Magnetic and chemical characterisation of a diagenetic magnetic mineral formed in the sediments of productive lakes

Hilton, J.; Lishman, J.P.; Chapman, Jenna

doi:10.1016/0009-2541(86)90012-4

Cited by 36 publications

(28 citation statements)

References 12 publications

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“…In clastic-dominated sediment systems such as Lake Elsinore, the amount of magnetic material is a function largely of the flux of allochthonous sediment into the lake's basin. There are, however, other factors that can affect sediment magnetic susceptibility such as post-depositional diagenesis (Hilton , 1985;Hilton et al, 1986), dilution from organic matter and/or carbonates, and mineral segregation by wave action (Smoot and Benson, 2004). Because both cores LESS02-8 and -10 were collected from near the modern shore position, it is expected that the sediments are influenced strongly by wave action and similar nearshore current processes throughout similar lake stands (Fig.…”

Section: Magnetic Susceptibilitymentioning

confidence: 99%

Hydrologic variability and the onset of modern El Niño–Southern Oscillation: a 19 250‐year record from Lake Elsinore, southern California

Kirby

Lund

Poulsen

2005

J Quaternary Science

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2005. Hydrologic variability and the onset of modern El Niñ o-Southern Oscillation: a 19 250-year record from Lake Elsinore, southern California.ABSTRACT: There are very few terrestrial palaeoclimate archives spanning the Last Glacial Maximum through the Holocene from coastal southern California. Yet, knowledge of past climate dynamics is critical for assessing present and future constraints on the region's dwindling freshwater resources. We present initial results from two drill cores extracted from the present-day edge of Lake Elsinore, southern California's largest natural lake. Using a multiproxy approach including lithologic description, mass magnetic susceptibility, LOI 550 C (total organic matter), and LOI 950 C (total carbonate), we infer first-order, long-term climate change over the past 19 250 calendar years. Furthermore, we suggest possible first-order forcing mechanisms that drive this change, which include presence/absence of continental ice sheets, insolation, and complex ocean-atmosphere interactions. Our results indicate four distinct millennial-scale climate modes over the past 19 250 calendar years. These modes include a wet Last Glacial Maximum (19 250-17 120 cal. yr BP), a relatively dry late-Glacial/Holocene transition (17 120-9450 cal. yr BP), a wet early Holocene (9450-7670 cal. yr BP), and a highly variable mid-to-late Holocene climate (i.e., alternating wet/dry cycles; 7670 cal. yr BP-present). We attribute the mid-to-late Holocene climate interval to the onset of El Niñ o-Southern Oscillation ca. 7000 cal. yr BP and a more vigorous hydrologic system. These results are supported by a variety of regional terrestrial and marine palaeoclimate archives.

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Section: Magnetic Susceptibilitymentioning

confidence: 99%

Hydrologic variability and the onset of modern El Niño–Southern Oscillation: a 19 250‐year record from Lake Elsinore, southern California

Kirby

Lund

Poulsen

2005

J Quaternary Science

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“…Particular geochemical conditions are required for the preservation of ferrimagnetic sulfide phases [Westrich and Berner, 1984;Canfield and Berner, 1987], however, greigite has increasingly been recognized as an important remanence carrier in sediments deposited under sulfate-reducing conditions, largely as a result of more frequent application of mineral magnetic (thermomagnetic and SIRM/z) and geochemical (X ray diffraction) techniques in paleomagnetic studies. Hilton et al [1986] proposed an authigenic/diagenetic origin for a potentially large part of the mineral magnetic content of organic sediments from productive lakes, however, the significance of authigenic magnetic phases in marine environ-menCs is underestimated in the model of Hilton [ 1987]. This is particularly the case because greigite has been so widely identified in marine sediments [e.g., Tric et al, 1991;Horng et al, 1992;Roberts and Turner, 1993;Reynolds et al, 1994].…”

