Weathering, Soil, and the Minerals in Wine

2018 ◽  
Author(s):  
Alex Maltman
Keyword(s):  
William Wordsworth ◽  
Chemical Weathering ◽  
Building Stone ◽  
Higher Plant ◽  
Terra Rossa ◽  
Bare Rock ◽  
Iron Minerals ◽  
Rock Fragments ◽  
Fresh Surface ◽  
Outer Coating

Weathering of rocks is the crucial first step in making vineyards possible. For where the debris produced by weathering—the sediment we met in Chapter 5—becomes mixed with moist humus, it will be capable of supporting higher plant life. And thus we have soil, that fundamental prerequisite of all vineyards, indeed of the world’s agriculture. So how does this essential process of weathering come about? Any bare rock at the Earth’s surface is continually under attack. Be it a rocky cliff, a stone cathedral, or a tombstone, there will always be chemical weathering—chemical reactions between its surface and the atmosphere A freshly hewn block of building stone may look indestructible, but before long it will start to look a bit discolored and its surface a little crumbly. We are all familiar with an analogy of this: a fresh surface of iron or steel reacting with moisture and oxygen in the air to form the coating we call rust. In his “Guide to the Lakes” of England, William Wordsworth put the effects of weathering far more picturesquely: “elementary particles crumbling down, over-spread with an intermixture of colors, like the compound hues of a dove’s neck.” A weathered rock is one that is being weakened, broken down. The rock fragments themselves are further attacked, which is why stones in a vineyard often show an outer coating of discolored material, sometimes referred to as a weathering rind (Figure 9.1; see Plate 22). If the stone is broken open, it may show multiple zones of differing colors paralleling the outer surface of the fragment and enclosing a core of fresh rock. Iron minerals soon weather to a powdery combination of hematite, goethite, and limonite, and the rock takes on a reddish-brown, rusty-looking color. The great example of such weathering in viticulture is the celebrated terra rossa, but the rosy soils in parts of Western Australia and places further east such as McLaren Vale and the Barossa Valley are also due to iron minerals. Several Australian wines take their names from this “ironstone.”

scholarly journals Geochemical Implications of Rare Earth Elements in Terra Rossa in Tropical Karst Area: A Case Study in Northern Vietnam

2020 ◽  
Vol 10 (3) ◽  
pp. 858 ◽  
Author(s):  
Zhang Liankai ◽  
Ji Hongbing ◽  
Wang Shijie ◽  
Luo Gang ◽  
Liu Xiuming ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Chemical Weathering ◽  
Karst Area ◽  
Oxidation Condition ◽  
Terra Rossa ◽  
Northern Vietnam ◽  
Material Sources ◽  
Karst Areas ◽  
Tropical Karst

Research on weathered crusts on carbonate rock is essential for paleoenvironmental studies in karst areas. Terra rossa, widely distributed in tropical karst areas, has not been studied in terms of its material sources and geochemistry. Two typical terra rossa profiles on dolomite (SC profile located at Sang Cai, Hoa Binh province) and limestone (TG profile located at Tong Gia, Lao Cai province) in Northern Vietnam were selected to examine the geochemical characteristics and the evolutionary processes of rare earth elements (REEs). Chondrite and bedrock normalized patterns indicated that these two profiles are in situ weathering crusts, meaning they are the residual material remaining after chemical weathering of the lower carbonate rocks. The average value of total REE in the SC profile is 381.19 ppm, which is 30 times higher than the bedrock. In the TG profile, the value is 386.26 ppm, 13 times higher than the bedrock. Compared with the profiles in nearby subtropical areas in Southeast China, the REE enrichment coefficients of terra rossa in Northern Vietnam are much higher. The REE depletion was also different between the SC and TG profiles. The light and heavy REE fractionations in the SC profile are higher than in the TG profile. Paleoclimate inversion analysis shows that the SC profile experienced a stable oxidation condition, whereas the TG profile was subjected to several reducing environments since a weathering crust formed.

