Primary control of paleoproduction on organic matter preservation and accumulation in the Kimmeridge rocks of Yorkshire (UK)

Ramanampisoa, L.; Disnar, Jean-Robert

doi:10.1016/0146-6380(94)90160-0

Cited by 47 publications

(24 citation statements)

References 43 publications

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“…Classically, two particular slopes, corresponding to HI equal to 750 and 300 mgHC g −1 TOC, respectively, are represented in the S2 vs. TOC diagrams in order to identify the chemical quality or the origin of the organic compounds (Ariztegui et al, 2001). Values of HI inferior to 300 mgHC g −1 TOC can point towards organic matter oxidation in the sediment or a contribution of terrestrial material (Ramanampisoa and Disnar, 1994;Disnar et al, 2003;Calvert, 2004;Jacob et al, 2004;Simonneau et al, 2013). Inversely, HI values superior to 300 mgHC g −1 TOC suggest well-preserved organic matter in the sediment or higher contributions of lacustrine algal particles, the specific pole of which is represented by HI values superior to 750 mgHC g −1 TOC (Talbot and Livingstone, 1989).…”

Section: Methodsmentioning

confidence: 99%

Mass-movement and flood-induced deposits in Lake Ledro, southern Alps, Italy: implications for Holocene palaeohydrology and natural hazards

Simonneau

Chapron²,

Vannière

et al. 2013

Clim. Past

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High-resolution seismic profiles and sediment cores from Lake Ledro combined with soil and riverbed samples from the lake's catchment area are used to assess the recurrence of natural hazards (earthquakes and flood events) in the southern Italian Alps during the Holocene. Two well-developed deltas and a flat central basin are identified on seismic profiles in Lake Ledro. Lake sediments have been finely laminated in the basin since 9000 cal. yr BP and frequently interrupted by two types of sedimentary events (SEs): light-coloured massive layers and dark-coloured graded beds. Optical analysis (quantitative organic petrography) of the organic matter present in soil, riverbed and lacustrine samples together with lake sediment bulk density and grain-size analysis illustrate that light-coloured layers consist of a mixture of lacustrine sediments and mainly contain algal particles similar to the ones observed in background sediments. Light-coloured layers thicker than 1.5 cm in the main basin of Lake Ledro are synchronous to numerous coeval mass-wasting deposits remoulding the slopes of the basin. They are interpreted as subaquatic mass-movements triggered by historical and pre-historical regional earthquakes dated to AD 2005, AD 1891, AD 1045 and 1260, 2545, 2595, 3350, 3815, 4740, 7190, 9185 and 11 495 cal. yr BP. Dark-coloured SEs develop high-amplitude reflections in front of the deltas and in the deep central basin. These beds are mainly made of terrestrial organic matter (soils and lignocellulosic debris) and are interpreted as resulting from intense hyperpycnal flood event. Mapping and quantifying the amount of soil material accumulated in the Holocene hyperpycnal flood deposits of the sequence allow estimating that the equivalent soil thickness eroded over the catchment area reached up to 5 mm during the largest Holocene flood events. Such significant soil erosion is interpreted as resulting from the combination of heavy rainfall and snowmelt. The recurrence of flash flood events during the Holocene was, however, not high enough to affect pedogenesis processes and highlight several wet regional periods during the Holocene. The Holocene period is divided into four phases of environmental evolution. Over the first half of the Holocene, a progressive stabilization of the soils present through the catchment of Lake Ledro was associated with a progressive reforestation of the area and only interrupted during the wet 8.2 event when the soil destabilization was particularly important. Lower soil erosion was recorded during the mid-Holocene climatic optimum (8000–4200 cal. yr BP) and associated with higher algal production. Between 4200 and 3100 cal. yr BP, both wetter climate and human activities within the drainage basin drastically increased soil erosion rates. Finally, from 3100 cal. yr BP to the present-day, data suggest increasing and changing human land use

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Section: Methodsmentioning

confidence: 99%

Mass-movement and flood-induced deposits in Lake Ledro, southern Alps, Italy: implications for Holocene palaeohydrology and natural hazards

Simonneau

Chapron²,

Vannière

et al. 2013

Clim. Past

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“…Other studies have shown, however, that organic matter in modern deep‐sea sediments may occur in high amounts where oxygen is not significantly depleted [ Pedersen and Calvert , 1990; Martinez et al , 1996; Prakash Babu et al , 1999]. Moreover, studies on Jurassic anoxic sediments showed that productivity more than anoxia may have been the primary control on organic content variability [ Bertrand and Lallier‐Verges , 1993; Ramanampisoa and Disnar , 1994].…”

