Journal articles on the topic 'Structural New Caledonia'
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Ozanne-Rivierre, Francoise. "Structural Changes in the Languages of Northern New Caledonia." Oceanic Linguistics 34, no. 1 (June 1995): 44. http://dx.doi.org/10.2307/3623111.
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Webb, Donald W. "The genus Chrysopilus in New Caledonia (Diptera: Rhagionidae)." Canadian Entomologist 143, no. 6 (December 2011): 706–34. http://dx.doi.org/10.4039/n11-037.
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AbstractSeventeen new species of Chrysopilus Macquart are described from New Caledonia with illustrations of the male head, wing, and genitalia. The new species are C. bicoloratus sp. nov., C. brunneabdominalis sp. nov., C. caliginosus sp. nov., C. chazeaui sp. nov., C. everti sp. nov., C. irwini sp. nov., C. frankmcalpinei sp. nov., C. mandjelia sp. nov., C. melinus sp. nov., C. noumea sp. nov., C. petersoni sp. nov., C. plautifrons sp. nov., C. sarramea sp. nov., C. shewelli sp. nov., C. teskeyi sp. nov., C. vockerothi sp. nov., and C. woodi sp. nov. Keys are provided to identify the species from New Caledonia.
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Ibanez, Thomas, Jérôme Munzinger, Gilles Dagostini, Vanessa Hequet, Frédéric Rigault, Tanguy Jaffré, and Philippe Birnbaum. "Structural and floristic diversity of mixed tropical rain forest in New Caledonia: new data from the New Caledonian Plant Inventory and Permanent Plot Network (NC-PIPPN)." Applied Vegetation Science 17, no. 3 (November 13, 2013): 386–97. http://dx.doi.org/10.1111/avsc.12070.
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Le Cohu, Rene, Horst Lange-Bertalot, Bart Van de Viver, and Loic Tudesque. "Analysis and critical evaluation of structural features in four Cymbellaceae taxa from New Caledonia." Fottea 20, no. 1 (April 1, 2020): 75–85. http://dx.doi.org/10.5507/fot.2019.017.
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Read, J., T. Jaffre, E. Godrie, G. S. Hope, and J. M. Veillon. "Structural and floristic characteristics of some monodominant and adjacent mixed rainforests in New Caledonia." Journal of Biogeography 27, no. 2 (March 2000): 233–50. http://dx.doi.org/10.1046/j.1365-2699.2000.00407.x.
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Manceau, A., G. Calas, and A. Decarreau. "Nickel-bearing clay minerals: I. Optical spectroscopic study of nickel crystal chemistry." Clay Minerals 20, no. 3 (September 1985): 367–87. http://dx.doi.org/10.1180/claymin.1985.020.3.08.
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AbstractNickel crystal chemistry was systematically studied in various phyllosilicates, mainly the natural phases selected from the ‘garnierites’ of the supergene ore deposits of New Caledonia. Minerals which do not usually occur in New Caledonian parageneses were synthesised, as they could represent intermediate phases of genetic importance. In the kerolite-pimelite series, a linear relationship occurred between the ratioI(13,20)/I(02,11)of thehkbands and Ni-content. Diffuse reflectance spectra were used to derive the crystal chemical parameters of Ni. These confirmed its divalent character and its occupation of octahedral sites; the resulting structural distortion was slight and could not be detected in some minerals. There was no optical evidence for Ni atoms in 4-fold coordination. The two main parameters which showed significant variations among the studied phases were site distortion and crystal field stabilization energy (CFSE). Site distortion was at a maximum in trioctahedral smectites and sepiolite. CFSE depended on the mineralogy, crystallinity and chemical composition (Al-content) of the phase. Finally, clay minerals are classified according to the increasing stability of Ni in the octahedral sheet, which has been tentatively related to the geochemical distribution of this element. Secondary minerals are usually enriched vs. primary ones and among them are nepouite and kerolite which exhibit a high CFSE in contrast to sepiolite.
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WELLS, ALICE, KJELL ARNE JOHANSON, and PETER DOSTINE. "Why are so many species based on a single specimen?" Zoosymposia 14, no. 1 (July 15, 2019): 32–38. http://dx.doi.org/10.11646/zoosymposia.14.1.5.
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A considerable number of insect species, including Trichoptera, are described from a single specimen, also known as a 'unique' or a 'singleton'. We ask the question of whether this reflects failure to consider variation and related species, lack of collecting effort, or true rarity. In an attempt to answer this question we examine the available literature and data on the Trichoptera of Tasmania and New Caledonia. We note a low level of taxonomic synonymy among species in these faunas. Moreover, a significant proportion of species from Tasmania that were based originally on singletons have been re-collected subsequently, but this is not true for New Caledonia. The possible significance of these figures is considered following examination of data on diversity and abundance of Hydroptilidae collected by regular, standardised light trapping over almost two years at a northern Australian tropical stream. We conclude that quite a large proportion of the Trichoptera species based on singletons are rare, valid species, but for others the appearance of rarity may be a consequence of inadequate collecting, particular behavioural attributes of the species, including seasonality, and failure to consider fully the structural diversity of related species. Lastly, we discuss briefly the consequences of rarity, apparent or real, on conservation management.
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de Vel, Olivier Y., and William Bour. "The structural and thematic mapping of coral reefs using high Resolution SPOT data: Application to the Tétembia reef (New Caledonia)." Geocarto International 5, no. 2 (June 1990): 27–34. http://dx.doi.org/10.1080/10106049009354256.
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Read, Jennifer, Patricia Hallam, and Jean-François Cherrier. "The anomaly of monodominant tropical rainforests: some preliminary observations in theNothofagus-dominated rainforests of New Caledonia." Journal of Tropical Ecology 11, no. 3 (August 1995): 359–89. http://dx.doi.org/10.1017/s026646740000883x.
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ABSTRACTNothofagusspecies dominate small patches of rainforest on ultramafic soils in New Caledonia, forming an almost monospecific upper canopy on some sites. These stands are commonly bordered by rainforests of greater floristic and structural complexity, also on ultramafic soils. In two lowland stands, the population size structures ofNothofagus aequilateralisstems greater than 50 cm high had an approximately skewed bell-shaped distribution with a modal size class of 15–25 cm stem diameter, and with no evidence of old trees. This indicates that the establishment ofNothofagushas occurred over a limited time span, without sufficient recent regeneration to allow the future replacement of the existing canopy trees. The factors initiating the major period of regeneration are not certain, but large-scale disturbance is implicated and evidence of past wild-fire on both sites is consistent with this hypothesis. It is unlikely that significant regeneration ofNothofaguswill occur as the stands mature and canopy gaps are created by the death of old trees, since saplings of other species already occur at high densities in the understorey and will probably pre-empt the resources made available by canopy gaps. Two other study sites were situated above 900 m asl. At Dzumac, in an apparently older stand dominated byN. codonandra, there is some evidence of recent regeneration, predominantly confined to a single large canopy gap. The population size structure ofN. baumanniaeon the fourth site, on the summit of Mt Mou, shows a closer approximation to a reverse-J curve. Seedlings, however, are relatively uncommon on this site, and the numerous saplings may be suppressed rather than young.Analyses of topsoil provided no consistent evidence to suggest that mineral content is controlling the distribution ofNothofagusacross vegetation boundaries.The environmental factors promoting the formation of these monodominant canopies are uncertain, but appear to involve large-scale disturbance by windstorm or fire. The population size structures suggest that the canopies of the two lowland stands, at least, are likely to become more species-rich, with a progressive decline in the frequency ofNothofagus. Therefore, these lowland monodominant forests cannot be regarded as equilibrium communities, irrespective of whether more detailed studies reveal environmental differences across the community boundaries. The status of the two high altitude sites is less certain.
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El Mendili, Yassine, Beate Orberger, Daniel Chateigner, Jean-François Bardeau, Stéphanie Gascoin, Sébastien Petit, and Olivier Perez. "Occurrence of SiC and Diamond Polytypes, Chromite and Uranophane in Breccia from Nickel Laterites (New Caledonia): Combined Analyses." Minerals 12, no. 2 (February 2, 2022): 196. http://dx.doi.org/10.3390/min12020196.
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Different techniques have been combined to identify the structure and the chemical composition of siliceous breccia from a drill core of nickel laterites in New Caledonia (Tiebaghi mine). XRD analyses show quartz as a major phase. Micro-Raman spectroscopy confirmed the presence of reddish microcrystalline quartz as a major phase with inclusion of microparticles of iron oxides and oxyhydroxide. Lithoclasts present in breccia are composed of lizardite, chrysotile, forsterite, hedenbergite and saponite. The veins cutting through the breccia are filled with Ni-bearing talc. Furthermore, for the first time, we discovered the presence of diamond microcrystals accompanied by moissanite polytypes (SiC), chromite (FeCr2O4) and uranophane crystals (Ca(UO2)2(SiO3OH)2.5(H2O)) and lonsdaleite (2H-[C-C]) in the porosities of the breccia. The origin of SiC and diamond polytypes are attributed to ultrahigh-pressure crystallization in the lower mantle. The SiC and diamond polytypes are inherited from serpentinized peridotites having experienced interaction with a boninitic melt. Serpentinization, then weathering of the peridotites into saprolite, did not affect the resistant SiC polytypes, diamond and lonsdaleite. During karstification and brecciation, silica rich aqueous solutions partly digested the saprolite. Again, the SiC polymorph represent stable relicts from this dissolution process being deposited in breccia pores. Uranophane is a neoformed phase having crystallized from the silica rich aqueous solutions. Our study highlights the need of combining chemical and mineralogical analytical technologies to acquire the most comprehensive information on samples, as well as the value of Raman spectroscopy in characterizing structural properties of porous materials.
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Quesnel, Benoît, Pierre Gautier, Michel Cathelineau, Philippe Boulvais, Clément Couteau, and Maxime Drouillet. "The internal deformation of the Peridotite Nappe of New Caledonia: A structural study of serpentine-bearing faults and shear zones in the Koniambo Massif." Journal of Structural Geology 85 (April 2016): 51–67. http://dx.doi.org/10.1016/j.jsg.2016.02.006.
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Dominique, Cluzel, Iseppi Marion, and Chen Yan. "Eocene pre- and syn-obduction tectonics in New Caledonia (Southwest Pacific), a case for oblique subduction, transcurrent tectonics and oroclinal bending; structural and paleomagnetic evidence." Tectonophysics 811 (July 2021): 228875. http://dx.doi.org/10.1016/j.tecto.2021.228875.
