Diana Jordanova

• Bulgarian Academy of Sciences

Loess-paleosol sequences (LPSs) from the Lower Danube region are valuable archives of paleoenvironmental changes during the glacial-interglacial epochs of the Pleistocene. The present study reports a compilation of major, trace and rare earth elements data on bulk material from loess and paleosols samples from nine LPSs from the Bulgarian part of t...

Environmental magnetism is recognised as a sensitive tool for reconstructing various processes related to the iron cycling in the terrestrial environment. Besides, archaeomagnetism as an interdisciplinary method in archaeology provides geophysical tools for dating and synchronisation of burnt clay remains throughout the last ~8000 years. Linking bo...

The Gluhite kamani Thracian rock-cut complex in the Eastern Rhodopes Mountain is famous with its more than 500 rock niches carved in the rock at heights up to 20 m. Continuous habitation starting from the final Chal-colithic (the second quarter of the 4 th millenium BCE) until the Late Classical-Early Hellenistic period (late 5 th-4 th century BCE)...

Identification of magnetic minerals, which determine the magnetic properties of natural rocks, sediments and soils, is of crucial importance for any further interpretation of their magnetic signature in environmental or paleogeographical context. One of the major and widely used methods for determination of kind of magnetic phases in natural materi...

The Campi Flegrei (CF) caldera, in southern Italy, is the source of some of the most powerful Late Pleistocene eruptions of the European sub-continent (e.g., Campanian Ignimbrite, Neapolitan Yellow Tuff eruptions). Although the CF caldera has been continuously and intensively investigated for decades, relatively little is known regarding its earlie...

Assessing the history, dynamics and magnitude of pre-historic explosive volcanic eruptions relies heavily on the completeness of the stratigraphic records, the spatial distribution, and the sedimentological features of the pyroclastic deposits. Near-vent volcanic successions provide fundamental but often patchy information, both in terms of record...

Eastern European loess-paleosol sequences (LPS) are excellent archives of past climate change. Millennial-timescale climate change is successfully evidenced in loess of the last and penultimate glacial periods. However, study designs with similar or lower sampling resolution strategies and/or single proxy investigations do not favor their identific...

Magnetic properties are sensitive paleoenvironmental proxies frequently used in studies of loess paleosol profiles. Understanding precisely the magnetic recording of soil responses to environmental and climatic changes needs combining pedologic data and geophysical proxies. Here we present a new high-resolution study of a 450 ka old loess-paleosol...

Retrieving well-dated terrestrial archives of Holocene climate change is fundamentally important for building robust climate models and predictions. In this study we obtained records of paleomagnetic direction and relative paleointensity of the Earth's magnetic field from an alluvial soil situated on a flood river terrace close to the well-dated an...

Soils from maritime Antarctica store important information about initialization of pedogenesis and role of the major factors of soil formation. Deciphering the interplay among all contributing agents is however challenging and needs involvement of an interdisciplinary approach. The main aim of our study is to contribute to this goal by assessing mi...

Loess-paleosol sequences (LPS) from the Lower Danube area are valuable terrestrial archives of environmental change in SE Europe during the Pleistocene. A twenty-seven meters thick sequence has been sampled in Central North Bulgaria near the city of Pleven within the Suhia Kladenetz (SK) quarry. The sedimentary sequence consists of seven loess unit...

Loess-paleosol sequences of the Lower Danube region are valuable terrestrial archives of past climate change, up to about 1 Myrs in certain locations. Previous studies on these archives have provided insightful views of past environmental changes but sometimes limited by low-resolution sampling, hiatus or short time coverage, or mono-disciplinary a...

Terrestrial climate archives like loess-paleosol sequences (LPSs) located in Eastern Europe are known to cover long periods of time and record climate fluctuations over the last hundreds of thousands of years (e.g. 1). Glacial cold and dry conditions, leading to loess accumulation, alternate with interglacial, warm and humid episodes, leading to th...

