scholarly journals Mars sedimentary rock erosion rates constrained using crater counts, with applications to organic-matter preservation and to the global dust cycle

Icarus ◽  
2017 ◽  
Vol 286 ◽  
pp. 212-222 ◽  
Author(s):  
Edwin S. Kite ◽  
David P. Mayer
Keyword(s):  
Organic Matter ◽  
Sedimentary Rock ◽  
Erosion Rates

Do public works decrease farmers' soil degradation? Labour income and the use of fertilisers in India's semi-arid tropics

2002 ◽  
Vol 7 (3) ◽  
pp. 487-506 ◽  
Author(s):  
Marrit van den Berg
Keyword(s):  
Organic Matter ◽  
High Risk ◽  
Soil Degradation ◽  
Public Works ◽  
Farm Income ◽  
Risk Environment ◽  
Erosion Rates ◽  
Strong Relation ◽  
Fertiliser Use ◽  
Semi Arid

This paper investigates the possibility of using public works to stimulate farmers' fertiliser use in India's SAT. Inadequate replenishment of removed nutrients and organic matter has reduced fertility and increased erosion rates. Fertiliser use, along with other complementary measures, can help reverse this process, which ultimately leads to poverty, hunger, and further environmental degradation. In a high-risk environment like India's SAT, there may be a strong relation between off-farm income and smallholder fertiliser use. Farmers can use the main source of off-farm income, wage income, to manage risk as well as to finance inputs. Consequently, the introduction of public works programmes in areas with high dry-season unemployment may affect fertiliser use. This study confirms the relevance of risk for decisions regarding fertiliser use in two Indian villages. Nevertheless, governments cannot use employment policies to stimulate fertiliser use. Public works even decrease fertiliser use in the survey setting.

Carbone organique: indicateur potentiel de paléoenvironnements; deux exemples

1981 ◽  
Vol 18 (12) ◽  
pp. 1838-1849 ◽  
Author(s):  
R. Bertrand ◽  
Y. Héroux
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Sedimentary Rock ◽  
Depositional Environment ◽  
Statistical Processing ◽  
Depositional Environments ◽  
The Other ◽  
Early Paleozoic

The paleoenvironment of deposition and the total organic carbon (TOC) content of two sedimentary rock sequences are studied. One has a Cenozoic age and is located on the Labrador shelf; the other is early Paleozoic and is found in the St. Lawrence Lowlands. In both sequences, variations in the paleoenvironments correspond to changes in the TOC content, despite important differences between them (age, tectonic and general paleogeographic contexts, lithologies, nature of the organic matter).A statistical processing of the data is used in order to show this parallelism between the paleoenvironment and the TOC content. In both cases, the higher the TOC content, the greater is the distance of the depositional environment from the shore. This result is in agreement with the conclusions of many other authors. This method may be very useful for detecting bathymetric variations in depositional environments, especially in monotonous sequences.

scholarly journals Organic matter of sediments of South Chukotka

2020 ◽  
Vol 157 ◽  
pp. 02016
Author(s):  
Boris Aparin ◽  
Alexander Grabovsky ◽  
Elena Sukhacheva ◽  
Elena Mingareeva ◽  
Svetlana Janson ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sedimentary Rock ◽  
High Pressures ◽  
Soil Formation ◽  
Microbial Decomposition ◽  
Silicon Compounds ◽  
Weathering Processes ◽  
Colloidal Form ◽  
Early Paleocene ◽  
High Pressures And Temperatures

The article discusses data on paleosol, mineralogy, and paleobotany obtained as a result of studying material collected from the Maastricht-Early Paleocene sediments of the Tanyurer Formation of South Chukotka. The burial of organic matter in the sedimentary rock of the Tanyurer Formation is associated with deflationary processes during the period of activation of volcanic activity. On the drained volcanic plateau of soil formation, a sod humus-accumulative process prevailed under the steppe vegetation. Humic substance dispersed in sedimentary rock was represented by a group of humins resistant to microbial decomposition. As a result of exposure to high pressures and temperatures, the colloidal form of humus was transformed into kerogen. Organic compounds (cellulose, lignin) in the plant tissue of buried tree trunks were replaced by silicon compounds. Weathering processes have affected the thin surface layer of dense sedimentary rock. Under the influence of the temperature and humidity gradient, loosening of loose rock and disintegration of clots of colloidal forms of humus occurred.

Soil characteristics and erosion in the UNESCO Geopark Estrela, Portugal.