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Pho, Nguyen Van, Pham Tich Xuan, and Pham Thanh Dang. "Occurrence of supergene nickel ores in the Ha Tri Massive, Hoa An District, Cao Bang Province." VIETNAM JOURNAL OF EARTH SCIENCES 40, no. 2 (January 19, 2018): 154–65. http://dx.doi.org/10.15625/0866-7187/40/2/11676.
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Nickel (Ni) laterites are regolith materials derived from ultramafic rocks and play an important role in the world's Ni production. Ni-laterite deposits are the supergene enrichment of Ni formed from the intense chemical and mechanical weathering of ultramafic parental rocks. In Vietnam, the weathering profile containing Ni laterite was first discovered in the Ha Tri massive (Cao Bang). This profile develops on the Ha Tri serpentinized peridotite rocks classified to the Cao Bang mafic-ultramafic complex (North Vietnam) and exhibits thick weathered zone (10 - 15m). This work carried out a detailed study of the weathering profile at the center of Ha Tri massive. Samples from different horizons of the profile were collected and analyzed in detail by XRF, XRD and SEM-EDX methods to establish the relationship between the Ni-rich supergene products and the parental peridotites (lherzolite) rocks in Ha Tri massive. The results show that the saprolite horizon is most Ni-rich in the weathering profile in Ha Tri. In this horizon, Ni-silicate minerals of garnierite group such as pimelite, nepouite and other Mg-Ni silicates have been found. The appearance of minerals of garnierite group is due to the exchange of Mg by Ni during weathering of peridotite minerals, especially olivine, which leads to the enrichment of the supergene Ni. The occurrence of Ni silicates suggests the existence of the supergene Ni ore in the weathering profile of the Ha Tri massive.References Bosio N.J., Hurst J.V., Smith R.L., 1975. Nickelliferousnontronite, a 15 Å garnierite, at Niquelandia, Goias Brazil. Clays Clay Miner., 23, 400-403. Brand N.W., Butt C.R.M., Elias M., 1998. Nickel Laterites: Classification and features. AGSO Journal of Australian Geology & Geophysics, 17(4), 81-88. Bricker O.P., Nesbitt H.W. and Gunter W.D., 1973. The stability of talc. American Mineralogist, 58, 64-72. Brindley G.W. and Hang P.T., 1973. The nature of garnierites. Structures, chemical composition and color characteristics. Clay and Clay Minerals, 21, 27-40. Brindley G.W. and Maksimovic Z., 1974. The nature and nomenclature of hydrous nickel-containing silicates. Clay Minerals, 10, 271-277. Brindley G.W. and Wan H.M., 1975. Composition structures and thermal behavior of nickel containing minerals in thelizardite-ne´pouite series. American Mineralogist, 60, 863-871. Brindley G.W., Bish D.L. and Wan H.M., 1979. Compositions, structures and properties of nickel containing minerals in the kerolite-pimelite series. American Mineralogist, 64, 615-625. Cluzel D. and Vigier B., 2008. Syntectonic mobility of supergene nickel ores from New Caledonia (Southwest Pacific). Evidence from faulted regolith and garnierite veins. Resource Geology, 58, 161-170. Colin F., Nahon D., Trescases J.J., Melfi A.J., 1990. Lateritic weathering of pyroxenites at Niquelandia, Goais, Brazil: The supergene behavior ofnickel: Economic Geology, 85, 1010-1023. Das S.K., Sahoo R.K., Muralidhar J., Nayak B.K., 1999. Mineralogy and geochemistry of profilesthrough lateritic nickel deposits at Kansa,Sukinda, Orissa. Joural of Geoogical. SocietyIndia, 53, 649-668. Decarreau A., Colin F., Herbillon A., Manceau A., Nahon D., Paquet H., Trauth-Badaud D.,Trescases J.J., 1987. Domain segregation in NiFe-Mg-Smectites. Clay Minerals, 35, 1-10. Freyssinet P., Butt C.R.M. and Morris R.C., 2005. Oreforming processes related to lateritic weathering. Economic Geology, 100th aniversary volume, 681-722.Garnier J., Quantin C., Martins E.S., Becquer T., 2006. Solid speciation and availability of chromium in ultramafic soils from Niquelandia, Brazil. Journal of Geochemical Exploration, 88, 206-209. Garnier J., Quantin C., Guimarães E., Becquer T., 2008. Can chromite weathering be a source of Cr in soils? Mineralogy Magazine, 72, 49-53. Gleeson S.A., Butt C.R. and Elias M., 2003. Nickel laterites: A review. SEG Newsletter, 54, 11-18. Gleeson S.A., Butt C.R., Wlias M., 2003. Nickellaterites: a review. SEG Newsletter, Society of Economic Geology, 54. Available from www.segweb.org. Golightly J.P., 1981. Nickeliferous laterite deposits. Economic Geology, 75th Anniversary volume, 710-735. Golightly J.P., 2010. Progress in understanding the evolution of nickel laterite. Society of Economic Geology, In Special Publication, 15, 451-485. Manceau A. and Calas G., 1985. Heterogeneous distribution of nickel in hydrous silicates from New Caledonia ore deposits. American Mineralogist, 70, 549-558. Nguyen Van Pho, 2013. Tropic weathering in Vietnam (in Vietnamese). Pubisher Science and Technology, 365p.Ngo Xuan Thanh, Tran Thanh Hai, Nguyen Hoang, Vu Quang Lan, S. Kwon, Tetsumaru Itaya, M. Santosh, 2014. Backarc mafic-ultramafic magmatism in Northeastern Vietnam and its regional tectonic significance. Journal of Asian Earth Sciences, 90, 45-60.Pelletier B., 1983. Localisation du nickel dans les minerais ‘‘garnieritiques’’ de Nouvelle-Caledonie. Sciences Ge´ologique: Me´moires, 73, 173-183.Pelletier B., 1996. Serpentines in nickel silicate ores from New Caledonia. In Grimsey E.J., and Neuss I. (eds): Nickel ’96, Australasian Institute of Miningand Metallurgy, Melbourne, Publication Series 6(9), 197-205. Proenza J.A., Lewis J.F., Galı´ S., Tauler E., Labrador M., Melgarejo J.C., Longo F. and Bloise G., 2008. Garnierite mineralization from Falcondo Ni-laterite deposit (Dominican Republic). Macla, 9, 197-198. Soler J.M., Cama J., Galı´ S., Mele´ndez W., Ramı´rez, A., andEstanga, J., 2008. Composition and dissolution kinetics ofgarnierite from the Loma de Hierro Ni-laterite deposit,Venezuela. Chemical Geology, 249, 191-202. Springer G., 1974. Compositional and structural variations ingarnierites. The Canadian Mineralogist, 12, 381-388. Springer G., 1976. Falcondoite, nickel analogue of sepiolite. The Canadian Mineralogist, 14, 407-409.Svetlitskaya T.V., Tolstykh N.D., Izokh A.E., Phuong Ngo Thi, 2015. PGE geochemical constraints on the origin of the Ni-Cu-PGE sulfide mineralization in the Suoi Cun intrusion, Cao Bang province, Northeastern Vietnam. Miner Petrol, 109, 161-180.Tran Trong Hoa, Izokh A.E., Polyakov G.V., Borisenko A.S., Tran Tuan Anh, Balykin P.A., Ngo Thi Phuong, Rudnev S.N., Vu Van Van, Bui An Nien, 2008. Permo-Triassic magmatism and metallogeny of Northern Vietnam in relation to the Emeishan plume. Russ. Geol. Geophys., 49, 480-491.Trescases J.J., 1975. L'évolution supergene des roches ultrabasiques en zone tropicale: Formation de gisements nikelifères de Nouvelle Caledonie. Editions ORSTOM, Paris, 259p.Tri T.V., Khuc V. (eds), 2011. Geology and Earth Resources of Vietnam. Publishing House for Science and Technology, 645p (in English). Villanova-de-Benavent C., Proenza J.A., GalíS., Tauler E., Lewis J.F. and Longo F., 2011. Talc- and serpentine-like ‘‘garnierites’’ in the Falcondo Ni-laterite deposit, Dominican Republic. ‘Let’s talk ore deposits’, 11th Biennial Meeting SGA 2011, Antofagasta, Chile, 3p.Wells M.A., 2003. Goronickel laterite deposit. New Caledonia. CRC LEME, p.3.
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Wu, Yu-Chou, An-Shik Yang, Li-Yu Tseng, and Chin-Lung Liu. "Myth of ecological architecture designs: Comparison between design concept and computational analysis results of natural-ventilation for Tjibaou Cultural Center in New Caledonia." Energy and Buildings 43, no. 10 (October 2011): 2788–97. http://dx.doi.org/10.1016/j.enbuild.2011.06.035.
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Park, Adrian F., Robert L. Treat, Sandra M. Barr, Chris E. White, Brent V. Miller, Peter H. Reynolds, and Michael A. Hamilton. "Structural setting and age of the Partridge Island block, southern New Brunswick, Canada: a link to the Cobequid Highlands of northern mainland Nova Scotia." Canadian Journal of Earth Sciences 51, no. 1 (January 2014): 1–24. http://dx.doi.org/10.1139/cjes-2013-0120.
