Theories of Origin for the Georgia Kaolins&lt;subtitle&gt;A Review&lt;/subtitle&gt;

Dombrowski, Thomas

doi:10.1346/cms-sp-1.4

Cited by 10 publications

(2 citation statements)

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“…Similarly they are richer in SiO 2 than the kaolins of Buwambo (Uganda), Saxony and Bavaria (Germany), Devon and St. Austell (UK), and Bretagne (France). The kaolins of Latium are the largest deposits of volcanic origin in central Italy (Veglio et al, 1996), whereas the soft kaolins of Georgia, USA, formed from weathering of gneiss and granite source rocks (Dombrowski, 1993).…”

Section: Discussionmentioning

confidence: 99%

Characterization of El-Tih kaolin quality using mineralogical, geochemical and geostatistical analyses

2013

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Detailed multi-scale characterization of the kaolin quality and the controlling depositional environment is crucial for optimal quality upgrading and for prioritizing potential exploitation areas. In the present work, the quality of El-Tih kaolin, Egypt, was investigated using the chemical/mineralogical characteristics as well as the field observations of the clay. Chemical analysis of major oxides was carried out using energy dispersive X-ray fluorescence (EDS-XRF) spectrometry. Mineralogical analyses were carried out using X-ray diffraction (XRD) and scanning electron microscopy coupled with wavelength-dispersive X-ray spectroscopy (SEM-WDS). Spatial heterogeneity of the quality was evaluated applying kriging geostatistical techniques and potential zones were identified.Results clarified an upward gradual deterioration of the quality via a decrease in the Al2O3 content and thickness of the clay layers, and an increase in the TiO2 content. According to the kriging maps, areas of high potentiality indices (PI) characterized by high Al2O3 and low SiO2 content and maximum thickness of the kaolin are located to the west and east, and decrease toward the central part of the study area. The high PI zones are dominated by pseudo-hexagonal platy kaolinite, often forming accordion- and book-like aggregates with subordinate quartz and traces of Fe and Ti oxides, yielding minimal TiO2 and Fe2O3 contents. These zones of high PI are considered optimal for exploitation. Kaolinite was formed as a result of intensive weathering of rhyolite/granite and basalt in the source area, and subsequent erosion, transportation and deposition of the weathering mantles in a flood environment with marked depositional energy variations. Results allowed comparison with worldwide kaolin occurrences, and suggested the suitability of the studied kaolins for use in paper coating and filling and in higher-grade ceramics, after removal of free Fe- and Ti-oxide impurities.

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Section: Discussionmentioning

confidence: 99%

Characterization of El-Tih kaolin quality using mineralogical, geochemical and geostatistical analyses

2013

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“…The Chaswood Formation occupies a position at the inner edge of the Mesozoic-Tertiary "Coastal Plain" sediment wedge, similar to that of the commercially important kaolin of Georgia (Dombrowski, 1993), although the Georgia kaolins differ in age (Late Cretaceous, Paleogene) and depositional environment of the host sediment (estuarine and deltaic). Hurst and Pickering (1989) demonstrated that, in Georgia, commercial kaolins are restricted to the recharge area of the regional coastal plain aquifer immediately southeast of the pinchout of Mesozoic-Cenozoic wedge against Appalachian basement.…”

Section: A Genetic Model For the Formation Of Kaolin Deposits In The mentioning

confidence: 99%

Genetic Model and Exploration Guidelines for Kaolin Beneath Unconformities in the Lower Cretaceous Fluvial Chaswood Formation, Nova Scotia

