Serra De Monchique Research Articles

Exploring High-Resolution Chemical Distribution Maps of Incompatible and Scarce Metals in a Nepheline Syenite from the Massif of “Serra de Monchique” (Portugal, Iberian Peninsula)

In this case study, 2D micro energy dispersive X-ray fluorescence (µ-EDXRF) surveys were performed in the nepheline syenite (NS) of “Serra de Monchique” located in the southwest region of Portugal (Algarve, Iberian Peninsula). The results allow the identification in the mineral matrix of certain elements classified as critical raw materials (CRMs). Due to substitution effects, some scarce transition elements, such as Zn and Ni, are present and camouflaged in alkali silicate minerals, while others, such as Co, are included in ferromagnesian mineral phases. As expected, incompatible elements are preferably distributed on the surface of aluminosilicate mineral phases such as Rb and Ga, or exclusively in K-bearing feldspar phases, as it is the case of Sr. Interesting CRMs such as Ti, Zr, and Nb are well individualized in oxides, as well as in sphene and apatite. The detected antagonistic chemical distribution between Ti and Fe, and the good spatial relation between Ti and Ca confirms that Ti is present as sphene and, in areas with absent Si, probably occurs as rutile. Nb has a distribution pattern quite similar to Zr and occurs due to substitution effects. It was possible to conclude that there is probable co-existence of Zr-REE-Nb in specific mineral phases such as apatite, zircon, and other Zr-oxides. These results evidence and confirm NS as a potential source of multiple industrial minerals and distinct scarce elements which are incorporated in oxide or phosphate phases that can be more effectively separated in the beneficiation process.

Combining wildfire behaviour simulations and network analysis to support wildfire management: A Mediterranean landscape case study

The recent extreme wildfire events in the Mediterranean region overwhelmed fire suppression capabilities of national authorities, evidencing the need for a paradigm shift in forest and wildfire management. Wildfire spread and behaviour simulations can provide relevant information to assess fire hazard and to guide decision-makers in implementing fuel treatment strategies. Here, we quantify the influence of spatial arrangement of fuels on fire spread connectivity by developing a new graph-based connectivity index and by applying well established graph-based metrics. These spatial connectivity metrics provide useful information for wildfire hazard and fuel management plans, since they can be used to map vegetation patches able to generate large and intense wildfires, with consequent large impacts. This approach was applied in the fire-prone landscape of Serra de Monchique, southwestern Portugal, under different fire weather scenarios and various linear fuelbreak layout options. We show that network metrics allow the location of the most important areas of wildfire connectivity whereas wildfire suppression may be challenging under specific fire weather conditions. We further show how the construction of fuelbreaks allows to modify the wildfire spread by directly reducing the overall connectivity by 20% and the amount of area with limited opportunities for ground-based suppression by up to 70%, which may, however, be insufficient under extreme weather conditions. This information can be used to prioritize the implementation of fuelbreak segments given their relevance to contain wildfire spread across the landscape and to provide defensible areas for ground-based wildfire suppression. We anticipate that these network metrics will be helpful to both land planners and wildfire researchers seeking to disrupt fuel connectivity and assess different fuel reduction strategies in fire-prone Mediterranean regions.

On Anchonidium Bedel, 1884 sensu stricto, with descriptions of two new species from the Iberian peninsula (Coleoptera, Curculionidae: Molytinae)

Specimens attributed to the type species of the genus AnchonidiumBedel, 1884, A. unguiculare (Aubé, 1850) were re-examined. As a result Anchonidium braunerti sp. nov. from the southern Serra de Monchique, and A. spathiferum sp. nov. from mountain chains in northern Portugal (Serra da Estrela, Serra do Marão) are described. The revised distribution of A. unguiculare is mapped.

