No abstract

The Eastern Segment forms a complex crustal terrane that occupies the southeastern part of the Southwest Scandinavian Domain adjacent to the less deformed 1.65-1.85 Ga Transscandinavian Igneous Belt (TIB). New U-Pb data from the Eastern Segment indicate that orthogneisses and granitoid rocks have protolith ages equivalent to the later magmatic phases of the TIB and that the earliest thermotectonic episodes in the Eastern Segment occurred between 1.70 and 1.61 Ga during the Gothian Orogeny. The comparable ages for Eastern Segment gneisses and TIB rocks represent permissive evidence for the hypothesis that the orthogneiss protoliths intruded into the western margin of Fennoscandia and are not exotic with respect to the pre-Gothian craton.The eastern limit of Gothian deformation is thus interpreted to be an intracratonic deformation front that coincides with the later Sveconorwegian deformation front along the Protogine Zone south of Lake Vanern. The post-Gothian anorogenic period was interrupted, in at least the eastern part of the Eastern Segment, by a thermal and magmatic event at 1.47 Ga that generated granitic dykes and (re)crystallized titanite. Sveconorwegian U-Pb ages and field observations are compatible with a thrusting and exhumation of western supracrustal terranes over the Eastern Segment during the Sveconorwegian Orogeny, followed by isostatic unroofing and cooling of the lower deck at 950-930 Ma. Available, albeit limited, Sveconorwegian titanite ages in the Eastern Segment young from east to west, ranging from 950 to 930 Ma, and are substantially younger than those dated in the western terranes of SSD.

Soil‐site productivity relationships for Norway spruce (Picea abies (L.) Karst.) were studied on a single, but widespread soil catena (Bath‐Lordstown‐Mardin‐Volusia; ∼1.1 million ha) in central New York. Soils and vegetation data collected from 37 unthinned plantations (45‐55‐yr old) were used to develop multiple regression soilsite predictor equations and discriminant classification functions. Efforts were made through sampling procedures to reduce extraneous sources of variation inherent in many previous soil‐site studies (e.g., parent materials, geographic area, stand density, stand age, cultural practices, and seed sources). Results of regression analyses showed that three to seven independent variables could explain 53 to 82% of the variation in mean annual volume increment (MAI). Stratifying the data set by a common planting density (2990 stems ha−1) generally improved the precision of the regression equations. Independent tests of the soil‐site equations across diverse drainage conditions showed a significant correlation between predicted and measured values of MAI (r = 0.70). More accurate predictions resulted (r = 0.80) when the equations were restricted to moderately well‐ and well‐drained soils only. Discriminant functions correctly reclassified (jackknifed analysis) 81% of the 37 stands into two MAI productivity groups. In general, results from the discriminant analyses supported interpretations made from the regression analyses. Soil properties, such as textural components, coarse fragments, pH, exchangeable cations, organic C, and cation exchange capacity (CEC), were most consistently correlated with Norway spruce volume production. Topographic properties made little or no independent contribution to the predictive models developed for growth. Results should aid yield predictions and site classification decisions for Norway spruce in New York.

Dry matter production data were obtained for jack pine (Pinusbanksiana Lamb.) stands growing at three density levels on two sites. Regression equations relating tree weight to diameter and height were calculated for stem wood, stem bark, branches, needles, cones, and total aboveground biomass, as well as for periodic net annual increment of these components. Different sets of equations were needed to evaluate biomass on each site, but density levels within sites could be grouped. Total net periodic annual weight increment was linearly related to foliage weight and basal area, but a levelling-off at higher densities was evident when basal area was replaced by stand density index or bole area equivalent as the measure of density.