Mass specific magnetic susceptibility variation with depth along soil profiles developed on loess parent material is one of the most frequently used physical parameter in local, regional and global correlations of loess deposits. It is also utilized as a paleo-precipitation proxy, defined either as absolute difference between susceptibilities of th...

This study aims to evaluate the urban pollution by combined magnetometric and geochemical analyses on road dusts from three towns in the vicinity of Cu-smelter and ore mining. A collection of 117 road dust samples was investigated for their magnetic characteristics (magnetic susceptibility (χ), frequency dependent susceptibility, anhysteretic and i...

Loess-paleosol sequences (LPSs) are proven valuable archives for continental paleoclimatic reconstructions. However, studied LPSs worldwide, spanning multiple glacial-interglacial cycles, are seldomly sampled and analyzed at a continuous high resolution. Exceptionally, in a quarry setting near the city of Pleven (Bulgaria), a new LPS, with a thickn...

Archeological materials from the most ancient open‐pit gold mine in Europe have been investigated using mineral magnetic methods as part of the multidisciplinary research of the site. The aim of the study was to employ rock‐magnetic characteristics (magnetic susceptibility, anhysteretic remanent magnetization, isothermal remanent magnetization and...

Fire as a global phenomenon plays crucial role in the Earth’s climate feedbacks and forcing. However, human’s influence is becoming increasingly important during the Anthropocene epoch. Burnt Neolithic houses are among the most impressive remains from fire-related ancient human activities. Mineral magnetic properties and firing temperature estimate...

The global character of the millennial-scale climate variability associated with the Dansgaard–Oeschger (DO) events in Greenland has been well-established for the last glacial cycle. Mainly due to the sparsity of reliable data, however, the spatial coherence of corresponding variability during the penultimate cycle is less clear. New investigations...

Magnetic properties of loess-paleosol sequences are widely utilized as sensitive, easily-obtained and reliable proxy archives of past climate change in continental settings. However, soil formation in aeolian landscapes may occur under different and changing conditions of dust sedimentation, which will affect the growth and development of the pedog...

The global character of the millennial-scale climate variability associated with the Dansgaard-Oeschger (DO) events in Greenland has been well-established for the last glacial cycle. Mainly due to the sparsity of reliable data, however, the spatial coherence of corresponding variability during the penultimate cycle is less clear. New investigations...

Strong wildfires pose significant damage to all soil qualities and lead to land degradation. The complex nature and properties of fire‐derived materials require multidisciplinary efforts for their reliable characterization. The main objective of our study was to evaluate the suitability of magnetic properties of fire‐affected soils as proxy paramet...

Determination of ancient firing temperatures of archaeological pottery is a widely discussed topic in archaeometry. Here, a set of magnetic characteristics (magnetic susceptibility, isothermal and anhysteretic remanences, hysteresis parameters) and color parameters were studied for a collection of pottery fragments and burnt clay from house destruc...

The key reference loess sequence of Viatovo in NE Bulgaria, lying within the lower Danube basin, records climatic and environmental changes over the last 800 ka. This 20 m thick loess sequence consists of seven loess units (L1 to L7) intercalated by six paleosols (S1 to S6) below the modern soil (S0). The Matuyama-Brunhes palaeomagnetic boundary ha...

Wildfires strongly affect soils, including iron biogeochemical cycling and carbon storage. Thus, it is important to reveal the dynamics of iron oxide synthesis and transformations during and after a wildfire. This study investigates the temporal stability of strongly magnetic minerals appearing after a wildfire. Following a designed experimental fi...

While numerous high-resolution studies concerning Last Glacial aeolian sequences are available for Europe, the approach of the penultimate glacial in this geographical area is still poorly developed. In order to bridge this gap, this study focuses on the Bulgarian sequence of Harletz, along the Danube River, where extremely high sedimentation rates...

Among the main environmental factors, which influence the functioning of the soil system are wildfires. Their impact on vegetation cover and mineral soil has long been studied in relation to carbon cycling and preservation of soil health. Information about the changes caused by past wildfires in two forest soils, Umbrisol and Albic Luvisol, were ob...