Coscinodon monchiquensis R.D.Porley, Ochyra & Ignatova (Grimmiaceae), a new species from the Algarve, southern Portugal

Coscinodon monchiquensis is described as a new species from the Serra de Monchique in the western part of the Algarve region in southern Portugal. It differs from the widespread C. cribrosus in having only slightly plicate leaves (in the latter species the leaves are usually strongly plicate to the base), a weakly recurved leaf margin in the proximal ⅓ and very fragile and markedly fenestrate peristome teeth which fall away after dehiscence giving the mature capsules a gymnostomous appearance. In cases where C. cribrosus has only weak plications to mid-leaf, the plane leaf margin at once separates it from C. monchiquensis. The affinities of C. monchiquensis are discussed, and molecular phylogenetic analysis of the nrITS region indicates its sister position to all other congeners. A key to the determination of European members of Coscinodon and similar taxa is given.

Geochemical and mineralogical controls on the distribution of rare earth elements in the laterites of Serra de Monchique, Portugal

Current European manufacturing relies heavily on imports from China for unprocessed rare earth elements (REEs) and rare earth oxides (REOs). It has been suggested that the EU holds viable reserves ...

Cork oak (Quercus suber L.) forests of western Mediterranean mountains: a plant community comparison

Cork oak landscapes hold high socio-economic and biodiversity values. In the western Mediterranean they comprise open wood pastures as well as the denser forest stands that occur particularly in mountain regions. The aim of the current study was to compare the cork oak (Q. suber) forest vegetation of the Serra de Monchique (southern Portugal) with the more extensive formations of the Sierra del Aljibe (southern Spain). In particular, we sought to understand the degree of similarity of plant species composition and diversity components – species richness, endemicity and taxonomic singularity – between the two areas, with a view to establishing the importance of this vegetation type in its regional setting. We analyse vegetation plot data on vascular plant occurrence in the forests of the study areas through ordination and cluster analysis. Species richness, endemicity and taxonomic singularity are examined for the forest areas as well other common vegetation types in their vicinity. We find an overlap in species composition across Portugal and Spain, but also important local differences. In both areas, endemicity levels are low in comparison with other common vegetation types, but total and woody species richness is relatively high. We discuss these results in relation to previous comparisons between Aljibe and similar communities in the Tingitanian peninsula of northern Morocco. We conclude that the cork oak forests of this western Mediterranean region represent a conservation priority. They are faced with multiple threats, and their survival depends on a range of conservation approaches.

A new species of Microlestes Schmidt-Gobel, 1846 (Coleoptera: Carabidae) Southwest of the Iberian Peninsula (Portugal) with illustrated keys for the identification of the Iberian-Balearic species

A new species of Microlestes Schmidt-Gobel, 1846 is described from the southwest of the Iberian Peninsula, Portugal. This new species was found in the Rede Natura 2000 Serra de Monchique area (Algarve). Microlestes aljezurensis n. sp. presents three anatomical characteristics that make it a very singular species: 1) unlike other Microlestes species, it shows a pronounced sexual dimorphism in the legs in the form of dentiform processes, more or less conspicuous, in the male mesofemur, mesotibia and metatibia; 2) the last abdominal sternite shows a slight marginal notch in the male; and 3) the median lobe of the aedeagus shows a tooth on the ventral side. Comments on the ecology and distribution are presented for this species. An illustrated key to the identification of the Iberian-Balearic species, with illustrations of the genitalia and other anatomical characteristics, is also included.

Remotely sensed indicators of forest conservation status: Case study from a Natura 2000 site in southern Portugal

The successful implementation of habitat conservation measures demands regular and spatially explicit monitoring and reporting on conservation status at a range of scales, based on indicators of both habitat range and condition (structure and functions required for long-term maintenance). Such is the case with the Natura 2000 protected areas in Europe. Focusing on the cork oak (Quercus suber) forests of one such area, the Serra de Monchique in southern Portugal, we test the complementarity and joint effectiveness of airborne multispectral and laser scanning (lidar) in providing robust indicators of conservation status. Principal forest types and other land covers are mapped to an accuracy of up to 70% (11 land cover classes) and 81% (5 classes) by fusing the two remote sensing datasets, results that are superior to using either one alone. Using previously tested relationships between lidar height metrics, forest vegetation structure and species diversity, we develop a map predicting areas of high (22% of area), medium (25%) and low (53%) condition. We recommend the further development and testing of remotely sensed range and condition indicators of conservation status for their application in important forested sites across Europe and beyond.

