Clay Sources Research Articles

The evolution of Crema (Cream) wares in the Valley of Oaxaca – Insights from INAA and ceramic petrography

The visually distinctive pastes of crema (cream) ceramics hold a special place in reconstructing the prehistory of highland Oaxaca, Mexico. Their characteristic large, white, angular (crystalline) inclusions have been linked to a single clay source located just north of Monte Albán, thus the ware is often interpreted as a marker of contact with Monte Albán. To assess this assumption of a single, localized production area, we analyze a large sample of crema ceramics from the Valley of Oaxaca ranging in date from ca. 700 BCE to 850 CE. Specifically, we combine both INAA (N = 754) and ceramic petrography (N = 27) to examine the internal consistency of crema wares and address the question of whether all cremas share the same chemical and mineralogical signature indicating a common provenance, or whether chemical and mineral subgroups reflect different manufacturing locales for this important ware. Our results indicate that cremas have a longer and more complex history than previously thought, and potentially affect how we employ this ceramic ware to understand the influence of Monte Albán within the valley and beyond.

Reaction mechanism of alkali-activated brick clay mill residues

The need for low-carbon and low-cost building materials has become increasingly urgent in these years due to the concern over climate change. Clay-based geopolymer or alkali-activated materials can be one possibility to meet the need. Some researchers have reported the synthesis of high-strength alkali-activated materials from untreated clay sources. However, the investigation into the reaction mechanism of the alkali-activated clay is still limited. This would be one reason why this method has not been adopted in practice yet. Thus, this paper attempted to elucidate the reaction mechanism of a kind of alkali-activated material derived from brick clay mill residues. Both the FTIR and XRD results revealed that the clay minerals, muscovite/illite and kaolinite, within the mill residues indeed participated into the alkali activation process. The elevated curing temperature played a vital role in activating these two minerals. The dissolution of both the muscovite/illite and kaolinite at 65 °C was weak because the movement of the water molecules of the alkaline activator was not sufficiently intense to cleave the interlayer spacing of the two mineral crystals as identified by XRD. As the curing temperature increased, the dissolution of both the minerals were enhanced. The best temperature for kaolinite was found at 110 °C, and for muscovite/illite, it was 155 °C. The results also showed that the ingredient of the alkaline activator impacted the alkali activation of the mill residues. According to the changes in chemical bonds identified by FTIR, the dissolution of kaolinite was found to be more intense when the alkalinity of the activator was stronger. In comparison, the favorable alkalinity for dissolving muscovite/illite could neither be excessively high nor low. This study proposed a schematic mechanism of the alkali-activated mill residue in the end.

Partial Substitution of Binding Material by Bentonite Clay (BC) in Concrete: A Review

Concrete consumes millions of tons of cement, which causes global warming as cement factories emit huge amounts of carbon dioxide into the atmosphere. Thus, it is essential to explore alternative materials as a substitute of OPC, which are eco-friendly and at the same time cost-effective. Although there are different options available to use industrial waste instead of cement, such as waste glass, waste marble, silica fume fly ash, or agriculture waste such as rice husk ash, wheat straw ash, etc., but bentonite clay is also one of the best options to be used as a binding material. There are a lot of diverse opinions regarding the use of bentonite clay as a cement substitute, but this knowledge is scattered, and no one can easily judge the suitability of bentonite clay as a binding material. Accordingly, a compressive review is essential to explore the suitability of bentonite clay as a cementitious material. This review focuses on the appropriateness of bentonite clay as a binding material in concrete production. The attention of this review is to discuss the physical and chemical composition of BC and the impact of BC on the fresh and mechanical performance of concrete. Furthermore, durability performance such as water absorption, acid resistance and dry shrinkage are also discussed. The results indicate that bentonite clay increased the mechanical and durability performance of concrete up to some extent but decrease its flowability. The optimum proportion of bentonite clay varies from 15 to 20% depending on the source of bentonite clay. The overall study demonstrates that bentonite clay has the creditability to be utilized partially instead of cement in concrete.

