The Mesoproterozoic Hallandian event - a region-scale orogenic event in the Fennoscandian Shield

The Sveconorwegian Province occupies the southwestern part of the Fennoscandian Shield. The easternmost tectonic unit of the Province is the 1710-1660 Ma parautochthonous Eastern Segment, which bears the imprint of at least two metamorphic events; the 1460-1380 Ma Hallandian and the 1150-970 Ma Sveconorwegian. However, the nature and extent of the Hallandian event have been difficult to access due to the Sveconorwegian, effectively masking earlier metamorphic assemblages, structures and relations between rock units. This thesis aims to characterize the Hallandian event by investigating pre-Sveconorwegian deformation and metamorphism in an area of the Eastern Segment that largely escaped later Sveconorwegian reworking. These results are then considered in a regional perspective and related to ~1.45 Ga magmatism and metamorphism observed elsewhere in Fennoscandia. Considering the compiled data from this time period, it now appears that the Hallandian event indeed was a true orogenic event that affected a large portion of the Fennoscandian Shield. In the study area, located within the Protogine Zone in the eastern part of the Eastern Segment near Jönköping, Sveconorwegian reworking is restricted to discrete, N-S trending shear-zones. Between these shear-zones, structures, mineral assemblages and geochronological information from pre-Sveconorwegian events are preserved. The first paper provides field, mineral and chemical characteristics, as well as a baddeleyite U-Pb crystallization age of 1455±6 Ma for the Jönköping Anorthositic Suite which is abundant across the study area as small intrusive bodies. In these plagioclase-porphyritic and equigranular anorthositic rocks, deformation is restricted to thin, E-W-trending shear-zones. In the second paper we investigate the deformed country-rocks and date metamorphism and the development of the E-W to SE-NW trending gneissic fabric at 1450-1400 Ma, using U-Pb secondary ion mass spectrometric (ion probe) analysis of complex zircons. The folding event is bracketed between 1440 and 1380 Ma, corresponding to the ages of leucosome formation and the emplacement of a cross-cutting aplitic dyke. In the third paper, the gabbroic Moslätt dolerites are dated at 1269±12 Ma using the U-Pb system in baddeleyite. These have well-preserved magmatic parageneses in contrast to nearby metamorphosed mafic dykes of the 1450-1420 Ma Axamo Dyke Swarm. This precludes the Sveconorwegian event from having caused amphibolite facies metamorphism in the area. In the fourth paper, the first estimate of Hallandian pressure and temperature conditions is obtained from mineral assemblages in one of the E-W-trending shear-zones. Pressure-temperature estimates and hornblende microtextures collectively suggest deformation under conditions of 7-8 kbar and 500-550°C. In the fifth paper we constrain the age of the gneissic fabric in the granitoid country-rock at around 1422 Ma by dating a member of the syn-kinematic felsic Axamo dykes, using the U-Pb ion probe technique. It is suggested that the mafic and plagioclase-porphyritic members of the Axamo Dyke Swarm were emplaced coeval with the Jönköping Anorthositic Suite. This thesis is the first contribution which recognizes the Hallandian as a regional scale orogenic event, acknowledging all the major features of that age in the Fennoscandian Shield. These features include ~1460 Ma rifting, deposition of clastic sediments and extrusion of continental basalts in central Fennoscandia, 1460-1440 Ma emplacement of I- to A-type granitoids in southern Fennoscandia, 1450-1420 Ma deformation and metamorphism in southern Sweden and on Bornholm, and 1410-1380 Ma post-kinematic pegmatite dykes and intrusions of granite, monzonite and charnockite in the Eastern Segment. The spatial and temporal trends of these features suggest a tectonic model in which the rifting and mafic magmatism to the north are the far-field effects of north-eastward subduction of an oceanic plate, with the subduction zone located to the southwest of present-day Fennoscandia. Collision with an unknown (micro-) continent led to crustal shortening as Fennoscandia overrode this unknown continent. Post-collisional collapse triggered decompressional melting of heated continental crust, resulting in the emplacement of post-kinematic dykes and plutons