A comparison of the resilience of four habitats to fire, and the implications of changes in community composition for conservation: a case study from the Serra de Monchique, Portugal

Background: The occurrence of fire is natural in many ecosystems but recently the number and frequency of fires has increased. Aim: To provide an assessment of the resilience of four habitats in the Serra de Monchique to fire and to assess the implications of changes in community composition for conservation. Methods: Plots were established in heathland, rhododendron scrub, rocky outcrops and woodland and the vegetation recorded pre-fire and two and four years post-fire. A one-off survey of a range of heathland plots with different fire history was also conducted. Results: The rarer habitats (rhododendron scrub, woodland and rocky outcrops) were less resilient to fire than the more abundant heathland habitat. Fire caused an increase in the cover and number of therophyte and hemicryptophyte species, and the more typical dominant species failed to reach their natural cover. In the heathlands Erica australis (an indicator species for the ‘dry heathland’ habitat of European community interest) increased and Cistus salvifolius and Ulex minor decreased in cover with time since fire. Conclusions: The rarer habitats were least resilient to fire, which is of considerable conservation importance since fire frequency is predicted to increase with climate change. Higher fire frequencies caused a change towards a less valuable heathland type.

Rock and scree plant communities in the Serra de Monchique (SW Portugal)

AbstractThe vegetation of rock and scree habitats in the Serra de Monchique, a mountain range of mid altitude in the hinterland of the Algarve has been studied to see which plant communities grow in relation to substrate, altitude, aspect and micro‐relief. The associations are discussed in a West Mediterranean context.The Serra is a humid outpost in Southern Portugal. Rock habitats exist in the central part on syenite, a bedrock material with high base saturation. Weathering results in rock outcrops, poor in fissures, and in consolidated boulders and sandy soils. The central part is surrounded by schist, graywakes and sandstones, offering rock and scree habitats. New associations described are the rock heathland Halimio calycini‐Ericetum australis, the Sileno melliferae‐Ranunculetum bupleuroides on boulders, a Margotia gummifera ‐Iris xiphium ‐rock pasture and the Mucizonio hispidae‐Cheilanthetum tinaei in shaded fissures. The following associations are first documented for the area: Anogrammo‐Umbilicetum rupestris (on humid terrace walls), the Sedo hirsuti‐Polypodietum cambrici (humid rock surfaces in higher regions), the Asplenio ceterach‐Cheilanthetum acrostichae (rock fissures) and the Phagnalo saxatilis‐Rumicetum indurati (on screes). Rumex induratus occurs together with Dittrichia revoluta as an apophyte on road embankments and colonizes, with Scrophularia frutescens, riverine gravel.In contrast to rock communities on limestone and dolomite in the Algarve lowland and the hotspot of endemism at Cabo São Vicente, no endemic rock species occur in the Serra de Monchique. The vegetation mosaic on the syenite outcrops however is unique and deserves high priority in nature conservation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The 40Ar/39Ar age dating of the Madeira Archipelago and hotspot track (eastern North Atlantic)

