Limestone Pebbles Research Articles

Characterization of Limestone Surface Impurities and Resulting Quicklime Quality

Quicklime, rich in CaO(s), is generated by calcining limestone at high temperatures. Parallel-flow regenerative lime kilns are the most energy-effective industrial method available today. To prevent major disruptions in such kilns, a high raw material quality is necessary. Under some conditions, impurity-enriched material may adhere to limestone pebbles and enter the kiln. In this study, limestone and corresponding quicklime were analyzed to evaluate the extent and composition of surface impurities and assess the effect on quicklime product quality, here defined as free CaO. This was performed by sampling and analyzing limestone, quarry clay, laboratory-produced quicklime, and industrially produced quicklime with XRF, SEM/EDX, and XRD; interpretations were supported by thermodynamic equilibrium calculations. In the laboratory-produced quicklime, the surface impurities reacted with calcium forming Larnite, Gehlenite, Åkermanite and Merwinite, reducing the quicklime quality. The results showed that the limestone surface layer comprised 1.2 wt.-% of the total mass but possessed 4 wt.-% of the total impurities. The effect on industrially produced quicklime quality was lower; this indicated that the limestone surface impurities were removed while the material moved through the kiln. Multicomponent chemical equilibrium calculations showed that the quarry clay was expected to be fully melted at 1170 °C, possibly leading to operational problems.

A recent update in red-listing of Estonian lichens: threat status of 168 species was assessed for the first time


 
 
 The threat status of 168 lichenized species growing mostly on rocks or ground were assessed in 2022 for the first time in Estonia. The IUCN Red List system (categories and criteria) were used for that purpose. Most of the assessed taxa were microlichens (163), while five macrolichen species were also evaluated. Among the assessed species, 91 were assigned to the threat categories (Critically Endangered – CR, Endangered – EN and Vulnerable – VU), 17 species were assigned to the category Near Threatened (NT), and 41 species were assigned to the category Least Concerned (LC). Category Data Deficient (DD) was assigned for 17 species and the category Regionally Extinct (RE) for two species. Among the threat categories, 35 species were assigned to the category EN, 34 species to VU, and 22 species to CR. In general, most of the evaluated species (81%, 137 species) were growing on different types of rock, 16% (28 species) of species were growing on soil, mosses or plant debris, and three taxa were growing on other substrata. Most of the threatened epigeic and epilithic microlichens were recorded on alvar grasslands growing on ground, limestone pebbles and flatrock or erratic boulders. Er- ratic boulders in various forest types and calcareous cliffs in clint forest were also important habitats for threatened species. Moreover, different rock substrates of anthropogenic origin (walls, buildings and abandoned limestone quarries) performed as significant habitat type for epilithic species. Bush encroachment of open habitats, especially in semi-natural grasslands, serves as the main threat for epigeic and epilithic lichens.
 
 

Bifaces or not bifaces? Role of raw materials in the Middle Pleistocene. The example of levels E-E1, B and F (610–670 ka) at Notarchirico (Italy)

Notarchirico is the earliest Acheulean Italian site. On account of the wide variety of artefacts (cores, flakes, pebble tools and bifaces for some levels) and raw materials, it is also a key site for analysing behavioural variability in the Acheulean record before 600 ka, and for investigating the significance of occupation levels with and without bifaces. In this paper, we focus on the upper part of the sequence, which was excavated by M. Piperno in the 1980s and recently securely dated between 610 and 670 ka by 40Ar/39Ar. The deposits of Notarchirico consist of a superimposition of sandy and silty sediments, with more or less intense occupation levels interspersed with sterile layers. Here we present the technological analysis of the lithic assemblages of three paleosurfaces, F, E/E1 and B. The lithic corpus from levels F and B yielded some bifaces, whereas no bifaces were found in levels E/E1, where artefacts are mainly on small flint nodules and small limestone pebbles. Technological strategies are described in the three levels, in particular previously unpublished core technologies, and compared to the rest of the site sequence and to comparable Southern European sites. We present the different hominin strategies, their modes of adaptation to diverse types and geometries of raw materials and the concomitant cultural shifts and discussed by this way the role of activities and traditions.