AMS Analysis of Tectonic Gauge

The Harletz loess‐palaeosol sequence is located in northwestern Bulgaria and represents an important link between well‐studied loess sequences in eastern Romania and further sites to the west of the Carpathians (e.g. Serbia and Hungary). The aim of this study was to establish a chronostratigraphy of the deposits, using various methods of luminescen...

Archeological remains from the Neolithic period in SE Europe are characterized by the presence of massive burnt daub relics sintered at high temperatures. These findings raised the hypothesis of deliberate house burning as a strategy for ensuring the survival of place and the development of social memory in Neolithic society. Although highly discus...

Maximum firing temperatures were determined for a large (198 samples) and variable collection of ceramic sherds from Bulgaria using magnetic susceptibility measurements. The data obtained were combined with the existing archaeological evidences as a first attempt to elucidate the technological development of pottery production in four important Bul...

View Related Events Program: Geomagnetism, Paleomagnetism and Electromagnetism

Pilot study on soil contamination degree around the Maritza East thermal power plants, evaluated through applying magnetic methods, is presented. The magnetometry method is based on the well-established fact that anthropogenically contaminated with fly ashes soils display enhanced magnetic susceptibility, as well as other specific magnetic characte...

Former zinc and lead mines that have been operating for half a century are located in the massif of Bou Caid (Tissemsilt, Algeria). Hazardous heavy metals emitted from the mines are abundant in the surrounding soil and cause strong metal pollution in the region. This paper investigates the extent of lead and zinc mine activity derived pollution by...

Copper ore mining and processing are among the most harmful anthropogenic influences for the environment and they are a subject of international and national law regulations. Recultivation of areas influenced by mining and processing industry is commonly applied and monitored in order to restore as much as possible the natural environment. In this...

Rock-magnetic and geochemical characteristics of three Vertisol profiles with different degree of textural differentiation have been studied. Thermomagnetic analyses, thermal demagnetization of laboratory remanences and acquisition of isothermal remanence curves are applied for identification of iron oxide mineralogy. The main magnetic minerals in...

Thermomagnetic analysis of magnetic susceptibility k(T) was carried out for a number of natural powder materials from soils, baked clay and anthropogenic dust samples using fast (11°C/min) and slow (6.5°C/min) heating rates available in the furnace of Kappabridge KLY2 (Agico). Based on the additional data for mineralogy, grain size and magnetic pro...

Establishing topsoil magnetic database at a national scale provides important information for soil classification, evaluation of soil drainage, indirect estimation of the total soil carbon and initial planning in precision agriculture. The Bulgarian database consists of 511 topsoil samples from the upper 20 cm of natural unpolluted soils. Samples h...

An experimental approach for estimation of cumulative soil erosion by using magnetism of Chernozem soils is presented. An agricultural land of 4.5 ha, utilized for crop production, has been mapped at 10 × 10 m grid interval by using magnetic methods. Field measurements of magnetic susceptibility show high sensitivity to the present soil surface con...

Magnetic properties of road dusts from 26 urban sites in Bulgaria are studied. Temporal variations of magnetic susceptibility (χ) during eighteen months monitoring account for approximately 1/3rd of the mean annual values. Analysis of heavy metal contents and magnetic parameters for the fraction d < 63 μm reveal significant correlations (p < 0.05)...

The lower levels of the archaeological sequence of Kozarnika cave (north-western Bulgaria) provide levels with non-Acheulian core-and-flake (as opposed to pebble-core) industries. Associations with numerous taxa of large mammals indicate that the date of the lower layers of the cave falls between MNQ17 and MNQ19. These layers produced several bones...

Magnetic and geochemical analyses on a collection of 84 soil samples from the alluvial plain of Ogosta river and its tributaries (NW Bulgaria) have been carried out for revealing the pollution pathways and the role of iron oxides in mobilization, vertical re-distribution and occurrence of different heavy metals in Fluvisols. Three depth soil profil...

