Hubbry Logo
SapropelSapropelMain
Open search
Sapropel
Community hub
Sapropel
logo
7 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Sapropel
Sapropel
Sapropel
View on Wikipedia
from Wikipedia

Sapropel (a contraction of Ancient Greek words sapros and pelos, meaning putrefaction and mud (or clay), respectively) is a term used in marine geology to describe dark-coloured sediments that are rich in organic matter. Organic carbon concentrations in sapropels commonly exceed 2 wt.% in weight.

The term sapropel events may also refer to cyclic oceanic anoxic events (OAE), in particular those affecting the Mediterranean Sea with a periodicity of about 21,000 years.

Formation

[edit]

Sapropels have been recorded in the Mediterranean sediments since the closure of the Eastern Tethys Ocean 13.5 million years ago. The formation of sapropel events in the Mediterranean Sea occurs approximately every 21,000 years and last between 3,000 and 5,000 years. The first identification of these events occurred in the mid-20th century. Since then, their formulative conditions of have been investigated.

The occurrence of sapropels has been related to the Earth's orbital parameters (Milankovitch cycles). The precession cycles influence the African monsoon, which influences the Mediterranean circulation through increases in freshwater inputs.

Sapropels develop during episodes of reduced oxygen availability in bottom waters, such as an oceanic anoxic event (OAE). Most studies of formational mechanisms infer some degree of reduced deep-water circulation. Oxygen can only reach the deep sea by new deep-water formation and consequent "ventilation" of deep basins. There are two main causes of OAE: reduction in deep-water circulation or raised oxygen demand from upper level.

A reduction in deep-water circulation will eventually lead to a serious decrease in deep-water oxygen concentrations due to biochemical oxygen demand associated with the decay of organic matter. This sinks into the deep sea as a result of export production from surface waters. Oxygen depletion in bottom waters then favors the enhanced preservation of the organic matter during burial by the sediments. Organic-rich sediments may also form in well-ventilated settings that have highly productive surface waters; here the high surface demand simply extracts the oxygen before it can enter the deep circulation current thus depriving the bottom waters of oxygen.

Significance

[edit]

Sapropelic deposits from global ocean anoxic events form important oil source rocks. Detailed process studies of sapropel formation have concentrated on the fairly recent eastern Mediterranean deposits,[1] the last of which occurred between 9.5 and 5.5 thousand years ago.

The Mediterranean sapropels of the Pleistocene reflect increased density stratification in the isolated Mediterranean basin. They record a higher organic carbon concentration than non-sapropel times; an increase in the δ15N and corresponding decrease in δ13C tells of rising productivity as a result of nitrogen fixation.[2] This effect is more pronounced further east in the basin, suggesting that increased precipitation was most pronounced at that end of the sea.[2]

In the Black Sea

[edit]

In the Black Sea, sapropels are distributed at a depth of 500 to 2200 m, and in different morpholithological zones they have different thicknesses. Deep sea sediments are called the sediments formed outside the zone of influence of hydrogenic factors such as wind-driven waves and internal waves as well as of the transgressive and regressive cycles of the Black Sea basin. Here, under the conditions of relative stagnation, can be observed uninterrupted cross-sections because this area was under the sea level during the entire Pleistocene and Holocene. Deep sea organogenic mineral sediments (DSOMS) are those sediments that contain more than 3% organic carbon. The sapropels form a single horizon with constant thickness typical of the Black Sea basin. Analogues of the sapropels on the continental shelf and the upper part of the continental slope are the green aleurite-pelite, oozes with accumulation of plant detritus and decomposed shells of Mytilus galloprovincialis. The transition from aleurite-pelitic oozes to sapropels is facial. The organic matter in the sapropels is of heterogeneous origin. They are composed primarily of planktogenic organisms (about 80%) and continental organic matter (20%). The planktonic organisms are well preserved in most cases under the conditions of the hydrogen sulfide zone. The main components of the sapropels are the dinoflagellate cysts, diatom algae, coccolithophorids, peridiniales. The mineral part of sapropel muds is represented by a poly-component mixture of clay minerals. The minerals illite and montmorillonite predominate, chlorite and kaolinite occur in subordinate quantities. Individual grains of quartz, feldspar, volcanic glass and others are rarely found among them. Carbonate minerals are mainly represented by calcite and dolomite. It is generally accepted that the main source of hydrogen sulfide in the Black Sea today are the processes of anaerobic decomposition of organic matter by sulfate-reducing bacteria (SRB). The organic substance that is fixed at the bottom of the basin in the form of organogenic-mineral sediments (sapropels) is a product of the mass extinction of the plankton biomass as a result of the Black Sea flood. There is an excess of a huge amount of organic matter, which creates favorable conditions for the development of bacterial sulfate reduction. [3]

