Early Ordovician shelly phosphorites of the Baltic Phosphate Basin

Ilyin, A. V.; Heinsalu, H

doi:10.1144/gsl.sp.1990.052.01.18

Cited by 7 publications

(5 citation statements)

References 2 publications

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“…4b) occurred during the Neoproterozoic-Cambrian (Cook and Shergold, 1984;Cook, 1992), the Permian-Triassic (Larina et al, 2019), the Cretaceous-Eocene, and the late Cenozoic (Schöllhorn et al, 2019). In addition, relatively smaller phosphorite deposits accumulated during other Phanerozoic periods, such as the Ordovician phosphorites of Sweden (Ilyin and Heinsalu, 1990), the Devonian phosphorites of northern Iran (Salama et al, 2018) and Brazil (Abram and Holz, 2020), and the Jurassic phosphorites of North America (Poulton and Aiken, 1989) and the Russian Platform (Kholodov and Paul, 2001). In our model, the development of phosphorite deposits is suggested to have been the result of highly efficient, rapid biologically-driven P cycling, which led to large amounts of P being transferred to the sedimentary reservoir over short periods of time.…”

Section: Ediacaran-phanerozoic Phosphogenesis Episodesmentioning

confidence: 99%

A Five‐stage Evolution of Earth's Phosphorus Cycle

JIAO,

DODD,

ALGEO

et al. 2023

Acta Geologica Sinica (Eng)

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Phosphorus (P) is a key biological nutrient and probably the ultimate limiter of marine productivity during Earth history. In recent years, a wealth of new knowledge has revolutionized our understanding of the global P cycle, yet its long‐term evolution remains incompletely documented. In this paper, we review the effects of three major controlling factors on the long‐term evolution of the global P cycle, i.e., tectonics, marine redox conditions, and bio‐evolution, on the basis of which a five‐stage model is proposed: Stage I (>∼2.4 Ga), tectonic‐lithogenic‐controlled P cycling; Stage II (∼2.4 Ga to 635 Ma), low‐efficiency biotic P cycling; Stage III (∼635 Ma to 380 Ma), transitional biotic P cycling; Stage IV (∼380 Ma to near‐modern), high‐efficiency biotic P cycling; and Stage V (Anthropocene), human‐influenced P cycling. This model implies that the earlier‐proposed Ediacaran reorganization of the marine P cycle may represent only the start of a ∼250–Myr–long transition of the Earth's P cycle (Stage III) between the low‐efficiency biotic mode of the Proterozoic (Stage II) and the high‐efficiency biotic mode of the Phanerozoic (Stage IV). The development of biologically‐driven, high‐efficiency P cycling may have been a key factor for the increasing frequency and volume of phosphorite deposits since the late Neoproterozoic.

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Section: Ediacaran-phanerozoic Phosphogenesis Episodesmentioning

confidence: 99%

A Five‐stage Evolution of Earth's Phosphorus Cycle

JIAO,

DODD,

ALGEO

et al. 2023

Acta Geologica Sinica (Eng)

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“…occurs on top of a complex of commonly cross-bedded siltstone and sandstone (Kallavere Fm.) containing debris or rich coquinas of phosphatic brachiopods denoting a large-scale skeletal phosphorite accumulation episode during the Cambrian-Ordovician transition (Ilyin & Heinsalu 1990;Hiller 1993). These siliciclastic deposits also contain interbeds and lenses of black shales.…”

Section: Geological Backgroundmentioning

confidence: 99%

“…Another critical factor of black shale development is bioproduction. The formation of rich skeletal phosphorite complexes during the initial stage of the Late Cambrian-early Tremadocian transgression suggests enhanced bioproductivity in considered marginal settings of the Baltic palaeobasin (Ilyin & Heinsalu 1990). The primary OM of the Türisalu Fm.…”