The 40Ar/39Ar ages for 35 volcanic rocks and 14C ages for two charcoal samples from the Madeira Archipelago and Ampère Seamount (eastern North Atlantic) are presented. The volcanic evolution of Madeira can be divided into a voluminous shield stage (>4.6–0.7 Ma) and a subsequent low‐volume posterosional stage (<0.7–0 Ma). Volcanism during the shield stage originated from a two‐armed rift system, composed of the E–W oriented Madeira rift arm and the N–S oriented Desertas rift arm. Average growth rates for the submarine (5500 km3/Ma) and subaerial (100–150 km3/Ma) shield stages on Madeira are among the lowest found for ocean island volcanoes. It is proposed that Madeira represents the present location of a >70 Myr old hotspot which formed Porto Santo Island (11.1–14.3 Ma), Seine, Ampère (31 Ma), Corral Patch and Ormond (65–67 Ma [Féraud et al., 1982, 1986]) Seamounts, and the Serra de Monchique (70–72 Ma [McIntyre and Berger, 1982]) complex in southern Portugal. Age and spatial relationships result in a calculated absolute African plate motion above the hotspot of 1.2 cm/yr around a rotation pole located at 43°36′N/ 24°33′W.

Karyotype and Allozyme Characterization of the Iberian Leptynia attenuata Species Complex (Insecta Phasmatodea)

Abstract Karyological and allozymatic characterizations of recently collected samples of the Iberian Leptynia attenuata complex support the occurrence of three genetically differentiated groups, for which parallel morphological observations evidenced only partially diagnostic characters. The groups are: the Portuguese population of Foia (Serra de Monchique), referred to as the nominal taxon, L. attenuata; the Spanish populations of the Sistema Central, referred to as L. montana; the populations of the Toledo district, referred to as L. caprai. These taxa seem to represent a case of incipient speciation, with chromosomal and genetic differentiation ahead of the morphological one. Chromosome repatternings, affecting autosomes as well as sex chromosomes, appear to go together with the evolutionary events.

Continental Lithospheric Contribution to Alkaline Magmatism: Isotopic (Nd, Sr, Pb) and Geochemical (REE) Evidence from Serra de Monchique and Mount Ormonde Complexes

contaminated samples discarded using data from fresh clinopyroxene Isotopic results (Sr, Nd, Pb), as well as concentrations of major separates and results of leaching experiments, the initial Sr isotopic and trace elements (REE) are reported for whole-rock samples and compositions of Mount Ormonde samples are found to be unmineral separates from the onland alkaline complex of Serra de radiogenic ( Sr/Sr=0·7031±1) and identical to those obtained Monchique (South Portugal) and the offshore alkali basalt volcanic at Serra de Monchique ( Sr/Sr=0·7032±1). In contrast, a suite of Mount Ormonde (Gorringe Bank). These two genetically systematic mean difference of 2 eNd units is observed between related alkaline complexes were emplaced at the east Atlantic Serra de Monchique [eNd(T) = +4·8] and Mount Ormonde continent–ocean boundary during the Upper Cretaceous, i.e. 66–72 [eNd(T) = +6·6] whole-rock samples. Surprisingly, a variation m.y. ago. Taken together, Serra de Monchique and Mount Ormonde is also observed at Mount Ormonde between the whole-rock samples may be seen as one of the few examples of within-plate magmatism and one of the two analysed clinopyroxene separates. Whereas that straddles the continent–ocean boundary. Major and trace Mount Ormonde whole-rock samples invariably yielded eNd(T)= element compositions fail to reveal any significant differences between +6·6 (mean value), a value of +0·5 is obtained for one onland and offshore complexes. This is particularly true regarding clinopyroxene separate, whereas another gives +6·0. The above less differentiated samples (mg-number [0·40) which show the geochemical and isotopic results make it possible to assign respective same progressive and continuous enrichment of their trace element patterns, with no specific anomaly (e.g. negative Nb anomaly) being roles to the asthenosphere, lithosphere and crust in the petrogenesis of Serra de Monchique and Mount Ormonde complexes. We propose present in samples from the onland complex. Initial Pb and Sr isotopic compositions also do not allow any distinction to be made that both complexes share a common mantle source whose isotopic characteristics are very similar to the source of oceanic island basalts. between Serra de Monchique and Mount Ormonde samples. Initial Pb isotope ratios are moderately high (19·1< Pb/Pb < 19·8; Continental mantle lithosphere, already characterized isotopically by studies of peridotite massifs within the Iberian peninsula, acts Pb/Pb = 15·6) in both cases. Moreover, once the effects of Sr contamination by seawater are taken into account and the most as a contaminant which is evident onland on the whole-rock scale,

