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Abstract The Triassic volcanic rocks of Wrangellia erupted at an equatorial to tropical latitude that was within 3000 km of western North America. The mafic and ultramafic volcanic rocks are compositionally and isotopically similar to those of oceanic plateaux that were generated from a Pacific mantle plume-type source. The thermal conditions, estimated from the primitive rocks, indicate that it was a high temperature regime (TP > 1550 °C) consistent with elevated temperatures expected for a mantle plume. The only active hotspot currently located near the equator of the eastern Pacific Ocean that was active during the Mesozoic and produced ultramafic volcanic rocks is the Galápagos hotspot. The calculated mantle potential temperatures, trace elemental ratios, and Sr–Nd–Pb isotopes of the Wrangellia volcanic rocks are within the range of those from the Caribbean Plateau and Galápagos Islands, and collectively have similar internal variability as the Hawaii-Emperor island chain. The paleogeographic constraints, thermal estimates, and geochemistry suggests that it is possible that the Galápagos hotspot generated the volcanic rocks of Wrangellia and the Caribbean plateau or, more broadly, that the eastern Pacific (Panthalassa) Ocean was a unique region where anomalously high thermal conditions either periodically or continually existed from ~ 230 Ma to the present day.

AbstractThe Challis-Kamloops belt of south-central British Columbia is a regionally extensive (>65,000 km2) magmatic province that erupted within the North American Cordillera during the Eocene (55-45 Ma). The inland volcanic belt runs parallel to the coast, and the rocks were emplaced mainly within extensional basins indicating volcanism was attributed to rift-related decompressional melting. The rocks include both calc-alkaline and tholeiitic mafic and intermediate types (i.e., low-Fe, medium-Fe, and high-Fe suites). Voluminous volcanic units (Buck Creek, Goosly Lake, Swans Lake) of the Buck Creek volcanic complex (~3,000 km2 in area) within the Nechako plateau erupted within 1-2 million years and show significant internal chemical variability. All rock types have similar Sr-Nd isotopic (87Sr/86Sri=0.70435-0.70487; εNdt=+2.6-+4.0) ratios indicating they originated from the same sub-Cordilleran mantle source. Petrological modeling using the most primitive rocks of the Buck Creek, Goosly Lake, and Swans Lake magmatic pulses demonstrates that the chemical variability observed in each system can be explained by hydrous fractional crystallization in the upper crust (≤0.1 GPa) under moderately oxidizing to oxidizing conditions (ΔFMQ 0 to +0.7). The primary difference between the low-Fe to medium-Fe (calc-alkaline) Buck Creek suite model and the high-Fe to medium-Fe (tholeiitic) Swans Lake suite model is water content as the Swans Lake model has lower (H2O=0.75 wt.%) starting water than the Buck Creek and also the Goosly Lake models (H2O=1.25-2.00 wt.%). Moreover, the intermediate to silicic rocks of the complexes are compositionally similar to rocks associated with “slab failure” suggesting that rifting and mantle melting were related to asthenospheric upwelling through a slab tear. The implications are that the chemical variability of the rock suites are primarily related to fractional crystallization and that the mantle source is heterogeneous with respect to water content which is likely due to heterogeneities in the processes related to pre-Eocene subduction.

The Tukhum granitic pluton is a part of the Mesozoic composite Khentei batholith of north-central Mongolia, which belongs to the Central Asian Orogenic Belt. The shallow-seated pluton (∼900 km2) is made up of two distinct biotite granite intrusions dated at ∼191 and 183 Ma and hosts a tungsten deposit associated with the younger phase. Both intrusions are composed of ferroan A2-type granites, which are fractionated and silica-rich (>71 wt.%). Their mantle-normalized plots are relatively enriched in Cs, Rb, U, and Th and depleted in Ba, Sr, Eu, Nb, and Ti. They have εNd(t) ranging from ∼0 to +1 and Nd model ages ∼650–900 Ma. The granites were derived by partial melting of a Neoproterozoic middle/lower crustal source of felsic/intermediate composition, followed by fractional crystallization. The younger intrusion also contains leucogranites with a trace element composition indicative of a combined crystal and fluid fractionation. The source of this younger intrusion was enriched in rare metals (W, Sn). The tungsten deposit is associated with the last stages of the evolution of the granitic magma. The origin of the pluton as well as the Khentei batholith is related to a mantle plume, which provided the heat triggering a crustal melting. The plume resulted in the eastward movement of large-scale magmatism over time, from the Tarim traps (300–275 Ma) through the large Khangai magmatic center (270–240 Ma) to the Khentei batholith (230–180 Ma) in north-central Mongolia.