Contrast lithologic borders between coccolitic mud (Unit 1), sapropel mud (Unit 2), seekreide (lutite) (Unit 3), geological research along the route of South Stream pipeline with R/V Akademik (June, 2009) in the Bulgarian Exclusive Economic Zone in the Black Sea, depth 1500 m.[4]

Non-conventional source of energy

[edit]

Bulgarian Professor Petko Dimitrov is the creator of the idea for the application of sapropel sediments from the bottom of the Black Sea as a natural ecological fertilizer and biological products.[5][3] According to the Romanian tycoon Dinu Patriciu, the sapropel sediments have the potential to be a source of non-conventional energy.[6] Patriciu has created a marine exploration project in the Black Sea which examines the sapropel sediments of that region. Sediment cores are collected and investigated by several universities and research institutes across the world.[6]

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Sapropel

View on Grokipedia
from Grokipedia
The term "sapropel" derives from sapros ('rotten') and pēlos ('mud'). is a dark-colored, fine-grained rich in , typically containing more than 2% organic carbon by weight, that accumulates in low-oxygen (anoxic or dysoxic) aquatic environments such as oceans, estuaries, and lakes. It consists primarily of decomposed remains of aquatic organisms, , and , along with associated minerals like silicates, carbonates, and sulfides, forming a slimy, unconsolidated deposit that preserves organic material due to restricted under anaerobic conditions. In marine settings, sapropels are prominent in semi-enclosed basins like the , where they form during episodes of bottom-water oxygen deficiency triggered by climatic forcings, such as enhanced activity and river discharge (e.g., from the ), which stratify the and reduce deep-water ventilation. These layers, often sharply bounded and laminated, record orbital cycles like minima and serve as key indicators of past paleoceanographic and paleoclimatic changes, with notable examples including Pleistocene sapropels S1 to S5 deposited over the last 500,000 years. Freshwater sapropels, found in lake bottoms, develop through sedimentation of organic detritus in Holocene-era mild climates, featuring 15–95% organic content (including humic acids and waxes) mixed with , dolomite, and trace elements, at accumulation rates of 0.1–6.64 mm per year. Geologically, sapropels signify nutrient-rich, low-energy depositional environments and contribute to understanding ancient anoxia events, while their high organic content makes them precursors to source rocks in some basins. Beyond geology, lacustrine varieties have applications in as fertilizers and in for therapeutic properties due to their bioactive compounds.

Definition and Characteristics

Definition

Sapropel is a term derived from the Greek words sapros (rotten) and pelos (mud or clay), first introduced by geologist Henry Potonié in 1904 as an international designation for organic-rich sediments in the fields of and . In geological classification, sapropel refers to a dark-colored, organic-rich sedimentary deposit characterized by an organic carbon content of at least 2 wt.%, primarily accumulated in aquatic environments such as lakes, seas, and oceans. This definition, established through early analyses of sediment cores, emphasizes its role as a distinct type of formed from the of aquatic organic material under low-oxygen conditions. Sapropels are differentiated from coarser clastic sediments, which consist mainly of transported mineral grains like or , by their finely laminated texture and enrichment in sulfide-derived iron sulfides, resulting in a slimy, black mud predominantly composed of biogenic . This fine-grained, laminated structure arises from the settling of microscopic organic particles in stagnant water bodies, contrasting with the granular nature of clastic deposits. The primary types of sapropels are lacustrine, which form in freshwater lakes through the accumulation of and algal remains, and marine, which develop in saline oceanic or coastal settings from planktonic and bacterial sources.