Complementarity of LA-ICP-MS and petrography in the analysis of Neolithic pottery from the Scheldt River valley, Belgium

This paper presents the results of laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) analysis of the clay fraction in 70 Late Mesolithic and Early/Middle Neolithic pottery sherds from the Scheldt basin and 10 sampled sediments. The elemental concentration results were visualized using multivariate chemometric techniques and compared to the results of petrographic analysis of the same ceramics in order to investigate the complementarity of both approaches. In addition, the results for the pottery and sediments were compared for clay sourcing purposes. Overall, the elemental analysis was able to confirm part of the observations from the petrographic analysis. However, a large part of the ceramics chemical clustering was driven by heterogeneity in the elemental composition that does not stem from differences in the clay source used. Furthermore, no conclusions could be drawn on the use of the sampled sediments for pottery production. Therefore, it is concluded that LA-ICP-MS analysis of the clay fraction in pottery can complement petrography, but petrographic analysis remains indispensable for clay sourcing of pottery from northern Belgium.

English

Aflatoxin occurrence in poultry feed causes aflatoxicosis in birds and poses health hazards to the consumers. Aflatoxin B1 (AfB1) is the most predominant and toxic metabolite that is controlled through addition of argillaceous clays as non-nutritive additives. Non-smectitic indigenous clay reserves need testing as AfB1 adsorbent. With detailed mineral and adsorption characteristics, three indigenous non-smectitic clays: (i) palygorskite, (ii) palygorskite-smectite mix, and (iii) interstratified smectite with hydroxy interlayered smectite were tested against 250 µg kg-1 AfB1 contamination in a poultry feeding trial with three replications at 1% and 2% (w/w) with positive and negative controls. A total of 330 Ross-308 male broiler chicks, initially reared on clean feed under controlled conditions of light and humidity, were distributed into eleven treatment combinations in a completely randomized design with 30 birds in each treatment on an equal weight basis with three replications at day 14 and fed on experimental feeds for three weeks. Three birds from each pen were randomly slaughtered at day 35 and for each replicated treatment, body weight gain, feed intake, and internal organs weight and morphology were recorded. AfB1 contamination reduced weight gain (p 0.0001), feed conversion ratio (p 0.0001) and feed intake (p 0.0001) while clays addition in the toxin feed effectively controlled AfB1 toxicity as suggested by improved body weight, weight gain rate and feed consumption compared to the toxin fed birds. The liver morphology was comparatively better in palygorskite-smectite mix treatment when applied at 1% and the darkish colour was also improved with addition of the clay in the toxin feed. AfB1 feeding caused a 75% reduction in weight gain compared to the clean feed. Palygorskite and palygorskite-smectite mix clays were better than interstratified clay in increasing weight gain and caused a 60% and 65% increase over toxin feed treatment when applied at 1% and 2%, respectively. In conclusion, the indigenous clay sources overall and palygorskite-smectite mix in particular has the potential for use as a mycotoxin binder for controlling AfB1 incidence in poultry

Study of clay soil properties when using the method of concentrated lime exposure

Introduction. In the Siberian Federal Area, the abundance of clay soils sources with above-optimal moisture content significantly complicates the technology of operations, reduces the speed of work, and makes some reserves unusable. To solve these problems, the use of quicklime in preparation for quarrying of clay soils with above-optimal moisture content was considered.The experimental studies have been carried out on the dynamics of soil drainage (lightweight dust loam) from drilling a well filled with lightweight lime (concentrated lime method). During this study, three experiments were carried out on soil masses with different initial humidity, two of which were carried out under the influence of lime and one (control) without the effect thereof.In addition, the change in optimum humidity and maximum density of dry soil during lime injection into loamy soil (dosage from 2% to 6% by mass) was evaluated. On the basis of the results obtained and the analysis of literature sources rational distances between slots (wells) are justified when using concentrated lime action technology to drain soils with increased humidity in quarries.Negotiations and conclusions. On the basis of the results obtained in the course of the study, it can be concluded that drying the soil with lime by the proposed concentrated method has a positive effect on the physical and mechanical characteristics of the soil.