Alkaline igneous complexes host deposits of rare earth elements (REE), which represent one of the most economically important resources of heavy REE and Yttrium (Y). The hosts are differentiated rocks ranging from nepheline syenites and trachytes to peralkaline granites. These complexes usually occur in continental within-plate tectonic settings associated with rifts, faults, or hotspot magmatism. The REE mineralization is found in layered alkaline complexes, granitic stocks, and late-stages dikes and rarely trachytic volcanic and volcaniclastic deposits. The bulk of REE is present in accessory minerals, which can reach percentage levels in mineralized zones. The mineralization contains various REE-bearing minerals that can display complex replacement textures. Main REE minerals present in these deposits are bastnäsite, eudialyte, loparite, gittinsite, xenotime, monazite, zircon, and fergusonite. The parent magmas of alkaline igneous complexes are derived from partial melts of mantle sources. Protracted fractional crystallization of the magma led to an enrichment in REE, particularly in the late stages of magma evolution. The primary magmatic mineralization is commonly overprinted (remobilized and enriched) by late magmatic to hydrothermal fluids. Elevated abundances of U and Th in the deposits make a gamma-ray (radiometric) survey an important exploration tool, but also represent a significant environmental challenge for exploitation.

In forest protection, various types of trap systems are used against spruce bark beetles to treat the foci of infested areas. Traditionally, these include pheromone traps, treated trap trees, and recently also the application of Storanet insecticide nets used for the sanitation of infested wood (trees), which also serve as treated trap trees when pheromones are applied, and the Trinet P system, a variation to a treated trap tree - a tripod. On an aluminium tripod, there is a Storanet insecticide net baited with a pheromone dispenser similar to other types of trap systems. The sex ratio proves to be a significant aspect in the assessment of individual types of trap systems. It is more favourable to catch a larger number of female individuals given that they bear the future development of the population. With a higher number of captured male individuals, the number of females per one male in the insect gallery increases, and the population cannot be reduced sufficiently. The results show that all three types of measures can be characterised by a lower ratio of captured males (approximately 40%) and a higher representation of females (around 60%). Differences in individual types of trap systems are insignificant.

The study evaluates the results of a long-term research trial lasting 50 years in two research plots established in the 1970s aimed at solving the decline of the silver fir in the Czech Republic. A total of 103 different provenances occurring naturally across 12 countries were planted in research plots No. 67, Černovice (Českomoravská vrchovina), and No. 77, Nové Hrady (Novohradské hory). The total tree height, diameter at breast height (DBH) and assessment of the health status of all trees in the area were measured with the same methodology. Subsequently, the volume of large wood was calculated by the volume equation, and the growing stock per hectare was recalculated. Based on our analysis of average height growth, it was found that trees with the best growth came from provenances that included the Czech provenances CZ 70 - Ždírec nad Doubravou, CZ 82 - Vizovice, CZ 42 - Lukov, CZ 76 - Nýrsko, Suchý Kámen, and CZ 53 - Opočno. The last three mentioned provenances also dominated in other growth parameters (DBH and volume of large wood). Of the foreign provenances, D 146 - Schwarzwald mit Baar, S 9 - Kriváň, and S 6 - Čierny Váh produced trees that showed above-average values. The smallest growth in height was found in the trees from the provenances BG 132 - Rila, Borovets, F 104 - Departement de ľ Aude, I 228 - Vallombrosa, A 93 - Wörschachwald. Although some trees of Italian provenance achieve above-average volume, due to high mortality, they are not suitable for economic use in the forests of the Czech Republic. Based on the European zoning for forests, the units from the Central European region (3.11.0 - České Polabí, 3.32.0 - Schwarzwald with foothills and Baar, and 9.14.0 - Southern Apennine Mountains) were the best rated in all parameters. Specimens from 9.12.0 - Mountain forest of the northern Apennines, and 4.05.0 - Vosges showed the lowest parameters.

In 2021, measurements were done at two international provenance research trials for silver fir originating from the same series of experiments. The investigation was carried out in the location Vítkov and Úsov, where both trials were established. Biometric data (tree height, diameter at breast height) were measured and qualitative traits (stem shape, occurrence of stem forking, stem damage, bark pattern, and defoliation) were assessed during the early mature stage of the experiment. Overbark stem volume and per-hectare standing volume were also calculated. Sixty-five provenances of domestic and foreign origin were evaluated in both trials. Although the results do not indicate unequivocally the most suitable or most productive provenance in the trials, provenances of Czech origin including the ones originating from the surrounding natural forest areas perform consistently better than the average. The least productive provenances, on the other hand, were those from parts of Bulgaria, Austria, and especially Italy, which achieved the poorest results even in stem shape. In Czech conditions, therefore, Italian fir provenances have not proved so successful as they have in the United Kingdom.