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The Partridge Island block is a newly identified tectonic element in the Saint John area of southern New Brunswick, located south of and in faulted contact with Proterozoic and Cambrian rocks of the Ganderian Brookville and Avalonian Caledonia terranes. It includes the Lorneville Group and Tiner Point complex. The Lorneville Group consists of interbedded volcanic and sedimentary rocks, subdivided into the Taylors Island Formation west of Saint John Harbour and West Beach Formation east of Saint John Harbour. A sample from thin rhyolite layers interbedded with basaltic flows of the Taylors Island Formation at Sheldon Point yielded a Late Devonian – Early Carboniferous U–Pb (zircon) age of 358.9 +6/–5 Ma. Petrological similarities indicate that all of the basaltic rocks of the Taylors Island and West Beach formations are of similar age and formed in a continental within-plate tectonic setting. West of Saint John Harbour, basaltic and sedimentary rocks of the Taylors Island Formation are increasingly deformed and mylonitic to the south, and in part tectonically interlayered with mylonitic granitoid rocks and minor metasedimentary rocks of the Tiner Point complex. Based on magnetic signatures, the deformed rocks of the Tiner Point complex can be traced through Partridge Island to the eastern side of Saint John Harbour, where together with the West Beach Formation, they occupy a thrust sheet above a redbed sequence of the mid-Carboniferous Balls Lake Formation. The Tiner Point complex includes leucotonalite and aegirine-bearing alkali-feldspar granite with A-type chemical affinity and Early Carboniferous U–Pb (zircon) ages of 353.6 ± 5.7 and 346.4 ± 0.7 Ma, respectively. Based on similarities in age, petrological characteristics, alteration, iron oxide – copper – gold (IOCG)-type mineralization, and deformation style, the Partridge Island block is correlated with Late Devonian – Early Carboniferous volcanic–sedimentary–plutonic rocks of the Cobequid Highlands in northern mainland Nova Scotia. Deformation was likely a result of dextral transpression along the Cobequid–Chedabucto fault zone during juxtaposition of the Meguma terrane.
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Vigneron, Sophie. "The Repatriation of Human Remains in France: 20 Years of (Mal)practice." Santander Art and Culture Law Review, no. 2 (6) (2020): 313–38. http://dx.doi.org/10.4467/2450050xsnr.20.022.13025.
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This article analyses three cases of repatriation of human remains by French public museums in order to critically examine the difficulties in the changing institutional practice. It critically ssesses the statutory and administrative processes that have been used to repatriate human remains and identifies the difficulties that have been and are mostly still encountered. Firstly, it evaluates the public/private conundrum of ownership of human remains in French law, which explains why Parliament had to intervene to facilitate the repatriation of remains in public museum collections, whereas a private society could repatriate the skulls of chief Ataï and his doctor to New Caledonia without legal difficulties. Secondly, it reviews the need for parliamentary intervention for the repatriation of the remains of Saartjie Baartman to South Africa and several Mokomokai to New Zealand. Finally, it criticizes the administrative deadlock that has prevented the development of a repatriation practice that could have b en established after the successful repatriation of the remains of Vamaica Peru to Uruguay. Unfortunately, the process has remained opaque and ineffective, owing to a variety of factors; in particular the ambiguity regarding the role of the Commission scientifique nationale des collections, which is set to be abolished and whose role will be undertaken by the Haut conseil des Musées de France, and a lack of political, financial, and structural support from the Ministry of Culture. Until these shortcomings are addressed and clear criteria for repatriation are drawn up, it is unlikely that France will develop a coherent, transparent, and effective process for the repatriation of human remains.
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Hu, Meijuan, Shuang Zhao, Jinlin Liu, Yichao Tong, Zhangyi Xia, Jing Xia, Shuang Li, Yuqing Sun, Jiaxing Cao, and Jianheng Zhang. "The Morphology, Genetic Diversity, and Distribution of Ulva meridionalis (Ulvaceae, Chlorophyta) in Chinese Seas." Journal of Marine Science and Engineering 10, no. 12 (December 3, 2022): 1873. http://dx.doi.org/10.3390/jmse10121873.
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Green tides originate from the rapid growth of green macroalgae and their large accumulation. In the past few decades, the severity and frequency of green tides have increased and the range of their geographical distribution has widened. In recent years, Ulva meridionalis Horimoto et Shimada has been reported in many countries. This species has stable morphological characteristics, and its length can reach 3 m in indoor cultures. Its cells contain pyrenoids, and the sporangium and gametangium of each cell contain 8 spores and 16 gametes, respectively, which confer a high proliferation potential. The phylogenetic tree constructed in this study showed that the Internal Transcribed Spacer sequence identified U. meridionalis with a high identification reliability, and the genetic relationship between U. meridionalis and Ulva pertusa in the ITS sequence was close. The haplotype network analysis clarified the relationship of the U. meridionalis samples collected from four different sea areas in China and indicated that they were closely related. Five haplotypes were identified: Hap_2 and Hap_1 were the most frequent, and they were also the haplotypes shared among the three groups. The degree of subspecies formation was not reached among these U. meridionalis samples collected from the Chinese seas. Up to 20 years ago, U. meridionalis had only been recorded in Japan. After 2011, it has been found to be widely distributed in the United States, China, French New Caledonia, French Polynesia, and Australia, where it proliferates. It has spread as a new kind of green tide-forming macroalga. The present study found that U. meridionalis is widely distributed in the Chinese seas; specifically, there have been small-scale blooms in the Bohai Sea, the Yellow Sea, and the South China Sea. Further investigations should focus on establishing whether U. meridionalis will cause large-scale green tide events in the future.
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Bui, Van Ngoc, Duong Huy Nguyen, Nhat Huy Chu, Yvan Bettarel, Jean-Christophe Auguet, Thierry Bouvier, and Ha Hoang Chu. "Diversity and Biogeography of Coral Mucus-Associated Bacterial Communities: The Case of Acropora formosa." Journal of Marine Science and Engineering 11, no. 1 (January 3, 2023): 74. http://dx.doi.org/10.3390/jmse11010074.
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The role of microorganisms in coral health, disease, and nutrition has been demonstrated in various studies. Environmental factors including pH, temperature, and dissolved oxygen also play crucial roles in maintaining sustainable coral ecosystems. However, how geographical and environmental factors influence bacterial diversity and community composition is unclear. Here, bacterial communities associated with Acropora formosa coral were sampled from four different locations—Phu Quoc Islands (Vietnam), Nha Trang (Vietnam), Ujung Gelam (Indonesia), and Bourake (New Caledonia)—and compared using tagged 16S rRNA sequencing. We identified 24 bacterial phyla, 47 classes, 114 orders, and 495 genera from 18 samples. Overall, Proteobacteria (1039 distant amplicon sequence variants [ASVs]) and Firmicutes (589 ASVs) were predominant, while Verrucomicrobiota (75 ASVs) and Planctomycetota (46 ASVs) were minor taxa. Alpha diversity analyses revealed that the bacterial community associated with Acropora formosa from Ujung Gelam had the highest indexes (Observed and Chao1), while the figures for Bourake were the lowest. Non-metric multidimensional scaling analysis (NMDS) showed significant differences in bacterial communities among locations (ADONIS, p = 1 × 10−4). Temperature was strongly correlated with the distribution of bacterial communities in Bourake, whereas pH and dissolved oxygen were significantly correlated with the presence of coral-associated bacterial communities in Phu Quoc and Nha Trang. Across all samples, 28 potential biological markers and 95 core ASVs were found, revealing significant differences in coral-associated bacterial communities. Collectively, these findings provide a comprehensive understanding of bacterial communities living in coral reefs across different geographic sites, which could be useful springboards for further studies.
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Sluiter, Ian R. K., David T. Blackburn, and Guy R. Holdgate. "Fire and Late Oligocene to Mid-Miocene peat mega-swamps of south-eastern Australia: a floristic and palaeoclimatic interpretation." Australian Journal of Botany 64, no. 8 (2016): 609. http://dx.doi.org/10.1071/bt16165.
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The Late Oligocene to Mid-Miocene (25–13 million years ago) brown coals of the Gippsland Basin in southern Victoria, Australia, were deposited in peat mega-swamps, unlike any in the world at the present day. The swamps preserve a rich botanical suite of macro- and microfossils, many of which can be identified with plant genera and families present today in Australia, New Caledonia, New Zealand and New Guinea. The peat-forming environments also preserve evidence of past burning in the form of micro-charcoal as well as macro-charcoal, the latter being evident as regional lenses or layers of fusinite, generally in coals of the darkest colour termed dark lithotypes. The presence of micro-charcoal in dark and some other lighter lithotypes indicated that fires also burnt locally, although they may have been extinguished before regional-scale burning occurred. It is also feasible that some peat mega-swamp plant communities dominated by rainforest angiosperm plants may have been fire excluders and prevented widespread fires from developing. Pollen and macrofossil evidence is presented of a distinctive southern conifer and angiosperm flora with an open canopy, primarily associated with the darkest coals that formed in the wettest parts of the peat-forming environment. Elsewhere, swamp forests with a large rainforest component grew on swamps raised appreciably above the regional groundwater table in a structural context akin to the ombrogenous peats of tropical coastal Sumatra and Sarawak. These vegetation types were not fire prone, but may have occasionally burnt at a local scale or at forest margins. Evidence is presented for the existence of seasonal climatic conditions that would appear to have facilitated a drying-out of the peat swamps in the warmest months of the year. A mesothermal climate was invoked where mean annual precipitation was at least 1500 mm, and possibly as much as 2000 mm, and mean annual temperatures were ~19°C.
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Gascuel, Didier, Yves-Marie Bozec, Emmanuel Chassot, Audrey Colomb, and Martial Laurans. "The trophic spectrum: theory and application as an ecosystem indicator." ICES Journal of Marine Science 62, no. 3 (January 1, 2005): 443–52. http://dx.doi.org/10.1016/j.icesjms.2004.12.013.
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Abstract Trophic spectra represent the distribution of biomass, abundance, or catch by trophic level, and may be used as indicators of the trophic structure and functioning of aquatic ecosystems in a fisheries context. As a theoretical background, we present a simple ecosystem model of biomass flow reflecting predation and ontogenetic processes. Biomass trophic spectrum of total biomass can be modelled as the result of three major factors and processes: trophic efficiency, transfer kinetics, and extent of top-down control. In the simulations, changes in the spectrum highlight fishing impacts on trophic structure and reveal some functional characteristics of the underlying ecosystem. As examples of potential applications, three case studies of trophic spectra are presented. Catch trophic spectra allow description of structural differences among European fishing areas and periods. Abundance trophic spectra of coral-reef fish assemblages display different trophic signatures, characterizing different reef habitats in New Caledonia and highlighting fishing effects in a marine protected area context. Biomass trophic spectra of demersal resources off Northwest Africa show a shift in ecosystem structure that can be attributed to the rapid increase in fishing pressure during the past few decades. Off Senegal, total biomass remained fairly constant, suggesting a strong top-down control linked to fisheries targeting high trophic level species. Off Guinea, exploitation rates are spread over a wider range of trophic levels, and the total biomass of demersal resources tended to decrease. The trophic spectrum is concluded to be a useful indicator describing and comparing systems in time and space, detecting phase shifts linked to natural or anthropogenic perturbations, and revealing differences in ecosystem functioning.