Hundert

Piper

Pe‐Piper

2006

Exploration and Mining Geology

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Potentially commercial deposits of kaolin are found in the fluvial Lower Cretaceous Chaswood Formation, the sedimentologically proximal equivalent of deltaic sediments of the offshore Scotian basin. The geological setting of the kaolin deposits has been interpreted from high-resolution seismic-reflection profiles and boreholes, and mineralogical studies on one reference borehole. The kaolin is a product of early diagenesis involving meteoric water below the water table. The distribution of kaolin is controlled by the presence of intraformational unconformities that were sites of ground water recharge, and are marked by the development of oxisols above the water table. Such diagenesis was facilitated by interbedded, loosely consolidated, permeable sandstone. The highest-grade kaolin deposits are found in areas close to river belts, where overbank muds were not sufficiently drained to develop paleosols, but where later uplift created intraformational unconformities. In the sandstone, meteoric water flow altered feldspars to kaolin, thus yielding commercial silica sand deposits. It also altered ilmenite to rutile, which is concentrated as secondary placers in modern rivers that have eroded the Chaswood Formation and tills derived therefrom.Sommaire -Des dépôts de kaolin potentiellement économiques ont été notés dans la Formation de Chaswood d''âge Crétacé Inférieur, laquelle constitue un équivalent latéral en milieu fluviatile aux sédiments deltaïques du bassin de Scotian. Le contexte géologique de ces dépôts de kaolin a été interprété a partir de profils de seismique-réflection à haute résolution, de sondages, et d'études minéralogiques sur un sondage de référence. Ce kaolin est un produit diagénétique précoce formé par de l'eau météorique sous le niveau de la nappe phréatique. La distribution du kaolin est contrôlée par la présence de zones de recharge associées à des discordances intraformationelles marquées par le développement d'oxisols au-dessus du niveau de la nappe phréatique. La présence d'interlits de grès perméables faiblement consolidés a contribué à l'efficacité de ce processus diagénétique. Les dépôts de kaolin les plus riches se trouvent en périphérie des rivières, là ou les boues de la plaine d'inondation n'étaient pas suffisamment bien drainées pour permettre le développement de paléosols, mais où des mouvements verticaux subséquents ont crée des discordances intraformationelles. La circulation d'eau météorique dans les grès a entraîné l'altération des feldspaths en kaolin, générant ainsi des dépôts économiques de sable de silice. Elle a aussi causé l'altération de l'ilménite en rutile, que l'on trouve dans des placers secondaires situés dans des rivières contemporaines qui ont érodé la Formation de Chaswood et les tills qui en sont dérivés.

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Rare-Earth Minerals in Kaolin Ore, Mine Tailings, and Sands – Central Georgia, Upper Coastal Plain

Boxleiter

Elliott

2023

Clays and clay miner.

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The total concentrations of rare-earth elements (REE) in the mined kaolin (0.02–0.06 wt.%), kaolin mine tailings (0.03–1.9 wt.%), and the kaolin-associated Marion Member sand lithology (0.03–4.6 wt.%) opened questions regarding the modes of occurrence of the REE and the role(s) of chemical weathering and secondary processes to explain the presence of REE in these materials. The REE were hosted primarily by phosphate minerals (monazite, xenotime) based on mineralogic analyses (scanning electron microscopy, X-ray diffraction). Enrichments in the light rare-earth elements (LREE: La–Gd) and the high correlation coefficient values were noted between P and the total REE concentrations (r2 = 0.99) for the sands and the mine tailings. Lower correlation coefficient values were noted between total REE concentrations and Zr (r2 = 0.31). The coarse fractions of the mined kaolins were enriched in the heavy rare-earth elements (HREE: Y, Tb–Lu) relative to the kaolin-associated sand lithologies. The REE inventory cannot be explained solely by mineral inheritance within the mined kaolins. Lower correlation coefficient values between P and total REE, positive Eu/Eu* anomalies, and the presence of xenotime overgrowths on zircon showed the importance of the role of chemical weathering of the detrital minerals during post-depositional processes (such as diagenesis) leading to redistributed and fractionated REE within the mined kaolin. The possibility of adsorption of the REE to kaolin mineral surfaces in the fine fraction of the mined kaolins remains open and permits further study to characterize fully the multi-modal fractionation of REE possible in the Georgia kaolin deposits.

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Theories of Origin for the Georgia Kaolins<subtitle>A Review</subtitle>

Cited by 10 publications

References 0 publications

Characterization of El-Tih kaolin quality using mineralogical, geochemical and geostatistical analyses

Characterization of El-Tih kaolin quality using mineralogical, geochemical and geostatistical analyses

Genetic Model and Exploration Guidelines for Kaolin Beneath Unconformities in the Lower Cretaceous Fluvial Chaswood Formation, Nova Scotia

Rare-Earth Minerals in Kaolin Ore, Mine Tailings, and Sands – Central Georgia, Upper Coastal Plain

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