scholarly journals Carbon Isotopic Signature and Organic Matter Composition of Cenomanian High-Latitude Paleosols of Southern Patagonia

Geosciences ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 378
Author(s):  
Augusto Nicolás Varela ◽  
María Sol Raigemborn ◽  
Patricio Emmanuel Santamarina ◽  
Sabrina Lizzoli ◽  
Thierry Adatte ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Isotope ◽  
Southern Hemisphere ◽  
Isotopic Signature ◽  
Climatic Conditions ◽  
Organic Carbon Content ◽  
Oceanic Anoxic Event ◽  
Palynological Data ◽  
Stable Pattern ◽  
Southern Patagonia

The Cenomanian Mata Amarilla Formation (MAF) in southern Patagonia (~55° S paleolatitude, Austral-Magallanes Basin, Argentina) is composed mainly of stacked fluvial deposits with intercalated paleosols, which document Cenomanian environments at high-paleolatitudes in the Southern Hemisphere. We performed a multiproxy study of the paleosols and sediments of the MAF in order to (1) understand the composition of the soil- and sediment-derived organic matter (OM), (2) apply carbon isotope stratigraphy as a tool to correlate patterns obtained from the MAF with existing marine and non-marine δ13Corg records worldwide, and (3) investigate the relationship between variations in spore-pollen assemblages of the MAF and the climatic conditions prevailing in the Cenomanian Southern Hemisphere. An integrated dataset was generated, including total organic carbon content, Rock-Eval pyrolysis data, stable isotope (δ13Corg) composition, and palynological data, combined with published paleosol-derived mean annual temperatures and mean annual precipitations. The results indicated that the OM preserved in the MAF paleosols allowed its use as a chemostratigraphic tool. The MAF δ13Corg curve showed the rather stable pattern characteristic for the Early to Late Cenomanian interval. The absence of the major positive carbon isotope excursion associated with oceanic anoxic event 2 provided an upper limit for the stratigraphic range of the MAF. The palynological data suggested the development of fern prairies during warmer and moister periods at the expense of the background gymnosperm-dominated forests. Overall, the multiproxy record provided new insights into the long-term environmental conditions during the Cenomanian in the high latitudes of the Southern Hemisphere.

A carbon-isotope perturbation at the Pliensbachian–Toarcian boundary: evidence from the Lias Group, NE England

2009 ◽  
Vol 147 (2) ◽  
pp. 181-192 ◽  
Author(s):  
KATE LITTLER ◽  
STEPHEN P. HESSELBO ◽  
HUGH C. JENKYNS
Keyword(s):  
Organic Matter ◽  
Carbon Isotope ◽  
Similar Pattern ◽  
Oceanic Anoxic Event ◽  
European Section ◽  
Extinction Event ◽  
Anoxic Event ◽  
Global Extinction ◽  
Isotope Record ◽  
Bulk Organic Matter

AbstractA perturbation in the carbon-isotope record at the time of the Pliensbachian–Toarcian boundary (~ 184 Ma) in the Early Jurassic is reported, based on new data from Yorkshire, England. Two sharp δ13Corg negative excursions, each with a magnitude of ~ −2.5 ‰ and reaching minimum values of −28.5 ‰, are recorded in the bulk organic-matter record in sediments of latest Pliensbachian to earliest Toarcian age. A similar pattern of negative carbon-isotope excursions has been observed at the stage boundary in the SW European section at Peniche, Portugal in δ13Ccarbonate, δ13Cwood and δ13Cbrachiopod records. The isotopic excursion is of interest when considering the genesis and development of the later Toarcian Oceanic Anoxic Event (OAE), as well as the second-order global extinction event that spans the stage boundary. Furthermore, the isotope excursion potentially provides a chemostratigraphic marker for recognition of the stage boundary, which is currently achieved on the basis of different ammonite faunas in the NW European and Tethyan realms.

scholarly journals Record of Early Toarcian carbon cycle perturbations in a nearshore environment: the Bascharage section (easternmost Paris Basin)

2014 ◽  
Vol 6 (1) ◽  
pp. 1073-1100 ◽  
Author(s):  
M. Hermoso ◽  
D. Delsate ◽  
F. Baudin ◽  
L. Le Callonnec ◽  
F. Minoletti ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Carbon Isotope ◽  
Isotopic Signature ◽  
Oxygen Isotopic Composition ◽  
Black Shales ◽  
Positive Trend ◽  
Oceanic Anoxic Event ◽  
Carbon Isotope Excursion ◽  
Oxygen Isotopic ◽  
Global Nature

