Search results for "visual_art"

Bone diagenesis in arid environments; An intra-skeletal approach

2014

Bone trace element content and isotopic composition are closely related to human nutrition. The investigation of archaeological bone geochemistry can help us to better understand the relationship between past populations and their environment alongside cultural practices as inferred from dietary reconstruction. However, dietary in- formation may be altered post-mortem by diagenetic processes in soil. In this study, bone mineralogy (Ca/P, sec- ondary minerals, organic matter content and bone apatite crystallinity), histology, element content (Mg, Na, F, Sr, Ba, Mn, Fe, La, Ce and U) and stable isotope composition (δ13Candδ18O carbonate) were investigated at the intra- individual scale in ord…

2017

We present a new multi-analytical approach to the characterization of black pigments in Spanish Levantine rock art. This new protocol seeks to identify the raw materials that were used, as well as reconstruct the different technical gestures and decision-making processes involved in the obtaining of these black pigments. For the first of these goals, the pictorial matter of the black figurative motifs documented at the Les Dogues rock art shelter (Ares del Maestre, Castellon, Spain) was characterized through the combination of physicochemical and archeobotanical analyses. During the first stage of our research protocol, in situ and non-destructive analyses were carried out by means of porta…

Early evidence of fire in south-western Europe: the Acheulean site of Gruta da Aroeira (Torres Novas, Portugal)

2020

The site of Gruta da Aroeira (Torres Novas, Portugal), with evidence of human occupancy dating to ca. 400 ka (Marine Isotope Stage 11), is one of the very few Middle Pleistocene localities to have provided a fossil hominin cranium associated with Acheulean bifaces in a cave context. The multi-analytic study reported here of the by-products of burning recorded in layer X suggests the presence of anthropogenic fires at the site, among the oldest such evidence in south-western Europe. The burnt material consists of bone, charcoal and, possibly, quartzite cobbles. These finds were made in a small area of the cave and in two separate occupation horizons. Our results add to our still-limited know…

Depositional environments and iron ooid formation in condensed sections (Callovian Oxfordian, South-eastern part of the Paris basin, France)

2005

Carbonate platforms across Western Europe were superseded at the Middle–Upper Jurassic (Callovian–Oxfordian) boundary either by alternating marl–limestone and widespread marl deposits or by condensed sections containing iron ooids. The characteristics of marine condensed sections in the south-eastern part of the Paris Basin (France) and their distribution pattern are examined here, and a model of iron ooid formation is developed. Iron ooids are found from the shoreface to the offshore zone. They are most abundant in the median-to-distal offshore transition zone, where they originally formed. They also occur commonly, albeit often as reworked grains, in the proximal offshore zone, to which t…

Revised phosphate-water fractionation equation reassessing paleotemperatures derived from biogenic apatite.

2010

8 pages; International audience; Oxygen isotopes of biogenic apatite have been widely used to reassess anomalous temperatures inferred from oxygen isotope ratios of ancient biogenic calcite, more prone to diagenetic alteration. However, recent studies have highlighted that oxygen isotope ratios of biogenic apatite differ dependent on used analytical techniques. This questions the applicability of the phosphate–water fractionation equations established over 25 years ago using earlier analytical techniques to more recently acquired data. In this work we present a new phosphate–water oxygen isotope fractionation equation based on oxygen isotopes determined on fish raised in aquariums at contro…

Landscape and wood-fuel in Akrotiri (Thera, Greece) during the Bronze Age

2017

Abstract Wood charcoal macroremains originating from the archaeological site of Akrotiri, Thera (Greece) have been analyzed. The results obtained suggest the existence of thermophilous vegetation on the island from the Early Cycladic period right up to the catastrophic eruption of the volcano in the Late Cycladic I period. The comparative evaluation of the results gained from this study and the previous ones indicates that during the Early Cycladic period an open Pinus type brutia/halepensis (Cyprus/Aleppo pine) forest prevailed on the island, accompanied by maquis vegetation. From the Middle Cycladic period and onwards a shift towards open maquis vegetation is observed. At the same time, s…

Wood as a structural element in the houses of Akrotiri on Thera, Greece. The anthracological evidence

2021

Abstract The highly destructive eruption of the volcano of Santorini during the Late Cycladic I period as a fortunate consequence caused the buildings of the archaeological site of Akrotiri on Thera (Greece) to be remarkably well preserved. The present study deals with wood charcoal macroremains from the construction timbers of two buildings from this site, namely Xeste 3, a semi-public building and the House of the Ladies, a private building. The data suggest the extensive use of Olea europaea for the construction of the wooden floors of the upper storeys, the doors and the infrastructure of the walls. Other taxa systematically used for the beams of the floors of the upper storeys were Pin…

Different parts of the same plants. Charcoals and seeds from Cova de les Cendres (Alicante, Spain)

2018

Abstract The analysis of archaeobotanical macroremains from Cova de les Cendres (Teulada-Moraira, Alicante, Spain) allows a better understanding of the dynamic of the vegetation during the Upper Palaeolithic in the region. The anthracological sequence shows that Pinus type nigra/sylvestris dominates in the area during the Upper Palaeolithic, while more open formations of Juniperus and Fabaceae spread in Upper Solutrean and Early-Middle Magdalenian. The carpological analysis that has been carried out in the Middle Magdalenian level has brought to light different species of Juniperus (J. sabina, J. communis and J. oxycedrus). This information indicates that during the period, Cova de les Cend…

The aminophosphonate glyphosine enhances phycobiliprotein yields from selected cyanobacterial cultures

2017

Among added-value products obtained from cyanobacterial cultures are phycobiliproteins, photosynthetic pigments that have found an increasing number of applications as natural dyes for food, cosmetics, pharmaceuticals, and antioxidants. To obtain sustainable production, we aimed at maximizing phycobilin yield through the increase of either the final biomass or the specific content of these pigments by varying culture parameters, such as chemical composition and pH of the medium or quality and intensity of the light. Here, we report that the addition to the culture medium of millimolar or submillimolar concentrations of the aminophosphonate glyphosine [(N,N-bis(phosphonomethyl)glycine], form…

Adhesion enhancement of cribellate capture threads by epicuticular waxes of the insect prey sheds new light on spider web evolution

2017

To survive, web-building spiders rely on their capture threads to restrain prey. Many species use special adhesives for this task, and again the majority of those species cover their threads with viscoelastic glue droplets. Cribellate spiders, by contrast, use a wool of nanofibres as adhesive. Previous studies hypothesized that prey is restrained by van der Waals' forces and entrapment in the nanofibres. A large discrepancy when comparing the adhesive force on artificial surfaces versus prey implied that the real mechanism was still elusive. We observed that insect prey's epicuticular waxes infiltrate the wool of nanofibres, probably induced by capillary forces. The fibre-reinforced composi…