Physical and Chemical Properties

Sapropels are characterized by their dark coloration, ranging from black to dark brown, which arises from the high concentration of and associated minerals such as . These sediments exhibit a fine-grained texture, predominantly composed of - to clay-sized particles, with distributions typically including 7-13% clay, 57-74% , and 13-36% in recent examples. They often display a laminated structure, with thin laminae formed by alternating layers of organic-rich material and minor biogenic components like foraminifer tests, observable on millimeter to centimeter scales. When freshly deposited, sapropels can appear gelatinous due to their high water content, which reaches up to 90%, contributing to a soft, jelly-like consistency often described as "black ." Chemically, sapropels are distinguished by elevated organic carbon levels, typically ranging from 2% to 30% by weight, far exceeding the threshold for as sediments. They are enriched in , often as , with contents around 0.7-1.4%, alongside higher concentrations of (0.25-0.35%) and (up to 2.85 mg/kg in certain recent examples from saline lakes), reflecting trapping in anoxic environments. In contrast to diatomites, sapropels contain relatively low biogenic silica, as their derives more from algal and bacterial sources than siliceous . Biomarkers within sapropels include minor sterols from terrestrial higher , porphyrins associated with , and compounds like isorenieratene from green bacteria, indicating predominantly marine algal and bacterial origins with limited terrestrial input. Physically, sapropels exhibit low , typically 1.15-1.2 g/cm³, and high , often exceeding that of surrounding sediments due to the loosely packed organic matrix and preserved fabric, which enhances their preservation potential. This porosity is particularly pronounced in well-preserved examples, correlating with silica-to-calcium ratios and contributing to the sediment's lightweight nature.

Formation Processes

Mechanisms of Formation

Sapropel formation is primarily driven by the establishment of anoxic conditions in bottom waters, which prevent the oxidation of and facilitate its accumulation. These anoxic environments arise from stratification induced by freshwater influx, such as increased river discharge during humid climatic phases, which reduces the density of surface waters and inhibits vertical mixing and deep-water renewal. Poor circulation in semi-enclosed basins further exacerbates oxygen depletion, while episodes of high organic flux from surface waters can overwhelm the limited oxygen supply, leading to dysoxia or below the pycnocline. The preserved in sapropels is predominantly derived from marine planktonic sources, including such as diatoms and dinoflagellates, with contributions from under anoxic conditions. This marine origin is evidenced by analyses showing algal and sterols dominant in the sediments. Minimal bioturbation by infaunal , due to the toxic anoxic environment, preserves fine laminations in the deposits, enhancing the fidelity of the stratigraphic record. Key processes begin with enhanced primary productivity in surface waters, fueled by nutrient upwelling or from nutrient-rich deep waters exposed by stratification, often involving release from anoxic sediments in a loop. This productivity surge leads to increased of organic particles to the seafloor, followed by rapid burial that shields the material from degradation. In the anoxic sediments, sulfate-reducing bacteria dominate remineralization, converting to (H₂S), which further inhibits aerobic respiration and promotes preservation through sulfide-mediated reactions. These formation cycles typically last 1,000 to 5,000 years per event, paced by orbital forcings, particularly precession-driven insolation maxima that intensify systems and freshwater inputs.