Late Paleozoic microfaunas in the pebbles of the Podlipoglav conglomerate, Central Slovenia

The Paleozoic conglomerate at Podlipoglav in the transitional area between the External and Internal Dinarides of Slovenia contains limestone pebbles that have been examined micropaleontologically. The recovered conodont faunas are marked by the obvious absence of shallow-water taxa. The Lower to Middle Devonian faunas are characterized by relatively abundant polygnathids that are assigned to the Emsian and early Eifelian excavatus-nothoperbonus, laticostatus and costatus Zones. The Pennsylvanian conodont faunas contain relatively deep-water Neolochriea or gondolellids indicating an early Bashkirian and Moscovian age. A presence of the radiolarian species Pseudoalbaillella nodosa suggests a deep-water setting during the early Moscovian and it is the oldest yet-reported albaillellid finding in Central Europe.

Plants use water in the pores of rock fragments during drought

Soils are composed of both fine and coarse materials. Coarse material (> 2 mm) is considered to be inert and is usually discarded in models of plant water balance, even though it affects soil properties. No studies have yet attempted to assess whether rock fragments may act as a water reservoir for plants. Cuttings of Populus euramericana were planted in 5-L pots containing reconstituted soil made up of fine earth (silty clay loam texture) and either limestone or inert (quartz) pebbles (rock fragments 2–5 cm) at 0, 20, and 40% volume in a cross-factorial experiment. Two drought periods were applied and the growth, evapotranspiration, water stress status by stomatal conductance, and water content of the two soil phases (fine earth and pebbles) were monitored. First, pebbles can contain water, and ignoring this water induced and underestimations of the soil available water content by respectively 11% and 30% for the treatment with 20% and 40% limestone pebbles. Second, the plants grown on limestone pebbles were up to 70% less stressed than the plants grown on inert pebbles during drought. Third, stomatal conductance, a water stress indicator, was correlated with the water content of both the fine earth and the limestone pebbles. These results demonstrate that limestone rock fragments can retain available water and act as a reservoir during drought periods.

Discovery of Middle Jurassic trench deposits in the Bangong-Nujiang suture zone: Implications for the timing of Lhasa-Qiangtang initial collision

The Mesozoic trench deposits in the Bangong-Nujiang suture zone in central Tibet can provide critical information for reconstructing the paleotectonic evolution of the Bangong-Nujiang Ocean and constraining the timing of the Lhasa-Qiangtang initial collision. In this paper, the Gamulong Formation, which is well exposed in the Dong Co area, western Bangong-Nujiang suture, central Tibet, was studied. The sedimentological analysis shows that the Gamulong Formation was deposited in a submarine fan environment. The youngest detrital zircon age and fossils from limestone pebbles within the Gamulong Formation combine to determine a Middle Jurassic age. The pebbles in the conglomerate are dominated by limestones and sandstones, which is consistent with the sandstone petrology showing limestone and sandstone fragments as the main framework components. Detrital zircon U-Pb ages from the sandstones yield age populations of 164–178 Ma, 200–500 Ma, 700–1000 Ma, 1700–2100 Ma and ~2500 Ma. The corresponding zircon εHf(t) values are distributed between −23.5 and +11.1. These zircon features are similar to those from the Qiangtang terrane. Accordingly, the provenance results imply that the Gamulong Formation was recycled from the accretionary complex (Mugagangri Group mélange) in the Bangong-Nujiang suture zone and the forearc basin deposits (Lower-Middle Jurassic Sewa/Shaqiaomu/Jiebuqu formations) in the southern Qiangtang subterrane. The Gamulong Formation is characterized by sedimentary recycling in the trench, likely in response to a tectonic event (possibly the continental collision). Together with the previous studies, this work on the occurrence of the Gamulong Formation indicates that the Lhasa-Qiangtang initial collision could have occurred in Middle Jurassic time (~166 Ma).