Abstract. In order to understand the significance of worldwide deposition of black shale facies in the Early Toarcian (~ 183 Ma), considerable attention has been drawn to this Early Jurassic sub-Stage over the last three decades. The discovery of a pronounced negative carbon isotope excursion (CIE) within the black shales disrupting the generally positive trend in carbon isotopes has stimulated many studies, particularly with a view to establish the local vs. global nature of this major geochemical phenomenon. Here we document the sedimentological and chemostratigraphic evolution of a proximal environment in the Luxembourgian sedimentary area, the so-called Gutland. At Bascharage, Lower Toarcian sediments record the isotopic signature of the Early Toarcian Oceanic Anoxic Event (OAE) by a pronounced positive trend that testifies for widespread anoxia. The expression of the carbon isotope perturbation in this section however, is unusual compared to adjacent NW European sections. A first −7 ‰ negative CIE, whose onset is recorded at the top of the tenuicostatum zone, can be assigned to the well-documented and potentially global T-CIE with confidence using the well-constrained ammonite biostratigraphic framework for this section. In this interval, facies contain only a limited amount of carbonate as a result of intense detrital supply in such a proximal and shallow environment. Stratigraphically higher in the section, the serpentinum zone records a subsequent CIE (−6 ‰) that is expressed by four negative steps, each being accompanied by positive shifts in the oxygen isotopic composition of carbonate. The preservation state of coccoliths and calcareous dinoflagellates in the second CIE is excellent and comparable to that observed in under- and overlying strata, so this cannot be an artefact of diagenesis. Considering the nature of this record, and the lack of such a pronounced event in the serpentinum zone in coeval sections in Europe, we hypothesise that this second CIE was caused by local factors. The geochemical record of carbonate with a relatively light carbon and relatively heavy oxygen isotopic composition is compatible with the so-called Küspert model, by which a CIE can be explained by an influx of 12C-rich and cold waters due to upwelling bottom water masses. With the ongoing effort of high-resolution studies of the Meso-Cenozoic eras, further CIEs are likely to be found, but it has to be remembered that their (global) significance can only be determined via an integrated sedimentological, mineralogical, micropalaeontological and geochemical approach.

scholarly journals Climate variability and ocean fertility during the Aptian Stage

2015 ◽  
Vol 11 (3) ◽  
pp. 383-402 ◽  
Author(s):  
C. Bottini ◽  
E. Erba ◽  
D. Tiraboschi ◽  
H. C. Jenkyns ◽  
S. Schouten ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Climatic Conditions ◽  
Low Fertility ◽  
Ontong Java Plateau ◽  
Direct Role ◽  
High Productivity ◽  
Oceanic Anoxic Event ◽  
Continental Runoff ◽  
Maximum Warming

Abstract. Several studies have been conducted to reconstruct temperature variations across the Aptian Stage, particularly during early Aptian Oceanic Anoxic Event (OAE) 1a. There is a general consensus that a major warming characterized OAE 1a, although some studies have provided evidence for transient "cold snaps" or cooler intervals during the event. The climatic conditions for the middle–late Aptian are less constrained, and a complete record through the Aptian is not available. Here we present a reconstruction of surface-water palaeotemperature and fertility based on calcareous nannofossil records from the Cismon and Piobbico cores (Tethys) and DSDP Site 463 (Pacific Ocean). The data, integrated with oxygen-isotope and TEX86 records, provide a detailed picture of climatic and ocean fertility changes during the Aptian Stage, which are discussed in relation to the direct/indirect role of volcanism. Warm temperatures characterized the pre-OAE 1a interval, followed by a maximum warming (of ~ 1.5–2 °C) during the early phase of anoxia under intense volcanic activity of the Ontong Java Plateau (OJP). A short-lived cooling episode interrupted the major warming, following a rapid increase in weathering rates. Nannofossils indicate that mesotrophic conditions were reached when temperatures were at their highest and OJP volcanism most intense, thus suggesting that continental runoff, together with increased input of hydrothermal metals, increased nutrient supply to the oceans. The latter part of OAE 1a was characterized by cooling events, probably promoted by CO2 sequestration during burial of organic matter. In this phase, high productivity was probably maintained by N2-fixing cyanobacteria, while nannofossil taxa indicating higher fertility were rare. The end of anoxia coincided with the cessation of volcanism and a pronounced cooling. The mid-Aptian was characterized by highest surface-water fertility and progressively decreasing temperatures, probably resulting from intense continental weathering drawing down pCO2. The lowest temperatures, combined with low fertility, were reached in the middle–late Aptian across the interval characterized by blooming of Nannoconus truittii. The prolonged cooling was followed by significant warming across the Aptian–Albian boundary. The data presented suggest that OJP activity played a direct role in inducing global warming during the early Aptian, whereas other mechanisms (weathering, deposition of organic matter) acted as feedback processes, favouring temporary cooler interludes.