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Tähtinen, Petri, Graziano Guella, Giacomo Saielli, Cécile Debitus, Edouard Hnawia, and Ines Mancini. "New Sulfur-Containing Polyarsenicals from the New Caledonian Sponge Echinochalina bargibanti." Marine Drugs 16, no. 10 (October 11, 2018): 382. http://dx.doi.org/10.3390/md16100382.
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Arsenicin A (C3H6As4O3) was isolated from the New Caledonian poecilosclerid sponge Echinochalina bargibanti, and described as the first natural organic polyarsenic compound. Further bioguided fractionation of the extracts of this sponge led us to isolate the first sulfur-containing organic polyarsenicals ever found in Nature. These metabolites, called arsenicin B and arsenicin C, are built on a noradamantane-type framework that is characterized by an unusual As–As bonding. Extensive NMR measurements, in combination with mass spectra, enabled the assignment of the structure for arsenicin B (C3H6As4S2) as 2. The scarcity of arsenicin C and its intrinsic chemical instability only allowed the collection of partial spectral data, which prevented the full structural definition. After the extensive computational testing of several putative structures, structure 3 was inferred for arsenicin C (C3H6As4OS) by comparing the experimental and density functional theory (DFT)-calculated 1H and 13C NMR spectra. Finally, the absolute configurations of 2 and 3 were determined with a combined use of experimental and time-dependent (TD)-DFT calculated electronic circular dichroism (ECD) spectra and observed specific rotations. These findings pose great challenges for the investigation of the biosynthesis of these metabolites and the cycle of arsenic in Nature. Arsenicins B and C showed strong antimicrobial activities, especially against S. aureus, which is comparable to the reference compound gentamycin.
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Cave, A., M. Leboeuf, H. Moskowitz, A. Ranaivo, IRC Bick, W. Sinchai, M. Nieto, T. Sevenet, and P. Cabalion. "Alkaloids of Cryptocarya phyllostemon." Australian Journal of Chemistry 42, no. 12 (1989): 2243. http://dx.doi.org/10.1071/ch9892243.
Full textAbstract:
The known alkaloids (-)-antofine (1), dehydroantofine (5),(-)-cryptowoline (6), (4- cryptowolidine (7), and (-)-cryptowolinol (8), were isolated from the New Caledonian lauraceous plant Cryptocarya phyllosternon, together with five new bases: two secophenanthro-indolizidines, (-)-phyllostemine (2) and (-)-phyllosteminine (3), one pyrrolidinylacetophenone, (-)-phyllostone (4), and two quaternary tetrahydrobenzylisoquinolines, (+)-phyllocryptine (9) and (+)-phyllocryptonine (10). Chemical and spectroscopic methods were used for identification and structural investigation. A synthesis of phyllocryptonine has permitted its stereostructure to be determined.
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Thrane, Kristine. "Palaeoproterozoic age of a basement gneiss complex in the Charcot Land tectonic window, East Greenland Caledonides." Geological Survey of Denmark and Greenland (GEUS) Bulletin 6 (December 30, 2004): 57–66. http://dx.doi.org/10.34194/geusb.v6.4818.
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The Charcot Land tectonic window exposes crystalline basement gneisses, which form part of the foreland of the East Greenland Caledonides. These gneisses were previously believed to be Archaean in age, on the basis of imprecise K-Ar analyses carried out in the early 1980s on hornblende from amphibolitic bands and inconclusive Rb/Sr isotope data. New U-Pb singlezircon ion microprobe analyses on the gneisses of the window yield upper intercept ages of 1916 ± 21 and 1928 ± 11 Ma, and are interpreted to represent the age of crystallisation of the igneous protolith. The foreland gneisses of the Charcot Land window are similar in age to parts of the allochthonous gneiss complexes of structurally overlying thrust sheets, but the two terranes have different lithological and structural characteristics. No Archaean rocks have been identified with certainty in any of the East Greenland Caledonian foreland windows.
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McCarthy, William, R. John Reavy, Carl T. Stevenson, and Michael S. Petronis. "Late Caledonian transpression and the structural controls on pluton construction; new insights from the Omey Pluton, western Ireland." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 106, no. 1 (March 2015): 11–28. http://dx.doi.org/10.1017/s1755691015000201.
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ABSTRACTThe Galway Granite Complex is unique among the British and Irish Caledonian granitoid terranes, as it records punctuated phases of magmatism from ∼425–380 Ma throughout the latest phase of the Caledonian Orogeny. Remapping of the Omey Pluton, the oldest member of this suite, has constrained the spatial distribution and contact relationships of the pluton's three main facies relative to the nature of the host rock structure. The external contacts of the pluton are mostly concordant to the limbs and hinge of the Connemara Antiform. New AMS data show that a subtle concentric outward dipping foliation is present, and this is interpreted to reflect pluton inflation during continued magma ingress. Combined field, petrographic and AMS data show that two sets of shear zones (NNW–SSE and ENE–WSW) cross-cut the concentric foliation, and that these structures were active during the construction of the pluton. We show that regional sinistral transpression at ∼420 Ma would have caused dilation along the intersection of these two fault sets, and suggest that this facilitated centralised magma ascent. Lateral emplacement was controlled by the symmetry of the Connemara Antiform to ultimately produce a discordant phacolith. We propose that regional sinistral transpression at ∼420 Ma influenced the siting of smaller intrusions over NNW–SSE faults, and that the later onset of regional transtension caused larger volumes of magma to intrude along the E–W Skird Rocks Fault at ∼400 Ma.
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HADLEY, M. J., A. RUFFELL, and A. G. LESLIE. "Gamma-ray spectroscopy in structural correlations: an example from the Neoproterozoic Dalradian succession of Donegal (NW Ireland)." Geological Magazine 137, no. 3 (May 2000): 319–33. http://dx.doi.org/10.1017/s0016756800003976.
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The Caledonian Horn Head Slide is a spectacular ductile shear zone transecting Neoproterozoic Appin Group Dalradian metasediments in Donegal (NW Ireland). Two conflicting stratigraphic interpretations exist for the inverted succession exposed in the hanging wall of the structure. These are based on correlation with two quite separate exposed pelite formations elsewhere. The two formations are lithologically indistinct and unfossiliferous. Here we document the novel use of assayed and logged spectral gamma-ray measurements in comparing the contentious pelite in the hanging wall of the Horn Head Slide to the two possible correlative pelite formations from a wide area of their unequivocal outcrop. The data from the contentious pelite show a clear statistical and stratigraphical affinity with one candidate unit only, thus providing the stratigraphical definition necessary for refining previous cross-sections. A new model, based on our spectral gamma-ray correlation, is proposed to account for the northwestwards directed emplacement of the Lower Falcarragh Pelite Formation along the slide. This model requires pre-Caledonian normal faulting as a precursor to the ensuing compressional event in which stratigraphically younger rocks were thrust over older, a common instance in fold and thrust belt geometry. Our work suggests that spectral gamma-ray measurements may provide a rapid, field-based method for differentiating unfossiliferous pelite or mudstone units at outcrop and in geophysical well-logs, even in structurally complex areas.
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Alsop, G. I. "The geometry and structural evolution of a crustal-scale Caledonian fold complex: the Ballybofey Nappe, northwest Ireland." Geological Magazine 131, no. 4 (July 1994): 519–37. http://dx.doi.org/10.1017/s0016756800012139.
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AbstractThe gross geometries exhibited by crustal-scale fold nappes are considered a consequence of both original stratigraphic relationships associated with sub-basin configuration, coupled with the nature of the structural regime and tectonic processes involved in the generation of the nappe pile. The Neo-Proterozoic Dalradian metasediments of northwestern Ireland provide a well-constrained and correlatable stratigraphy which defines a sequence of sub-reclined, tight-isoclinal Caledonian (c. 460 Ma) fold nappes. Within this fold complex, the dominant structure is the crustal-scale Ballybofey Nappe, which may be traced for 40 km along strike and is responsible for a regional (500 km2) stratigraphie inversion. The gentle, NE-plunging attitude of this fold results in a complete spectrum of tectonic levels and deformation gradients being exposed. Relatively low strains in the upper fold limb gradually increase down through the nappe, resulting in the generation of composite foliations and lineations and the development of a 10 km thick shear zone which culminates in a high strain basal detachment with underlying pre-Caledonian basement. The Ballybofey Nappe nucleated and propagated along a major zone of lateral sedimentary facies variation, coincident with the margin of a major Dalradian sub-basin. The large amplitude of the nappe is strongly influenced by the lateral heterogeneity within the metasedimentary sequence, and is associated with a minimum of 25–30 km ESE-directed translation concentrated within the overturned limb. Additional significant displacement is also focused along the basal décollement. Generation of the nappe complex resulted in significant crustal thickening and amphibolite facies metamorphism consistent with 15–18 km of burial, induced by a sequence of nappes propagating in the direction of overshear. The ESE-directed translation of the major fold nappes is away from the Caledonian foreland and a gravity-driven mechanism of nappe emplacement is suggested. Rigorous structural analysis within the cohesive stratigraphie framework enables relationships between the tectonic evolution and stratigraphic patterns to be distinguished, thus allowing models of fold nappe generation and mid-crustal deformation to be evaluated.
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Ghent, E. D., J. C. Roddick, and P. M. Black. "40Ar/39Ar dating of white micas from the epidote to the omphacite zones, northern New Caledonia: tectonic implications." Canadian Journal of Earth Sciences 31, no. 6 (June 1, 1994): 995–1001. http://dx.doi.org/10.1139/e94-088.
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An 40Ar/39Ar study of white micas from high-pressure metamorphic rocks of northern New Caledonia yielded cooling ages of 37 ± 1 Ma for both epidote and omphacite zone samples. Whole-rock samples from the lawsonite zone yielded ages in the range 44–51 Ma with complicated age spectra, probably reflecting both detrital and newly grown micas. The areal extent of the mica samples, over 300 km2, suggests that the epidote and omphacite zone rocks cooled through the muscovite closure temperature, about 350 °C, as a coherent cooling unit. Simple thermal modeling suggests that these rocks could have closed at similar times if the unroofing rate were greater than 2–10 mm∙a−1. Lawsonite zone rocks occur structurally within about 0.5 km of garnet–omphacite rocks, suggesting the possibility of major postmetamorphic tectonic displacement.