Rocky-shore unconformities marking the base of Badenian (Middle Miocene) transgressions on Mt. Medvednica basement (North Croatian Basin, Central Paratethys)

Badenian (Middle Miocene) transgressive deepening-upward successions located in the NE part of Mt. Medvednica (North Croatian Basin, Pannonian Basin System) unconformably overlie Mesozoic basement. Triassic and Upper Cretaceous limestone pebbles, cobbles, and boulders of the Badenian basal conglomerates display abundant in situ bivalve borings of Gastrochaenolites and sponge borings of Entobia. This Gastrochaenolites-Entobia ichnoassemblage is related to the Entobia subichnofacies of the Trypanites ichnofacies, characterizing littoral rocky-shore environments (wave-cut platforms and marine transgressive surfaces with a low or null rate of sedimentation). Gastrochaenolites torpedo, Gastrochaenolites lapidicus, and Entobia recorded in Badenian basal conglomerates (compared with modern Northern Adriatic rocky-shore environments), enabled more precise palaeoenvironmental interpretations. The occurrence of G. torpedo (produced by lithophaginid bivalves) on all sides of individual limestone lithoclasts in the Gornje Oresje basal conglomerate, coupled with truncation of the formation (possibly indicating multiphase colonization), reflect gravel transport, roll-over, overturning and erosion by wave action in high-energy rocky-shore settings. Gornje Psarjevo-2 basal conglomerate boulders were probably not subjected to significant movement and abrasion, as suggested by good preservation of both G. lapidicus (potentially produced by gastrochaenid bivalves), associated G. torpedo, as well as abundant shallow Entobia borings. The Badenian Gastrochaenolites-Entobia ichnoassemblage also could be the result of a composite development. However, direct cross-cutting relationships between G. torpedo and G. lapidicus and/or Entobia were rarely observed. In addition, Badenian boring tracemakers might have coexisted at the same water depth. Northeast Mt. Medvednica Badenian successions probably formed during different Central Paratethys transgressive pulses (NN5 and NN6 Zones). However, exact timing of Badenian transgressions, stratigraphic correlations and tectono-eustatic implications are unresolved, due to sparsely integrated biostratigraphic and high-precision geochronological studies of Early–Middle Miocene North Croatian Basin deposits and due to the absence of a uniform biostratigraphic zonation and regional chronostratigraphic division of Central Paratethys.

Integrated stratigraphy, facies analysis and correlation of the upper Albian–lower Turonian of the Esfahan area (Iran): Unravelling the conundrum of the so-called “Glauconitic Limestone”

The so-called “Glauconitic Limestone of Esfahan” is a thin (<4 m) but very conspicuous lithological unit that is well known for its late Albian to middle Cenomanian ammonite faunas. However, it consists of two genetically unrelated stratigraphical units: the lower part commonly comprises fine-grained bioclastic limestones that are poor in macrofossils and rest with a sharp basal surface on mid-upper Albian strata of the deep-marine Bazyab Formation; the microbiostratigraphy shows this part to be mid-late Albian in age (Pseudothalmanninella ticinensis Zone), thus constituting a lithostratigraphical equivalent of the lower Debarsu Formation. The upper part of the “Glauconitic Limestone” consists of a fossiliferous glauconitic conglomerate with large rounded limestone pebbles to boulders and phosphatized bio-/lithoclasts, yielding the famous ammonite faunas of the unit. It has a major erosional unconformity at its base that may cut out the Debarsu Formation over short distances and it shows a fining-upward trend grading into an overlying marl and argillaceous limestone unit. These observations demonstrate that the glauconitic conglomerate initiated a new depositional cycle and is thus genetically related to the overlying fine-grained strata. Consequently, the glauconitic conglomerate is regarded as the basal Takhte-Sheitan Member (new) of the Kolah-Qazi Formation (new), formalized herein. The matrix of the upper part of the Takhte-Sheitan Member could be dated as mid-late Cenomanian (upper Rotalipora cushmani Zone) and the overlying fine-grained offshore deposits of the Kolah Qazi Formation as latest Cenomanian to early Turonian by means of foraminifera, ammonites, inoceramid bivalves and carbon stable isotopes. Thus, the late Albian to middle Cenomanian phosphatized ammonites from the Takhte-Sheitan Member are derived, i.e., represent classic remanié faunas. The Takhte-Sheitan Member is regarded as a complex, condensed transgressive lag onlapping a considerable palaeotopography after a late mid- to early late Cenomanian tectonic event. The overlying marl and argillaceous limestones of the Kolah-Qazi Formation indicate a considerable deepening in response to a major eustatic sea-level rise and highstand across the Cenomanian–Turonian boundary associated by increased organic carbon burial related to the oceanic anoxic event (OAE) 2. The carbon stable isotope curve from the base of the Kolah-Qazi Formation (Takhte-Sheitan Member) up-section into the marls and argillaceous limestones shows the conspicuous structure of the major positive excursion of the OAE 2 and serves as precise tool for the high-resolution chemostratigraphic calibration of the Iranian sections. It provides a new reference curve for the OAE 2 in the Middle East.

