Bay of Biscay and Pyrenees

The different hypotheses proposed for the creation of the Bay of Biscay are reviewed. New geological and geophysical data collected in the last two years in the Bay and in the Pyrenean domain give new insight into the tectogenesis of the Pyrenees. Geological data of the Pyrenean area provide tight constraints on the hypothesis of formation of the Bay. The most probable hypothesis is an opening by rotation of the Iberian Peninsula around a pole of rotation situated near Paris, which resulted in strike-slip motion along the North Pyrenean fault during the Upper Mesozoic. A progressive westward migration of the pole initiated in the late Cretaceous blocked the motion along the fault and led to the main Eocene tectogenetic Pyrenean phase.     

Precambrian geology of the Adirondack highlands,a reinterpretation

The Precambrian geology of the Adirondack highlands was previously interpreted as a sedimentary terrane repeatedly invaded during the Grenville orogenic cycle by igneous intrusions to form successively the large anorthosite massif and satellites, numerous olivine gabbro and dolerite bodies, gneisses of the quartz-syenite and charnockite series, and granites. A reinterpretation is suggested.In two representative areas major bodies of anorthosite and gneisses of the quartz-syenite and charnockite series are shown to occupy cores of mantled domes and nappes. They are parts of an older basement complex formed during an earlier, pre-Grenville orogenic cycle. Most of the now-recognizable Grenville metasediments were supracrustal rocks deposited on the denuded surface of this basement terrane. Olivine-basaltic magma invaded both the basement and the supracrustal rocks, forming gabbro and ophitic dolerite bodies. The Grenville orogenic cycle (ca. 1100 m.y. B.P.) deformed and metamorphosed all these rocks to a complex of mantled domes, folds, and nappes. The geology of the older basement rocks is heavily masked by the Grenville orogeny.The pre-Grenville basement consists of relatively homogenous masses of metaanorthosite, metanorite, charnockite, and gneisses of granitic composition. The supracrustal rocks occur in well-defined stratigraphic sequences of varied metasediments, gneisses, and charnockites. Conglomerates, arkoses, and acidic volcanics may all metamorphose to foliated rocks of granitic composition. Charnockites formed by high-grade metamorphism of initially dry, pre-existing quartzofeldspathic rocks including metamorphic and plutonic igneous rocks in the basement complex and acidic volcanics in the supracrustal sequence. Water content of rocks also controlled the extent of magmatism during the Grenville orogenic period. Anatectic granite is mainly limited to small, nebulite-bordered granite bodies, and to the presence of venitic migmatites in metamorphosed rocks with granitic components.

---

Zusammenfassung Die Gesteinsserien des Präkambriums in den Adirondack-Highlands wurde früher als Sedimente gedeutet, in welche während des Grenville-Orogenzyklus mehrfach Eruptiv-Intrusionen eindrangen. Dadurch sollen nacheinander das große Anorthosit-Massiv mit seinen Satelliten, zahlreiche Olivingabbro- und Dolerit-Körper, die Gneise der Quarz-Syenit- und Charnockit-Serie und die Granite entstanden sein. Eine andere Erklärung wird hier vorgeschlagen.In zwei typischen Gebieten werden größere Körper von Anorthosit und von Gneisen der Quarz-Syenit- und Charnockit-Serie beschrieben, welche die Kerne der ummantelten Gneisdome und der Decken einnehmen. Sie sind Teile eines älteren Grundgebirges, das in einem früheren Prä-Grenville-Zyklus entstanden ist. Die meisten der heute bekannten Grenville metasediments bestanden aus suprakrustalen Gesteinen, die auf der heute abgetragenen Oberfläche dieses Grundgebirges abgelagert wurden. Olivin-basaltisches Magma drang sowohl in das Grundgebirge als auch in die suprakrustalen Gesteine ein, wodurch Gabbro- und ophitische Doleritkörper entstanden. Der Grenville-Orogenzyklus (vor etwa 1,1×10⁹ Jahren) metamorphisierte diese Gesteine zu dem Komplex der ummantelten Gneisdome, Falten und Decken. Die Geologie des älteren Grundgebirges ist durch die Grenville-Orogenese stark verändert worden.Das Prä-Grenville-Grundgebirge besteht aus verhältnismäßig homogenen Meta-Anorthositen, Metanoriten, Charnockiten und Gneisen mit granitischer Zusammensetzung. Die suprakrustalen Gesteine kommen in gut bestimmten, stratigraphischen Abfolgen von verschiedenen Metasedimenten, Gneisen und Charnockiten vor. Konglomerate, Arkosen und saure Vulkanite dürften durch Metamorphose in geschieferte Gesteine granitischer Zusammensetzung übergegangen sein. Charnockite entstanden durch intensive Metamorphose der anfangs trockenen, vormals quarz- und feldspatreichen Gesteine, welche Metamorphite und Plutonite des Grundgebirges und saure Vulkanite der suprakrustalen Serie einschließen. Auch der Wassergehalt der Gesteine beeinflußte den Grad des Magmatismus während des Grenville-Orogenzyklus. Anatektischer Granit ist hauptsächlich an kleine, von Nebulit umgebene Granit-Körper und an die Anwesenheit von Venit-Migmatiten in metamorphen Gesteinen granitischer Zusammensetzung gebunden.