Geological and Temporal Context

Sapropels first appear in the geological record approximately 13.5 million years ago, coinciding with the closure of the East during the , which reorganized oceanic circulation and created conditions favorable for organic-rich sediment accumulation in restricted basins. These deposits became prominent features of sediments, especially in the proto-Mediterranean region, where tectonic isolation enhanced the preservation of under low-oxygen environments. The temporal distribution of sapropels shows a strong cyclicity tied to Milankovitch , particularly the cycle with a periodicity of about 21,000 years, which modulates seasonal insolation gradients. During minima, enhanced boreal summer insolation strengthens the African monsoon, leading to increased continental runoff and stratification in marginal seas that suppresses deep-water oxygenation and promotes sapropel formation. Globally, sapropels are predominantly distributed in semi-enclosed basins, including the , , and ancient lacustrine systems in , where limited exchange with open oceans allows for persistent bottom-water anoxia. In contrast, open-ocean environments rarely preserve such layers due to vigorous circulation and oxygenation that prevent accumulation. The concept of sapropel emerged in the early within European limnological studies of lake sediments, where the term—derived from Greek roots meaning "rotten mud"—described fine-grained, organic-rich deposits formed under anaerobic conditions. Marine sapropels were first systematically identified in the late 1940s through piston coring in the eastern Mediterranean during the Swedish Deep-Sea Expedition, with broader recognition and temporal analysis advancing in the and via initial deep-sea efforts that revealed their cyclic patterns in marine sequences.

Paleoenvironmental Significance

Role in Anoxic Events

Organic-rich black shales, analogous to sapropels, serve as localized expressions of broader oceanic anoxic events (OAEs), particularly during the mid-Cretaceous period (approximately 120–80 million years ago), where they were deposited across ocean basins under conditions of widespread oxygen depletion. These deposits, formed in diverse settings such as oceanic plateaus and continental margins, often exhibit high (TOC) contents exceeding 2–10 wt%, enabling their role as primary source rocks for hydrocarbons in systems. For instance, black shales associated with OAE2 (Cenomanian-Turonian boundary, ~94 Ma) are globally distributed and have generated significant oil and gas reserves due to their kerogen-rich composition preserved in anoxic environments. The preservation of organic matter in these black shales during OAEs is fundamentally tied to anoxic bottom waters, which inhibit microbial decay and bioturbation, allowing fine-grained sediments laden with planktonic debris to accumulate as laminated black shales. In the , the Early OAE (~183 Ma) exemplifies this process, with basinal restriction and water mass stagnation leading to widespread black shale deposition rich in marine algae-derived organics, as evidenced by Re-Os dating and geochemical proxies indicating sulfidic conditions. Feedback mechanisms involving black shale formation amplify the duration and intensity of OAEs through enhanced organic carbon burial, which sequesters isotopically light carbon (¹²C) from the ocean-atmosphere system, thereby influencing global oxygenation levels and climate dynamics. During events like OAE2, increased burial rates—up to several times background levels—draw down atmospheric CO₂, promoting cooling and potentially stabilizing anoxic conditions via reduced deep-water ventilation; this is coupled with phosphorus recycling from sediments under anoxia, which fuels surface productivity and perpetuates the cycle. Such feedbacks can extend OAEs by hundreds of thousands of years, as modeled for Cretaceous episodes where benthic phosphorus release exceeds uptake, sustaining high export production. Isotopic records in black shales provide evidence of these dynamics, with negative carbon excursions (δ¹³C) often marking the onset of OAEs and signaling surges in marine productivity driven by enrichment. For example, initial δ¹³C shifts of -2 to -4‰ in during OAE1a (~120 Ma) and OAE2 reflect increased CO₂ availability from volcanic inputs, which enhanced photosynthetic fixation and organic export, as seen in black shale sections from the Pacific and Atlantic. These excursions precede positive δ¹³C peaks from burial, highlighting the transient productivity boosts that characterize anoxic episodes.

