scholarly journals Benchmark soils on alluvial, fluvial and fluvio-glacial formations of the upper-Segre valley .

2014 ◽  
Vol 3 ◽  
Author(s):  
Rosa María Poch Claret ◽  
Jaume Boixadera ◽  
Iolanda Simó
Keyword(s):  
Calcium Carbonate ◽  
Spatial Differentiation ◽  
Soil Development ◽  
Parent Material ◽  
Alluvial Fan ◽  
Soil Taxonomy ◽  
Age Related ◽  
Clay Formation ◽  
Soil Forming Processes ◽  
Geomorphic Surfaces

The upper reaches of the Segre river, flowing through the Pyrenees, offers a variety of geomorphic surfaces that allow us to study soil chronosequences. The objective of this work is to widen the knowledge about the main characteristics and formation processes of some benchmark soils developed on fluvio-glacial, alluvial-fan and terrace materials of Pleistocene and Holocene age related to the Segre river, either siliceous or carbonatic. This knowledge will allow us to identify soil forming processes, commonly found in Mediterranean environments such as carbonate redistribution, clay formation and mobilization and rubefaction, all as functions of parent material and age. Five profiles, ranging from the Lower Pleistocene to the Holocene were classified according to Soil Taxonomy/WRB. The Montferrer profile (Calcic Palexeralf /Calcic Cutanic Luvisol (Chromic) is a deep, partly decarbonated soil, with calcium carbonate accumulation in depth covering glacial features. The Torre del Remei profile (Typic Paleustalf /Cutanic Luvisol) developed on silicic moraines and shows an extreme clay formation and illuviation. The Alp (Typic Haplustalf /Cutanic Luvisol) and Tartera (Petric Calciustept /Petric Calcisol) soils are developed on alluvial fans with calcium carbonate sources. The former is partly decarbonated, whilst the latter is rubefacted on top and shows speleothem-like carbonate pendants with superposition of clay illuviation. The youngest profile, Abellerols, (Typic Calciustept /Typic Calcisol) shows only a partial decarbonation and calcite accumulation at depth. The results show that soil development is determined by the age of the surface and the source of calcite, either in the parent rock or brought by subsurface flow: clay illuviation is extreme in absence of it. Special morphologies of carbonate pendants are indicators of environmental conditions. The coexistence of clay coatings and secondary calcite can be explained by recarbonatation or by spatial differentiation of soil environments in the profile. One of the implications of this research is the inconsistence of using soil development indices based on morphological indicators when soils are formed on different parent materials and are subjected to different geomorphic dynamics.

scholarly journals Soil development and soil biology on King George Island, Maritime Antarctic

2011 ◽  
Vol 32 (2) ◽  
pp. 105-116 ◽  
Author(s):  
Manfred Bölter
Keyword(s):  
Standing Stock ◽  
Soil Development ◽  
Parent Material ◽  
Special Focus ◽  
Soil Biology ◽  
King George Island ◽  
Maritime Antarctic ◽  
Soil Taxonomy ◽  
Volcanic Origin ◽  
Few Data

Soil development and soil biology on King George Island, Maritime AntarcticThis review covers aspects of soil science and soil biology of Antarctica with special focus on King George Island, South Shetlands, the martitime Antarctic. New approaches in soil descriptions and soil taxonomy show a great variety of soil types, related to different parent material, mainly volcanic origin, as well as on influences by soil biological processes. The spread of higher rooting plants attract microorganisms, nematodes and collemboles which in turn build new organic material and change the environment for further successors. Microbial communities are drivers with respect to metabolic and physiological properties indicating a great potential in a changing environment. The literature review also shows a lack of investigations on processes of carbon and nitrogen turnover, despite wide knowledge on its standing stock in different environments. Further, only few reports were found on the processes of humification. Only few data are available which can be regarded as long term monitorings, hence, such projects need to be established in order to follow ecological changes.

scholarly journals Clay formation and podzol development from postglacial moraines in Switzerland

Clay Minerals ◽  
1999 ◽  
Vol 34 (2) ◽  
pp. 319-332 ◽  
Author(s):  
D. Righi ◽  
K. Huber ◽  
C. Keller
Keyword(s):  
Acid Soils ◽  
Soil Development ◽  
Parent Material ◽  
Soil Horizon ◽  
Significant Finding ◽  
X Ray Diffraction ◽  
Soil Parent Material ◽  
Fine Clay ◽  
Clay Formation ◽  
Mixed Layers