scholarly journals An open marine record of the Toarcian oceanic anoxic event

2011 ◽  
Vol 3 (1) ◽  
pp. 385-410 ◽  
Author(s):  
D. R. Gröcke ◽  
R. S. Hori ◽  
J. Trabucho-Alexandre ◽  
D. B. Kemp ◽  
L. Schwark
Keyword(s):  
Organic Matter ◽  
Carbon Cycle ◽  
Carbon Isotope ◽  
Isotope Composition ◽  
Global Carbon Cycle ◽  
Open Ocean ◽  
Black Shales ◽  
Oceanic Anoxic Event ◽  
Anoxic Event ◽  
Global Carbon

Abstract. Oceanic anoxic events were time intervals in the Mesozoic characterized by widespread distribution of marine organic-rich sediments (black shales) and significant perturbations in the global carbon cycle. The expression of these perturbations is globally recorded in sediments as excursions in the carbon isotope record irrespective of lithology or depositional environment. During the Early Toarcian, black shales were deposited on the epi- and peri-continental shelves of Pangaea and these sedimentary rocks are associated with a pronounced (ca. 7‰) negative (organic) carbon isotope excursion (CIE) which is thought to be the result of a major perturbation in the global carbon cycle. For this reason, the Early Toarcian is thought to represent an oceanic anoxic event (the T-OAE). Associated with this event, there were pronounced perturbations in global weathering rates and seawater temperatures. Although it is commonly asserted that the T-OAE is a global event and that the distribution of black shales is likewise global, an isotopic and/or organic-rich expression of this event has as yet only been recognized on epi- and peri-continental Pangaean localities. To address this issue, the carbon isotope composition of organic matter (δ13Corg) of Early Toarcian cherts from Japan that were deposited in the open Panthalassa Ocean was analysed. The results show the presence of a major (>6‰) negative excursion in δ13Corg that, based on radiolarian biostratigraphy, is a correlative of the Early Toarcian negative CIE known from European epicontinental strata. Furthermore, a secondary ca. −2‰ excursion in δ13Corg is also recognized lower in the studied succession that, within the current biostratigraphical resolution, is likely to represent the excursion that occurs close to the Pliensbachian/Toarcian boundary and which is also recorded in European epicontinental successions. These results from the open ocean realm suggest that, in conjunction with other previously published datasets, these major Early Jurassic carbon cycle perturbations affected all active global reservoirs of the exchangeable carbon cycle (deep marine, shallow marine, atmospheric). An extremely negative δ13Corg value (−57‰) during the peak of the T-OAE is also reported, which suggests that the inferred open ocean mid-water oxygen minimum layer within which these sediments are thought to have been deposited was highly enriched in methanotrophic bacteria, since these organisms are the only plausible producers of such 12C-enriched organic matter.

scholarly journals Record of Early Toarcian carbon cycle perturbations in a nearshore environment: the Bascharage section (easternmost Paris Basin)

Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 793-804 ◽  
Author(s):  
M. Hermoso ◽  
D. Delsate ◽  
F. Baudin ◽  
L. Le Callonnec ◽  
F. Minoletti ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Carbon Isotope ◽  
Isotopic Signature ◽  
Oxygen Isotopic Composition ◽  
Black Shales ◽  
Positive Trend ◽  
Oceanic Anoxic Event ◽  
Carbon Isotope Excursion ◽  
Oxygen Isotopic ◽  
Global Nature