Characterization of bituminite in Kimmeridge Clay by confocal laser scanning and atomic force microscopy

This work investigates bituminite (amorphous sedimentary organic matter) in Upper Jurassic Kimmeridge Clay source rock via confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM). These petrographic tools were used to provide better understanding of the nature of bituminite, which has been historically difficult to identify and differentiate from similar organic matter types in source rocks. As part of an International Committee for Coal and Organic Petrology (ICCP) working group, an immature (0.42% vitrinite reflectance), organic-rich (44.1 wt% total organic carbon content) sample of Kimmeridge Clay was distributed to multiple laboratories for CLSM characterization. The primary observations from CLSM imaging and spectroscopy include: 1) the interpreted presence of Botryococcus algae as a contributor to bituminite precursors; 2) color red-shift of sulfide reflectance and bituminite auto-fluorescence from below the sample surface; 3) positive alteration of bituminite from laser-induced photo-oxidation of the sample surface, including fluorescence blue-shift; 4) fluorescence blue-shift associated to higher fluorescence intensity regions in bituminite indicative of compositional (fluorophore) differences; 5) the need for fluorescence spectroscopy standardization as applied via CLSM; and 6) the suitability of CLSM fluorescence spectroscopy to predict solid bitumen reflectance from bituminite spectral emission via calibration to an extant dataset. Secondary CLSM observations include detection of reflected laser light from highly reflective inclusions in bituminite, including sulfides and fusinite, and radiolytic alteration of bituminite caused by substitution of U for Fe in sulfides. Findings from AFM include the observation that surface roughening or surface flattening of bituminite are induced by differential broad ion beam (BIB) milling and are dependent on the location and scale of AFM topology measurement. This result highlights our still limited understanding of the effects of BIB milling on sedimentary organic matter and indicates the need for further research before this technique can be advanced as a standard practice in petrographic sample preparation. Collectively, the results of this study illustrate the general applicability and versatility of AFM and CLSM as tools for organic petrology research, specifically for better understanding of the nature and properties of the bituminite maceral.

Physicochemical and mechanical properties of cementitious matrices reinforced by red clay powder

In this work, the effort is directed to study the physicochemical and mechanical properties of red clay reinforced mortar. Numerous tests have been conducted to test the behavior of such mixtures of red clay and cement. Berrechid (Morocco) is the source of the red clay. The cement matrices were prepared by mixing Portland cement, sand, water, and an addition of red clay powder that ranged from 2 to 14% by weight of cement. XRF analyses were performed on red clay powder, cement, and cement matrices, and XRD analysis was carried out on red clay powder. The compressive strength of these matrices was measured during their curing period (7, 14, 21, and 28 days) to evaluate their mechanical performances. The results of the tests showed that the compressive strength could reach more than 39 MPa by the addition of 6% of this clay, which improves the rate of compressive strength by up to 53% in comparison to just the mortar. The addition of red clay to the cement matrix shows better performance in terms of the containment of radionuclides.

Activated carbons synthesized from sucrose using porous clay heterostructures as template for CO2 adsorption

• Activated carbons were synthesized from sucrose using PCH as template • Physicochemical properties can be controlled through synthesis conditions • The pretreatment with KOH improve textural properties at lower temperatures • Materials synthesized with KOH exhibited stronger adsorbate-adsorbent interactions In this work we have analyzed the synthesis of microporous materials using sucrose as carbon source and porous clay heterostructures as template to promote a hierarchical organization of pores, which is a novelty in the synthesis of carbonaceous materials. The study comprises the evaluation of the synthesis conditions such as the addition of a base (KOH) or the variation of the pyrolysis temperature (600, 750 and 900°C). The studied materials were characterized via X ray diffraction, Transmission Electron Microscopy, gas adsorption, Attenuated Total Reflectance, Raman spectroscopy and X-ray Photoelectron Spectroscopy. Additionally, the performance of the synthesized adsorbents in terms of CO 2 uptake at three temperatures (0, 25 and 45°C) was assessed and compared with similar materials reported in the literature. The results suggested by and large that the use of the base and the highest pyrolysis temperature (900°C) during the synthesis enhances the CO 2 adsorption at the different evaluated temperatures. Nonetheless, it is at the lowest pyrolysis temperature i.e., 600°C, where one can observe a more accentuated superior performance of the material synthesized with base than that obtained without the addition of KOH.