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L. W. Perry, George, and N. J. Enright. "Spatial modelling of "alternative" future landscapes under climate change and fire suppression, Mont Do, New Caledonia." Pacific Conservation Biology 9, no. 4 (2003): 248. http://dx.doi.org/10.1071/pc040248.
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The vegetation dynamics and disturbance regimes of the south-west Pacific have been significantly altered following human settlement. Previously forested landscapes are now dominated by a matrix of flammable early successional vegetation within which patches of mesic, fire-sensitive forest are embedded. Future environmental change, and in particular climate change, will further affect disturbance regimes in these ecosystems. If ignition frequency and fire extent increase, then the persistence of these landscapes in their current composition and structure is uncertain. Using a spatially explicit landscape ecological model, we explored the implications of climatically altered fire regimes for landscape composition and structure in a mountain-top reserve in New Caledonia. The outcomes of the modeling suggest that increased ignition probability and vegetation flammability would lead to a maquis (heathland)-dominated landscape structurally simpler than that seen today. The feasibility of fire suppression as a means of managing altered fire regimes was explored using a series of model experiments. Fire suppression has been problematic in some systems, especially those where fire hazard increases over time. However, in this ecosystem, and others in the south-west Pacific, it may be a viable alternative for managing fire because fire hazard, in terms of flammability, peaks early in the succession and then decreases over successional time.
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Vejbæk, Ole Valdemar. "Seismic Stratigraphy and Tectonics of Sedimentary Basins around Bornholm Southern Baltic." Danmarks Geologiske Undersøgelse Serie A 8 (October 1, 1985): 1–30. http://dx.doi.org/10.34194/seriea.v8.7027.
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Identification of structural elements in the offshore area around Bornholm has been possible with the use of reflection seismic data. The area straddles the Fennoscandian Borderzone, extending into the Danish Polish Trough. Major structural depressions are the Rønne Graben, the Arnager Graben (new name), the Christiansø Half-graben and the Hano Bay Basin. Structural highs are the Christiansø High, the Hammervand High, the Bornholm Gat Uplift, The Dueodde High (new name), the Southern Bornholm High (new name) and Bornholm High. The Palaeozoic sediments show rapidly increasing thicknesses to the south towards the Caledonian deformation front, and to the east towards the Peribaltic Syneclise. The present distribution of thick Palaeozoic sediments is however primarily a result of Late Palaeozoic–Early Mesozoic erosion. Occurences of Triassic, Jurassic and Lower Cretaceous sediments are primarily restricted to graben areas. These were generated in a Late Carboniferous-Early Permian tension dominated right-lateral wrench fault system parallel to the Tornquist line. The Mesozoic sediments of the above-mentioned ages were deposited in expanding basins interrupted by tectonic activity, which resulted in renewed restriction of sediments to graben areas accompanied by erosion on structural highs. Late Jurassic and Late Early Cretaceous tectonic events are identified. The most spectacular tectonic event is of an Early Tertiary age. The Rønne Graben and the Arnager Graben were subjected to compression in a right lateral fault system during this phase, and were subsequently uplifted and erosion occurred accompanied by reverse faulting and minor folding.
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Goodenough, K. M., B. N. Young, and I. Parsons. "The minor intrusions of Assynt, NW Scotland: early development of magmatism along the Caledonian Front." Mineralogical Magazine 68, no. 4 (August 2004): 541–59. http://dx.doi.org/10.1180/0026461046840207.
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AbstractThe Assynt Culmination of the Moine Thrust Belt, in the northwest Scottish Highlands, contains a variety of Caledonian alkaline and calc-alkaline intrusions that are mostly of Silurian age. These include a significant but little-studied suite of dykes and sills, the Northwest Highlands Minor Intrusion Suite. We describe the structural relationships of these minor intrusions and suggest a classification into seven swarms. The majority of the minor intrusions can be shown to pre-date movement in the Moine Thrust Belt, but some appear to have been intruded during the period of thrusting. A complex history of magmatism is thus recorded within this part of the Moine Thrust Belt. New geochemical data provide evidence of a subduction-related component in the mantle source of the minor intrusions.
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Kos'ko, M., and E. Korago. "Review of geology of the New Siberian Islands between the Laptev and the East Siberian Seas, North East Russia." Stephan Mueller Special Publication Series 4 (September 17, 2009): 45–64. http://dx.doi.org/10.5194/smsps-4-45-2009.
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Abstract. The New Siberian Islands comprise De Long Islands, Anjou Islands, and Lyakhov Islands. Early Paleozoic, Mesozoic and Cenozoic sediments and igneous rocks are known on the De Long Islands. Cambrian slate, siltstone, mudstone and silicified limestone occur on Bennett Island. Ordovician volcanogenic turbidites, lavas, and small intrusions of andesite-basalt, basalt, dolerite, and porphyritic diorite were mapped on Henrietta Island. The igneous rocks are of calc-alkaline island arc series. The Ordovician age of the sequence was defined radiometrically. Early Paleozoic strata were faulted and folded presumably in the Caledonian time. Early Cretaceous sandstone and mudstone are known on Bennett Island. They are overlain by a 106–124 Ma basalt unit. Cenozoic volcanics are widespread on the De Long Islands. Zhokhov Island is an eroded stratovolcano. The volcanics are mostly of picrite-olivine type and limburgite. Radiometric dating indicates Miocene to Recent ages for Cenozoic volcanism. On the Anjou islands Lower-Middle Paleozoic strata consist of carbonates, siliciclastics, and clay. A Northwest-southeast syn-sedimentary facies zonation has been reconstructed. Upper Paleozoic strata are marine carbonate, clay and siliciclastic facies. Mudstone and clay predominate in the Triassic to Upper Jurassic section. Aptian-Albian coal bearing deposits uconformably overlap lower strata indicating Early Cretaceous tectonism. Upper Cretaceous units are mostly clay and siltstone with brown coal strata resting on Early Cretaceous weathered rhyolite. Cenozoic marine and nonmarine silisiclastics and clay rest upon the older units with a transgressive unconformity including a weathering profile in the older rocks. Manifestations of Paleozoic and Triassic mafic and Cretaceous acidic magmatism are also found on these islands. The pre-Cretaceous structure of the Anjou islands is of a block and fold type Late Cimmerian in age followed by faulting in Cenozoic time. The Lyakhov islands are located at the western end of the Late Cimmerian South Anyui suture. Sequences of variable age, composition, and structural styles are known on the Lyakhov Islands. These include an ancient metamorphic sequence, Late Paleozoic ophiolitic sequence, Late Mesozoic turbidite sequence, Cretaceous granites, and Cenozoic sediments. Fold and thrust imbricate structures have been mapped on southern Bol'shoi Lyakhov Island. North-northwestern vergent thrusts transect the Island and project offshore. Open folds of Jurassic–Early Cretaceous strata are characteristic of Stolbovoi and Malyi Lyakhov islands. Geology of the New Siberian Islands supports the concept of a circum Arctic Phanerozoic fold belt. The belt is comprised of Caledonian, Ellesmerian, Early Cimmerian and Late Cimmerian fold systems, manifested in many places on the mainland and on islands around the Arctic Ocean. Knowledge of the geology of the New Siberian Islands has been used to interpret anomalous gravity and magnetic field maps and Multi Channel Seismic (MCS) lines. Two distinguishing structural stages are universally recognized within the offshore sedimentary cover which correlate with the onshore geology of the New Siberian Islands. Dating of the upper structural stage and constituent seismic units is based on structural and stratigraphic relationships between Late Mesozoic and Cenozoic units in the archipelago. The Laptev Sea–western East Siberian Sea seismostratigraphic model for the upper structural stage has much in common with the seismostratigraphic model in the American Chukchi Sea.
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BURNS, I. M., M. B. FOWLER, R. A. STRACHAN, and P. B. GREENWOOD. "Geochemistry, petrogenesis and structural setting of the meta-igneous Strathy Complex: a unique basement block within the Scottish Caledonides?" Geological Magazine 141, no. 2 (March 2004): 209–23. http://dx.doi.org/10.1017/s0016756804009070.
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The Strathy Complex of the Scottish Caledonides is a bimodal association of amphibolites and siliceous grey gneisses that structurally underlies adjacent metasediments of the Moine Supergroup. Both rock units record a common polyphase Caledonian tectonometamorphic history. New elemental and radiogenic isotope data indicate that both end-members of the Strathy suite were derived from a depleted mantle source, that they are cogenetic and that they may have been related by crystal fractionation. δ18O values and their correlations with major and trace elements suggest that the protoliths were hydrothermally altered at temperatures below 200 °C. Tectonomagmatic discrimination based on relatively immobile elements and isotope systems, plus comparison with geochemically similar bimodal supracrustal associations elsewhere, strongly support the conclusion that the igneous protoliths of the Strathy Complex formed in an oceanic destructive margin setting. If TDM model ages of c. 1000 Ma approximate protolith crystallization, the Strathy Complex may have formed as juvenile crust in the peri-Rodinian ocean broadly contemporaneous with the Grenville orogenic cycle.
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MOUND, LAURENCE A., and DESLEY J. TREE. "Fungus-feeding phlaeothripine Thysanoptera in the genus Holothrips from Australia and New Caledonia, with a structurally similar new genus, Holoengythrips." Zootaxa 3860, no. 2 (September 4, 2014): 125. http://dx.doi.org/10.11646/zootaxa.3860.2.2.
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Johansson, Å., D. G. Gee, L. Björklund, and P. Witt-Nilsson. "Isotope studies of granitoids from the Bangenhuk Formation, Ny Friesland Caledonides, Svalbard." Geological Magazine 132, no. 3 (May 1995): 303–20. http://dx.doi.org/10.1017/s0016756800013625.