AbstractThe fine silt (2–5 μm) and fine clay (<0.1 μm) fractions from four acid soils developed from moraines of increasing age (80, 400, 3,000 and 6,500 years old) in Switzerland, were studied by X-ray diffraction and chemical analyses. The soil parent material is homogeneous at the four sites and the soils can be considered as forming a chronosequence of soil development leading to the formation of Podzols. Mineralogical evolution of silt-sized phyllosilicates and fine clay fractions follows different pathways according to their composition and the soil horizon in which they are located. Dioctahedral and trioctahedral minerals in the soil parent material were both weathered in the Bw and Bs horizons but the trioctahedral phase more strongly and faster than the dioctahedral one. Weathering products are mica-vermiculite mixed-layers, vermiculite and finally gibbsite and Fe oxy-hydroxides. Weathering of the trioctahedral fraction was faster in the eluvial A or E horizons than in the B horizons, being almost complete after 3,000 years of soil development. Appreciable weathering of the dioctahedral fraction occurs only in the eluvial horizons leading to the formation of mica-smectite mixed-layers and smectite. Although smectite has been reported in the E horizon of Podzols in different environments, the significant finding in this work is the presence of this mineral in soils developed from the same parent material. This supports the fact that smectite is the end- product of mica alteration in strongly leached and acidified E horizons of Podzols.

scholarly journals Soil – landscape relationships in the Empordà basin (Catalonia, NE Iberian Peninsula)

2016 ◽  
Vol 6 ◽  
Author(s):  
Jaume Boixadera ◽  
Montserrat Antúnez ◽  
Rosa Maria Poch Claret
Keyword(s):  
Calcium Carbonate ◽  
Calcareous Soils ◽  
Human Action ◽  
Parent Material ◽  
Soil Conditions ◽  
Dune System ◽  
Soil Landscape ◽  
Textural Changes ◽  
Soil Forming Processes ◽  
Pedogenetic Processes

Soils developed in representative landforms, which were previously mapped at a detailed scale in the Empordà Basin, were selected to characterize their main pedogenetic processes and to improve the soil maps through a better understanding of the soil – landscape relationships. This basin is a relatively large region (1,300 km<sup>2</sup>) in Northeastern Catalonia, where Neogene and Quaternary sediments outcrop. They are alluvial and delta fan deposits that mainly reflect a continental environment. Besides varying degrees of soil rubefaction, we can identify calcium carbonate redistribution, clay illuviation and sodication as the main soil forming processes, together with abrupt textural changes, vertic and redoximorphic features. These processes and features are expressed under different morphologies in the area, depending not only on parent material, landform and age, but also on human action, which allows us to refine the conceptual soil-landscape model. Calcium carbonate redistribution is a key process reflecting both changing general environmental conditions and local chemical soil conditions. The actual soil characteristics and the soil forming processes allow us to propose that (i) aeolian dust inputs in these soils have been low to moderate throughout, and that (ii) the rainfall pattern in the last part of the Holocene was able to remove these dust inputs, but unable to leach carbonates from medium textured, moderately calcareous soils in the area when they are some kilometres from the sea and not directly affected by the dune system.

scholarly journals Phosphorus dynamics during early soil development in extreme environment

2021 ◽  
Author(s):  
Zuzana Frkova ◽  
Chiara Pistocchi ◽  
Yuliya Vystavna ◽  
Katerina Capkova ◽  
Jiri Dolezal ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Soil Development ◽  
Parent Material ◽  
Available P ◽  
Extreme Condition ◽  
Organic P ◽  
Soil P ◽  
Early Stages ◽  
P Pools ◽  
Microbial P

Abstract. At the early stages of pedogenesis, the dynamics of phosphorus (P) in soils are controlled by microbial communities, the physicochemical properties of the soil and the environmental conditions. While various microorganisms involved in carrying out biogeochemical processes have been identified, little is known about the actual contribution of microbial processes, such as organic P hydrolysis and microbial P turnover, to P cycling. We thus focused on processes driven by microbes and how they affect the size and cycling of organic and inorganic soil P pools along a soil chronosequence in the Chamser Kangri glacier forefield (Western Himalayas). The rapid retreat of the glacier allowed us to study the early stages of soil formation under cold arid climate. Biological P transformations were studied with the help of the isotopic composition of oxygen (O) in phosphate (δ18OP) coupled to sequential P fractionation performed on soil samples from four sites of different age spanning 0 to 100–150 years. The mineral P, i.e. 1M HCl-extractable P, represented still 95 % of the total P stock after approximately 100 years of soil development. Its isotopic composition was similar to the parent material also at the most developed site. Primary phosphate minerals, therefore, mostly composed this pool. The δ18OP of the available P and the P bound to Fe and Al oxides instead differed from that of the parent material, suggesting that these pools underwent biological turnover. The isotopic composition of O in of the available P was mostly controlled by the microbial P, suggesting fast exchanges occurred between these two pools possibly fostered by repeated freezing-thawing and drying-rewetting cycles. The release of P from organic P become increasingly important with soil age, constituting one third of the P flux to available P at the oldest site. Accordingly, the lighter isotopic composition of the P bound to Fe and Al oxides at the oldest site indicated that this pool contained phosphate released by organic P mineralization. Compared to previous studies on early pedogenesis under alpine or cold climate, our findings suggest a much slower decrease of the P-bearing primary minerals during the first 100 years of soil development under extreme condition. However, they provide evidence that, by driving short-term P dynamics, microbes play an important role in controlling the redistribution of primary P into inorganic and organic soil P pools.