Geophysical methods are widely applied to soils for resolving different tasks in precision agriculture, pollution evaluation, erosion estimation, etc. Environmental magnetic methods were applied in our study on a collection of soil samples from area near Rosslau (Germany), which was gathered on the basis of a field electromagnetic induction study....

Settled indoor and outdoor dusts in urban environment represent an important source of secondary pollution. Magnetic characteristics of the settled dust from six cities in Bulgaria are explored, allowing comparison on a national (country) scale. Monthly variations of the mass-specific magnetic susceptibilities (χindoor) and (χoutdoor) and calculate...

The Kapitan-Dimitrievo pluton was emplaced within the 15km wide Maritsa shear zone during the Late Cretaceous. It has well-known U–Pb zircon age (78.54±0.13Ma) and appears as a late-syntectonic intrusion that marked the last ductile deformation in the Maritsa shear zone. Magnetite is believed to be the main carrier of the magnetic fabric in this pl...

Restricted area from the most south-eastern part of Bulgaria at the Bulgarian-Turkish border is characterized by continental Mediterranean climate. Peculiarity of the area is determined by the proved absence of Quaternary glaciations and predominance of Mediterranean flora (mainly oak (Fagus orientalis) with widely distributed rhododendron (Rhodode...

The role of hematite and goethite as palaeoenvironmental indicators in loess-palaeosol sediments is studied by diffuse reflectance spectroscopy (DRS) and rock magnetic methods. Forty five selected samples from four loess-palaeosol profiles in Bulgaria were used to deduce the behaviour of the hematite/goethite ratio in loess and palaeosol units, whi...

A detailed field and laboratory study on small 0.84-ha test site of agricultural land near Sofia (Bulgaria) has been carried out in order to test the applicability of magnetic methods in soil erosion estimation in the particular case of strongly magnetic parent material. Field measurements of magnetic susceptibility were carried out with grid size...

Iron in its diverse forms in soils is an important indicator of a number of past and/or ongoing environmental processes. Iron oxide mineralogy pertinent to a particular soil type could be obtained with high resolution using magnetic methods. Planosols are a particular soil type characterized by surface water-logging leading to development of great...

A detailed magnetic study of three soil profiles of Calcic Chernozem, Luvic Phaeozem and Orthic Luvisol, described in the Soil Atlas of Bulgaria, was carried out in order to reveal the potential of magnetic methods for characterization of soil forming processes and properties of pedogenic iron oxides. Thermomagnetic analysis of susceptibility and S...

Detailed magnetic study on vegetation samples from several strongly polluted and clean sites in Bulgaria is carried out in order to evaluate suitability of different species as passive dust collectors in magnetometry. From each location, available species among lichens, mosses, poplar leaves, dandelion, needles have been sampled. Magnetic susceptib...

The aim of the study is to reveal the potential of various geophysical methods and approaches to give fast, high-resolution lateral image of soil properties. Geophysical equipment on platforms, operated by UFZ (Leipzig) team and point measurements of field magnetic susceptibility have been carried out on a small test field close to the biggest meta...

Anaerobic soils are characterized by the presence of specific soil conditions (for example high water table, underlying horizon of high clay content, surface water logging, etc.), which favor the establishment of reductomorphic features in soils. These have well distinguished magnetic signature due to the fact that anaerobic conditions often cause...

Magnetic mineralogy and magnetic grain size distribution along depth of soil profiles and on a lateral scale reflect in a very sensitive way changes in micro-environmental conditions like soil texture, clay content, soil reaction, Eh - pE conditions, etc. Magnetic measurements of field magnetic susceptibility and laboratory measurements of various...

Plants are widely used in classical biomonitoring studies, due to the ability of different vegetation species to accumulate dust and toxic elements in their tissues or to bound them to surface structures. The aim of the present investigation is to study magnetic signature of foliose and fruticose lichens and mosses, gathered from several polluted a...

Complicated shapes of thermomagnetic curves representing temperature dependence of magnetic susceptibility k(T) are quite usual in many rock magnetic studies on soils and sediments. They, however, can give also useful information about the kinetics of mineral alteration and provide an additional tool for characterization of the initial material. Ex...