Centaurea prolongi and C. crocata in Portugal: an old confusion

Centaurea crocata, described in 1984 from the Serra de Monchique in the Algarve (S Portugal), has a long history of confusion with C. prolongi from S Spain. From the study of herbarium specimens and of living plants, authors conclude that all previous Portuguese citations of C. prolongi belong actually to C. crocata. However, authors' studies confirm the real presence of C. prolongi in some relictic localities in the limestones of the extreme south of the Algarve. A morphologic comparison between the two species is performed and authors suggest for C. crocata a hypothetical hybrid origin between C. prolongi and a species of sect. Chamaecyanus.

Petrology and origin of the type monchiquites and associated lamprophyre dykes of Serra de Monchique, Portugal

SynopsisThe term ‘monchiquite’ has suffered such conflicting usage that a redefinition is here proposed:monchiquitesare alkaline lamprophyres with essential brown amphibole and/or biotite but not necessarily with olivine, possessing a near-isotropic feldspar-free base of glass (hyalomonchiquites), analcime (analcime-monchiquites) or nepheline (nepheline-monchiquites). This effectively reverts to Rosenbusch's original definition, whilst accommodating established practices in the subsequent literature. Notwithstanding certain published interpretations, the type monchiquites from Monchique and Rio de Janeiro are hyalomonchiquites.The Monchique monchiquites are associated with camptonites and sannaites in a dyke swarm invading the Monchique foyaitic intrusion. Field, petrological, geothermometric and geochemical evidence is presented to suggest that these dykes resulted from two mixing processes: (i) a version of Bowen's classic reaction between mafic crystals and alkaline liquids—here between cumulus divines and foyaitic magma; (ii) hybridisation of hydrous theralitic and nepheline syenite magmas, restricted by liquid immiscibility. The secondary origin of certain dykes is evinced by extreme mineralogical disequilibrium. The monchiquites could represent a more advanced stage of such processes than the camptonites and sannaites.

A Monchiquite from Mount Girnar, Junagarh (Kathiawar)

I. Monchiquites and their Isotropic Groundmass The term monchiquite is now recognized as the designation of a rock, consisting mainly of ferromagnesian silicates in an isotropic groundmass, which has approximately the chemical composition and specific gravity of analcime. The name was given in 1890 by Hunter &amp; Rosenbusch [10] 1 to a rock occurring in narrow dykes, near Cabo Frio in the Serra de Tingua and elsewhere in Brazil, and containing pyroxene, soda-hornblende, mica, and olivine-phenocrysts in a colourless—or, rarely, transparent brown—matrix. This material, which they assumed to be a glass, contains numerous microlites of the porphyritic minerals and, when in a fresh condition, is completely isotropic. It has a specific gravity of 2·31. In a few cases nepheline and, rather more frequently, a felspar with twin lamellation occur. The groundmass is very subject to alteration, natrolite and analcime being formed [20] p. 539 &amp; [24] p. 233. In one instance fluidal structure was noticed to be present. The rock was distinguished from camptonite on account of its glassy base, and received the name of monchiquite, as L. van Werveke had described a similar rock from the Serra de Monchique in Southern Portugal [7]. Rocks with a groundmass of the same character, but without olivine, have been reported from Bohemia by Bořicky [4,5] and Hibsch [15]. Nepheline [5] p. 176, and leucite [15] p. 99, are sometimes present. J. R. Williams [11] described similar rocks from Arkansas, in which he believed a glassy base had once existed but had since become