Glacial geomorphology in Utsjoki, Finnish Lapland proposes Younger Dryas fault-instability

Northern Fennoscandia has experienced high-magnitude postglacial fault (PGF) events, yet the role of seismic tremors in subglacial deformations and meltwater discharge has remained obscure. We studied glacial geomorphology in Utsjoki, Finnish Lapland, an area characterized by the Utsjoki drumlin field fanning out north and northeast to the Younger Dryas End Moraines (YDEMs) in northern Norway. Paleolandslides were common on fells (i.e. mountains shaped by Pleistocene glaciations) and were formed in nunatak position evidencing fault-instability in app. 11,900 calibrated (cal) BP. An anastomosing network of eskers was found throughout Utsjoki, and was probably generated through short-lived sliding bed stages during the discharge of subglacial lake(s). The formation of networks is different from time-transgressive evolution of single-ridged eskers in arborescent (treelike) systems. The most probable triggering mechanism for the meltwater outburst(s) was an earthquake tremor(s) associated with fault-instability during the late and post-Younger Dryas (YD). The alignment of the esker network was inconsistent with parallel-to-iceflow streamlining and the eskers erode or superimpose drumlins. Hence the esker network post-dates the streamlining. In some cases, hummocky (Pulju) moraine was observed to coexist with esker network and peculiar ‘kettle’ and ‘liquefaction’ features. We propose that glacio-seismotectonic events contributed not only to landslides but were also the primary force behind subglacial evolution of esker networks and possibly even hummocky moraine.     

Heavy metals in Baltic herring and cod

The monitoring programme of harmful substances in selected species in the Baltic Sea was started in 1979. In the present study, three-year averages of Zn, Cu, Cd and Pb in cod liver (Hg in cod muscle) and herring muscle are reported. The concentrations of heavy metals in cod show areal differences roughly in accordance with the concentrations of heavy metals in sea water. No significant differences between heavy metal concentrations in North Atlantic and Baltic Sea species were found, except for mercury, for which values in the Baltic Sea species are lower than in those from the North Atlantic.     

Spatial inference with an interchangeable rule format

Rule interchange between information systems is expanding as new interoperable rule formats are emerging from research. However, existing spatial inference systems generally operate on locally stored data with an internal rule format. Consequently, their design offers little support or facilities for rule interchange. This article presents the requirements, components and design for a spatial inference system with rule interchange. Computational efficiency and overall functionality of the design are considered separately, with the latter demonstrated using encoded agricultural legislation and data. A spatial inference system with rule interchange is based on three primary components: rule representation, spatial functionality and data integration. Of these, the interoperable rule representation and data integration distinctly differ from existing spatial inference systems. The presented inference system combines a spatial superset of the W3C Rule Interchange Format (RIF) with full Open Geospatial Consortium simple feature access (OGC SFA) functionality and on-demand data integration utilising Resource Deception Framework (RDF). The design was found to be effective with a computational efficiency depending predominantly on the spatial operations. This design could be further adapted to implement spatial extensions for existing inference systems. Considerable benefits were also discovered when RIF was used as the native language for the inference engine, thereby removing the need for rule transformations and facilitating on-demand data integration with the GML.     

Quantification of glacial till chemical composition by reflectance spectroscopy

Chemometric modelling of soil element concentrations from diffuse visible and near-infrared (VSWIR, 350–2500 nm) reflectance spectroscopic measurements holds potential for soil element analyses. Research has demonstrated it particularly for organic agricultural soils, yet little is known about the VSWIR response of glacial tills. Soils with low organic matter content developed on unstratified glacial materials were studied at two geologically similar sites on the mafic metavolcanic rocks of the Lapland Greenstone belt in northern Finland. The till samples (n = 217) were composed primarily of quartz, plagioclase and amphibole having less than 3% of clinochlore, talc and illite. VSWIR spectra of mineral powder (<0.06 mm) samples were measured in the laboratory, and the spectral reflectance was regressed against partial elemental concentrations of till obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES) following hot aqua regia digestion. Partial least-squares regression (PLSR) analyses resulted in simultaneous prediction (R² = 0.80–0.89) of several soil chemical elements such as Al (validation RMSE 1802 mg kg⁻¹), Ba (5.85 mg kg⁻¹), Co (0.86 mg kg⁻¹), Cr (6.94 mg kg⁻¹), Cu (2.54 mg kg⁻¹), Fe (2088 mg kg⁻¹), Mg (449.6 mg kg⁻¹), Mn (0.82 mg kg⁻¹), Ni (3.24 mg kg⁻¹), V (4.88 mg kg⁻¹), and Zn (0.80 mg kg⁻¹). The electronic and vibrational molecular processes causing absorption might be responsible for accurate predictions of major elements such as Al, Fe and Mg. However, the concentrations of other major and trace elements could be predicted by the PLSR because they were cross-correlated to spectrally active soil elements or extraneous soil properties. Therefore, the applicability of the results is highly sample set specific. Further, the results show that in local scale studies at geologically fairly homogenous areas the limited spread of the data may restrict the use of the spectroscopic–chemometric approach. This paper demonstrates the capability of laboratory VSWIR spectroscopy for determining element concentrations of glacial tills. Further work should focus on overcoming the issues of sampling scale and understanding the causality for cross-correlation in quantification of the elements.     