Weathering profiles, mass-balance analysis, and rates of solute loss: Linkages between weathering and erosion in a small, steep catchment

2002 ◽  
Vol 114 (9) ◽  
pp. 1143-1158 ◽  
Author(s):  
Suzanne Prestrud Anderson ◽  
William E. Dietrich ◽  
George H Brimhall
Keyword(s):  
Chemical Weathering ◽  
Dynamic Equilibrium ◽  
Solid Phase ◽  
Water Flux ◽  
Solute Flux ◽  
Denudation Rate ◽  
Rock Fragments ◽  
Denudation Rates ◽  
Uplift Rates ◽  
Balance Analysis

Abstract In a headwater catchment in the Oregon Coast Range, we find that solid-phase mass losses due to chemical weathering are equivalent in the bedrock and the soil. However, the long-term rate of mass loss per unit volume of parent rock is greater in the soil than in the rock. We attribute this finding to the effects of biotic processes in the soil and to hydrologic conditions that maximize contact time and water flux through the mineral matrix in the soil. This result stems both from earlier work in which we demonstrated that rock and soil contribute equally to the solute flux and from arguments presented here that the basin is in dynamic equilibrium with respect to erosion and uplift. The silica flux of 10.7 ± 7.1 t·km−2·yr−1 from the basin is several times larger than the flux from older soils elsewhere, but comparable to the flux from sites with similar physical erosion rates. This result argues that physical denudation or uplift rates play an important role in setting the chemical denudation rate. Physical processes appear to influence chemical-weathering rates in several ways. First, they limit chemical evolution by removing material, thus setting the residence time within the weathered rock and the soil. Second, bioturbation mixes rock fragments into the more reactive soil and maintains high soil porosity, allowing free circulation of water. Because the weathering in the soil is more intense than in the rock, we argue that the chemical denudation rate will diminish where uplift rates—and, hence, physical-denudation rates—are great enough to lead to a bedrock-dominated landscape. Chemical denudation rates will increase with physical-denudation rates, but only as long as the landscape remains mantled by soil.

scholarly journals Proposal for geological classification and nomenclature of soils: both genetic-descriptive and compositional-mineralogical

2020 ◽  
Vol 42 (1) ◽  
pp. 81-97
Author(s):  
Luis Enrique Cruz-Guevara ◽  
Luis Felipe Cruz-Ceballos ◽  
Gladys Marcela Avendaño-Sánchez ◽  
Mario García-González
Keyword(s):  
Chemical Weathering ◽  
Soil Classification ◽  
Original Structure ◽  
Rock Fragments ◽  
Sedimentary Deposits ◽  
Geological Processes ◽  
Detailed Classification ◽  
Clay Layers ◽  
Physical And Chemical

Numerous systems with detailed classification of soil are in existence. Most of them are based on a variety of complex criteria, such as material type and properties like the amount of organic material, presence of clay layers, and the presence of oxidation or reduction iron-rich horizons, as well as depositional characteristics, its landform morphology and depositional formation processes. Many of these have been developed for use in fields such as agronomy and geotechnics. This paper focuses on the classification of the soil by determining its materials, their origin and the geological processes that shape them, following these basic assumptions: (1) The soil initially comes from the weathering of a parent substrate that can be either sedimentary deposits (for example, alluvial or fluvial) or of any type of rock (igneous, metamorphic or sedimentary), (2) the parent substrate structure is composed by original sequential facies (e.g. foliation, igneous cumulates or stratigraphic intercalation of sedimentary layers), (3) the physical and chemical weathering and the biogenic activity and productivity processes that occur in the soil modify both the original structure and the constituents of the parental substrate, resulting in the formation of new materials, the conservation of others, and the overprint of the sequential facies of the soil (horizons A, B and C) developed on the original parental sequential facies, additionally (4) some materials will be lost from the system and others will be incorporated into it. Finally, a strictly compositional-mineralogical classification of soil is also proposed, which corresponds essentially to the main groups of minerals: silicates, carbonates, phosphates, oxides and hydroxides, sulfates, organic rich matter, nitrates, sulphides, borates, native elements and halides, named in sedimentology as monomaterials, plus the polymaterials or rock fragments (RF). This classification offers an advantage when examining materials that are not genetically linked to the parent substrates, making each soil profile unique, by highlighting the role played by the parental materials in this process. This classification is intended to complement, but not replace any existing soil classification

Boreal Vegetation and Soil Carbon Dynamics in Response to a Changing Climate and Soil Variables

2021 ◽  
Author(s):  
John Galbraith ◽  
Pavel Krasilnikov ◽  
Cornelia Rumpel
Keyword(s):  
Boreal Forest ◽  
Vegetation Change ◽  
Precipitation Amount ◽  
Carbon Dynamics ◽  
The Arctic ◽  
Higher Plant ◽  
Rock Fragments ◽  
Changing Climate ◽  
Soil Variables ◽  
Air Temperatures