Thickness of calcium carbonate coats on stones of the Heishanxia terraces of the Yellow River and dating of coarse clastic sedimentary geomorphic surfaces

2002 ◽  
Vol 47 (19) ◽  
pp. 1594-1600 ◽  
Author(s):  
Chengqi Xing ◽  
Gongming Yin ◽  
Guoyu Ding ◽  
Yanchou Lu ◽  
Xuhui Shen ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Yellow River ◽  
The Yellow River ◽  
Clastic Sedimentary ◽  
Geomorphic Surfaces

scholarly journals Characteristic of Dystrustepts in the Venezuelan Andes

2009 ◽  
Vol 33 (6) ◽  
pp. 1777-1784
Author(s):  
Guido Ochoa ◽  
Jajaira Oballos ◽  
Juan Carlos Velásquez ◽  
Isabel López ◽  
Jorge Manrique
Keyword(s):  
Principal Component ◽  
Parent Material ◽  
Soil Taxonomy ◽  
Organic C ◽  
Discrimination Analysis ◽  
Large Group ◽  
The Us ◽  
Acid Reaction ◽  
Large Groups ◽  
Soil Groups

The majority (60 %) of the soils in the Venezuelan Andes are Inceptisols, a large percentage of which are classified as Dystrustepts by the US Soil Taxonomy, Second Edition of 1999. Some of these soils were classified as Humitropepts (high organic - C-OC-soils) and Dystropepts by the Soil Taxonomy prior to 1999, but no equivalent large group was created for high-OC soils in the new Ustepts suborder. Dystrusepts developed on different materials, relief and vegetation. Their properties are closely related with the parent material. Soils developed on transported deposits or sediments have darker and thicker A horizons, a slightly acid reaction, greater CEC and OC contents than upland slope soils. Based on the previous classification into large groups (Humitropepts and Dystropepts) we found that: Humitropepts have a slightly less acid and higher values of CEC than Dystropepts. These properties or characteristics seem to be related to the fact that Humitropepts have a higher clay and OC content than the Dystropepts. Canonical discrimination analysis showed that the variables that discriminate the two great soil groups from each other are OC and silt. Data for Humitropepts are grouped around the OC vector (defining axis 3, principal component analysis), while Dystropepts are associated with the clay and sand vectors, with significant correlation. Given the importance of OC for soil properties, we propose the creation of a new large group named Humustepts for the order Inceptisol, suborder Ustepts.

scholarly journals Chronology of terraces in the Rio Grande rift, Socorro basin, New Mexico: Implications for terrace formation

Geosphere ◽  
2020 ◽  
Vol 16 (6) ◽  
pp. 1457-1478
Author(s):  
Brad D. Sion ◽  
Fred M. Phillips ◽  
Gary J. Axen ◽  
J. Bruce J. Harrison ◽  
David W. Love ◽  
...  
Keyword(s):  
New Mexico ◽  
Late Quaternary ◽  
Rio Grande ◽  
New Age ◽  
Alluvial Fan ◽  
Rio Grande Rift ◽  
Arid Environments ◽  
Alluvial Deposits ◽  
Continental Scale ◽  
Geomorphic Surfaces