Devonshire marbles: history of the industry and the geology of these classic British ornamental stones

Devonshire ‘marbles’ come from Mid– to Late Devonian limestones of south Devon, UK. They are not true marbles in the geological sense but were nonetheless tectonically buried during the Variscan orogenesis. They retain abundant palaeontological and sedimentological characters, overstamped by limited to extensive veining, deformation and brecciation. Recent work has revealed how these marbles have been used to decorate a wealth of buildings in Britain and overseas. There were two distinct industries, one that produced decorative marble for architectural use, and one that produced portable artefacts such as specimen marble tables and ornaments. The stones used in these two sister industries can be very different, a result of different sourcing of the same Devonshire limestones. A third industry sought to slice and polish local limestone pebbles to reveal their diverse coral, stromatoporoid and other fossil contents, and was aimed at tourists, collectors and museums. The history and early development of the marble industry are explored and the distinct characteristics of the stones used in Devonshire marble inlay are explained. The stones used in the parallel architectural trade are analysed elsewhere.

کانه زایی مس- نقره سولفید توده ای آتشفشان زاد نوع بشی در توالی آتشفشانی- رسوبی کرتاسه پسین: مثال موردی کانسار گرماب پایین، جنوب شرق شاهرود

کانسار مس- نقره گرماب پایین در توالی آتشفشانی- رسوبی کرتاسه پسین زیر پهنه سبزوار واقع ‌شده است. کانه زایی به شکل هندسی چینه‌سان و چینه‌کران در افق چینه‌ای خاص به همراه نهشته‌های برون‌دمی رخ‌داده است. سنگ میزبان کانه زایی را سنگ‌های آتشفشانی آندزیتی- داسیتی و آذرآواری‌های وابسته تشکیل می‌دهند. کانه زایی از کمرپایین به سمت کمربالا در چهار رخساره رگه- رگه‌چه ای، توده‌ای- نیمه توده‌ای، لایه‌ای و رسوبات برون‌دمی رخ‌داده است. کانی‌شناسی ماده معدنی شامل کانی‌های اولیه نظیر پیریت، مگنتیت و کالکوپیریت و کانی‌های ثانویه نظیر مس طبیعی، مالاکیت، کوپریت، کولیت و اکسیدهای آهن- منگنز است. دگرسانی سنگ دیواره، به‌طور عمده از نوع کلریتی و به مقدار کمتر شامل سیلیسی، آرژیلیتی و زئولیتی است. حداکثر عیار طلا و نقره در کانسار به ترتیب 1 و 19 گرم در تن است. به نظر می‌رسد که بروز فعالیت آتشفشانی زیردریایی در یک حوضه پشت‌کمانی در کرتاسه پسین، به تشکیل این کانسار سولفید توده‌ای نوع بشی منجر شده است.