Characterization of soils with respect to their fertility, sustainable use and conservation require extensive, time- consuming and costly analyses. Establishment of well defined relationships between certain physical, geochemical and magnetic parameters would be useful tool in pedometrics, giving opportunity to carry out large scale studies on soil...

Two Luvisol profiles from Bulgaria have been sampled in detail with the aim to better reveal iron oxide mineralogy, genesis and grain size variations in pedogenic fraction. Combination of magnetic investigations, chemical analyses and physical characteristics (pH, mechanical grain size fractions) are used for this purpose. Both soil profiles show s...

One of the best preserved terrestrial records of past climate are in loess-palaeosol sequences around the world. Except classical Chinese loess, European sequences are widely used for palaeoenvironmental reconstructions. Low Danube loess deposits are part of the south-eastern loess cover, linking loess belt in Asia with Central European loess. Its...

The emplacement mode of Upper Cretaceous plutons from the southwestern part of the Sredna Gora Zone (Bulgaria): structural and AMS study Several plutons located in the southwestern part of the Sredna Gora Zone — Bulgaria are examples of the Apuseni-Banat-Timok-Sredna Gora type of granites emplaced during Late Cretaceous (86-75 Ma) times. The studie...

Soil magnetometry is already frequently applied as a tool for rapid evaluation of contamination in different case-studies. It relies on the well established fact that most of the industrial wastes contain strongly magnetic fraction, which enhances magnetic response of the top-soil. Current regional-scale study applies magnetometry on ∼2800 km2 area...

The results of a palaeomagnetic investigation of a 27m thick loess/palaeosol sequence in Viatovo (NE Bulgaria) are presented in this paper. The sequence consists of topsoil S0, seven loess horizons (L1–L7) and six interbedded palaeosols (S1–S6) overlying a red clay (terra rossa) complex. Magnetic viscosity experiments, IRM acquisition, AMS analysis...

Loess-palaeosol deposits in the lower Danube area represent the southeastern edge of the loess cover in Europe. Detailed rock magnetic investigations of the loess/palaeosol sequence in Viatovo in NE Bulgaria reveal that magnetite and maghemite of very fine superparamagnetic grain size are responsible for the magnetic enhancement of palaeosol units....

In this paper, basic rock magnetic studies of Holocene loess-soil samples from northeastern Bulgaria are reported. The sites are related to the Danube river and located at different distances southwards, thus representing various pedogenic conditions. The study is primarily aimed at determining the main magnetic carrier(s) and their physical charac...

In a number of AMS studies, the presence and deciphering of composite magnetic fabrics is of major importance for a correct interpretation of the data. On the basis of several examples from intrusive rocks (diorites and dolerites) we show that the use of laboratory heatings can help to extract at least one component of the composite magnetic fabric...

Measurements of low-field magnetic susceptibility (K) and its anisotropy (AMS) on different rock types during stepwise alternating field (AF) demagnetization in increasing fields revealed not only significant changes of the AMS principal susceptibilities, but also an increase of the mean magnetic susceptibility (Km). Studied collections of loess/pa...

We studied the evolution of anisotropy of magnetic susceptibility (AMS) during stepwise alternating fields (AF) demagnetization on various kinds of rock samples (loess and palaeosols, diorite, granite, gneiss) with very different degree of magnetic anisotropy. The variation of the magnetic fabric appears to be related to both the magnetic fabric be...

Mineral composition of cigarette ashes is well studied in the literature, but no reports are available about the magnetic fraction. Our study presents an investigation of the basic magnetic characteristics of ashes from several commercially available cigarette brands and a wood ash. Magnetic susceptibility, which is a concentration-dependent parame...

Rock magnetic studies of three loess-palaeosol sections from Bulgaria (Harletz and Orsoja in the NW and Durankulak in the NE at the Black Sea coast) have been carried out. Thermomagnetic analyses of magnetic susceptibility point to magnetite as the major ferrimagnetic carrier in the loess and palaeosol units. Maghemite gives a significant contribut...