2021 ◽  
Author(s):  
Gerald Raab ◽  
Wasja Dollenmeier ◽  
Dmitry Tikhomirov ◽  
Markus Egli ◽  
Gonçalo Vieira ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Erosion ◽  
Slope Angle ◽  
Organic Matter Content ◽  
Soil Characteristics ◽  
Natural Conditions ◽  
Soil Material ◽  
Erosion Rates ◽  
Weathering Degree ◽  
Weathering Indices

<p>In Europe, a high soil erosion risk is modelled for the Mediterranean area such as the Iberian Peninsula (e.g., EEA, 2009), while actual field data often lacks behind. Here we present the first <sup>239+240</sup>Pu soil erosion results (last ~60 years) in the UNESCO Geopark Estrela, Portugal. We investigated soils in a former vastly glaciated and a non-glaciated area. We hypothesized that erosion rates in relatively young areas (max. about 16–20 kyr) will be distinctly higher than in old areas (several 100 kyr). We assumed that soil structure, organic matter and weathering degree in younger (natural) soils are still less favourable and do not yet protect efficiently enough soils from erosion. Besides soil erosion, we explored the weathering degree of the soil material using chemical weathering indices, determined the soil surface age using meteoric <sup>10</sup>Be and looked at a broad set of physico-chemical soil characteristics of these two landscape settings.</p><p>A glimpse of our first Plutonium results indicates that the differences between these two settings are rather minor. Soil erosion rates in these natural conditions (Geopark) predominantly depend on slope. With increasing slope angle, a maximum soil erosion rate of ~1600 [t km<sup>-2</sup> yr<sup>-1</sup>] is reached. Not surprisingly, the age estimates of the soils within the formerly glaciated area confirmed the start of formation after the beginning of ice-decay. The formerly glaciated area is depleted in C and N compared to the never glaciated area. In the never glaciated area, a higher soil weathering degree is found by multiple weathering indices and an overall lower SiO<sub>2</sub> content. Although past glacial activities rejuvenated the soil material (expressed by a lower weathering degree) and affected the soil organic matter content, soil erosion susceptibility does not seem to be higher compared to never glaciated areas. Under natural conditions, a quasi-steady state with respect to soil erosion seems to be reached fairly before 20 kyrs.</p>

Effects of oxidative weathering on the composition of organic matter in coal and sedimentary rock

2015 ◽  
Vol 81 ◽  
pp. 8-19 ◽  
Author(s):  
Shuji Tamamura ◽  
Akio Ueno ◽  
Noritaka Aramaki ◽  
Hiroyuki Matsumoto ◽  
Kagemi Uchida ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sedimentary Rock

scholarly journals Mapping Soil Erosion Sensitive Areas in Organic Matter Amended Soil Associations in the Ntabelanga area, Eastern Cape Province, South Africa

2020 ◽  
Vol 24 (9) ◽  
pp. 1693-1702
Author(s):  
Cosmas Parwada ◽  
Johan van Tol
Keyword(s):  
Organic Matter ◽  
Soil Erosion ◽  
Conservation Priorities ◽  
Rainfall Erosivity ◽  
Soil Association ◽  
Erosion Rates ◽  
R Factor ◽  
K Factor ◽  
Soil Erosion Rates ◽  
Shallow Soils

The study aims to map areas sensitive to erosion by water and rainfall erosivity after addition of organic matter (OM) in highly unstable soils. A soil association map was created using digital soil mapping methodology. Soil samples from six soil associations were incubated and analysed for several soil erodibility measures and inferred to the soil association map. Soil stabilization against soil erosion by use of OM was evaluated for 30 weeks under two simulated rainstorms, intermittent rainstorms (IR) and single rainstorm (SR). Rainfall erosivity (R-factor) was calculated from theduration of a rainstorm and the total amount of rainfall received under rainfall simulations. Erodibility factor (K-factor) was estimated using the soil OM content and texture. Largest area (40%) was covered by shallow soils and K-factor range of 0.0693-0.0778 t.ha.hha-1MJ-1mm-1. Largest (60.2%) area had a structural stability index of 0.8 and 42.7% of the area was covered by a dispersion ratio value range of 0.65-0.70. The area size with erosion rates of > 15 t/ha/yr was drastically reduced from 1 to 8 weeks after OM application thereafter gradually increased under both IR and SR.  Soil erosion rates of < 5 t-1 ha-1 yr-1 and > 15 t-1 ha-1 yr-1 were most and least observed respectively under both storms. R-factor was higher under IR than SR and the smallest areas with soil erosion rates of > 15 t-1 ha-1 yr-1 contributed most to the lost soil. Organic matter confers soil resistance to erosion up to a certain period before losing its effectiveness. The study provided first assessment of erosion dynamics, basis for identifying  conservation priorities which may be applicable in similar areas. Keywords: Erosivity, planning, rainstorm, soil conservation, soil degradation

scholarly journals Thermobaric depth settings of sedimentary rock basins and their fluid dynamics: Сommunication 2. Superhigh pressures and mud volcanoes