Beach deposits containing Middle Paleolithic archaeological remains from northern Israel

Beach deposits of the last interglacial maximum, MIS 5e, are common on the Mediterranean coasts, however only a few of them contain archaeological remains. Four beach deposits containing Paleolithic remains were previously identified on the Carmel coast of northern Israel which relate to the MIS 5e sea-level high stand of the last interglacial maximum. Here we report on a newly identified outcrop of beach deposit containing archaeological remains from Rosh Haniqra, on the northern Galilee coast, termed the Rosh Haniqra railway hill section. This beach deposit is in the form of a tilted lens (12.5 m long and 1.5 m thick) and is composed of seven layers, containing limestone pebbles and cobbles, crushed and whole marine shells, flaked flint implements and a mammalian bone, cemented by calcite. While the previously known Carmel coast beach deposits are embedded above or in kurkar deposits (aeolian calcareous cemented quartz sandstone), the Rosh Haniqra railway hill beach deposit lies directly on Cretaceous bedrock and is overlain by a 5 m-thick layer of kurkar. Based on the typology of the lithic artifacts and their similarity to other Middle and Late Mousterian flint assemblages found in beach deposits and loamy red soils along the northern Israeli coast, the Rosh Haniqra railway hill beach deposit probably dates to the MIS 5e high sea stand. However, its attribution to the earlier MIS 7 stage dating to ca. 200 ka, cannot be entirely discounted. Future absolute dating of the deposits may clarify this issue.

A Keleti-Bakony triász időszaki vulkanogén képződményeinek petrográfiai vizsgálata és képződési körülményeik értelmezése

A Tethys közép-európai triász időszaki fejlődéstörténetének nyomozása az egymástól távolabbi területeken található nem vulkanogén üledékes kőzetek összehasonlító vizsgálatával régóta eredményesen zajlik. A térben és időben is sokkal változatosabb kifejlődésű vulkanogén képződmények ezirányú vizsgálatában rejlő lehetőségek még messze nincsenek kihasználva. Ennek leginkább az lehet az oka, hogy ezeknek a hazai kőzeteknek a részletes kőzettani leírása még nem történt meg. Ladin vulkanogén törmelékes képződmények a Dunántúli-középhegységen belül a Keleti-Bakony területéről ismertek. Az itt található középső–késő-triász vulkanogén kőzetek részletes petrográfiai vizsgálata lehetőséget teremtett arra, hogy kőzettani alapon is összevessük más hasonló korú, képződésük idején egymáshoz sokkal közelebb elhelyezkedett Dunántúli-középhegységben és Déli-Alpokban megtalálható vulkáni képződményekkel.A vizsgált keleti-bakonyi összletek az inotai Hideg-völgy útbevágásában lévő egykori felszíni feltárásban, valamint a Várpalota Vpt–3 és a Bakonykúti Bút–2 fúrások anyagában tanulmányozhatók. A vulkanogén összlet két részre tagolható: az alsó részben uralkodóan vulkanit törmelékszemcsékből álló, szenesedett növénymaradványt és elszórtan crinoidea váztöredékeket tartalmazó finomszemcsés üledékes kőzetet, fölül vulkanit- és mészkőkavicsokat nagy mennyiségben tartalmazó, Daonella vázelemekben gazdag durvaszemcsés rétegcsoportot találhatunk. A vulkáni törmelék szemcsék között döntően intermedier (andezit), kisebb mennyiségben bázisos (bazaltsalak, bazalt és mikrodolerit) és savanyú (riolit, aplit) vulkanitok és ezekhez kapcsolódó kristálytörmelékek jelennek meg.A vulkanogén összlet forrását olyan középső- és felső-triász vulkáni kőzetek (bázisos-intermedier lávakőzetek és freatomagmás kitörések termékei) szolgáltatták, melyeknek mai rokon képviselői a Dunántúli-középhegységben (legközelebb a balatonfői területen), de legnagyobb kiterjedésben a vele ezen időszakban szomszédos Déli-Alpokban fordulnak elő. A felső vulkanogén konglomerátum / kavicsos homokkő képződésére jó analógia a déli-alpi Wengeni Formáció és Marmoladai Konglomerátum keletkezése. E formációk nagy vastagságú törmelékes összlete szárazulatra került, döntően mészkő és bázisos-intermedier kőzetek lepusztulásával, majd tenger alatti tömegmozgásokkal üledékgyűjtő medencékbe történő felhalmozódásával keletkezett. Az alsó vulkanogén homokkő keletkezése ettől némiképp eltér. Bázisos-intermedier összetételű törmelékanyaga első lépésben sekélytengeri/szárazföldi környezetben freatomagmás kitörés eredményeként halmozódott fel, majd közvetlen ezután tenger alatti lejtő mentén történő áthalmozódás után ülepedett le véglegesen.