Looking for Ephesian workshops: an integrated petrographic, geochemical, and chrono-typological approach to Late Hellenistic Ephesos lamps

In this pilot study, Late Hellenistic mold-made lamps from Ephesos are investigated by combining chrono-morphological and stylistic features with thin-section petrography and neutron activation analysis. Coeval wares of Ephesian production and clay samples collected around the site as well as published data from the Bonn database are considered local reference material. The results point to a network of local/regional workshops sharing facilities and/or a labor force dedicated to distinct tasks. The whole evidence is consistent with the very beginning of a nucleated workshop industry able to optimize the productivity of mold-made wares and fill the demand of an increased regional and supra-regional market. The typological and compositional variability of the latest phases could suggest a gradual transfer of potting activities towards areas providing better-suited clay sources.

Characterization of Ogwuta Source Clay Using Advanced Analytical Tools

One of the naturally abundant minerals with diverse industrial applications is the clay mineral. The choice of application depends on the characteristics of the clay. In this study, internal composition of the large and untapped Ogwuta clay deposit located in Afikpo, South Eastern Nigeria was further investigated as a guide to its applications. Scanning Electron Microscope (SEM), Thermogravimetric (TG), and X-ray diffraction (XRD) techniques were employed to access its composition. The scanning electron micrograph revealed that the clumping of the clay particles was due to edge-to-edge, edge-to-face or face-to-face flocculation. Thermogravimetric analysis revealed that at temperature range of 153-325°C, the observed weight percent loss (13.67%), consistent with kaolinitic clays, was due to the removal of water of crystallization of the interlayer cations. X-ray diffraction result further revealed kaolinite as the predominant mineral with the presence of quartz and polygorskite.
 This study has revealed the applicability of Ogwuta source clay in both industrial and manufacturing activities.

Systematics of smectite hydrogen-isotope composition: Structural hydrogen versus adsorbed water

Atmospheric water adsorbed onto clay mineral surfaces, of smectite group minerals in particular, can contaminate hydrogen released from structural hydroxyl groups during hydrogen-isotope analysis. Interlayer cation composition and cation hydration enthalpy, in particular, can affect the magnitude of this excess hydrogen yield and hence the hydrogen isotope composition (δ2H) of smectites. To evaluate this problem, δ2H of different cation-saturated (Ca2+, Na+, K+), dried forms of six smectite standards from the Clay Minerals Society Source Clays were measured using a modified sample drying and on-line High-Temperature-Conversion-Elemental-Analysis (TCEA) Continuous-Flow-Isotope-Ratio-Mass-Spectrometry (CF-IRMS) protocol. More negative interlayer cation hydration enthalpies (Ca2+ > Na+ > K+) led to higher residual adsorbed water contents, which produced poorer δ2H reproducibility for the determination of smectite hydroxyl hydrogen. The lowest adsorbed water contribution and the most reproducible and possibly accurate δ2H for smectite hydroxyl hydrogen was obtained for K-saturated smectites dried for both 4 and 24 h at 220 °C prior to isotopic analysis and transferred to a “Zero-Blank” autosampler in ≤2.5 min. This approach provided the lowest measurement error for hydroxyl δ2H and facilitated much greater sample throughput than classical methods for smectitic clays. This study proposes a protocol for hydroxyl δ2H determination in smectitic clay minerals, and reveals the effect of H-isotope fractionation of adsorbed water during sample preparation.

Characterization of pottery from the Neolithic Huadizui site, Henan province, China by using a multi‐analytical approach

AbstractThis paper represents the first study on the Xinzhai Culture pottery from Huadizui site, China using X‐ray diffraction (XRD), X‐ray fluorescence spectrometry (XRF), and petrographic. Huadizui pottery is considered to be produced locally, and the raw materials for making pottery come from the Xiaoqinling‐Xiong'er Mountain and Songshan Mountain chain. There are at least two or three clay sources or workshops in the Huadizui site, which is evidenced by petrographic characteristics and the chemical composition of samples. All of the investigated samples were mainly related to quartz and feldspar pellets. The corresponding relationship between the characteristics of the matrix and pottery categories reflects potters pursuing the function of vessels at that time. The range of firing temperature of almost all vessels is between 750 and 950°C.