---

Résumé L'interprétation géologique Précambrienne des plateaux de l'Adirondack était considérée jusqu'à ce jour comme un terrain sédimentaire envahi à plusieurs reprises pendant le cycle orogénique de Grenville par des intrusions ignées pour former successivement le grand massif anorthosite et ses satellites, de nombreux corps gabbro-olivines et dolérites, des gneiss de séries quartzsyénites et charnockites, et des granites. Nous suggérons une réinterprétation.Dans deux domaines représentatifs, les corps principaux d'anorthosite et les gneiss de séries quartz-syénite et charnockite se révèlent comme occupant les noyaux de dômes recouvertes et de nappes. Ce sont des parties d'un fond complexe plus ancien formé pendant un cycle orogénique pré-Grenville antérieur. La plupart des «métasédiments Grenville» maintenant reconnaissables étaient des roches sédimentaires et volcaniques, déposées sur la surface dénudée de ce terrain de fond. Le magma olivine-basaltique a envahi à la fois le fond et les roches sédimentaires et volcaniques, formant du gabbro et des corps ophitiques et dolérites.Le cycle orogénique de Grenville (ca. 1100 m. y. B. P.) a déformé et métamorphosé toutes ces roches en une completié de dômes recouvertes, de plis et de nappes. La géologie des roches de fond plus anciennes est lourdement masquée par l'orogénie de Grenville.Le fond pré-Grenville consiste en masses relativement homogènes de métaanorthosite, métanorite, charnockite et en gneiss de composition granitique. Les roches sédimentaires et volcaniques apparaissent en séries stratigraphiques bien définie d'une variété de métasédiments, de gneiss et de charnockite. Des conglomérates, des arkoses et des roches volcaniques acides peuvent toutes se métamorphoser en roches foliacées de composition granitique. Des charnockites ont dû leur formation à un métamorphisme à haut degré de roches quartzofeldspathiques pré-existantes, initialement sèches, y compris les roches ignées métamorphiques et plutoniques dans le système du fond et acidovolcaniques dans la roche sédimentaire et volcanique subséquente. Le contenu aqueux des roches contrôlait également l'importance du magmatisme pendant la période orogénique de Grenville. Le granite anatectique se réduit principalement à des corpuscules granitiques bordés de nébulite et à la présence de migmatites vénétiques dans des roches métamorphosées aux composants granitiques.

---

Adirondack Highland'a (CACIII). .