<p>Many soils in the Boreal forest regions of the Arctic store very large amounts of carbon in the active layer above permafrost, and store significant amounts of carbon within the permafrost. Soils that are well drained, high in rock fragments, shallow to rock or rubble, or covered with ice are exceptions. No other region on Earth stores more carbon on average than the Arctic regions, especially in wetlands. However, changes in vegetation and soil are expected under warming climates. Research questions have arisen about future changes in vegetation and net carbon flux as soil and air temperatures climb, as precipitation amount and type changes, and as the growing season lengthens. A review of recent literature will be conducted to look at effects of vegetation change and annual carbon dynamics in Boreal forest and wetland soils under warming climates. Environmental variables such as soil temperature, hydrology, microbial and higher plant growth, digestibility of young and old carbon, fire, location zone, extent and type of permafrost thaw slow vs sudden collapse), and N and P nutrient balances will affect carbon stocks in addition to changing climate.</p>

scholarly journals Assessing the weathering of granitic stones on historical urban buildings by geochemical indices

2016 ◽  
Vol 20 (3) ◽  
pp. 1 ◽  
Author(s):  
Jorge Sanjurjo-Sánchez ◽  
Carlos Alves ◽  
Juan Ramón Vidal Romani
Keyword(s):  
Chemical Weathering ◽  
Building Materials ◽  
Building Stone ◽  
Urban Environments ◽  
Granitic Rocks ◽  
Chemical Components ◽  
Original Structure ◽  
Salt Weathering ◽  
Weathering Rates ◽  
Weathering Indices

Weathering involves important processes that alter the original structure, texture and chemical components of rocks and minerals. Bulk changes produced by weathering in granitic rocks have been studied by several methods, including chemical weathering indices. They are based on the assumption that some ions are more easily leached from minerals in relation to others. Such methods have also been briefly tested on building stone but not in urban environments, where fast stone weathering rates are typically observed, mainly due to interaction of minerals with several pollutants and where other specific processes, such as salt weathering, can occur. The aim of this work is to discuss the use of weathering indices in the study of weathering rates on granitic stones applied in four historical buildings of an urban area. Results suggest that some factors can cause scatter of results in the relation indices vs. exposition age in the built environment, namely previous weathering degree in rock massifs and the quarry, different orientation of façades and different exposure to urban pollutants. Indices that consider some highly mobile cations that are present in other building materials (namely Ca that is related to leaching from mortar joints) should be avoided due to the uptake of such elements by the stone pores or used to assess this some types of weathering. Moreover, the use of some indices shows more reliable results. Evaluación de la meteorización de rocas graníticas en edificios históricos urbanos por medio de indices geoquímicos  ResumenLa meteorización implica importantes procesos que alteran la estructura, textura y componentes químicos originales de las rocas y minerales. Los cambios producidos por la meteorización en rocas graníticas han sido estudiados por varios métodos, incluyendo los índices de meteorización química. Éstos se basan en la suposición de que algunos iones son lavados de los minerales más fácilmente que otros. Tales métodos también se han probado, aunque en pocos casos, en rocas de edificios, pero no de ambientes urbanos, en donde se han observado típicamente elevadas tasas de meteorización, principalmente por la interacción de los minerales con varios compuestos contaminantes y en dónde otros procesos específicos, tales como la erosión por sales, pueden producirse. El objetivo de este trabajo es discutir el uso de índices de meteorización en el estudio de las tasas de meteorización de rocas usadas en cuatro edificios históricos de un área urbana. Los resultados sugieren que algunos factores pueden causar la dispersión de los resultados obtenidos a través de los índices en relación al tiempo de exposición en el ambiente construido, principalmente por el grado de meteorización previo de la roca en los macizos rocosos y en la cantera, la orientación de las fachadas y la diferente exposición a compuestos contaminantes. Los índices que consideran algunos cationes altamente móviles que están presentes en otros materiales de construcción (principalmente el Ca que se relaciona con la meteorización de morteros en las juntas) deben ser evitados debido a que penetran en los poros de las rocas de edificios o deben ser usados para evaluar algunos tipos de meteorización. Por otra parte, el uso de algunos índices muestra resultados más fiables.

