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Publications (64)
Ancient Gerasa (Jerash, since the Islamic period) is a city with a rich archaeological heritage from prehistory onwards, with the periods from Roman times into the Early Islamic period best attested. A Danish-German team has been working in the Northwest Quarter of the city since 2011. Among the findings was a Roman period monumental cistern that w...
Ancient Gerasa (its Greco-Roman name)/Islamic Jerash (its later Arab name) is one of the most well-known pre-modern urban sites in northern Jordan, which flourished throughout antiquity and into the early Islamic period. Direct dating of mortar and plaster in Jerash is challenging due to the area’s abundance of geological carbonates that hamper the...
Radiocarbon dating of mortars is a method for absolute dating of historical mortared stone structures. Successful mortar dating studies have answered chronological questions, while other studies have revealed that mortar samples can have complications and contaminants. These can cause inconclusive results even with present state‐of‐the‐art techniqu...
The 15th century cross-vaults of the medieval Modena Cathedral (UNESCO site) consist of intricate patches of different masonry portions bound by three types of lime mortars and at least two types of gypsum mortars. Such anomalous structure suggests multiple repair works over time after damaging earthquakes.
The absolute dating of lime mortars (¹⁴C)...
Current methodologies for radiocarbon dating of mortars typically use mechanical and chemical separation to isolate fractions of carbon dioxide from suitable lime binder carbonates. These methods have a moderate frequency of success, but difficulties are often encountered with (a) secondary crystallisation, (b) the presence of incompletely burnt li...
Dating lime mortar samples using the radiocarbon ( ¹⁴ C) method can be difficult. This is because the contamination is similar to the primary dating material (CaCO 3 ) and consequently difficult to remove. Mortar can also have late-in-formation pyrogenic carbonate from interactions with the environment after the initial hardening phase, such as rec...
Four lime mortar samples from the Mérida amphitheatre in Spain were dated in 2001 and re-dated in 2019 with refined dating methods and focus on carbon dioxide that was released in late CO 2 fractions when dissolved in phosphoric acid. The samples were difficult to date because they contained highly soluble, young carbonate contamination that domina...
A comparison of two different mechanical separation procedures, a settling process and sieving process, was performed in the samples preparation for radiocarbon dating of archaeological lime mortars from the Tower Keep at Irulegi Castle (Navarre, Spain). The different fractions obtained by the two different mechanical separation procedures were con...
After the last damaging earthquake in 2012, an anti-seismic reinforcement project of the cathedral of Modena was designed giving us the opportunity to investigate and date the building materials. Radiocarbon ( ¹⁴ C), optically stimulated luminescence (OSL), and thermoluminescence (TL) dating techniques were performed on the vaults with the aim to (...
When sampling mortars for radiocarbon ( ¹⁴ C) dating it is crucial to ensure that the sample has hardened rapidly relative the resolution of the dating method. Soft and porous lime mortars usually fulfill this criterion if the samples are taken from an uncovered surface from less than a few centimeters deep. However, hard, concrete-like mortars may...
Lime lumps and bulk mortars show different ¹⁴ C contamination when analyzed in several CO 2 fractions isolated from the effervescence of an ongoing hydrolysis reaction. Age profiles of both materials are therefore highly complementary and together they can provide a reliable date. Furthermore, they can also reveal the complexity of the radiocarbon...
Absolute dating of mortars is crucial when trying to pin down construction phases of archaeological sites and historic stone buildings to a certain point in time or to confirm, but possibly also challenge, existing chronologies. To evaluate various sample preparation methods for radiocarbon ( ¹⁴ C) dating of mortars as well as to compare different...
Seven radiocarbon laboratories: Åbo/Aarhus, CIRCE, CIRCe, ETHZ, Poznań, RICH, and Milano-Bicocca performed separation of carbonaceous fractions suitable for ¹⁴ C dating of four mortar samples selected for the MOrtar Dating Inter-comparison Study (MODIS). In addition, optically stimulated luminescence (OSL) analyses were completed by Milano-Bicocca...
Absolute dating of mortars is crucial when trying to pin down construction phases of archaeological sites and historic stone buildings to a certain point in time or to confirm, but possibly also challenge existing chronologies. It should become a standard tool for archaeometric research as it contributes considerably to the historical, artistic, so...
A singular Roman dwelling, octagonal in ground-plan, was excavated in the year 2000, in Premià de Mar. It is a freestanding pavilion within a larger settlement called Gran Via-Can Ferrerons. It was not possible to date it archaeologically because the basement trenches did not contain any significant dating artefacts. Archaeological research underta...
Jerash (Gerasa) in northwestern Jordan is an important Decapolis city displaying urban development for more than a millennium beginning in the late Hellenistic period (1st century CE). Despite more than a hundred years of archaeological explorations at the site there are still major questions about the city's urban development which are left open d...
AMS-based radiocarbon dating was applied to Medieval lime mortars made from burned shells and aggregate including both shore sediments and neovolcanic rocks. Three mortar samples from the city of Leiden near Amsterdam were prepared using the same kind of acid hydrolysis technique as has been earlier used for dating mortars made from burned marble a...