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AbstractThe Caledonian Hecla Hoek succession in Ny Friesland, eastern Svalbard has been interpreted, for many decades, to be a continuous stratigraphic sequence. Early Palaeozoic and Neoproterozoic strata in its upper parts pass more or less conformably down into amphibolite facies rocks (Stubendorffbreen Supergroup) at depth. Recent isotopic age-determination and structural studies have indicated that the Stubendorffbreen succession is tectonostratigraphic and made up of at least three major thrust sheets. This paper provides new data from two meta-igneous units within the succession, the Bangenhuk and Instrumentberget gneisses. Both are granitoid sheets, consisting mainly of red, strongly lineated gneisses of monzogranitic composition; the Bangenhuk unit also contains some lenses of little deformed granitoids, as well as cross-cutting aplite dykes, amphibolitized dolerites and subordinate metasedimentary rocks. The latter are locally cut by granitoids. U—Pb zircon dating of six samples of variably deformed Bangenhuk granitoids, including one cross-cutting aplitic dyke, has yielded ages between 1720 and 1770 Ma, the higher values generally from the less deformed samples. The Instrumentberget gneissic granite yielded an age of 1737+46−41 Ma. These ages are interpreted to date the time of intrusion of the granitoids at around 1750 Ma; the younger ages may have been slightly lowered by Caledonian deformation, particularly those from specimens located close to a major fracture (the Billefjorden Fault Zone) in Wijdefjorden—Austfjorden. U—Pb dating of titanite from the least deformed granitoid also yields comparable Palaeoproterozoic ages; in the more deformed rocks, however, titanites give evidence of Caledonian ductile deformation at c. 410 Ma. The Rb—Sr system of the corresponding whole rock samples has been disturbed and yields an errorchron age of about 1650 Ma and, for some samples, an impossibly low initial Sr ratio. The Sm—Nd system may be more intact and yields initial εNd values of −2 to −3, suggesting some contribution from older crustal material to the granitoid magmas. The results indicate the presence of extensive units of Palaeoproterozoic granitic basement within the Lower Hecla Hoek succession of Ny Friesland, supporting the hypothesis that the latter is composed of tectonically intercalated basement and cover units.
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Fritsch, Emmanuel, Etienne Balan, Sabine Petit, and Farid Juillot. "Structural, textural, and chemical controls on the OH stretching vibrations in serpentine-group minerals." European Journal of Mineralogy 33, no. 4 (August 3, 2021): 447–62. http://dx.doi.org/10.5194/ejm-33-447-2021.
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Abstract. The OH stretching vibrational properties of eight serpentine samples from veins of the New Caledonian ophiolite have been investigated by Fourier-transform infrared spectroscopy (FTIR) in the mid-infrared and near-infrared ranges and by Raman spectroscopy. The samples were selected for their monophasic composition (Lz: lizardite; Ctl: chrysotile; and Atg: antigorite) making them representative of the three serpentine species. Comparison of fundamental and overtone spectra allowed us to interpret most of the observed bands and to propose consistent spectral decomposition in individual components. The OH stretching bands related to intrinsic vibrational properties of the minerals are distinguished from those associated with chemical substitutions in octahedral sites (mainly Fe and Ni for Mg substitutions). Observations made on the most symmetric Lz are consistent with previous interpretations and underline the effect of macroscopic parameters on OH stretching bands in the FTIR spectra. The major importance of the distribution of OH bond lengths in the broadening of the vibrational signals of the less symmetric and more distorted Atg is confirmed. The combination of the three spectroscopic methods makes it possible to unravel the occurrence of two different types of interlayer OH environments in Ctl nanotubes. One corresponds to the features observed at 3684 and 7171 cm−1 in the fundamental and overtone spectra, respectively, and is similar to the local OH environment observed in Lz. The other corresponds to broader signals observed at 3693 and 7200 cm−1 in the fundamental and overtone spectra, respectively. It reflects a distribution of OH bond lengths likely related to local structural misfits between adjacent layers in the tubular structure of Ctl.
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Brück, Peter M., Kenneth T. Higgs, Nadia Maziane-Serraj, and Michel Vanguestaine. "New palynological data from the Leinster Lower Palaeozoic massif, southeastern Ireland." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 91, no. 3-4 (2000): 509–14. http://dx.doi.org/10.1017/s026359330000835x.
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ABSTRACTIn southeastern Ireland, the tectonic evolution of the northwestern Avalonian margin is rather poorly understood and only partially constrained. This is because the stratigraphy comprises in the main unfossiliferous turbidites. Nevertheless, some authors have attempted to define ‘terranes’ and ‘tracts’ in the region, aided by several significant Caledonoid-trending structural breaks that can be determined in the field. Palynological work was carried out in the early 1970s and established a range of ages from approximately mid Cambrian to late Silurian, although much of the succession proved barren. In the current study, the Lower Palaeozoic sequences W of the Leinster Granite and in the Slievenamon Inlier to the S have been palynologically re-investigated. Previous work proposed an unbroken succession from lower Ordovician Ribband Group turbidites and volcanics younging westwards conformably into upper Silurian Kilcullen Group sediments. The new study clearly shows that the Ordovician palynomorphs in the older part of the Kilcullen Group are reworked. In fact, there exists a major stratigraphical break between the Ribband Group dated as early Ordovician, Arenig, and the Kilcullen Group which is entirely Silurian, late Llandovery to early Wenlock in age. This major break has a minimum strike length of 150 km and is most likely much longer, extending some hundreds of kilometres SW to Dingle and possibly equating with a similar discontinuity in the Isle of Man to the NE. This break would thus appear to be a major feature within the succession of the northwestern Avalonian margin.
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Perron, Paul, Michel Guiraud, Emmanuelle Vennin, Isabelle Moretti, Éric Portier, Laetitia Le Pourhiet, and Moussa Konaté. "Influence of basement heterogeneity on the architecture of low subsidence rate Paleozoic intracratonic basins (Reggane, Ahnet, Mouydir and Illizi basins, Hoggar Massif)." Solid Earth 9, no. 6 (November 7, 2018): 1239–75. http://dx.doi.org/10.5194/se-9-1239-2018.
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Abstract. The Paleozoic intracratonic North African Platform is characterized by an association of arches (ridges, domes, swells, or paleo-highs) and low subsidence rate syncline basins of different wavelengths (75–620 km). The Reggane, Ahnet, Mouydir and Illizi basins are successively delimited from east to west by the Amguid El Biod, Arak-Foum Belrem, and Azzel Matti arches. Through the analysis of new unpublished geological data (i.e., satellite images, well logs, seismic lines), the deposits associated with these arches and syncline basins exhibit thickness variations and facies changes ranging from continental to marine environments. The arches are characterized by thin amalgamated deposits with condensed and erosional surfaces, whereas the syncline basins exhibit thicker and well-preserved successions. In addition, the vertical facies succession evolves from thin Silurian to Givetian deposits into thick Upper Devonian sediments. Synsedimentary structures and major unconformities are related to several tectonic events such as the Cambrian–Ordovician extension, the Ordovician–Silurian glacial rebound, the Silurian–Devonian Caledonian extension/compression, the late Devonian extension/compression, and the Hercynian compression. Locally, deformation is characterized by near-vertical planar normal faults responsible for horst and graben structuring associated with folding during the Cambrian–Ordovician–Silurian period. These structures may have been inverted or reactivated during the Devonian (i.e., Caledonian, Mid–Late Devonian) compression and the Carboniferous (i.e., pre-Hercynian to Hercynian). Additionally, basement characterization from geological and geophysics data (aeromagnetic and gravity maps), shows an interesting age-dependent zonation of the terranes which are bounded by mega-shear zones within the arches–basins framework. The old terranes are situated under arches while the young terranes are located under the basins depocenter. This structural framework results from the accretion of Archean and Proterozoic terranes inherited from former orogeny (e.g., Pan-African orogeny 900–520 Ma). Therefore, the sedimentary infilling pattern and the nature of deformation result from the repeated slow Paleozoic reactivation of Precambrian terranes bounded by subvertical lithospheric fault systems. Alternating periods of tectonic quiescence and low-rate subsidence acceleration associated with extension and local inversion tectonics correspond to a succession of Paleozoic geodynamic events (i.e., far-field orogenic belt, glaciation).
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Mancini, Ines, Graziano Guella, Michel Sauvain, C�cile Debitus, Anne-Ga�lle Duigou, Fr�d�ric Ausseil, Jean-Louis Menou, and Francesco Pietra. "New 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrimidinium alkaloids (phloeodictynes) from the New Caledonian shallow-water haplosclerid sponge Oceanapia fistulosa. Structural elucidation from mainly LC-tandem-MS-soft-ionization techniques and discovery of antiplasmodial activity." Organic & Biomolecular Chemistry 2, no. 5 (2004): 783. http://dx.doi.org/10.1039/b313348f.
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Kampf, A. R., J. J. Pluth, Y. S. Chen, A. C. Roberts, and R. M. Housley. "Bobmeyerite, a new mineral from Tiger, Arizona, USA, structurally related to cerchiaraite and ashburtonite." Mineralogical Magazine 77, no. 1 (February 2013): 81–91. http://dx.doi.org/10.1180/minmag.2013.077.1.08.
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AbstractBobmeyerite, Pb4(Al3Cu)(Si4 O12)(S0.5Si0.5O4)(OH)7 Cl(H2O)3, is a new mineral from the Mammoth - Saint Anthony mine, Tiger, Pinal County, Arizona, USA. It occurs in an oxidation zone assemblage attributed to progressive alteration and crystallization in a closed system. Other minerals in this assemblage include atacamite, caledonite, cerussite, connellite, diaboleite, fluorite, georgerobinsonite, hematite, leadhillite, matlockite, murdochite, phosgenite, pinalite, quartz, wulfenite and yedlinite. Bobmeyerite occurs as colourless to white or cream-coloured needles, up to 300 m m in length, that taper to sharp points. The streak is white and the lustre is adamantine, dull or silky. Bobmeyerite is not fluorescent. The hardness could not be determined, the tenacity is brittle and no cleavage was observed. The calculated density is 4.381 g cm-3. Bobmeyerite is biaxial (-) with α ≈ β = 1.759(2), γ = 1.756(2) (white light), it is not pleochroic; the orientation is X = c; Y or Z = a or b. Electron-microprobe analyses provided the empirical formula Pb3.80Ca0.04Al3.04Cu2+0.96Cr3+0.13Si4.40S0.58O24.43Cl1.05F0.52H11.83. Bobmeyerite is orthorhombic (pseudotetragonal), Pnnm with unit-cell parameters a = 13.969(9), b = 14.243(10), c = 5.893(4) Å, V = 1172.5(1.4) Å3 and Z = 2. The nine strongest lines in the X-ray powder diffraction pattern, listed as [dobs (Å)(I)(hkl)], are as follows: 10.051(35)(110); 5.474(54)(011,101); 5.011(35)(220); 4.333(43)(121,211); 3.545(34)(040,400); 3.278(77)(330,231,321); 2.9656(88)(141,002,411); 2.5485(93)(051,222,501); 1.873(39)(multiple). Bobmeyerite has the same structural framework as cerchiaraite and ashburtonite. In the structure, which refined to R1 = 0.079 for 1057 reflections with F > 4σF, SiO4 tetrahedra share corners to form four-membered Si4O12 rings centred on the c axis. The rings are linked by chains of edge-sharing AlO6 octahedra running parallel to [001]. The framework thereby created contains large channels, running parallel to [001]. The Cl site is centred on the c axis alternating along [001] with the Si4O12 rings. Two non-equivalent Pb atoms are positioned around the periphery of the channels. Both are elevencoordinate, bonding to the Cl atom on the c axis, to eight O atoms in the framework and to two O (H2O) sites in the channel. The Pb atoms are off-centre in these coordinations, as is typical of Pb2+ with stereo-active lone-electron pairs. A (S, Si, Cr)O4 group is presumed to be disordered in the channel. The name honours Robert (Bob) Owen Meyer, one of the discoverers of the new mineral.