Abstract. In order to understand the significance of the worldwide deposition of black shale facies in the Early Toarcian (~ 183 Ma), considerable attention has been drawn to this Early Jurassic sub-stage over the last 3 decades. The discovery of a pronounced negative carbon isotope excursion (CIE) within the black shales disrupting the generally positive trend in carbon isotopes has stimulated many studies, particularly with a view to establish the local versus global nature of this major geochemical phenomenon. Here we document the sedimentological and chemostratigraphic evolution of a proximal environment in the Luxembourgian sedimentary area. At Bascharage, Lower Toarcian sediments record the isotopic signature of the Early Toarcian oceanic anoxic event (OAE) by a pronounced positive trend that testifies for widespread anoxia. The expression of the carbon isotope perturbation in this section, however, is unusual compared to adjacent NW European sections. A first −7‰ negative CIE, whose onset is recorded at the top of the tenuicostatum zone, can be assigned to the well-documented and potentially global Toarcian carbon isotope excursion (T-CIE) with confidence using the well-constrained ammonite biostratigraphic framework for this section. In this interval, facies contain only a limited amount of carbonate as a result of intense detrital supply in such a proximal and shallow environment. Stratigraphically higher in the section, the serpentinum zone records a subsequent CIE (−6‰) expressed as four negative steps, each being accompanied by positive shifts in the oxygen isotopic composition of carbonate. The preservation state of coccoliths and calcareous dinoflagellates in the second CIE is excellent and comparable to that observed in under- and overlying strata, so this cannot be an artefact of diagenesis. Considering the nature of this record, and the lack of such a pronounced event in the serpentinum zone in coeval sections in Europe, we hypothesise that this second CIE was caused by local factors. The geochemical record of carbonate with a relatively light carbon and relatively heavy oxygen isotopic composition is compatible with the so-called Küspert model, by which a CIE can be explained by an influx of 12C-rich and cold waters due to upwelling bottom water masses.

scholarly journals Soil fertility status and sweet potato cultivation in composted mounds under humid lowland tropical climatic conditions

2020 ◽  
Vol 17 (2) ◽  
pp. 144
Author(s):  
Patrick S. Michael
Keyword(s):  
Organic Matter ◽  
Sweet Potato ◽  
Sandy Loam ◽  
Soil Bulk Density ◽  
Climatic Conditions ◽  
Sandy Loam Soil ◽  
Organic Carbon Content ◽  
Loam Soil ◽  
Soil Fertility Status ◽  
Organic Matter Addition

<p>The importance of organic matter addition in composted mounds in terms of nutrients status, nutrient uptake, and environmental impact under different climatic conditions need to be studied. This study was conducted to assess the importance of Cogon grass materials addition as organic matter in composted mounds used for sweet potato cultivation on selected sandy loam soil properties under humid lowland, tropical climatic conditions. A replicated trial with four treatments with or without organic matter or sweet potato plants was set in a completely randomized design. After 6 months, soil samples were collected from two profiles in each treatment and analyzed for selected soil physiochemical properties. Data collected from each profile was pooled, averages taken, and statistically analyzed. The results showed organic matter addition increased water holding capacity and electrical conductivity, lowered soil bulk density, pH, and soil organic carbon content. Cultivation of sweet potato in soil with or without organic matter amendment, in general, depleted nitrogen, potassium, and magnesium contents and increased phosphorous availability. This study showed the addition of Cogon grass materials as organic matter in composted mounds has implications for the production of sweet potato in sandy loam soil in the tropics.</p>

scholarly journals Climate variability and relationship with ocean fertility during the Aptian Stage

2014 ◽  
Vol 10 (1) ◽  
pp. 689-738 ◽  
Author(s):  
C. Bottini ◽  
E. Erba ◽  
D. Tiraboschi ◽  
H. C. Jenkyns ◽  
S. Schouten ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
High Surface ◽  
Climatic Conditions ◽  
Low Fertility ◽  
High Fertility ◽  
Ontong Java Plateau ◽  
Direct Role ◽  
High Productivity ◽  
Oceanic Anoxic Event