Paleoclimatic Indicators

Sapropels serve as key proxies for reconstructing past climatic conditions, particularly through variations in organic carbon flux, which reflect enhanced primary productivity and increased precipitation during periods of intensified monsoons. Elevated (TOC) contents, often exceeding 2-30% in sapropels, indicate heightened riverine nutrient inputs and runoff from North African and European sources, driven by precession-forced wetter climates and stronger African monsoons during Green Sahara Periods (GSPs). These GSPs, aligned with summer insolation maxima, promoted enhanced export to the seafloor, as evidenced by correlations between TOC and barium-to-aluminum ratios (Ba/Al), which track primary productivity with minimal post-depositional alteration. Trace elements such as (Mo) and (U) provide robust indicators of conditions during sapropel formation, signaling the extent of bottom-water anoxia linked to climatic perturbations. Enrichments in Mo and U, with Mo showing the highest accumulation in sites, reflect euxinic to anoxic environments resulting from reduced deep-water ventilation and increased organic carbon burial under humid, monsoon-intensified regimes. These proxies outperform less reliable elements like (Cr) or (Cu), offering insights into dynamics that were climatically modulated, such as through stratification from freshwater influx. In the Mediterranean, sapropels exhibit pronounced east-west gradients in thickness and organic carbon content, underscoring regional aridity contrasts influenced by . Eastern sites, such as Ocean Drilling Program (ODP) Holes 966 and 969, record thicker sapropels with higher TOC extending back to 5.3 million years ago (Ma), while western sites like 964 and 967 show preservation only after 3.2 Ma, attributed to increased aridity and reduced sediment flux in the west during earlier GSPs. This gradient highlights how precession-driven variability amplified hydrological differences, with δ¹⁸O minima of -1 to -3‰ in eastern records confirming consistent wet phases. Modern hypoxic zones in semi-enclosed basins, such as the , offer analogies to sapropel deposition, informing predictions of future -driven . The 's seasonal or episodic hypoxia, affecting about 35% of coastal systems from 1955 to 2009 due to warming-induced stratification and nutrient loading, mirrors the rapid onset of sapropel S1 anoxia (~40 years) and TOC enrichments up to 6%, suggesting accelerated oxygen loss under high-emission scenarios (e.g., SSP5-8.5 by 2100); hypoxia has continued to increase as of 2023 assessments. These parallels indicate that ongoing warming could expand oxygen minimum zones (OMZs) in marginal seas, akin to past events. Sapropel deposition episodes drove significant shifts in deep-sea ecosystems, with potential for abrupt changes reflecting climatic instability. During phases, such as those accompanying sapropel S5, benthic metazoan diversity plummeted, with major faunal turnovers (e.g., in mollusks and echinoderms) occurring within decades to centuries as oxygen levels dropped below 0.5 mL/L, leading to hypoxic-tolerant assemblages dominated by . Recovery times extended over (>1,000 years), underscoring the vulnerability of seafloor communities to monsoon-linked anoxic events and their role in long-term ecological restructuring.

Major Deposits and Case Studies

Mediterranean Sapropels

Mediterranean sapropels are prominent organic-rich layers preserved in deep-sea sediment cores from the eastern and western sub-basins, occurring quasi-periodically since the epoch, approximately 5.3 million years ago, with intensified deposition during the . The most well-studied examples include sapropels S1 through S5, which are clustered within and represent discrete episodes of enhanced preservation spanning durations of roughly 3,000 to 6,000 years each. For instance, S1 formed between approximately 10.5 and 6.0 thousand years ago during the early , while S5 dates to about 128 to 121 thousand years ago in the last interglacial period.00319-2) These layers are identified in cores from sites like those drilled during Ocean Drilling Program Leg 160, where they appear as distinct, dark bands contrasting with lighter surrounding marls. The formation of these sapropels is primarily driven by , particularly minima in the cycle (approximately 21,000-year periodicity), which intensify African monsoons and increase freshwater runoff from major river systems such as the and sources. This enhanced discharge leads to stratification, reducing deep-water ventilation and promoting anoxic to euxinic conditions that preserve , while also boosting primary productivity through nutrient influx. Sea-level rise during deglaciations further contributes by expanding shelf areas and amplifying runoff effects, creating a for sapropel deposition across the basin. Characteristics of Mediterranean sapropels include elevated (Corg) contents, typically ranging from 1% to 10%, with values increasing eastward toward the Levantine Basin due to proximity to nutrient-rich runoff sources; for example, S5 reaches up to 15% Corg in southeastern Aegean sediments. Layer thicknesses vary regionally from 10 to 50 cm for S1 to over 1 m for thicker examples, reflecting local sedimentation rates of about 3 cm per thousand years.00091-7) Identification often relies on sapropel indices derived from color reflectance , where low (L*) values indicate the dark, organic-rich intervals, as seen in cores from Sites 964 and 967. A notable event is the deposition of sapropel S5 around 125,000 years ago, which occurred during a period of peak warmth and maximum intensity, resulting in widespread anoxia extending to shallow depths of about 200 m and exceptional organic preservation linked to dual pulses. This layer exemplifies the basin-wide synchrony of sapropel formation under orbital-climatic forcing, with its onset preceded by gradual freshening over millennia.