The use of magnetic susceptibility as a proxy for the relative degree of industrial pollution of soils and sediments is only qualitative and complications arise when unmixing the contributions from different sources. Detailed characterization of anthropogenic magnetic phases is needed in order to discriminate the input from different sources. The p...

The Cappadocia region, located in Central Turkey, is characterized by widespread lava flows and volcanoclastic deposits dating from Miocene to Quaternary. Gravity and aeromagnetic anomalies of the region appear to present similar high and low amplitude regions, although the aeromagnetic anomalies exhibit a rather complex pattern which is thought to...

A new approach for tracking mineralogical alterations during laboratory stepwise heating experiments is proposed. It uses the hysteresis loop obtained as a difference between the loops measured after thermal treatment at two different consecutive temperatures. Depending on the nature of the mineralogical alterations (the formation of a new ferrimag...

Magnetic methods provide a fast tool for delineation of industrial pollution. Mineral magnetic studies of anthropogenic magnetic phases in road dust from the industrial zone of Visakhapatnam city (India) reveal the presence of large anthropogenic spherules with diameters up to ∼300 μm. Different internal structures of the spherules and a wide varia...

The aim of the present study is to obtain a detailed characterization of fly ashes and nearby anthropogenic soils from different Bulgarian power plants, by using integrated rock magnetic and classical microscopic methods. These combined techniques, which enable a better understanding of the complexity of anthropogenic magnetic phases, impose the ne...

Magnetic methods have been widely used for delineation of environmental pollution of soils and sediments under certain conditions during the last decade. A number of structure-sensitive magnetic characteristics (coercive force, coercivity of remanence, remanent magnetization) were utilized for deduction of the grain size of the anthropogenic partic...

A common practice in archaeomagnetic studies in many laboratories is the impregnation of the material with water glass (siliceous gel) in order to achieve better consolidation before cutting. The purpose of this study is to establish if and how the presence of water glass in the burnt clay material affects its magnetic properties during heating. We...

Environmental Context. Industrial metal production, thermoelectric power plants, and similar technologies can release a large amount of particles (with sizes up to the millimetre scale) of heavy metals into the local surrounds. Up to 10% of these particles are strongly magnetic and easily detectable above the background magnetism. A map of the regi...

Fast and cost-effective detection of industrial pollution can significantly promote its ecological, economic, and social assessment. A magnetometric method, used for qualitative determination of anthropogenic contamination, meets these requirements but needs further development in more quantitative terms. It could be used successfully in numerous c...

Heating produces changes, which does not always correspond to simple enhancement of the magnetic fabric. Two methods are proposed to determine the anisotropy of magnetic susceptibility of the ferrimagnetic minerals formed or that have disappeared by chemical change during successive heating. The first diagonalizes the tensor from the difference bet...

Several events of anthropogenic impacts on the floodplain river sediments of the Danube along a section near the town of Oryakhovo (NW Bulgaria) have been detected using magnetic technique. In the field, magnetic susceptibility was measured using three susceptibility meters – MS2D, KT-5 and SM30. The differences in the surface susceptibility values...

In many natural samples changes in magnetic parameters occur when samples are heated for 10 minutes at 150 C. These changes are related to a reduction in stress in superficially oxidized magnetite grains. The stress originates from low-temperature oxidation (LTO) at ambient conditions. Measurements on pure magnetite grains are presented to support...

A collection of oriented rock samples from small plutonic bodies and dikes, outcropped near the Bulgarian Antarctic base at Livingston Island, has been studied. The suitability of the material for obtaining reliable paleomagnetic results has been tested, applying a set of rock magnetic methods. Thermomagnetic analysis of magnetic susceptibility K(T...

Combined microchemical and magnetic study of single anthropogenic particles has been carried out in order to check the validity and applicability of the relations between the magnetic parameters and chemistry/grain size of such magnetic phases. It is inspired by the wide use of magnetometry during the last years as a tool for screening and monitori...