Abstract. Several studies have been conducted to reconstruct temperature variations across the Aptian Stage, particularly during the Early Aptian Oceanic Anoxic Event (OAE)1a. There is a general consensus that a major warming characterized the OAE 1a, although some studies have provided evidence for transient "cold snaps" or cooler intervals during the event. The climatic conditions for the middle–late Aptian are less constrained, and a complete record through the Aptian is not available. Here we present a reconstruction of surface-water palaeotemperature and fertility based on calcareous nannofossil records from the Cismon and Piobbico cores (Tethys) and DSDP Site 463 (Pacific Ocean). The data, integrated with oxygen-isotope and TEX86 records, provide a detailed picture of climatic and ocean fertility changes during the Aptian Stage, which are discussed in relation to the direct/indirect role of volcanism. Warm temperatures characterized the pre-OAE 1a interval followed by a maximum warming (of ~2–3 °C) during the early phase of anoxia under intense volcanic activity of the Ontong Java Plateau (OJP). A short-lived (~35 ky) cooling episode interrupted the major warming, following a rapid increase of weathering rates. Nannofossils indicate that eutrophic conditions were reached when temperatures were at their highest and OJP volcanism most intense, thus suggesting that continental runoff, together with increased input of hydrothermal metals, increased nutrient supply to the oceans. The latter part of OAE 1a was characterized by cooling events, probably promoted by CO2 sequestration during burial of organic matter. In this phase, high productivity was probably maintained by N2-fixing cyanobacteria while nannofossil taxa indicating high fertility were rare. The end of anoxia coincided with the cessation of volcanism and a pronounced cooling. The mid-Aptian was characterized by high surface-water fertility and progressively decreasing temperatures, probably resulting from intense continental weathering drawing down pCO2. The lowest temperatures, combined with low fertility, were reached in the middle–late Aptian across the interval characterized by blooming of Nannoconus truittii. The data presented suggest that OJP activity played a direct role in inducing global warming during the early Aptian, whereas other mechanisms (weathering, deposition of organic matter) acted as feedback processes, favouring temporary cooler interludes.

scholarly journals An open ocean record of the Toarcian oceanic anoxic event

Solid Earth ◽  
2011 ◽  
Vol 2 (2) ◽  
pp. 245-257 ◽  
Author(s):  
D. R. Gröcke ◽  
R. S. Hori ◽  
J. Trabucho-Alexandre ◽  
D. B. Kemp ◽  
L. Schwark
Keyword(s):  
Organic Matter ◽  
Carbon Cycle ◽  
Carbon Isotope ◽  
Isotope Composition ◽  
Global Carbon Cycle ◽  
Open Ocean ◽  
Black Shales ◽  
Oceanic Anoxic Event ◽  
Anoxic Event ◽  
Global Carbon

Abstract. Oceanic anoxic events were time intervals in the Mesozoic characterized by widespread distribution of marine organic matter-rich sediments (black shales) and significant perturbations in the global carbon cycle. These perturbations are globally recorded in sediments as carbon isotope excursions irrespective of lithology and depositional environment. During the early Toarcian, black shales were deposited on the epi- and pericontinental shelves of Pangaea, and these sedimentary rocks are associated with a pronounced (ca. 7 ‰) negative (organic) carbon isotope excursion (CIE) which is thought to be the result of a major perturbation in the global carbon cycle. For this reason, the lower Toarcian is thought to represent an oceanic anoxic event (the T-OAE). If the T-OAE was indeed a global event, an isotopic expression of this event should be found beyond the epi- and pericontinental Pangaean localities. To address this issue, the carbon isotope composition of organic matter (δ13Corg of lower Toarcian organic matter-rich cherts from Japan, deposited in the open Panthalassa Ocean, was analysed. The results show the presence of a major (>6 ‰) negative excursion in δ13Corg that, based on radiolarian biostratigraphy, is a correlative of the lower Toarcian negative CIE known from Pangaean epi- and pericontinental strata. A smaller negative excursion in δ13Corg (ca. 2 ‰) is recognized lower in the studied succession. This excursion may, within the current biostratigraphic resolution, represent the excursion recorded in European epicontinental successions close to the Pliensbachian/Toarcian boundary. These results from the open ocean realm suggest, in conjunction with other previously published datasets, that these Early Jurassic carbon cycle perturbations affected the active global reservoirs of the exchangeable carbon cycle (deep marine, shallow marine, atmospheric).