Black Sea Sapropels

The hosts unique sapropel deposits characterized by their euxinic conditions, where anoxic and sulfidic waters prevail in the deep basin. These sediments are primarily found at water depths ranging from approximately 200 to 2,200 meters, covering much of the . The organic carbon content in these sapropels exceeds 3 wt%, often reaching 5–20 wt% in the laminated layers, reflecting enhanced preservation under oxygen-deficient conditions. The is predominantly of marine origin, derived mainly from planktonic sources such as and coccolithophores, with stable carbon isotopic compositions (δ¹³C around -22 to -24‰) indicative of productivity; terrestrial inputs contribute a lesser fraction, estimated at around 20% based on and isotopic analyses. The formation of these sapropels is closely linked to a major hydrographic shift around 7,600 years ago, when rising levels caused saline water to spill over the Bosporus Strait into the formerly freshwater lake, initiating a transition to brackish-marine conditions. This inflow enhanced vertical mixing and nutrient , boosting surface productivity and leading to the onset of permanent anoxia below about 150–200 meters depth by approximately 7,500 years ago. In the anoxic water column, sulfate-reducing bacteria thrive, converting sulfate to (H₂S) at rates of up to 10,000 tons per day, creating a toxic "dead zone" that inhibits aerobic life and promotes preservation. The euxinic environment is evidenced by biomarkers like isorenieratene derivatives from sulfur bacteria, confirming sulfidic conditions in the during deposition. A prominent sapropel layer, known as Unit II, accumulated between approximately 7,500 and 3,000 years ago, directly tied to fluctuations in Mediterranean inflow through the . This finely laminated unit, up to 90 cm thick in places, records peak organic carbon accumulation rates similar to underlying units but with reduced dilution by carbonates and clays, resulting from sustained anoxia and high during the mid-. Variations in inflow strength influenced gradients, modulating the extent of the chemocline and sapropel thickness across the basin. Today, sapropel-like sedimentation continues in the Black Sea's deep anoxic zone, with ongoing accumulation driven by persistent stratification and bacterial sulfate reduction. This process sustains high H₂S concentrations, posing ecological risks such as habitat loss for benthic organisms and threats to fisheries in overlying oxic waters, while also influencing regional carbon cycling and nutrient dynamics. The dead zone's expansion, exacerbated by , underscores the Black Sea's vulnerability to environmental changes.

Modern Research and Applications

Recent Scientific Studies

Recent advancements in sapropel research since the 2000s have been driven by drilling programs under the Ocean Drilling Program (ODP) and (IODP), providing high-resolution cores that reveal detailed formation mechanisms. For instance, analyses of ODP Site 964 cores from the have shown that during the deposition of sapropel S5 around 125 ka, by played a key role in enhancing primary productivity under stratified conditions, as evidenced by low δ¹⁵N values in indicating N₂ fixation inputs. Similarly, IODP Expedition 401, conducted from December 2023 to February 2024, recovered Miocene-to-Pliocene sediments from the , offering new insights into pre-Pleistocene sapropel precursors and their links to . Analytical techniques have evolved significantly in the , incorporating non-destructive methods like (XRF) core scanning for high-resolution elemental profiling and biomarker analysis for reconstructing paleoproductivity and microbial activity. scanning of sapropel S1 layers in cores has identified sharp boundaries and pulses, enabling precise mapping of events at sub-millennial scales. biomarkers, such as heterocyst glycolipids from nitrogen-fixing , have confirmed widespread N₂ fixation during S5 deposition, while modeling approaches simulate export productivity variations, revealing that enhanced riverine inputs could amplify organic carbon burial by up to 10-fold during sapropel onset. Studies on microbial communities using of sapropels have highlighted diverse anaerobic consortia, including sulfate-reducing thriving in euxinic conditions, underscoring the role of microbial mediation in preservation. In the 2020s, research has linked sapropel formation to abrupt shifts, with modeling showing that precessional insolation maxima triggered rapid freshwater influxes, leading to basin-wide anoxia within decades. Comparisons to modern oxygen minimum zones (OMZs) in the suggest that sapropel-like deoxygenation could expand under future warming, as intermediate water stagnation during S1 mirrors current OMZ intensification off the . Recent work addresses gaps in regional dynamics, including sapropels influenced by methane seeps, where a 2024 study on archaeal lipids in sediments indicates contributions from methane-metabolizing in anoxic zones. In the Mediterranean, teleconnection studies using stable isotope records have revealed east-west atmospheric linkages during S1, where African intensification propagated humidity gradients, synchronizing sapropel deposition across basins.