A combined petrographical—geochemical provenance study of the Newland Formation, Mid-Proterozoic of Montana

1992 ◽  
Vol 129 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Jürgen Schieber
Keyword(s):  
Chemical Weathering ◽  
Source Area ◽  
Source Rocks ◽  
Arid Climate ◽  
Provenance Study ◽  
Rock Fragments ◽  
Crystalline Dolomite ◽  
Chemical Index Of Alteration ◽  
Granitoid Gneisses ◽  
Semi Arid

AbstractA provenance study was conducted on the Mid-Proterozoic Newland Formation, in which petrographical features of sandstones and geochemical characteristics of shales were integrated to arrive at an internally consistent interpretation.Sandstones of the Newland Formation are typically arkosic sands and arkoses with very-well-rounded quartz and feldspar grains and only minor amounts of extrabasinal rock fragments. The predominant feldspar types are K-spar and microcline, feldspar grains are smaller than quartz grains, and feldspars show little alteration due to weathering. Detrital modes of Newland sandstones (QFL diagrams) indicate that they were derived from a stable cratonic source. These petrographical features imply a source area dominated by granites and granitoid gneisses, semi-arid to arid climate, tectonic quiescence, and overall peneplain conditions.Shales of the Newland Formation are dominated by illite, quartz silt, and fine crystalline dolomite. They have small La/Th rations, relatively large Hf contents, and small contents of Cr, Co, and Ni, all indicative of derivation from crust of granitic composition. Small Tio2/Al2O3ratios also suggest source rocks of granitic composition. The average chemical index of alteration (CIA) for Newland shales is 71.8, which in light of the probable granitoid source indicates modest amounts of chemical weathering. Relatively large SiO2contents and large K2O/Na2O ratios reflect derivation from stable cratonic areas and tectonic quiescence.Thus, in general, the petrography of sandstones and geochemistry of shales provides the same provenance clues for the Newland Formation. One notable discrepancy between the two approaches is that the sandstones indicate an arid to semi-arid climate with very minor chemical weathering, whereas the CIA of the shales indicates at least modest amounts of chemical weathering. This indicates on one hand the need to better calibrate the CIA with a large variety of muds from modern climatic settings, and on the other hand the possibility that this discrepancy is due to transport segregation.

The relation between the terra rossa and the carbonate-free residue of the underlying limestones and dolostones in Apulia, Italy

Clay Minerals ◽  
1988 ◽  
Vol 23 (4) ◽  
pp. 439-446 ◽  
Author(s):  
M. Moresi ◽  
G. Mongelli
Keyword(s):  
Carbonate Rocks ◽  
Biogenic Silica ◽  
Carbonate Rock ◽  
Chemical Weathering ◽  
Marked Decrease ◽  
Parent Material ◽  
Terra Rossa ◽  
Characteristic Distribution ◽  
Statistical Comparison ◽  
Geochemical Pattern

AbstractA statistical comparison has been made of chemical data for terra rossa and carbonate-free residues of Cretaceous limestones and dolostones in Apulia in order to evaluate the hypothesis that the terra rossa is a product of weathering of the underlying carbonate rocks. It has been shown that the differences in chemical composition between the residue of the carbonate rocks and the terra rossa are consistent with the former being the parent material of the latter. The transformation from carbonate rock residue to terra rossa was governed mainly by chemical weathering which produced a marked decrease in the K2O/Al2O3 (i.e. illite/kaolinite) ratio. The geochemical pattern of the Apulian terra rossa has been influenced by sedimentary processes which have led to a characteristic distribution of mineralogical components and a moderate contamination by biogenic silica.

Stabilizing pyritic material

1989 ◽  
Vol 4 ◽  
pp. 244-248 ◽  
Author(s):  
Donald L. Wolberg
Keyword(s):  
Significant Contribution ◽  
Organic Materials ◽  
Sedimentary Rocks ◽  
Iron Sulfides ◽  
Decomposition Products ◽  
Iron Minerals ◽  
Pyrite Formation ◽  
Organic Sediments ◽  
Freshwater Environments

The minerals pyrite and marcasite (broadly termed pyritic minerals) are iron sulfides that are common if not ubiquitous in sedimentary rocks, especially in association with organic materials (Berner, 1970). In most marine sedimentary associations, pyrite and marcasite are associated with organic sediments rich in dissolved sulfate and iron minerals. Because of the rapid consumption of sulfate in freshwater environments, however, pyrite formation is more restricted in nonmarine sediments (Berner, 1983). The origin of the sulfur in nonmarine environments must lie within pre-existing rocks or volcanic detritus; a relatively small, but significant contribution may derive from plant and animal decomposition products.

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