Mortar dating was applied to newly revealed, original mortar in the church of Dalby in Scania, southern Sweden which is considered to be the oldest still standing church in Scandinavia. Small white lime lumps were sampled by chipping from the supporting pillars in the interior of the church. Special emphasis was in sampling lime lumps because the c...
Since 1994, our team has gained extensive experience applying accelerator mass spectrometry (AMS) radiocarbon analysis for mortar dating, totaling over 465 samples and 1800+ measured CO 2 fractions. Several samples have been analyzed repeatedly. The research covers both Medieval and Classical archaeology. We therefore believe our experience can be...
This study focuses on radiocarbon dating of mortars that have withstood city fires and display visible fire damage effects. Some fire-damaged and undamaged original Medieval mortars from the same site have also been tested. The mortars were heated at different temperatures and then analyzed using the same preparation procedures as in 14 C dating of...
A large number of wood and bark samples have been analysed utilizing particle‐induced X‐ray emission (PIXE) and particle‐induced gamma‐ray emission (PIGE) techniques. Samples of common tree species like Scots Pine, Norway Spruce and birch were collected from a large number of sites in Southern and Southwestern Finland. Some of the samples were from...
Archaeologists and experts in ancient mortars fully understand the importance of reliable mortar dating. The ultimate motivation for long and costly archaeological excavations is often to establish the chronology of different mortared constructions. In contrast to other materials or artefacts that can be analyzed and dated, mortar is often abundan...
Fifteen years of research on accelerator mass spectrometry (AMS) radiocarbon dating of non-hydraulic mortar has now led to the establishment of a chronology for the medieval stone churches of the A °land Islands (Finland), where no contemporary written records could shed light on the first building phases. In contrast to other material for dating,...
Fifteen years of research on accelerator mass spectrometry (AMS) radiocarbon dating of non-hydraulic mortar has now led to the establishment of a chronology for the medieval stone churches of the Åland Islands (Finland), where no contemporary written records could shed light on the first building phases. In contrast to other material for dating, we...
Volcanic deposits from two volcanic districts, Monti Sabatini (MSVD) and Colli Albani (CAVD), NW and SE of Rome, were analyzed using the particle-induced X-ray emission (PIXE) technique, in order to obtain chemical fingerprints that can be used for provenance studies of filler materials in ancient Roman mortars. The rock samples were mounted on an...
Late stages of the Svecofennian orogeny in SW Finland were related to a tranpressional stress field and dextral movements along crustal scale shear zones under decreasing temperature and pressure conditions. In the Kemiö area, a minimum estimate for the time span of movements along one of these shear zones is obtained from the ages of 1840 to 1830...
Non-hydraulic mortars contain datable binder carbonate with a direct relation to the time when it was used in a building, but they also contain contaminants that disturb radiocarbon dating attempts. The most relevant contaminants either have a geological provenance and age or they can be related to delayed carbonate formation or devitrification and...
A total of over 200 different samples of bark and wood of Silver birch, Norway spruce and Scots pine were analysed. Samples were taken from several areas in western Finland, some with known sources of atmospheric heavy metal emission (Harjavalta, Ykspihlaja). The chemical analyses were performed by thick-target particle-induced X-ray emission spect...
Late-Svecofennian deformation was investigated in the Bjensböle area of SW Finland. The deformation history was revealed by following marker horizons of amphibolite, marble and black schist, in addition to microscopic studies and U-Pb monazite geochronology. The D1 structures are transposed and overprinted by D2 structures. The mesoscopic F2 folds...
Bark and wood samples were taken from the same individuals of Scots pine (Pinus sylvestris L.) from a polluted area close to a Cu-Ni smelter in Harjavalta and from some relatively unpolluted areas in western Finland. The samples were analysed by thick-target particle induced X-ray emission (PIXE) after preconcentration by dry ashing at 550 degrees...
Bark samples were taken from Scots pines (Pinus sylvestris L.) from a polluted area near a metal plant and from a relatively non-polluted site. Thick-target particle-induced X-ray emission (PIXE) was used for the analyses after different types of prepreparation of the samples. The bark samples were analysed directly by radially scanning from inner...
External beam particle-induced X-ray emission (PIXE) and PIGE were applied in a study of layered paint structures. A series of layered paint samples were prepared according to known late 18th century techniques. Special attention was paid to two-layer systems with lead white paint as the top layer. The effects of the opaque layer of lead white on t...
Trunk-wood samples of wood raw material incoming to a pulp mill were analysed by thick-target particle induced X-ray emission (PIXE). The tree species studied were pine and spruce from Finland. birch from Finland and Poland and eucalyptus from Uruguay. The wood samples were dry ashed to 550degreesC prior to the analysis in order to increase the,sen...
Plant materials were dry ashed at 550 degrees C and analysed using particle-induced prompt gamma-ray emission (PIGE). The analyses were performed with an external beam of 3 MeV protons incident on the target. Seven biological certified reference materials were analysed and used for the evaluation of the method for Na, Mg, Al, P and Mn. The elementa...