Economic and Environmental Uses

Sapropels represent an unconventional resource due to their high content, which can be converted into fuels through thermochemical processes such as briquetting for production. In the , sapropel layers are estimated to hold significant potential, primarily associated with gas hydrates and biogenic sources. Romanian entrepreneur Dinu Patriciu's efforts in the 2010s highlighted the sapropel's potential, estimating recoverable equivalent to approximately 6 billion barrels of oil through extraction and processing. Beyond energy, sapropels serve as nutrient-rich fertilizers, enhancing and crop yields due to their organic composition, including and minerals that improve and microbial activity. As of 2025, studies have further explored sapropel peloids in pelotherapy, identifying fungal diversity that may influence therapeutic applications. Their adsorption properties also enable use in , effectively binding such as , , , and from aqueous solutions, with removal efficiencies up to 90% under optimized conditions. Exploitation of sapropels poses environmental risks, including the potential release of (H₂S) and associated toxins from anoxic sediments, which could lead to water contamination and disruption during or extraction. Conversely, intact sapropel deposits contribute to by locking away organic carbon in sediments, with lake sapropels in northern regions burying up to several thousand tons of carbon per site, aiding long-term climate mitigation. Compared to oil shales or , sapropels exhibit higher content—often exceeding 4%—which complicates processing and reduces economic viability due to increased desulfurization needs and potential emissions.