The Breaking of Ochred Pebble Tools as Part of Funerary Ritual in the Arene Candide Epigravettian Cemetery

We present the analysis of 29 human-transported limestone pebbles found during recent excavations (2009–11) in the Final Epigravettian levels at the Caverna delle Arene Candide, Italy. All pebbles are oblong, most bear traces of red ochre and many appear intentionally broken. Macroscopic analyses demonstrate morphological similarity with pebbles used as grave goods in the Final Epigravettian necropolis excavated at the site in the 1940s. Mediterranean beaches are the most plausible source for the pebbles, which were carefully selected for their specific shape. Microscopic observation of the pebbles’ surfaces shows traces of ochre located on the edges and/or centres of most pebbles. A breakage experiment suggests that many pebbles were broken with intentional, direct blows to their centre. We propose that these pebbles were used to apply ochre ritually to the individuals buried at the site, and that some were subsequently ritually ‘killed’. This study emphasizes the importance of studying artefacts that are often ignored due to their similarities to simple broken rocks. It also provides a method to study pebbles as a distinct artefact category, and shows that even broken parts should be studied to understand the story told by such objects in the context of prehistoric human social systems.

Ubicazione delle cave di pietra da calce utilizzata come materia prima degli intonaci romani nella Lombardia occidentale

[it] La calce come materiale da costruzione ebbe larga diffusione nell’architettura romana della Lombardia occidentale. La presenza di carbonato di magnesio è stata per lo più riscontrata negli intonaci dipinti provenienti dai siti romani di Milano. Il carbonato di magnesio testimonia l’impiego di dolomia per la preparazione della calce e rocce di questa composizione affiorano per esteso nelle Prealpi lombarde: dolomie e calcari dolomitici grigio chiari (Dolomia del Salvatore, Ladinico-Anisico), dolomie grigie, talvolta con ciclotemi (Dolomia principale, Norico). Non sono conservate evidenze di cave o di forni romani in quest’area prealpina: i Romani sfruttarono gli stessi affioramenti dolomitici, situati lungo la sponda orientale del lago Maggiore, affioramenti da cui si produsse calce a partire dal Medio Evo in avanti. &#x0D; I depositi fluvio-glaciali del medio corso del fiume Adda tra Brivio e Trezzo (massi, ciottoli di calcari marnosi, calcari e dolomie che affiorano nel bacino fluviale) furono un’altra fonte medievale e moderna di materia prima, soprattutto per produrre una calce debolmente idraulica (chiamata “calce forte”), ma questo tipo di calce è assente negli intonaci romani.

RECONSTRUCTION OF A LOST CARBONATE FACTORY BASED ON ITS BIOGENIC DETRITUS (TERNATE-TRAVEDONA FORMATION AND GONFOLITE LOMBARDA GROUP - NORTHERN ITALY)