Soil contamination by toxic metal ions is one of the most serious environmental problems today. In this work soil samples from an area where a wood preservation plant has been active were studied. Chromium, copper and arsenic (CCA) are the main metal ions used in preservation of lumber. For the monitoring of these metal ions and of other elements i...
Chromium, copper and arsenic (CCA) have for decades been used for wood preservation. Of these elements especially arsenic is very toxic. As CCA impregnated wood is still today used for many construction purposes, a monitoring of these metal ions is of great environmental importance. Thick-target PIXE is a powerful method for the determination of tr...
The sensitivity in thick-target particle induced X-ray emission (PIXE) analyses of biological materials can be enhanced by dry ashing. The gain depends mainly on the mass reduction factor and the composition of the residual ash. The enhancement factor was 7 for the certified reference material Pine Needles and the limits of detection (LODs) were be...
Honey samples were dry ashed at 550°C and the ashes were directly analysed with the Thick-Target Particle Induced X-ray Emission (TTPIXE) technique. The elements P, K, Ca, Mn, Fe, Ni, Cu, Zn, Pb, Rb and Sr, were analysed quantitatively. The method allowed the determination of concentrations well below 100 ng/g for most of the elements studied. The...
Thick-target Particle Induced X-ray Emission (TTPIXE) was used for the quantitative determination of trace-element concentrations
in trunk wood. The wood samples were preconcentrated by dry ashing to improve the reliability of the sampling and the sensitivity
of the analytical method. Samples of Scots pine (Pinus sylvestris) and Norway spruce (Pice...
A method for refining lime mortar samples for 14C dating has been developed. It includes mechanical and chemical separation of mortar carbonate with optical control of the purity of the samples. The method has been applied to a large series of AMS datings on lime mortar from three medieval churches on the Åland Islands, Finland. The datings show co...
The 1840-1830 Ma old Perniö granite occupies the southern margin of the Sauvo-Perniö granite area located in the western part of the late Svecofennian granite-migmatite zone in southern Finland. The S-type Perniö granite is light to dark red, medium- to coarse-grained with euhedral K-feldspar phenocrysts forming the porphyritic texture of the grani...
Thick-target PIXE has been used for the quantitative determination of trace elements in annual growth rings of different tree species. A scanning device was developed for the remote control of the sample and a video-camera system for the exact monitoring of the spot to be analyzed. The samples were analyzed in steps of 1 mm. The widths of the tree...
Trace elements in biological materials were preconcentrated by dry ashing at 550°C in order to improve the detection limits for thick-target PIXE analyses. The analytical procedure was calibrated with equally prepared ashes of certified biological standard reference materials (SRMs). The matrix effects were studied both theoretically and experiment...
The thick-target PIXE technique was applied to direct analysis of trace elements in tourmaline minerals. The precision of the method varied between 1 and 10% and the detection limits were 1-10 ppm for most of the elements analyzed. The concentrations of 14 elements were calculated from their X-ray yields and the fluorine content was simultaneously...
Bimodal volcanics in SW Finland formed a primitive Svecofennian crust some 1.89 Ga ago. In Vestlax, on the Kemio island, some of these volcanics are well-preserved. Primary volcanic structures, like pillowed lavas and pyroclatic and rheomorphic flow structures were mapped and one of the felsic units was identified as a metaignimbrite. A stratigraph...
The late Svecofennian granite-migmatite (LSGM) zone in southwestern Finland is a ∼ 100 km wide and 500 km long belt transecting the southern Svecofennides from WSW to ENE. It was formed in an area of thin pillow lavas, volcaniclastic sediments and limestones. The area is interpreted as having been an early basin of crustal extension which was the l...
The c. 1.9 Ga old Enklinge volcano-plutonic centre is part of the Svecofennian province of SW Finland. The rocks of the area consist of an early subaquatic extrusion of mafic/intermediate to rhyolitic volcanics underlain by marbles, graywackes and quartz-feldspar-rich volcanoclastic sediments. The volcanic sequence is deformed and syntectonically i...
Svecofennian pillowed metalavas from SW Finland give Rb-Sr whole-rock ages close to 1.5 Ga and an initial strontium isotope ratio around 0.705. The low age is synchronous with the ages of two large rapakivi massives north and west of the pillow lavas, and it is suggested that it dates the thermal halo around the massives. The primitive and uniform...
The volcanic rocks of the Nagu-Korpo area in SW Finland form a thin (< 1000 m) formation that is folded into narrow synforms separated by migmatite-filled antiforms. In Nagu the volcanic formation comprises three units: a lower unit of subvolcanic banded gabbro sills, a middle unit of amphibolitic volcanic rocks and an upper unit consisting of a th...
Particle induced X-ray emission (PIXE) and particle induced gamma-ray emission (PIGE) were used to evaluate the losses of elements during dry ashing of biological materials at different heating temperatures. The materials studied were mushrooms, marine algae and pine bark. Samples of these materials were heated in a furnace at temperatures between...