The article evaluates 27 provenances of three subspecies of lodgepole pine on the Kovářská research plot (Krušné hory Mts.). The plot is part of a series of three established plots in various stand conditions. Two plots were already evaluated and the findings were published. At 34 years of age, we evaluated height, DBH, trunk shape, trunk forking, branch thickness, bark type, mortality, and defoliation. A total of 1,147 trees were measured. Above-average growth was achieved predominantly by the provenances of Pinus contorta subsp. latifolia (Engelmann ex S. Watson) Critchfield from middle elevations. In the Pinus contorta subsp. contorta Douglas ex Loudon, only the 2099 Port Orford provenance from Oregon demonstrated favourable results, and in the Pinus contorta subsp. murrayana (Balfour) Engelmann it was 2098 Chemult. High mortality was demonstrated mainly in the P. c. subsp. murrayana provenance from high mountainous elevations in California and P. c. subsp. contorta from coastal regions of Oregon. Provenances from middle elevations had relatively lower mortality, especially P. c. subsp. latifolia. The pines usually were of good quality although this was not the case for defoliation and branch thickness. In comparing all plots of the series, growth was fastest at the Sofronka location in western Bohemia and slowest at the south Bohemian Mláka location. Only the best provenances of lodgepole pine can equal the domestic Scots pine (Pinus sylvestris Linnaeus).

KEPPIE, J.D. & DOSTAL, J. 2007. Rift-related basalts in the 1.2–1.3 Ga granulites of the northern Oaxacan Complex, southern Mexico: evidence for a rifted arc on the northwestern margin of Amazonia. Proceedings of the Geologists’ Association, 118, 63–74. Meta-igneous granulites with estimated c. 1.3–1.2 Ga protolith ages in the northern Oaxacan Complex of southern Mexico have bimodal protoliths: rift-related basalts (probably continental tholeiites) and felsic volcanic rocks that could also have been arkosic sediments. Negative Nb, Ta and Ti anomalies in the mafic rocks are interpreted to reflect derivation from a mantle source previously enriched by subduction processes. In contrast, contemporaneous igneous country rocks in the southern Oaxacan Complex have arc affinities and the simplest interpretation suggests a south-to-north transition from arc to back-arc or intra-arc rift. Various locations in 1.2–1.0 Ga Rodinia reconstructions have been proposed for these and correlative rocks in Middle America: an autochthonous location; and as an allochthonous terrane originating either off northwestern or southern Amazonia or the Arequipa–Antofalla terrane. The collision between southern Amazonia and southern Laurentia at 1.2 Ga followed by relative northward travel (present-day coordinates) of Amazonia along eastern Laurentia appear to eliminate all but a northwestern Amazonian location for Middle America. The development of an arc complex on the northwestern margin of Amazonia would be consistent with the relative northward motion of Amazonia. [ABSTRACT FROM AUTHOR]

This study is focused on testing progenies of common and narrow-leaved ash based on the measurement of provenance trial plots established in various forest regions under different site conditions within the Czech Republic in the spring of 1999. Height and diameter growth of 35 provenances was measured and evaluated at the stand age of 10-14 years. The main goal of this research is to analyse and compare differences in growth between progenies originating from alluvial versus scree habitats as well as between the two evaluated ash species. Moreover, the influence of localities on growth was tested using standard provenances planted on all plots. The results of the last measurement were compared with those from the first survey in 2000 at the age of 4-5 years (1 year after planting). With the exception of DBH on the Koněprusy plot, statistically significant differences in height and diameter growth between provenances were verified. The results confirmed a very strong site influence on growth. The main conclusions indicate significant differences in growth parameters between provenances, faster growth of alluvial versus scree provenances on most lowland plots, and generally faster growth of narrow-leaved ash as compared to common ash.

The article aims to evaluate the research provenance plot established in 1980 in locality No. 214 - Hrubá Skála (in the north of the Czech Republic), where nine provenances of grand fir (Abies grandis (Douglas ex D. Don) Lindley) provided in the framework of the International Union of Forest Research Organizations project, and one provenance of grand fir, Norway spruce, silver fir and Douglas-fir from a standard commercial source are tested. We present the results of tree height, stem DBH, stem volume production and health status after 36 years. The results correspond with similar experiments in the Czech Republic and abroad and suggest that grand fir provenances from Vancouver Island (British Columbia, Canada) and the Washington (USA) State coastal region show the best production features, while the Oregon Cascades, Idaho and Montana provenances grow more slowly. Comparison with other tree species indicates that the production of grand fir at the investigated age exceeds the production of both Norway spruce and silver fir, and equalizes or gently exceeds even Douglas-fir.