Section: Authigenic/diagenetic Formation Of Ferrimagnetic Phasesmentioning

confidence: 99%

Environmental magnetism: Past, present, and future

Verosub¹,

Roberts²

1995

J. Geophys. Res.

503

248

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Environmental magnetism involves the application of rock and mineral magnetic techniques to situations in which the transport, deposition, or transformation of magnetic grains is influenced by environmental processes in the atmosphere, hydrosphere, and lithosphere. The first explicit description of environmental magnetism as a distinct field was in 1980. Since that time environmental magnetism has become a broad field that is finding application in an ever‐increasing array of scientific disciplines. In this review of the present state of environmental magnetic studies, we divide the field into three broad, but arbitrary, categories. The first involves the use of mineral magnetic assemblages in the geological record to study physical processes in depositional environments. This category includes the correlation of sediment cores using magnetic susceptibility measurements, studies of geomagnetic field behavior, the analysis of depositional and postdepositional mechanical processes that affect sediments, and the examination of magnetic parameters that might represent proxies for paleoclimatic variation. The second category encompasses studies of the processes responsible for variations in the magnetic minerals brought into a sedimentary environment. These provenance investigations include studies of changes in catchment‐derived sediment in lakes, fluctuations in contributions from terrigenous, aeolian and glaciogenic components in deep‐sea sediments, and the origin of atmospheric particulates. The final category addresses in situ changes and transformations of magnetic minerals in sedimentary environments, including pedogenesis, authigenetic/diagenetic formation of ferrimagnetic phases, dissolution of magnetic minerals due to reductive diagenesis, and contributions of biomagnetism to sedimentary magnetism. Because environmental magnetism can address problems in so many disciplines and because many of these problems may be inaccessible to other techniques, it is likely that the scope of environmental magnetism will continue to expand rapidly. Environmental magnetism is capable of providing important data for studies of global environmental change, climatic processes, and the impact of humans on the environment, all of which are major research initiatives in the international scientific community. These factors suggest that environmental magnetism has a bright and diverse future.

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“…Such results, interpreted in the light of the work of Hilton and Lishman (1985), Hilton et al (1986), Hilton (1990) and Snowball and Thompson (1988) would suggest that greigite formed a significant proportion of the magnetic minerals in the sediments. However, apart from a section from 480 to 610 cm in core ST77, where good correlations are observed between both original IRM and loss of IRM, and Mn (r= 0.684 and 0.694 respectively), no correlation was found between loss of magnetic remanence and variations in the factors often associated with the occurrence of greigite, such as sulphur or carbon con-181 centration (Hilton, 1986). On the contrary, in the upper part of the core, IRM3o0mv values (irrespective of whether the original, remeasured, or 'lost-during-storage' values were used) all correlate well (r = 0.74 to 0.93) with Mackereth's (1966) erosion indicators such as Na, K and Mg (Fig.…”

Section: Introductionmentioning

confidence: 87%

“…and Hilton et al (1986) demonstrated that the magnetic susceptibility of samples of late Holocene sediments from several English Lake District lakes declined during storage and slow oxidation from the initial fresh, wet state. Subsequently, Snowball & Thompson (1988) and Hilton (1990)have shown that greigite (Fe3S4), an authigenic iron sulphide, is present in some of the sediments associated with this loss of susceptibility and with a loss of isothermal and anhysteretic remanence.…”

Section: Introductionmentioning

confidence: 99%

Storage diagenesis versus sulphide authigenesis: possible implications in environmental magnetism

Oldfield

Darnley

Yates³

et al. 1992

J Paleolimnol

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Experiments involving the gradual drying out of controlled mixtures of soil and organic lake sediment during storage at room temperature show that this leads to\a loss of magnetic susceptibility and isothermal remanence greatly in excess of the initial values for the sediment components of the mixtures. We conclude that during storage in the moist state, soil-derived, fine-grained, ferrimagnetic iron oxides (magnetite and/or maghemite) are transformed to paramagnetic and/or imperfect antiferrimagnetic minerals. The imperfect anti-ferromagnetic component of the initial mixtures, which probably includes goethite, appears to survive and may even increase during storage. The experimental results compare well with the previously documented effects of storing wet sediment from the site, Peckforton Mere, Cheshire, U.K., over a comparable time interval. We conclude that transformation of fine grained ferrimagnets during 'storage diagenesis' may be responsible for many of the examples of loss of magnetic susceptibility and remanence attributed by other authors solely to the oxidation of an iron sulphide such as greigite. Only where greigite is positively identified is it valid to infer a contribution from it to the magnetic properties of lake sediments: loss of susceptibility or remanence during storage is not alone a sufficient basis for such an inference. Early drying of samples will normally avoid the effects of storage diagenesis; and recent sediment samples so treated will, where greigite formation, bacterial magnetite and magnetite dissolution are insignificant, provide a valid basis for source identification on the basis of magnetic properties.

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Magnetic and chemical characterisation of a diagenetic magnetic mineral formed in the sediments of productive lakes

Cited by 36 publications

References 12 publications

Hydrologic variability and the onset of modern El Niño–Southern Oscillation: a 19 250‐year record from Lake Elsinore, southern California

Hydrologic variability and the onset of modern El Niño–Southern Oscillation: a 19 250‐year record from Lake Elsinore, southern California

Environmental magnetism: Past, present, and future

Storage diagenesis versus sulphide authigenesis: possible implications in environmental magnetism

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