From clays to pottery: Role of geomaterials in the social - technological development of the Messina territory (Sicily, Italy) and archaeological-historical information on the main kilns

This contribution is intended to answer the question of why in teaching approaches it is important to speak about territory? The answer to the question is driven by the consideration that the territory, including the established human activities, encompasses the history, the events and the culture of the people who populated it. On this regard, it should be noted that the relationship between natural elements and human activities that refer to a given territory has a dynamic character since both influence each other and help to write the history of that place. In this framework, the proposed method is used as an interdisciplinary approach to the theme of clay minerals. These latter are hydrous aluminium phyllosilicates, with variable amounts of iron, magnesium, alkali metals, alkaline earths. They are the main constituents of soils, and have been used by humans since ancient times in agriculture and manufacturing. For this reason, clays played a basic role for the human civilization process since its earliest periods. Clays are recognized amongst the most important rock products, both as raw material and in the form of pottery, bricks, tiles, terra-cotta and many other tools for daily use. This is particular evident in Sicily, where, since ancient times, the availability of local clay sources favoured the diffusion of clay-artefacts and related workshops found over the territory. This paper makes reference to a lecture addressed to university students and includes: i) the description of the main mineralogical features and properties of clay minerals; ii) a brief discussion on the role played by clays in terms of clay-artefacts production in the historical and cultural evolution of the Messina territory; iii) a description of local clay outcrops; iiii) a presentation of the main kilns over the Messina territory, and in particular of unpublished archaeological information on the S. Pier Niceto kilns. The proposed approach aims to increase the interest of students towards the significant aspects that affected the social-economic growth of the Messina’s territory and on the importance that geo-materials had in the technological evolution of its civilization process.

Pottery of Early Iron Age from the Glinjeni II-La Șanț (North-Western Pontic Sea Region): Composition, Technology and Raw Material Sources

Transition to the Early Iron Age was marked by the appearance of innovations such as iron technology and changes in the lifestyle of local societies on the territory of the North-Western Pontic Sea region. One of the most interesting sites of this period is the Glinjeni II-La Șanț fortified settlement, located in the Middle Dniester basin (Republic of Moldova). Materials of different cultural traditions belonged to the Cozia-Saharna culture (10th–9th cc. BC) and the Basarabi-Șoldănești culture (8th–beginning of 7th cc. BC) were found on this site. The article presents the results of a multidisciplinary approach to the study of ceramic sherds from these archaeological complexes and cultural layers as well as raw clay sources from this area. The archaeometry analysis, such as the XRF-WD, the thin section analysis, SEM-EDX of ceramics, m-CT of pottery were carried out. The study of ancient pottery through a set of mineralogical and geochemical analytic methods allowed us to obtain new results about ceramic technology in different chronological periods, ceramic paste recipes and firing conditions. Correlation of archaeological and archaeometry data of ceramics from the Glinjeni II-La Șanț site gives us the possibility to differ earlier and later chronological markers in the paste recipes of pottery of 10th–beginning of 7th cc. BC in the region of the Middle Dniester basin.

Quantitative mineralogical analysis of clay-containing materials using ATR-FT-IR spectroscopy with PLS method.

A universal method for quantitative analysis of clay components, in terms of mineral composition, using ATR-FT-IR spectroscopy (in the mid-IR and far-IR regions) combined with partial least squares (PLS) regression technique (ATR-FT-IR-PLS) is reported. For the PLS method development, altogether 222 samples covering natural clay sources and various archaeological/cultural heritage artefacts were used as calibration and validation standards. This is the largest calibration set used for creating an ATR-FT-IR-PLS method for clay minerals. The quantitative compositions of these standards containing combinations of altogether 29 minerals for the PLS method were determined using XRD analysis. The developed ATR-FT-IR with PLS method is quick and easy to use, and enables analysis of very small sample amounts (down to a few mg). This is very important when working with samples from archaeological and cultural heritage objects. The developed ATR-FT-IR-PLS method enables quantifying the contents of 7 main classes of minerals in different clays with a root mean square error of prediction (RMSEP) ranging from 0.9 to 5.1 g/100g. This means that in some cases, depending also on the content of the mineral in the sample, the accuracy is at a semiquantitative level. This quantitative method was successfully applied to 11 cultural heritage case-study samples.