Catalyzing red list assessments of underrepresented Taxa through partner networks and student engagement

Global biodiversity decline is continuing largely unabated. The International Union for Conservation of Nature (IUCN) Red List of Threatened Species (hereafter, Red List) provides us with the gold standard for assessments, but taxonomic coverage, especially for invertebrates and fungi, remains very low. Many players contribute to the Red List knowledge base, especially IUCN Red List partners, IUCN-led assessment projects, and the Specialist Groups and Red List Authorities (RLA) of the IUCN Species Survival Commission. However, it is vital that we develop the next generation of contributors and bring in new, diverse voices to build capacity and to sustain the huge assessment effort required to fill data gaps. Here, we discuss a recently established partner network to build additional capacity for species assessments, by linking academia directly into the assessment processes run by Specialist Groups and RLAs. We aim to increase Red List “literacy” amongst potential future conservationists and help students to increase publication output, form professional networks, and develop writing and research skills. Professors can build Red List learning into their teaching and offer Red Listing opportunities to students as assignments or research projects that directly contribute to the Red List. We discuss the opportunities presented by the approach, especially for underrepresented species groups, and the challenges that remain

On the Evaluation of Probability Forecasts: An Application to Qualitative Choice Models

Using data from Nielsen HomeScan scanner panel for calendar year 2003, we develop binary choice models to focus on the decision made by a sample of U.S. households to purchase various non-alcoholic beverages. We evaluate the probabilities generated through those qualitative choice models using an array of techniques such as expectation-prediction success tables; receiver operating characteristics (ROC) curve, Kullback-Leibler Information criteria; calibration; resolution (sorting); the Brier score; and the Yates partition of the Brier score. In using expectation-prediction success tables, we paid attention to sensitivity and specificity. Use of a naïve 0.50 cut-off to classify probabilities resulted in the over or under estimation of sensitivity and specificity values compared to the use of the market penetration value. Area under the ROC curve is suggested as an alternative to the use of 0.5 cut-off as well as cut-off at market penetration level to classify probabilities, because this method treats a wide range of cut-off probabilities to come up with a coherent measure in classifying probabilities. The area under the ROC was highest for coffee for with-in-sample probabilities while it was highest for fruit juice model for out-of-sample probabilities. Kullback-Leibler Information Criteria which selects the model with the highest log-likelihood function value observed at out-of-sample observations (OSLLF) to evaluate probabilities show “closeness” or deviation of model generated probabilities to the true data generating probability overall, although this method does not offer classification of probabilities for events that occurred versus that did not. Again, with respect to OSLLF value, probabilities associated with fruit juice model outperform all other beverages. Forecast probabilities with respect to most of the beverage purchases were well calibrated. All resolution graphs were almost flat against a 45-degree perfect resolution graph, indicative of poor sorting power of choice models. The Brier score was lowest for fruit juices and the highest for low-fat milk. According to the calculated Brier score, probability forecasts for fruit juices outperformed other non-alcoholic beverages. Although the Brier score gave an overall indication of the ability of a model to forecast accurately, the components of the Yates decomposition of the Brier score provided a clearer and broader indication of the ability of the model to forecast. With-in-sample probabilities generated through logit model for coffee outperforms probabilities generated for other beverages based on area under the ROC curve, covariance between probabilities and outcome index and slope of covariance. Out-of-sample probabilities generated through logit model for fruit juice performs better than any other beverage category based on area under the ROC curve, Brier Score, and OSLLF value. In the event where researchers are confronted with alternative models that issue probability forecasts, the accuracy of probability forecasts in determining the best model can be measured through myriad of metrics. Even though traditional measures such as expectation-prediction success tables, calibration and log-likelihood approaches are still used, ROC charts, resolution, the Brier score and the Yates partition of the Brier score to evaluate probabilities generated through alternative models are highly recommended