Section: Introductionmentioning

confidence: 99%

Organic‐rich sediments in ventilated deep‐sea environments: Relationship to climate, sea level, and trophic changes

et al. 2003

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[1] Sediments on the Namibian Margin in the SE Atlantic between water depths of $1000 and $3600 m are highly enriched in hydrocarbon-prone organic matter. Such sedimentation has occurred for more than 2 million years and is geographically distributed over hundreds of kilometers along the margin, so that the sediments of this region contain a huge concentrated stock of organic carbon. It is shown here that most of the variability in organic content is due to relative dilution by buried carbonates. This reflects both export productivity and diagenetic dissolution, not differences in either water column or bottom water anoxia and related enhanced preservation of organic matter. These observations offer a new mechanism for the formation of potential source rocks in a well-ventilated open ocean, in this case the South Atlantic. The organic richness is discussed in terms of a suite of probable controls including local wind-driven productivity (upwelling), trophic conditions, transfer efficiency, diagenetic processes, and climaterelated sea level and deep circulation. The probability of past occurrences of such organic-rich facies in equivalent oceanographic settings at the edge of large oceanic basins should be carefully considered in deep offshore exploration.

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“…Numerous studies have reconstructed the palaeoceanographic conditions responsible for deposition of the sediments and postulated models to explain their enhanced TOC content as well as the correlation between TOC content and d 13 C TOC (e.g., Tyson et al, 1979;Cox and Gallois, 1981;Oschmann, 1988Oschmann, , 1991Miller, 1989;Huc et al, 1992;Hollander et al, 1993;Wignall, 1994a,b;Tyson, 1996;van Kaam-Peters et al, 1998;Saelen et al, 2000). Some of the models assume that these enhanced TOC values result from increased primary production (e.g., Oschmann, 1988;Huc et al, 1992;Bertrand and Lallier-Vergès, 1993;Herbin et al, 1993;Ramanampisoa and Disnar, 1994;Boussafir et al, 1995;Lallier-Vergès et al, 1997;Saelen et al, 2000); other models suggest enhanced preservation as the primary cause (Tyson et al, 1979;Sinninghe Damsté et al, 1998), whilst in various models both factors play a role (Tyson, 1996;Tribovillard et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Preservation of carbohydrates through sulfurization in a Jurassic euxinic shelf sea: Examination of the Blackstone Band TOC cycle in the Kimmeridge Clay Formation, UK

Dongen

Schouten

Damsté

2006

Organic Geochemistry

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A complete total organic carbon (TOC) cycle in the Upper Jurassic Kimmeridge Clay Formation (KCF) comprising the extremely TOC-rich (34%) Blackstone Band was studied to investigate the controlling factors on TOC accumulation. Compared with the under-and overlying strata, TOC in the Blackstone Band was enriched by a factor of six and, concomitantly, the d 13 C TOC shows a $4& enrichment. Al-normalized TOC values indicated that the enhanced TOC values were probably caused by increased TOC accumulation and not by a decreased dilution with inorganic matter. The amounts of short chain alkylated thiophenes and the sulfur-rich unresolved complex mixture (UCM) in the kerogen pyrolysates, as well as the TOC/Al ratios, correlated linearly with d 13 C TOC for sediments with TOC/Al ratios >1.7. The alkylated thiophenes and sulfur-rich UCM both originate from sulfurized carbohydrate carbon (C carb ), suggesting that the primary cause of the TOC maximum is the enhanced contribution of C carb to TOC. Since carbohydrates can be substantially 13 C-enriched over lipids in biomass, the enhanced contribution of C carb explains the enriched d 13 C TOC values. Compound specific isotope data showed that primary productivity during deposition of the KCF TOC cycle varied little, while a two member isotopic mixing model showed that the preservation of C carb relative to that of the lipid carbon may have increased by a factor of >10 in the Blackstone Band. The enhanced preservation of C carb was most likely caused by more frequent or longer lasting events of photic zone euxinia, as revealed by the concentration of isorenieratene derivatives. Enhanced contributions of C carb have also been observed in other KCF cycles, suggesting that enhanced preservation of C carb , rather than an increase in primary production, exerted direct control on the TOC cycles of the KCF.

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Primary control of paleoproduction on organic matter preservation and accumulation in the Kimmeridge rocks of Yorkshire (UK)

Cited by 47 publications

References 43 publications

Mass-movement and flood-induced deposits in Lake Ledro, southern Alps, Italy: implications for Holocene palaeohydrology and natural hazards

Mass-movement and flood-induced deposits in Lake Ledro, southern Alps, Italy: implications for Holocene palaeohydrology and natural hazards

Organic‐rich sediments in ventilated deep‐sea environments: Relationship to climate, sea level, and trophic changes

Preservation of carbohydrates through sulfurization in a Jurassic euxinic shelf sea: Examination of the Blackstone Band TOC cycle in the Kimmeridge Clay Formation, UK

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