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Gao, Dengliang, Taizhong Duan, Zhiguo Wang, and Xiaofei Shang. "Caledonian detachment deformation and deposition in the Fuling gas field of the southeastern Sichuan Basin in China: Implications for the Lower Silurian Longmaxi Shale gas exploration and production." Interpretation 6, no. 4 (November 1, 2018): SN119—SN132. http://dx.doi.org/10.1190/int-2018-0100.1.
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The Fuling gas field in the southeastern Sichuan Basin is the first and the largest shale gas play in China that has been producing primarily from the organic-rich shale in the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation. Newly processed 3D seismic data along with well-completion data in the gas field reveal important structural, depositional, and reservoir details in the Lower Paleozoic sedimentary section. Lateral (along-stratal) variations in time structure and bed curvature demonstrate the diversity in faults that can be classified based on their orientation (regional and cross-regional), scale (small, intermediate, and large), and mode (contractional, extensional, and wrench). Vertical (cross-stratal) variations in time structure and bed curvature demonstrate that the deformational intensity increases from the Lower Cambrian to the Upper Ordovician, then decreases from the Upper Ordovician to the Silurian. Seismic isochron and facies analyses indicate that the structural deformation influenced the syntectonic deposition of turbidite sand in a channel complex above the reservoir. The pore pressure, porosity, and gas productivity of the reservoir are the highest in the central portion of the field, where small-scale faults dominate, but drop significantly at the edges of the field, where large-scale lineaments dominate. The relationships suggest that faults and fractures could either reduce or enhance pore pressure, porosity, and gas productivity, depending on their scale. Large-scale faults have the most negative impact on gas enrichment and pressure build-up, leading to reduced pressure, porosity, and productivity; whereas, small-scale ones have the least negative or even positive impact on gas enrichment and pressure build-up, leading to increased pressure, porosity, and productivity. These observations and interpretations offer new insight into the dynamic interplay among tectonic deformation, syn-tectonic sedimentation, and reservoir integrity during the Caledonian (Late Ordovician to Silurian) in the southeastern Sichuan Basin (China).
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Michelsen, Olaf, and Lars Henrik Jensen. "Well records on the Phanerozoic stratigraphy in the Fennoscandian Border Zone, Denmark. Hans-1, Sæby-1, and Terne 1 wells." Danmarks Geologiske Undersøgelse Serie A 29 (October 31, 1991): 1–37. http://dx.doi.org/10.34194/seriea.v29.7049.
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The Hans-1, Sæby-1, and Terne-1 wells are located within the Danish part of the Fennoscandian Border Zone and provide significant new data pertaining to the evolution of this important tectonic belt. All three wells encountered Palaeozoic rocks; the Terne-1 well extended into the lower Palaeozoic. Two of the wells are located in the Danish waters of the Kattegat, and thus yield the first deep well data from this part of the border zone. The wells encountered Cambrian to Silurian, Carboniferous to Zechstein and Triassic to Upper Cretaceous successions. The Cambrian to Lower Silurian section is interpreted to represent shelf and shallow marine deposits comparable to those known from Scania and Bornholm. The inferred Upper Silurian section is calculated to be up to 2600 m thick and may represent the fill of a foreland basin in front of the Caledonian 4 deformation front. A hiatus comprising the Devonian to Lower Carboniferous is inferred. A 550 m thick Rotliegende sequence was drilled in the eastern part of the Sorgenfrei-Tornquist Zone; changes in structural dip indicate a syn-depositional faulting. Palaeozoic tectonism is also indicated by Late Carboniferous intrusive and extrusive volcanic rocks. Reworked volcanic rocks characterize the Rotliegende elastic sequence. A thin siliciclastic Zechstein sequence is recognized. The lithology and stratigraphy of the Mesozoic sections are in accordance with well data from the Danish Subbasin. The presence of a Middle Jurassic depocenter within the Sorgenfrei-Tornquist Zone may indicate a tectonically controlled subsidence of the zone. The occurrence of a Late Cretaceous to Early Tertiary inversion tectonism is supported by these new data.
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Kelling, Gilbert. "Southern Uplands geology: an historical perspective." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 91, no. 3-4 (2000): 323–39. http://dx.doi.org/10.1017/s026359330000821x.
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ABSTRACTFor more than two centuries the rocks of the Southern Uplands have provided successive generations of geologists with both illumination and frustration. This area furnished vital evidence to support Hutton's ideas of petrogenesis and his cyclical view of earth history. However, for much of the succeeding century construction of a credible and consistent stratigraphy and structure eluded the best efforts of the many workers drawn to this region. It was an English-born schoolmaster, Charles Lapworth, inspired by the ideas of foreign practitioners and fascinated by the hitherto-despised graptolite, who applied a technique (zonal stratigraphy) and developed a structural paradigm (isoclinal folding) that provided an elegant and coherent solution to the myriad problems bequeathed by previous attempts.So persuasive was Lapworth's model that the Geological Survey deployed its two finest mappers, Peach and Horne, to re-examine the entire region, using Lapworth's techniques. The outcome of that 10-year task is the monumental publication commemorated here. That work, and the ideas it espoused, remained virtually unchallenged for more than half a century and contributed to the application and elaboration of then-new geotectonic ideas, such as the geosynclinal concept.However, in the 1950s the application of new or neglected techniques (way-up criteria, turbidite sedimentology, greywacke petrography, microstructural analysis, etc.) led to drastic reappraisal of prevailing structural and stratigraphic models and introduced a new paradigm (colloquially termed the ‘Southern Uplands paradox’) that envisaged a dominant role for strike-parallel major reverse faults. In contrast to Lapworth's shale-based approach this new model focussed on evidence derived predominantly from the thick intervening greywacke sequences. Investigations led by the Edinburgh and St Andrews schools extended and amplified this new interpretation of Southern Uplands geology, elucidated details of the palaeogeographic setting and the evolution of both the depositional basins and the source areas, and suggested comparisons with other parts of the Caledonian-Appalachian orogen.The advent of plate tectonics revived interest in the Southern Uplands, first as a candidate subduction-related margin, then in the late 1970s an accretionary prism origin was proposed for the Southern Uplands imbricate thrust stack. The attractions of this hypothesis were manifest and it stimulated renewed activity by academics and the Geological Survey. Significant inconsistencies and perturbations in the simple accretionary prism concept have emerged from these more detailed studies and a range of convergence zone scenarios has been proposed. A Geological Society Meeting on the topic in 1986 furnished much new data and ideas but failed to yield conceptual consensus. Thus, as yet the latest Southern Uplands Controversy remains unresolved.Changes in the level of geological research activity in the Southern Uplands can be assessed from an analysis of the numbers of relevant publications appearing over five-year intervals. This survey reveals a pattern that broadly accords with the narrative outlined above and supports the concept of two complete and one as-yet incomplete cycles of model development and adoption. Each of these developmental cycles appears to follow the progression of stages in scientific development identified by Thomas Kuhn and common to many scientific disciplines.
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Higgins, A. K. "East Greenland Caledonides: stratigraphy, structure and geochronology." Geological Survey of Denmark and Greenland (GEUS) Bulletin 6 (December 30, 2004): 1–4. http://dx.doi.org/10.34194/geusb.v6.4814.
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The East Greenland Caledonides extend from 70° to 81°30′N, and have been the subject of a series of regional mapping programmes between 1968 and 1998. The entire orogen is now covered by five published 1:500 000 geological map sheets. The six papers in this bulletin concern a variety of topics relating mainly to Kronprins Christian Land (79°–81°30′N) and the Kong Oscar Fjord region (72°–75°N).The paper by Smith et al. on Lower Palaeozoic stratigraphy proposes amendments to several stratigraphical units that occur in Kronprins Christian Land and nearby Lambert Land. In the Kong Oscar Fjord region, two new formations are defined for quartzite and limestone/dolostone units that crop out in foreland windows, and the Lower Palaeozoic succession of the fjord region of East Greenland is formally placed in the Kong Oscar Fjord Group. The second paper by Smith et al. describes and formally defines the Neoproterozoic Rivieradal Group of Kronprins Christian Land. The paper by Higgins et al. analyses the thinskinned fold-and-thrust belt that marks the transition between foreland and orogen in Kronprins Christian Land, and presents a balanced cross-section restoration.The two geochronological papers by Thrane report the results of ion microprobe zircon analyses from orthogneisses in the Charcot Land window (72°N), and results of reconnaissance Pb-Pb dating by the stepleaching method.The final paper by Higgins & Leslie reviews the history of geological research in the Eleonore Sø and Målebjerg areas of the Kong Oscar Fjord region (72°–75°N). Recognition that the two areas are part of the Caledonian foreland implies that the two thrust sheets structurally overlying the Eleonore Sø and Målebjerg windows have large displacements (~ 100 km each), and that the 'stockwerke' concept of the orogen that focused on in situ vertical movements can finally be laid to rest.
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ROBERTS, R. J., F. CORFU, T. H. TORSVIK, L. D. ASHWAL, and D. M. RAMSAY. "Short-lived mafic magmatism at 560–570 Ma in the northern Norwegian Caledonides: U–Pb zircon ages from the Seiland Igneous Province." Geological Magazine 143, no. 6 (September 18, 2006): 887–903. http://dx.doi.org/10.1017/s0016756806002512.
