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New palaeomagnetic and petrographic data are presented from Cambrian rocks of SW Svalbard to test, for the first time, Palaeozoic reconstructions of the major terranes of Svalbard. In the course of thermal demagnetization three ChRM (characteristic remanent magnetization) components were identified, which were labelled HORNL, HORNM and HORNH, respectively, on the basis of their different unblocking temperatures. The HORNM magnetization is related to the Late Ordovician–Silurian formation of the synmetamorphic S1 foliation. The HORNM palaeopole (Φ = −18.5°, Λ = 359°, Dp/Dm = 5.8°/11.4°, Plat = 6°N) matches exactly the Silurian sectors of the Baltica–Laurentia apparent polar wander paths after the closure of Iapetus (455–415 Ma). The 450 Ma 40Ar–39Ar age determination from mica ages obtained from the broad zone of mylonites along the Billefjorden Fault Zone which separates the Central and Eastern terranes, also suggests that the two terranes were eventually amalgamated by 450 Ma. The HORNMVGP also lies very near the palaeopole derived from the Middle Proterozoic rocks of the Eastern Terrane (Ny Friesland), metamorphosed during Caledonian time, suggesting its close proximity to the study area (Central Terrane). The present study has shown that at least two of the major terranes of Svalbard, as defined by previous authors, occupied similar geographical locations by Silurian time, and the previously proposed large-scale Late Devonian left lateral displacements are not supported.

Palaeomagnetic−petrographic−structural analyses of Proterozoic-Lower Palaeozoic metamorphosed carbonates from 12 locations within Oscar II Land (Western Spitsbergen) have been carried out to determine their usefulness in palaeogeographic reconstructions for Caledonian time. Structural analyses confirm that metacarbonates record several stages of deformation: D1, D2 ductile phases related to Caledonian metamorphism and a D3 brittle phase related to Late Cretaceous-Paleogene evolution of the West Spitsbergen Fold Belt. The latter is represented by thrust faults, localized folds with strain slip cleavages and late extensional collapse. Petrographic investigations reveal that Caledonian greenschist facies metamorphism was characterized by the high activity of H 2 O−CO 2 −rich fluids which pro− moted extensive recrystallization and within−rock spatial reorganization of sampled meta− carbonates. Microscopic, SEM and microprobe analyses exclude the existence of any pri− mary pre−metamorphic ferromagnetic minerals (primary−related to sedimentation and or early diagenesis) and point to metamorphic 4C superstructure (Fe 7 S 8 ) pyrrhotite as the main ferromagnetic carrier in investigated rocks. This is confirmed by the three−component iso− thermal remanent magnetization (IRM) procedures and the results of thermal demagnetiza− tions. In 12 sites a total number of 72 independently oriented palaeomagnetic samples were collected from which 181 specimens were drilled and thermally demagnetized. Sampled metacarbonates are weakly magnetized (NRM <0.2mA/m). The statistically significant palaeomagnetic results were achieved only from 1 of 12 investigated sites. In one site situ− ated in the Western overturned limb of the Holmesletfjellet Syncline intermediate unblock− ing temperatures -"pyrrhotite related" component WTSJ5M superimposed on the S1 Cal− edonian schistosity was recognized (D = 100.7°, I = −21.4°a95% = 5.5°, k = 58.23). Coinci− dence of WTSJ5M with Silurian-Devonian sector of the Baltica reference path after unfold− ing of the syncline by the angle of 130°suggests synfolding origin of this direction. Further, this suggests that Holmesletfjellet Syncline originated as an open fold and has been trans− formed into an overturned syncline during the Late Caledonian shortening or in the Late Cretaceous-Palaeogene time.

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Background The aim of the present study was to evaluate the effect of 1MeTIQ on fear memory and social interaction in an MK-801-induced model of schizophrenia. The results obtained after administration of 1MeTIQ were compared with those obtained with olanzapine, an antipsychotic drug. Methods Sprague–Dawley rats received a single injection of MK-801 to induce behavioral disorders. 1MeTIQ was given either acutely in a single dose or chronically for 7 consecutive days. Olanzapine was administered once. In groups receiving combined treatments, 1MeTIQ or olanzapine was administered 20 min before MK-801 injection. Contextual fear conditioning was used to assess disturbances in fear memory (FM), and the sociability of the rats was measured in the social interaction test (SIT). Biochemical analysis was carried out to evaluate monoamine levels in selected brain structures after treatment. Results Our results are focused mainly on data obtained from neurochemical studies, demonstrating that 1MeTIQ inhibited the MK-801-induced reduction in dopamine levels in the frontal cortex and increased the 5-HT concentration. The behavioral tests revealed that acute administration of MK-801 caused disturbances in both the FM and SIT tests, while neither 1MeTIQ nor olanzapine reversed these deficits. Conclusion 1MeTIQ, although pharmacologically effective (i.e., it reverses MK-801-induced changes in monoamine activity), did not influence MK-801-induced social and cognitive deficits. Thus, our FM tests and SIT did not support the main pharmacological hypotheses that focus on dopamine system stabilization and dopamine–serotonin system interactions as probable mechanisms for inhibiting the negative symptoms of schizophrenia.

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This analysis was performed as a part of the palaeomagnetic project focused on the reconstruction of the palaeogeographic position of the Svalbard Archipelago and adjacent crustal units (European Arctic) in the Palaeozoic and Mesozoic. Three rock formations -Cambrian, Devonian and Carboniferous were sampled in the area of Hornsund, southern Spitsbergen. The main aim of the presented study is to identify ferromagnetic minerals (sensu lato) -the carriers of the natural remanent magnetisation in the investigated rocks. A wide range of magnetic methods were used: the Lowrie tests, unblocking temperatures determinations and the measurement of coercivity spectra as well as the Mössbauer studies. In Devonian and Carboniferous samples all applied methods indicate the domination of the hematite natural remanent magnetisation carrier. In Cambrian rocks magnetic measurements reveal a mixture of ferromagnetic (sensu lato) minerals with varying coercivities and unblocking temperatures. The Mössbauer data improve the identification, suggesting that in Cambrian rocks the carrier of the dominating natural remanent magnetisation component is maghemite.