Section: Sedimentary Framework Of Organic-rich Mud Accumulationmentioning

confidence: 99%

Depositional framework of the East Baltic Tremadocian black shale revisited

Hints

Hade

Соэсоо

et al. 2014

GFF

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This article presents a centimetre-to micrometre-scale study of sedimentary fabrics from Lower Ordovician metalliferous black shale from the Baltic palaeobasin. Two sections of the Türisalu Fm. NW and NE Estonia were analysed with light microscopy and scanning electron microscopy. This rock unit is characterised by mostly thin bedding (,10 mm), common occurrence of minor erosional features, and a large variety of sedimentary fabrics, including graded, cross-laminated and massive fabrics. Based on this, we suggest that dynamic sedimentation events, rather than commonly assumed slow net sedimentation, may be the dominant mechanism behind the accumulation of these beds. The storm-related near-bottom flows and the bed-load transport of mud particles were likely common distribution agents of organic-rich mud. The mud (re)distribution, mainly via near-bottom flows and controlled by flat seafloor topography and general clastic starvation, might explain the present lateral distribution and diachronous character of the Türisalu Fm. Documented traces of microbial mat growth and siliceous sponges in the NW Estonia indicate that in more sheltered settings, biogenic factors played a vital role in developing primary mud characteristics. The geochemical palaeoredox proxies, and high trace metal and organic matter content suggest that mud sedimentation could occur under anoxic conditions. The observed sedimentary fabrics and traces of bioturbation, however, favour prevailing oscillating redox conditions in the lower water column. The recorded heterogeneity of microfabrics indicates that dynamic transport and intermittent deposition together with biogenic factors likely forced the development of an array of unique (bio)geochemical microenvironments for syngenetic trace element sequestration.

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“…To a lesser extent, Estonian phosphorite also contains pyrite (FeS 2 ) and dolomite (CaMgCO 3 ) [3]. These matrix sandstones often show a well-developed, small scale, and randomly oriented cross bedding with individual bed sets about 20-30 cm thickness [4]. The proportion of these minerals varies with layers and deposits.…”

Section: Introductionmentioning

confidence: 99%

Effect of Flotation Time and Collector Dosage on Estonian Phosphorite Beneficiation

et al. 2021

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Phosphorus is an essential and non-substitutable element for the cellular processes of all living organisms. The main source of phosphorus in the biosphere is phosphate rock. With more than 700 Mt phosphate rock, Estonia holds the largest sedimentary phosphate rock deposits in the European Union. Estonian phosphate rock is particularly outstanding due to its remarkably low content of hazardous heavy metals such as Cadmium (<5 ppm) and trace elements of Uranium (<50 ppm). It is also a reliable source of valuable elements such as rear earth elements (REEs). The aim of this study was to investigate the distribution of the main minerals (apatite and quartz) between slimes, tailings, and concentrates that formed at the froth flotation of Estonian phosphate rock with the up-to-date level of know-how and techniques. Subsequently, the relationship between the obtained grades and recovery levels in concentrates was determined based on the collector dosage and flotation duration. It was observed that the fine fraction of the tailings contains 17.9–33.49 wt% P2O5 that can be added to the final product. Moreover, it was found that, with the lower dosage of the collector, the extended flotation time does not influence the phosphate grade and a high amount of quartz remains in the concentrates. It was also shown that, by raising the collector dosage and setting the flotation time, an adequate grade (>32 wt% P2O5) and recovery (up to 98%) can be gained. The results showed that Estonian phosphate rock can be beneficiated to produce a high-quality concentrate at high recovery levels by modifying the main flotation parameters depending on the properties of the ore.

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Early Ordovician shelly phosphorites of the Baltic Phosphate Basin

Cited by 7 publications

References 2 publications

A Five‐stage Evolution of Earth's Phosphorus Cycle

A Five‐stage Evolution of Earth's Phosphorus Cycle

Depositional framework of the East Baltic Tremadocian black shale revisited

Effect of Flotation Time and Collector Dosage on Estonian Phosphorite Beneficiation

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