Abstract The Rio Grande rift hosts a remarkable record of Quaternary river incision preserved in an alluvial terrace sequence that has been studied for more than a century. However, our understanding of Rio Grande incision history in central New Mexico since the end of basin filling ca. 0.78 Ma remains hampered by poor age control. Robust correlations among Rio Grande terrace sequences in central and southern New Mexico are lacking, making it difficult to address important process-related questions about terrace formation in continental-scale river systems. We present new age controls using a combination of 40Ar/39Ar, 36Cl surface-exposure, and 14C dating techniques from alluvial deposits in the central New Mexico Socorro area to document the late Quaternary incision history of the Rio Grande. These new age controls (1) provide constraints to establish a firm foundation for Socorro basin terrace stratigraphy, (2) allow terrace correlations within the rift basin, and (3) enable testing of alternative models of terrace formation. We identified and mapped a high geomorphic surface interpreted to represent the end of basin filling in the Socorro area and five distinct, post–Santa Fe Group (ca. 0.78 Ma) alloformations and associated geomorphic surfaces using photogrammetric methods, soil characterization, and stratigraphic descriptions. Terrace deposits exhibit tread heights up to 70 m above the valley floor and are 5 to &gt;30 m thick. Their fills generally have pebble-to-cobble bases overlain by fine-to-pebbly sand and local thin silt and clay tops. Alluvial-fan terraces and associated geomorphic surfaces grade to former valley levels defined by axial terrace treads. Carbon-14 ages from detrital charcoal above and below a buried tributary terrace tread show that the most recent aggradation event persisted until ca. 3 ka during the transition from glacial to modern climate conditions. Drill-log data show widespread valley fill ∼30 m thick that began aggrading after glacial retreat in northern New Mexico and southern Colorado (ca. 14 ka). Aggradation during this transition was likely due to hillslope destabilization, increased sediment yield, decreased runoff, and reduced stream competence. Chlorine-36 ages imply similar controls on earlier terraces that have surface ages of ca. 27–29, 64–70, and 135 ka, and suggest net incision during glacial expansions when increased runoff favored down-cutting and bedload mobilization. Our terrace chronology supports existing climate-response models of arid environments and links tributary responses to the axial Rio Grande system throughout the central Rio Grande rift. The terrace chronology also reflects a transition from modest (60 m/m.y.) to rapid (300 m/m.y.) incision between 610 and 135 ka, similar to patterns observed throughout the Rio Grande rift and the western United States in general.

The Nivolet CZ Ecosystem Observatory reveals rapid soil development in recently deglaciated alpine environments: Biotic weathering is the likely culprit

2020 ◽  
Author(s):  
Ilaria Baneschi ◽  
Ashlee Dere ◽  
Emma Aronson ◽  
Ramona Balint ◽  
Sharon Billings ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
High Altitude ◽  
Soil Development ◽  
Critical Zone ◽  
Parent Material ◽  
Rooting Depth ◽  
Organic C ◽  
C Storage ◽  
Topographic Positions ◽  
Alpine Environments

&lt;p&gt;Soils are a critical component of the Earth system in regulating many ecological processes that provide fundamental ecosystem services (Adhikari and Hartemink, 2016). Soil formation factors may be operating at faster timescales than is typically considered in recently deglaciated alpine environments, yielding important implications for critical zone services (e.g., water retention, the preservation of carbon (C) and nutrients, and chemical weathering fluxes). It remains unclear how variation in these properties are linked to soil development and soil organic C pools and fluxes, in part because sites varying in these characteristics also typically vary in vegetation and climate.&lt;/p&gt;&lt;p&gt;Here we leveraged the high-altitude alpine pastures of the Nivolet Critical Zone and Ecosystem Observatory, Gran Paradiso National Park (Italy) to examine biotic and abiotic dynamics and controlling factors of organic C and weathering under different topographic positions and geologic substrates in a small localized mountainous region. Soil profiles were sampled across a range of parent materials deposited after the Last Glacial Maximum, including gneiss glacial till, carbonate and calcschist/gneiss colluvium, and gneiss/carbonate/calcschist alluvium across ridgetop, midslope and footslope topographic positions. Organic C, C stable isotopes, major and trace element content, particle size distribution, and pH reveal how parent material and landscape position govern soil C storage and development. Even under the cold climate, limited season with liquid water, young-age deglaciated context, soils have developed incipient spodic horizons and calcschist clasts appears completely weathered in place.&lt;/p&gt;&lt;p&gt;Alkali and alkaline earth elements exhibit chemical depletion throughout the profiles, whereas in some profiles phosphorus concentrations reflects nutrient uplift processes (i.e., accumulating at the top of the profile and depleted in mid-horizons) likely driven by &amp;#8220;biotic&amp;#8221; cycling. Phosphorus is relatively high in uppermost horizons at carbonate and glacial sites, but is quite low in gneiss, even though TOC is relatively high, suggesting that plants underlain by gneiss are able to generate organic compounds with lower P availability. Though rooting depth distributions exhibit linear declines with depth, contrary the typically observed exponential decay behavior, our data suggest that roots serve as important biotic weathering agents prompting rapid soil development. All profiles have high organic carbon content at the surface, but&lt;/p&gt;&lt;p&gt;are twice as high in the footslope Gneiss profile as in the midslope Glacier and Carbonate profiles and in the floodplain Alluvial profile.&lt;/p&gt;&lt;p&gt;These data, in conjunction with microbial analysis and geochemical variation, suggest that biota are key agents promoting the observed high degree of soil development in these high altitude ecosystems. We demonstrate how in the early stages of soil development abiotic and biotic factors influence soil weathering and C storage across different parent material and topography.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Adhikari, K. and Hartemink, A. E.: Linking soils to ecosystem services &amp;#8211; A global review, Geoderma, 262, 101&amp;#8211;111, 2016&lt;/p&gt;

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