This work reconstructs a now completely eroded late Eocene to earliest Oligocene carbonate factory of Northern Italy, through the analysis of a carbonate deep-water-fan sequence (Ternate-Travedona Formation) and the limestone detritus dispersed into the late Oligocene clastic-wedge of the Gonfolite Lombarda Group. Textural characteristics and skeletal assemblages of the Gonfolite pebbles were studied and compared to those of the Ternate-Travedona Formation. The same skeletal assemblage and the same taxa were found in samples from both areas, suggesting their common origin. Whereas the Ternate-Travedona Formation skeletal grains were reworked during transport, the Gonfolite Lombarda Group pure-limestone pebbles are pristine fragments of the carbonate platform, that was uplifted and eroded from the late Eocene to the early Oligocene. Using both these sources of information it was possible to reconstruct the late Eocene environment and its facies distribution. The areas undergoing high hydrodynamic energy were dominated by free-living coralline-algal branches, rhodoliths and larger thick-tested benthic foraminifera. A coralline framework, associated with thin-tested benthic foraminifera and boxwork rhodoliths, was present in slightly deeper and sheltered environments. Episodic debris flows, mainly triggered by river floods, supplied the sub-marine fan of the Ternate-Travedona Formation. These events were able to down-cut through the narrow platform and rip off large fragments of the substrate. River runoff probably also supplied large quantities of organic matter, leading to local oxygen-depletion and preservation of organic matter. The combined stressful effects of bottom instability and riverine discharge probably excluded corals from the association. The integrated study of the Ternate-Travedona Formation, and of the limestone pebbles in the Gonfolite Group, have enabled the reconstruction of this otherwise lost Eocene carbonate factory.

Middle Palaeolithic technical behaviour: Material import-export and Levallois production at the SU 13 of Oscurusciuto rock shelter, Southern Italy

The Oscurusciuto rock shelter, located in southern Italy (Puglia), has yielded a long Middle Palaeolithic stratigraphy rich in lithic assemblages, fireplaces and faunal remains, attesting Neanderthal occupation during the MIS 3. This paper is focused on the stratigraphic unit 13, consisting of a sandy compact deposit mixed with pyroclastic sediment above a thick level of tephra-US 14, identified as Mt. Epomeo green tuff (dated Ar/Ar ~ 55 ka).Level 13 represents the first stable human occupation after the deposition of tephra. Our goal was to examine the lithic assemblage of this stratigraphic unit by means of an interdisciplinary approach (technology, RMU, refitting program) in order to identify the economic behaviour and technical strategies of Neanderthals occupying the stratigraphic unit 13 of Oscurusciuto.The technical strategies applied indicate fragmentation of the reduction processes, as well as probable events of importation and exportation of objects. The lithic material were introduced at different stages of manufacturing. Pieces were introduced in the form of rough objects (pebbles), as well as semi-finished items, and as finished tools. This fragmentation of the chaîne opératoire also demonstrate the palimpsest nature of the level which is made up of different events happening one after another.The main concept of debitage was Levallois, generally realized on local jasper and siliceous limestone pebbles or cortical flakes. Jasper and siliceous limestone flakes, backed flakes and convergent flakes were the technological objectives of the debitage. A marginal volumetric debitage aimed at producing bladelets was also attested.

Effects of transport and insertion of radio frequency identification (RFID) transponders on resistance and shape of natural and synthetic pebbles: applications for riverine and coastal bedload tracking

AbstractRFID transponders, especially low‐frequency Passive Integrated Transponders (PIT tags), are now commonly used for assessing bedload mobility in gravel‐bed rivers. Early studies reported high PIT tag recovery rates in small streams, but recovery rates in larger systems remain low. Explanatory factors for low recovery rates have been identified, but only antenna detection ranges and clustering effects have been precisely characterized. Burial below detection limit and dispersion beyond the study site have been indirectly estimated, and PIT tag destruction is assumed to be negligible. In this study, we quantified the resistance of natural limestone pebbles equipped with PIT tags as related to tag insertion methods and distance travelled in an annular flume. We then compared the performance of these natural pebbles with synthetic pebbles made of polyurethane resin and corundum. Creation of synthetic pebbles makes it possible to test bigger transponders with a greater detection range and no clustering effects, bypassing the existing constraints of RFID tracking. We found that breakage of limestone particles leading to PIT tag destruction is far too rare to explain low recovery rates in situ. Further, breakage is more affected by initial pebble characteristics than by PIT tag insertion method. Synthetic pebbles are more sensitive to attrition, but less likely to break. Natural and synthetic pebbles show slight differences in mobility patterns, transport distances, and abrasion resistances. One of the two synthetic pebbles travelled faster than the other three indicating that mobility is not only related to density but also potentially to shape. To address clustering and detection range issues, we equipped synthetic pebbles with AIT‐tags (Active Integrated Transponders). These were tested for integrity and transponder endurance and show great promise for future applications. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Acheulean in Monaco: Observatoire cave and its singular occupations