2019 ◽  
Vol 1 (1) ◽  
pp. 44-59
Author(s):  
V. N. Kholodov
Keyword(s):  
Fluid Dynamics ◽  
Organic Matter ◽  
Volcanic Activity ◽  
Sedimentary Rock ◽  
Oil And Gas ◽  
Mud Volcanoes ◽  
Oil And Gas Fields ◽  
Tectonic Faults ◽  
Gas Fields

The article discusses the patterns of placement of mud volcanoes, their spatial connection with tectonic faults, anticlinal uplifts, oil and gas fields. The connection of mud volcanic activity with ultrahigh pressures arising in the clay strata of the stratisphere as a result of phase transformations of clay minerals and organic matter is argued. The role of earthquakes in the formation of fractured clays, increasing their permeability and the formation of mud crates is emphasized. On the example of the mud volcano Aligula (Turkmenistan), the processes of dilution of sandstones and clays, the formation of volcanic mud-crates are considered.

scholarly journals Erosion and sediment enrichment ratio in volcanic soils

2020 ◽  
Author(s):  
Ludmila La Manna ◽  
César Mario Rostagno ◽  
Manuela Tarabini ◽  
Federico Gomez ◽  
Ana Navas
Keyword(s):  
Organic Matter ◽  
Soil Erosion ◽  
Rainfall Simulation ◽  
Enrichment Ratio ◽  
Drop Diameter ◽  
Volcanic Soils ◽  
Close Link ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Soil Losses

&lt;p&gt;Patagonian Andean region is widespread affected by soil degradation and erosion processes. The subhumid sector, which corresponds to the transition (ecotone) between the Andean forests and the Patagonian steppe, has suffered the highest human pressure and overgrazing, accelerating the soil erosion processes.&lt;/p&gt;&lt;p&gt;Near Esquel town (Subhumid sector of Chubut province, Argentina), where soils are mainly developed from volcanic ashes, erosion studies based on fallout radionuclides (Caesium-137) and simulated rainfalls were performed. Studies based on Caesium-137 showed that soil losses in the last 50 years were higher than 30 m&lt;sup&gt;3&lt;/sup&gt; ha&lt;sup&gt;-1&lt;/sup&gt; year&lt;sup&gt;-1&lt;/sup&gt; under different land uses.&lt;/p&gt;&lt;p&gt;Rainfall simulation experiments, carried out under the same conditions (Rain fall intensity: 100 mm h&lt;sup&gt;-1&lt;/sup&gt; for 30 minutes; Drop diameter: 2.5 mm; Drop velocity: 5.3 m s&lt;sup&gt;-1&lt;/sup&gt;) showed that erosion rates are highly affected by land use. Potential erosion rates in degraded rangelands varied between 143 and 750 g m&lt;sup&gt;-2&lt;/sup&gt;, depending on soil characteristics (such as texture and presence of non-crystalline materials), soil cover and slope. In mature exotic conifer afforestations, with soil completely covered by litter, soil erosion was negligible, varying between 0 and 10 g m&lt;sup&gt;-2&lt;/sup&gt;. Erosion rates increased both in young afforestations with open canopies (8 a 44 g m&lt;sup&gt;-2&lt;/sup&gt;), and in mature afforestations where fresh litter and duff layers were removed (35 a 200 g m&lt;sup&gt;-2&lt;/sup&gt;).&lt;/p&gt;&lt;p&gt;In the different studied systems, soil losses involved not the detachment of individual particles, but of soil micro aggregates rich in organic matter. Sediments enrichment ratio was always higher than 1, varying between 1.2 and 1.8. These results show that the sediments were enriched with organic matter, as compared to the contributing soils, indicating its selective removal. The erosion studies performed evidence the high erodibility of volcanic soils when their cover is lost, and the close link between erosion and carbon losses in these systems.&lt;/p&gt;

scholarly journals Salinity Constraints on Subsurface Archaeal Diversity and Methanogenesis in Sedimentary Rock Rich in Organic Matter

2007 ◽  
Vol 73 (16) ◽  
pp. 5387-5387 ◽  
Author(s):  
Patricia J. Waldron ◽  
Steven T. Petsch ◽  
Anna M. Martini ◽  
Klaus Nüsslein
Keyword(s):  
Organic Matter ◽  
Sedimentary Rock ◽  
Archaeal Diversity
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