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The Seiland Igneous Province (SIP) of northern Norway comprises a suite of mainly gabbroic plutons, with subordinate ultramafic, syenitic and felsic intrusions. Several intrusions from the Seiland Igneous Province have been dated by ID-TIMS U–Pb zircon and monazite analyses. The Hasvik Gabbro on the island of Sørøy, previously assigned an age of 700±33 Ma by Sm–Nd, yields a U–Pb zircon age of 562±6 Ma, within error of the Storelv Gabbro (569±5 Ma) and a diorite associated with the Breivikbotn Gabbro (571±4 Ma). Various intrusions on the Øksfjord peninsula give nearly identical ages of 565±9 Ma (gabbro), 566±4 Ma (monzonite), 565±5 Ma (monzodiorite), 570±9 Ma (norite), and 566±1 Ma (orthopyroxenite). These ages overlap with those from Sørøy, and define a single and short-lived period of gabbroic (to felsic) magmatism for the region between 570 and 560 Ma, pre-dating a subordinate episode of alkalic magmatism at 530–520 Ma. The U–Pb ages contradict the previous geochronological interpretation for the Finnmark area, which implied a period of 250 m.y. for the emplacement of the SIP intrusions. The new age data also clearly distinguish the Seiland intrusions, emplaced into the Sørøy Group metasediments of the Kalak Nappe Complex, from several older granitic intrusions (c. 850 to 600 Ma) that cut the Sørøy Group farther east and south. The coincident ages of the different Seiland intrusive bodies also contradict the previous structural model for the area, which posits that the different gabbro bodies were emplaced at intervals, with compressional deformation affecting the gabbros between periods of intrusion. The short time span between the main plutonic phases strongly suggests that the mechanism for the emplacement of mafic magma operated in a single, probably extensional, tectonic regime. The mafic intrusions were later deformed and metamorphosed to at least amphibolite facies, most likely by the Scandian (420 Ma) phase of the Caledonian Orogeny.
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Ruban, Dmitry A., Moujahed I. Al-Husseini, and Yumiko Iwasaki. "Review of Middle East Paleozoic plate tectonics." GeoArabia 12, no. 3 (July 1, 2007): 35–56. http://dx.doi.org/10.2113/geoarabia120335.
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ABSTRACT The Paleozoic Middle East terranes, neighboring the present-day Arabian and Levant plates, are shown by most authors to consist of ten major tectonic units: (1 and 2) the Helmand and Farah terranes of Afghanistan, southwest Pakistan and southeast Turkmenistan; (3 to 6) the Alborz, Central Iran (Lut, Yazd and Tabas) and Sanandaj-Sirjan terranes of Iran, and Northwest Iran (possibly extending into eastern Turkey); (7 and 8) the Pontides and Taurides terranes of Turkey; and (9 and 10) the Greater and Lesser Caucasus terranes between the Caspian and Black seas (Armenia, Azerbaijan, Georgia and southwest Russia). Published plate-tectonic reconstructions indicate that all ten terranes may have broken off from either: (1) the Gondwana Supercontinent in the mid-Silurian as part of the Hun Superterrane; or (2) the Pangea Supercontinent during the mid-Permian - Triassic as part of the Cimmeria Superterrane. To the north of Gondwana and Pangea, three successively younger Tethyan oceans evolved: (1) Proto-Tethys (Cambrian - Devonian); (2) Paleo-Tethys (mid-Silurian - Mesozoic); and (3) Neo-Tethys (mid-Permian - Cenozoic). Two regional Paleozoic unconformities in the Arabian Plate are generally linked to major regional-scale structural events, and commonly correlated to the Caledonian and Hercynian orogenies. These orogenies took place many thousands of kilometers away from the Arabian Plate and are considered unlikely causes for these unconformities. Instead, the breakaway of the Hun and Cimmeria superterranes are considered as alternative near-field tectonic sources. The older unconformity (middle Paleozoic event), represented by a mid-Silurian to Middle Devonian hiatus in North Arabia (Iraq and Syria), reflects an episode of epeirogenic uplift, which might be related to the mid-Silurian rift of the Hun Superterrane. The younger mid-Carboniferous Arabia-wide angular unconformity involved compressional faulting and epeirogenic uplift, and might be related to the earliest phase of subduction by the Paleo-Tethyan crust beneath Cimmeria (Sanandaj-Sirjan and nearby regions) before it broke off. Based on our review and regional considerations, we assign the Helmand, Farah, Central Iran, Alborz, Sanandaj-Sirjan, Northwest Iran, Lesser Caucasus, Taurides and Pontides to Cimmeria, whereas the Greater Caucasus is considered Hunic.
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Bouasria, Manal, Laidi Babouri, Fouzia Khadraoui, Daniel Chateigner, Stéphanie Gascoin, Valérie Pralong, Mohammed-Hichem Benzaama, Beate Orberger, and Yassine El Mendili. "Insight into the partial replacement of cement by ferronickel slags from New Caledonia." European Journal of Environmental and Civil Engineering, September 8, 2020, 1–19. http://dx.doi.org/10.1080/19648189.2020.1814421.
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Sand, Christophe. "Structural remains as markers of complex societies in southern Melanesia during prehistory: the case of the monumental forts of Mare Island, New Caledonia." Bulletin of the Indo-Pacific Prehistory Association 15 (January 25, 1996). http://dx.doi.org/10.7152/bippa.v15i0.11532.
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Lescoutre, Rodolphe, Bjarne Almqvist, Hemin Koyi, Théo Berthet, Peter Hedin, Olivier Galland, Sonia Brahimi, Henning Lorenz, and Christopher Juhlin. "Large-scale, flat-lying mafic intrusions in the Baltican crust and their influence on basement deformation during the Caledonian orogeny." GSA Bulletin, March 16, 2022. http://dx.doi.org/10.1130/b36202.1.
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The Fennoscandian Shield in central Sweden displays a complex structural and compositional architecture that is mainly related to the Proterozoic history of the Baltica paleocontinent. In its western parts, the Precambrian basement is covered by the allochthonous rocks of the Caledonide orogen, and direct information about the underlying crust is restricted to a few unevenly distributed basement windows in western Sweden and Norway. In this study, we use preliminary results from the second borehole of the Collisional Orogeny in the Scandinavian Caledonides project (COSC-2), new gravity data, forward gravity, and magnetic modeling and interpretation of seismic reflection profiles to assess the 3-D architecture of the basement. Our results reveal a wide (∼100 km) and dense network of mainly flat-lying and saucer-shaped dolerites intruding the volcanic and granitic upper crustal rocks of the Transscandinavian Igneous Belt. Similar intrusion geometries related to 1.2 Ga dolerites can be recognized in the Fennoscandian Shield. We discuss that the formation of these sill complexes occurred in a lithologically and structurally heterogeneous crust during transtension, which is in disagreement with the current understanding of sill emplacement that involves crustal shortening, layering, or anisotropy of the host rock. Our seismic interpretation and the structural observations from the COSC-2 drilling show that part of the Caledonian-related basement deformation was localized along the margins of the dolerite sheets. We propose that the dolerite intrusion geometry, akin to a flat-ramp geometry, guided the basement deformation during the Caledonian orogeny.
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Allen, Jenny A., Ellen C. Garland, Claire Garrigue, Rebecca A. Dunlop, and Michael J. Noad. "Song complexity is maintained during inter-population cultural transmission of humpback whale songs." Scientific Reports 12, no. 1 (May 30, 2022). http://dx.doi.org/10.1038/s41598-022-12784-3.
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AbstractAmong animal species, the songs of male humpback whales (Megaptera novaeangliae) are a rare example of social learning between entire populations. Understanding fine-scale similarity in song patterns and structural features will better clarify how accurately songs are learned during inter-population transmission. Here, six distinct song types (2009–2015) transmitted from the east Australian to New Caledonian populations were quantitatively analysed using fine-scale song features. Results found that New Caledonian whales learned each song type with high accuracy regardless of the pattern’s complexity. However, there were rare instances of themes (stereotyped patterns of sound units) only sung by a single population. These occurred more often in progressively changing ‘evolutionary’ songs compared to rapidly changing ‘revolutionary’ songs. Our results suggest that populations do not need to reduce complexity to accurately learn song patterns. Populations may also incorporate changes and embellishments into songs in the form of themes which are suggested to be learnt as distinct segments. Maintaining complex song patterns with such accuracy suggests significant acoustic contact, supporting the hypothesis that song learning may occur on shared feeding grounds or migration routes. This study improves the understanding of inter-population mechanisms for large-scale cultural transmission in animals.
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Corfu, F., and T. B. Andersen. "An hyperextension assemblage, imbricated in Archean - Paleoproterozoic crust, at the bottom of the Kalak Nappe Complex in the northern Scandinavian Caledonides." Journal of the Geological Society, February 24, 2022, jgs2021–140. http://dx.doi.org/10.1144/jgs2021-140.
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The breakup of continents generates dyke swarms, basins, and hyperextension assemblages. Once incorporated in new orogens the latter can provide crucial information on origins and tectonic processes. The Nålfjell Complex in the Caledonian Skillefjord Nappe of northern Norway has many of the characteristics of an hyperextension assemblage, notably the presence of solitary serpentinite bodies exposed by exhumation of serpentinized mantle, and now embedded in schists, amphibolites, mylonites, marbles, and felsic gneisses The Skillefjord Nappe is a lithologically diverse, imbricated and discontinuous allochthton. It comprises felsic gneisses and dykes dated by zircon U-Pb to ca. 3100, 2940, 2830, 2510 and 1800-1750 Ma. These rocks yield titanite ages of 2810-2700, 1750, 1660-1590 Ma and 420-430. Metagabbro intruded at 1995 Ma. The ages and evolution of the Skillefjord Nappe are very distinct from those of the structurally higher Svaertholt Terrane (>1030 Ma sediments deformed and intruded by granite at 980-950 Ma), and the Sørøy Terrane (characterized by a multistage 900 to 500 Ma evolution). The assembly of these disparate elements was completed at 420 Ma. The timing of hyperextension is uncertain. The serpentinites have a primitive Pb isotopic composition indicating old depleted mantle lithosphere. Extensional processes from the Palaeoproterozoic to Ediacaran are considered.Thematic collection: This article is part of the Caledonian Wilson cycle collection available at: https://www.lyellcollection.org/cc/caledonian-wilson-cycle