The Observatoire cave is located in the western end of the Principality of Monaco. Excavated very early – in 1916 – due to an event of an unexpected discovery, its lower unit, divided from c to k, delivered numerous assemblages including in particular handaxes, and more surprising, series of limestone large flakes and spherical pebbles. In the 1980's, new surveys were conducted and achieved a new layer (l) dated from 350 to 400ka (MIS 11-10). U–Th methods also gave two other dates within the stratigraphy: >178ka (>MIS 6) for stalagmitic floor II and >230ka (>MIS 7) for stalagmitic floor III. The oldest evidence of human occupations in Monaco – never studied in its integrality – deserved further and complete analysis of its successive assemblages. This work, based upon the use of unpublished archival data and a complete inventory and relocation of the pieces, provides precious and new information on the former “Old Paleolithic” filling. Petrographical, technotypological and morphofunctional analysis allowed highlighting the successive technoeconomic features. The correlation between the updated study of the industries coming from the old excavations and the unpublished results of the modern ones confirm the presence of a singular component (i–k units and l layer), out of the regional Paleolithic panorama. The lowest toolmakers selected subovoid and fist sized peripheral limestone pebbles, rarely andesitic, obviously for different in situ activities. They also shaped more voluminous and semi-local (?) limestone pebbles from which they imported standardized large flakes (≈100 × 100 mm) mostly used for their convex-cutting edge (cleaver). This specific and functional duo includes handaxes (k unit), pebble tools (l layer) and other products from few elaborated debitage made of semi-local (Ciotti) and allochtonous (Esterel, north of Var) siliceous materials. Consequently, it is considered within the Liguro-Provençal Acheulean panorama. The more recent knappers d–e–f-h1 left fewer traces (due to the function of their occupations?). They also rather favored the north peripheral (Ex-Vita) and ligurian (San Remo/Bordighera) areas while they employed more complex methods of debitage (Levallois recurrent unipolar, Levallois recurrent unipolar convergent, Levallois recurrent centripetal, unifacial/bifacial Discoid). In parallel of these productions (flakes, points and blades), shaping activities remained with the presence of two bifacial pieces (e unit) considered as support of tools, in contrast with the inferior bevel handaxe (k).

Bifaces used for percussion? Experimental approach to percussion marks and functional analysis of the bifaces from Terra Amata (Nice, France)

The structural analysis of the bifaces from the site of Terra Amata shows that, for seven pieces, the working edge is the distal part of the tool. Two bifaces bear use marks on this transversal working edge that can be related to use in handheld percussion. A specific experimental programme was developed to test these observations, consisting of striking different materials (fresh bone, dry wood, and fresh wood) with replicas of archaeological pieces made with the same limestone pebbles as those from the site. These experiments confirm the link between the marks on the transversal biface working edges and percussion activities.

Ocean current intensification during the Cretaceous oceanic anoxic event 2 – evidence from the northern Tethys

AbstractMesozoic Oceanic Anoxic Events (OAEs) are expressions of major physical oceanographic changes at times of perturbation of the global carbon cycle. A northern Tethyan record of OAE2 is preserved in expanded Cenomanian–Turonian pelagic limestone sections (Seewen Formation) in Eastern Switzerland. The new carbonate carbon‐isotope stratigraphy extracted from these limestones demonstrates that the OAE2 is condensed in all the studied successions and only the onset of the δ13C excursion (5.0‰) is present. The condensed interval is characterized by dissolution features, which are filled by a glauconite quartz sandstone. This bed is overlain by a well‐sorted sandstone with intercalated limestone pebbles (Götzis Member), which can be compared with palimpsest sands forming today along current‐swept shelves. The wide distribution of this thin sandstone layer within OAE2 indicates that an intense, erosive, east‐west trending shelf current was active during the highest sea level and most extreme carbon‐cycle perturbation of the OAE2.