Depositional history of peatland pines (Pinus sylvestris L.) in NW Enontekiö, Finnish Lapland: implications for Middle Holocene drought and temperature fluctuations

High altitude and latitude findings of subfossil peatland pine trees were unearthed from the region of NW Finnish Lapland and dated by ¹⁴C and tree-ring methods. The depositional history of the trees illustrated two distinct peatland pine phases dated to Middle Holocene intervals 4900–4400 and 4100–3400 cal. a BC. It seems evident that both thermal and hydroclimatic fluctuations have played roles of varying importance in the establishment of this pine population and its demise. The presence of these pines, from a site ~60 km north of the coniferous timberline and conditions ~1 °C and 100 degree-days colder than those at the present-day timberline, concurs with previous studies demonstrating the association between the high-latitude summer-temperature cooling and circumpolar timberline retreat since the Middle Holocene due to Milankovitch forcing. On the other hand, the peatland pine recruitment was made possible by drier than present surface conditions during the previously reconstructed Middle Holocene drought anomaly (Hyvärinen-Alhonen event). Our data suggest this event was not continuous but reached its two-phase climax during the peatland pine phases, with an interruption of several centuries with moister surface conditions between 4400 and 4100 cal. a BC. The findings highlight the sensitivity of well-dated peatland tree assemblages in terms of recording past climatic evolution and events and the need for new collections from north and south Fennoscandia and the Baltic region, for more detailed analyses over extended time intervals and regions.     

Identification of Mineralization in Geochemistry for Grid Sampling Using Generalized Additive Models

Mathematical Geosciences - The important goals of mineral exploration geochemistry are detection and identification of underlying mineralization. This paper deals with element concentration data...     

The Bothnian coupled oroclines of the Svecofennian Orogen: a Palaeoproterozoic terrane wreck

The accretion of magmatic arcs gives rise to elongate, linear orogens and is a key process in forming new continental crust. Many Precambrian continents are, however, presently equidimensional or have large areas without any clear linearity, such as the central part of the Palaeoproterozoic Svecofennian Orogen (1.92–1.77 Ga). One way of forming an equidimensional continental domain is by buckling of a linear orogen about vertical axes of rotation into one or more coupled oroclines. Here, we reinterpret existing data and demonstrate the occurrence of coupled Bothnian oroclines in the Svecofennian Orogen. Palinspastic restoration of the southern and northern Bothnian oroclines brings a 1000‐km‐long segment of the Svecofennian Orogen into an originally linear, NW‐striking geometry that restores the lithological belts, metamorphic zones and structural vergences to a common direction, and which indicates that the orogen consists of a SW‐facing arc, which has been shortened along NE‐verging folds and thrust faults.     

Nordic Geoscience and the 33rd International Geological Congress： Introduction

Geology has been of profound importance for the Nordic countries since the Middle Ages. Strong economies were built on an understanding of the occurrence in bedrock of minerals containing metals, e.g., silver, copper, zinc and iron, and eventually led to the establishment of the first Geological Surveys in Norway and Sweden in the middle of the nineteenth century. The geology of Norden ranges from the oldest to youngest rocks on the planet. Based on the papers in this special issue, this introduction provides a brief summary of the geological evolution of Norden, from the Archean of Greenland and northern Fennoscandia to the on-going volcanicity in Iceland on the MidAtlantic Ridge. It also refers to aspects of Geoscience that are particularly important for society in Norden, including geo-resources （petroleum, geothermal energy, nuclear energy, metals, industrial minerals and groundwater） and environmental geology （including natural and anthropogenic processes, medical geology, geo-hazards and climate）. Information on the early history of geology in Norden and the geological surveys is also included and, finally, an outline of the 33rd International Geological Congress with its main theme “Earth System Science： Foundation for Sustainable Development”.