated luminescence (OSL) signal from quartz. Micromorphological observations show clay illuviation, carbonate leaching, accumulation of secondary carbonates, calcite depletion, and other characteristic pedogenic features. These characteristics, combined with the luminescence chronology, reveal the presence of well-developed reddish-brown palaeoargillic horizons (Btk/Btky) with intensive soil formation processes taking place during the Last Interglacial to Middle Holocene (~107-4.5 ka) in our study area. Pedogenic evidence from the palaeosols suggests steps of polygenetic formation in the argillic horizons in response to alternating wetter and drier phases during this period. Four distinct phases of pedogenesis resulting in Btk/Btky horizons are identified: (i) Marine Isotope Stage (MIS) 5, (ii) MIS 3, (iii) the Last Glacial-Interglacial Transition Holocene, and (iv) the Late Holocene.

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“…To study the changes in soil properties during the occurrence of wind erosion desertification, some researchers conducted long-term dynamic monitoring through scientific observations and research stations set up in the field. Other researchers used space instead of time to conduct their studies [41][42][43][44]. By analyzing soils in the desert-oasis transition zone with distinct desertification gradient characteristics, they obtained the silt-clay content in different stages of desertification.…”

Section: Occurrence Regularity Of Silt-clay Minerals In Wind Eroded Dmentioning

confidence: 99%

“…The silt-clay contents of different desertification levels in different areas (Data from reference[19,23,31,32,[40][41][42][43][44][45][46][47][48][49][50][51][52][53]74]). …”

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confidence: 99%

Occurrence Regularity of Silt–Clay Minerals in Wind Eroded Deserts of Northwest China

Liu

Sun

et al. 2021

Sustainability

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Wind erosion desertification is the most serious type of land degradation in Northwest China, so it is an important task for ecological management in the region. As the core of ecological management, soil quality is mainly affected by the presence of silt–clay content. Therefore, the grasp of its occurrence regularity is the key to controlling wind erosion desertification. At present, research on silt–clay contents is mainly independent in each local area and lacks integrity, which makes it difficult to meet the overall evaluation and planning requirements. To this end, this paper reviewed the related studies on the occurrence and control of wind erosion desertification in recent years and collected nearly 300 relevant silt–clay content data points. We studied the occurrence regularity of silt–clay content during the occurrence and treatment of wind erosion desertification and revealed the mechanism of silt–clay content in different processes. On this basis, the degree of wind erosion desertification in the major areas of Northwest China in the last five years was evaluated by calculations based on soil typing theory, and the fractal dimension interval (2.41–2.53) for the critical discrimination of desertification in these areas was obtained. The results showed that there were obvious distribution intervals of silt–clay content for different degrees of wind erosion desertification. Qualitative changes in soil quality during degradation ranged from light to moderate wind erosion desertification. The occurrence and control of wind erosion desertification were largely affected by the processes of silt–clay particles loss and aggregation. Among the three main treatment measures, biological measures enhanced silt–clay content most significantly. In this study, the occurrence regularity of silt–clay minerals in wind erosion desertification in Northwest China was revealed as a whole. This study provided a preliminary overall judgement of the dynamic evolution of wind erosion desertification, which provided a reference for the overall evaluation and global governance planning of wind erosion desertification in Northwest China.

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Micromorphology, clay mineralogy, and geochemistry of calcic-soils from western Thar Desert: Implications for origin of palygorskite and southwestern monsoonal fluctuations over the last 30 ka

Cited by 15 publications

References 55 publications

Clean Process to Utilize the Potassium-Containing Phosphorous Rock with Simultaneous HCl and KCl Production via the Steam-Mediated Reactions

Clean Process to Utilize the Potassium-Containing Phosphorous Rock with Simultaneous HCl and KCl Production via the Steam-Mediated Reactions

Late Pleistocene–Holocene pedogenesis and palaeoclimate in western Asia from palaeosols of the Central Iranian Plateau

Occurrence Regularity of Silt–Clay Minerals in Wind Eroded Deserts of Northwest China

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