High purity alumina synthesised from iron rich clay through a novel and selective hybrid ammonium alum process

The demand for high purity alumina (HPA) has been steadily increasing due to its use in advanced electronics and battery applications. This paper presents an innovative synthesis pathway, which is one of a series of pathways investigated to obtain HPA from a local Australian clay source with minimal clay processing. The novelty in this work was centred around impurity control since the feed clay had a high proportion of iron phases (19%). Ammonium aluminium sulfate (NH4Al(SO4)2·12H2O) was used as an intermediate to both selectively recover aluminium from sulfuric acid leachates and as a transition to finer refinement of aluminium in a chloride system through crystallisation of aluminium chloride (AlCl3·6H2O). The aluminium chloride was decomposed at 800 °C and 1200 °C to yield alumina with a purity of >99.99% Al2O3. The HPA product was characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and was found to be comprised of transitional alumina phases including κ and χ-Al2O3 after calcination at 800 °C and α-Al2O3 after calcination at 1200 °C. The purity of the HPA was assessed using an acid digestion method followed by analysis with ICP-OES and ICP-MS.

3D petroleum systems modelling as an exploration tool in mature basins: A study from the Central North SeaUK.

In this paper we apply two different geoscience tools: 3D petroleum systems modelling and the findings of rock magnetic analysis to a reassessment of the hydrocarbon migration system from the Upper Jurassic Kimmeridge Clay source rock to the reservoirs in the Tertiary Tay sandstones in the Western Central Graben in the Central North Sea, UK. The Tay Sandstones provide an excellent laboratory to study vertical and lateral migration in an area where the subsurface geology is well constrained by both modern 3D seismic data and a high density of cored wells. Mature, super basins such as the North Sea are often characterised by a perception that most of the oil has been found and there is no reason to update models even if new data has become available. During the course of this study, two untested prospects in the Gannet and Guillemot complexes have been identified and are presented as examples of the value generated by this type of integrated approach which promotes new thinking and critical testing of conventional models.

The indigenous settlement of Monte Iato (western Sicily): an ethnoarchaeometric approach for outlining local Archaic ceramic productions

An ethnoarchaeometric approach has been followed to identify the textural and compositional characteristics of the ceramic pastes produced in ancient Iaitas/Ietas, an indigenous site located in western Sicily on Monte Iato, a few tens of kilometres from Palermo. This approach was primarily motivated by the lack of discovered Archaic kilns or production sites/workshops and the inability to identify reference groups. Raw clays were sampled in the territory of San Cipirello and San Giuseppe Iato (today’s municipalities both sited on the northern slopes of Monte Iato), together with representative historic tiles and bricks locally produced until fairly recently. Grain-size analysis and experimental firings were performed on the clay samples. A significant number of archaeological ceramic samples (incised and painted indigenous pottery dating back to the seventh–fifth centuries BCE) from stratigraphic excavations on Monte Iato, and hypothesized as local productions on a stylistic-morphological basis, was carefully selected for archaeometric analysis. This set of samples (90 in total, comprising raw clays, historic tiles/bricks and archaeological ceramics) underwent a combined chemical and mineralogical-petrographic analysis to identify any possible compositional matching. This approach enabled the identification of minero-petrographic and chemical markers pertinent to the indigenous Archaic pottery produced at Monte Iato, although no evidence of coeval ceramic kilns has been found so far. Local raw clay sources have been documented and some significant points of the chaîne opératoire adopted in antiquity have been noted (clay mixing and tempering practices). Attesting Monte Iato as a centre of ceramic production and defining both the microscopic fabric and the average composition of local pastes open up new perspectives in the complex issue concerning the production and regional circulation of incised and painted indigenous ceramics in Archaic Sicily.

Geochemical analysis of colonoware and brick artifacts from Brook Green Plantation using portable X-ray fluorescence spectrometry

This study used data collected using a portable X-ray fluorescence spectrometer to examine ceramic artifacts found during the excavation of historic Brook Green Plantation, in Georgetown County, South Carolina. Excavations at this site yielded culturally significant artifacts associated with African and African American people held in bondage during the 19th century. The geochemical composition of Colonoware and brick artifacts was compared to clay samples that were taken from six locations on the grounds of Brookgreen Gardens. Some Colonoware sherds were found to be consistent with a clay source close to the excavation site. This research is part of a larger goal to demonstrate the applicability of portable X-ray fluorescence spectrometry in the analysis and interpretation of archaeological ceramics.