Changes in carbon cycling across the OAE 1b cluster (Aptian-Albian transition): New insights from the Vocontian Basin

2020 ◽  
Author(s):  
Mickaël Charpentier ◽  
Clemens V. Ullmann ◽  
Arka Rudra ◽  
Hamed Sanei ◽  
Stéphane Bodin
Keyword(s):  
Organic Matter ◽  
Carbon Cycling ◽  
Carbon Isotope ◽  
Stable Carbon Isotope ◽  
Abrupt Onset ◽  
Oceanic Anoxic Event ◽  
Marine Organic Matter ◽  
Isotope Record ◽  
Stratigraphic Interval

&lt;p&gt;The Aptian-Albian transition is marked by the unfolding of the Oceanic Anoxic Event (OAE) 1b, a protracted environmental perturbation characterized by occurrence of several sub-events out of which the Kilian and Paquier events are the most well-known ones. So far, the conditions leading to the unfolding of the OAE 1b cluster and its sub-events, as well as their consequences, remain elusive as most of the studies have focussed on the Paquier level, thereby precluding a broader perspective on this event. In this study, we focus on an extended stratigraphic interval from the Brier section (Vocontian Basin, SE France) spaning the Kilian to Paquier levels interval. Our goal is to better understand the processes having led to organic matter (OM) accumulation across this stratigraphic interval as well as to constrain the exogenic carbon cycle framework in which these changes are inscribed. For this purpose, we have performed high-resolution bulk-rock pyrolysis analyses, paired stable carbon isotope measurements on both bulk carbonate and organic matter, and handheld XRF analyses.&lt;/p&gt;&lt;p&gt;Measured total organic contents (TOC) average 1.5% with peaks reaching 3% in the Paquier level. Apart for the Kilian, Paquier and HN 12 levels, which are characterized by the dominance of marine organic matter, the remainder of the studied interval is characterized by the accumulation of continental organic matter. Moreover, there is a good correlation between changes in the long-term TOC content and detrital input as inferred from changes in element concentration such as aluminium and thorium. A preservation model therefore best explains the long-term OM accumulation across the studied interval. Sporadic episodes of enhanced marine OM productivity account only for the deposition of the Kilian, Paquier and HN 12 levels.&lt;/p&gt;&lt;p&gt;Carbon isotope analyses shows that the Kilian and Paquier levels are both associated with a 0.5 &amp;#8211; 1&amp;#8240; negative excursion in the bulk carbonate record. In the bulk OM record, the C-isotope signal is however different. The Kilian level is hence characterized by a 3&amp;#8240; negative excursion whereas the Paquier level is characterized by a 4&amp;#8240; positive excursion. This discrepancy is due to the fact that the bulk OM C-isotope record is strongly influenced by the mixing of different types of organic matter. By applying a correction factor tacking into account the type of organic matter, as characterized by the pyrolysis analyses, both OM and carbonate C-isotope records can be reconciled.&lt;/p&gt;&lt;p&gt;Importantly, our paired C-isotope record shows that in between the Kilian and Paquier levels, two others episodes of similar negative C-isotope excursion occur, with an abrupt onset and a total amplitude of 1&amp;#8240;. These episodes likely correspond to the Monte Nerone level observed in Italy.&amp;#160; The unfolding of OAE 1b cluster is thus thightly tied to a very dynamic exogenic carbon cycling, characterized by repeated injections into the oceans-atmosphere of light isotopic carbon, potentially similar to the Early Eocene scenario.&lt;/p&gt;

Characterisation of production of organic rich topsoil from sludge

2000 ◽  
Vol 42 (9) ◽  
pp. 195-201 ◽  
Author(s):  
P. Andreasen ◽  
P. B. Mortensen ◽  
A. Stubsgaard ◽  
B. Langdahl
Keyword(s):  
Organic Matter ◽  
Oxygen Consumption ◽  
Oxygen Transport ◽  
Mineral Soil ◽  
Climatic Conditions ◽  
Growth Media ◽  
Soil Mixture ◽  
Water Suspension ◽  
Aerobic Process ◽  
Stable Product

The stabilisation of a sludge-mineral soil mixture and a method to evaluate the state of stabilisation were investigated. The organic matter and nitrogen content are reduced up to 50% during a stabilisation process of three months under Danish climatic conditions. The stabilisation was shown to be an aerobic process limited by oxygen transport within the mixture. The degree of stabilisation was evaluated by oxygen consumption in a water suspension and the results showed that a stable product was achieved when oxygen consumption was stable and in the level of natural occurring aerobic soils (0.1 mgO2/(g DS*hr). The study thereby demonstrates that a stability of a growth media can be controlled by the oxygen consumption method tested.

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