References

  1. https://www.dictionary.com/browse/sapropel
  2. https://www.sciencedirect.com/topics/earth-and-planetary-sciences/sapropel
  3. https://cp.copernicus.org/articles/16/933/2020/
  4. https://www.researchgate.net/publication/361048170_Sapropel_-_Mining_Characteristics_and_Potential_Use_in_Medicine
  5. https://link.springer.com/referenceworkentry/10.1007/978-94-007-6238-1_172
  6. http://www.deepseadrilling.org/42_1/volume/dsdp42pt1_13.2.pdf
  7. https://edis.ifas.ufl.edu/publication/FA200
  8. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/94GB00297
  9. https://www.merriam-webster.com/dictionary/sapropel
  10. https://archimer.ifremer.fr/doc/00114/22480/20161.pdf
  11. https://pmc.ncbi.nlm.nih.gov/articles/PMC8452724/
  12. https://www.researchgate.net/publication/227945055_Sedimentology_and_geochemistry_of_an_exceptionally_preserved_last_interglacial_sapropel_S5_in_the_Levantine_Basin_Mediterranean_Sea
  13. https://onlinelibrary.wiley.com/doi/10.1155/2020/8895667
  14. https://www.researchgate.net/publication/27687780_Molecular_palaeontology_of_eastern_Mediterranean_sapropels_Evidence_for_photic_zone_euxinia
  15. https://www-odp.tamu.edu/publications/161_SR/chap_31/c31_5.htm
  16. http://www.highstand.org/erohling/Rohling-papers/2015-Rohling-ea-Med-sapropel-review.pdf
  17. http://www-odp.tamu.edu/publications/160_SR/VOLUME/CHAPTERS/CHAP_21.PDF
  18. https://www.sciencedirect.com/science/article/abs/pii/S0031018202006132
  19. https://www-odp.tamu.edu/publications/160_SR/VOLUME/CHAPTERS/CHAP_29.PDF
  20. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019PA003566
  21. https://www.nature.com/articles/s41598-020-70652-4
  22. https://www.nature.com/scitable/knowledge/library/green-sahara-african-humid-periods-paced-by-82884405/
  23. https://www.sciencedirect.com/science/article/abs/pii/S0921818102001960
  24. https://agronomy.emu.ee/wp-content/uploads/2016/05/Vol14-_nr3_Stankevica.pdf
  25. http://www.highstand.org/erohling/Rohling-papers/1999-Rohling%2520and%2520Thunell-1999editorial.pdf
  26. https://www.researchgate.net/publication/27710997_Cretaceous_Oceanic_Anoxic_Events_Causes_and_consequences
  27. https://www.sciencedirect.com/science/article/abs/pii/S0031018205006474
  28. https://homepages.uc.edu/~algeot/McArthur-etal-Paleoceanog-2008.pdf
  29. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010PA001925
  30. https://cp.copernicus.org/articles/16/757/2020/
  31. https://pubmed.ncbi.nlm.nih.gov/11201737/
  32. https://cp.copernicus.org/articles/16/757/2020/cp-16-757-2020.pdf
  33. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GL089183
  34. https://doi.org/10.1016/j.palaeo.2023.111953
  35. https://doi.org/10.1016/j.earscirev.2023.104664
  36. https://doi.org/10.1073/pnas.1417130112
  37. https://doi.org/10.1016/0025-3227(94)90202-X
  38. https://pubs.geoscienceworld.org/gsa/geology/article/26/2/107/206791/Organic-carbon-accumulation-in-the-Holocene
  39. https://www.sciencedirect.com/science/article/pii/0168962287900510
  40. https://www.researchgate.net/publication/251410949_Organic_Matter_Sources_in_the_Black_Sea_as_Inferred_from_Hydrocarbon_Distributions
  41. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/98PA01161
  42. https://www.sciencedirect.com/science/article/abs/pii/S036031992305886X
  43. https://www.sciencedirect.com/science/article/abs/pii/S0012821X99000837
  44. https://pubs.geoscienceworld.org/gsa/geology/article/15/10/918/204214/Carbon-accumulation-rates-and-the-origin-of-the
  45. https://ui.adsabs.harvard.edu/abs/2013AGUFMPP24A..04Y/abstract
  46. https://pmc.ncbi.nlm.nih.gov/articles/PMC3666672/
  47. https://www.science.org/doi/10.1126/sciadv.1601897
  48. https://pubs.geoscienceworld.org/gsa/geology/article/47/11/1088/573752/Biomarker-evidence-for-nitrogen-fixing
  49. https://publications.iodp.org/proceedings/401/101/401_101.html
  50. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018PA003458
  51. https://www.nature.com/articles/s41598-017-06232-w
  52. https://www.sciencedirect.com/science/article/pii/S0031018223002195
  53. https://onlinelibrary.wiley.com/doi/full/10.1111/gbi.12589
  54. https://journals.sagepub.com/doi/abs/10.1177/09596836231211807
  55. https://www.isca.me/rjcs/Archives/v2/i5/5.ISCA-RJCS-2012-039_Done.php
  56. https://hotnews.ro/dinu-patriciu-am-investit-100-de-milioane-de-dolari-in-biomasa-de-pe-fundul-marii-negre-de-acolo-se-pot-scoate-6-miliarde-de-barili-echivalent-688522
  57. https://pubmed.ncbi.nlm.nih.gov/39971790/
  58. https://www.researchgate.net/publication/380494950_Investigation_on_applying_sapropel_for_removal_of_heavy_metals_cadmium_chromium_copper_and_zinc_from_aqueous_solutions
  59. https://www.academia.edu/38566374/THE_BLACK_SEA_PROBLEM_POSSIBLE_SOLUTIONS_Presentation_of_new_book_
  60. https://elibrary.ru/download/elibrary_49369949_35062234.pdf
  61. https://www.sciencedirect.com/science/article/pii/000925419400122O
Add your contribution
Related Hubs
User Avatar
No comments yet.