     

便携式光电望远镜用于流星暴观测的探讨

本文介绍了便携式人卫光电望远镜的主要性能特点,探讨了将其应用于狮子座流星暴观测的可能性。     

A hyperspectral experiment over tropical forests based on the EO-1 orbit change and PROSAIL simulation

ABSTRACT

We designed a unique hyperspectral experiment from the Earth Observing One (EO-1) orbit change to evaluate solar illumination effects over tropical forests in Brazil. Ten nadir-viewing Hyperion images collected over a fixed site and period of the year (July to August) were selected for analysis. We evaluated variations in reflectance and in 16 narrowband vegetation indices (VIs) with increasing solar zenith angle (SZA) from the pre-drift (2004–2008) to the EO-1 drift period (2011–2016). To detect changes in reflectance and shadows, we applied spectral mixture analysis (SMA) and principal component analysis (PCA) and calculated the similarity spectral angle (θ) between the vegetation spectra measured with variable SZA. The magnitude of the illumination effects was also evaluated from change-point analysis and nonparametric Mann-Whitney U tests applied over the time series. Finally, we complemented our experiment using the PROSAIL model to simulate the VIs variation with increasing SZA resultant from satellite drift. The results showed significant changes in Hyperion reflectance and VIs, especially when the EO-1 crossed the study area at earlier times and larger SZA in 2015 (9:05 a.m.; SZA = 59°) and 2016 (8:30 a.m.; SZA = 67°). Compared to the pre-drift period (10:30 a.m.; SZA = 45°), the SZA differences of 14° (2015) and 22° (2016) increased the shade fractions and decreased the vegetation brightness. PCA separated the pre-drift and drift reflectance datasets, showing shifts in scores due to changes in brightness. θ increased with SZA, indicating changes in the shape of the vegetation spectra with drift. For most VIs, the change-point analysis indicated 2015 (SZA = 59°) as the predominant year of detected changes. Compared to the EO-1 original orbit, the Plant Senescence Reflectance Index (PSRI), Anthocyanin Reflectance Index (ARI) and Structure Insensitive Pigment Index (SIPI) presented the largest positive changes during drift, while the Photochemical Reflectance Index (PRI), Visible Atmospherically Resistant Index (VARI) and Enhanced Vegetation Index (EVI) had the largest negative changes. The effect size of the illumination geometry on these VIs was large, as indicated by increasing values of the Cohen’s r metric toward 2016. The anisotropy of the Hyperion VIs was generally consistent with that from PROSAIL in the simulated pre-drift and drift periods. Focusing on structural indices, it affected the relationships between VIs and simulated leaf area index (LAI) at large SZA.     

Combining European Earth Observation products with Dynamic Global Vegetation Models for estimating Essential Biodiversity Variables

ABSTRACT

Global, fast and accessible monitoring of biodiversity is one of the main pillars of the efforts undertaken in order to revert it loss. The Group on Earth Observations Biodiversity Observation Network (GEO-BON) provided an expert-based definition of the biological properties that should be monitored, the Essential Biodiversity Variables (EBVs). Initiatives to provide indicators for EBVs rely on global, freely available remote sensing (RS) products in combination with empirical models and field data, and are invaluable for decision making. In this study, we provide alternatives for the expansion and improvement of the EBV indicators, by suggesting current and future data from the European Space Agencýs COPERNICUS and explore the potential of RS-integrated Dynamic Global Vegetation Models (DGVMs) for the estimation of EBVs. Our review found that mainly due to the inclusion of the Sentinel constellation, Copernicus products have similar or superior potential for EBV indicator estimation in relation to their NASA counterparts. DGVMs simulate the ecosystem level EBVs (ecosystem function and structure), and when integrated with remote sensing data have great potential to not only offer improved estimation of current states but to provide projection of ecosystem impacts. We suggest that focus on producing EBV relevant outputs should be a priority within the research community, to support biodiversity preservation efforts.     

In-flight performance analysis of the CHAMP BlackJack GPS Receiver

JPL's BlackJack receiver currently represents the most widely used geodetic grade GPS receiver for space applications. Using data from the CHAMP science mission, the in-flight performance of the BlackJack receiver has been assessed and the impact of various software updates performed during the 2.5 years since launch is described. Key aspects of the study comprise the channel allocation, anomalous data points, and the noise level of the code and carrier data. In addition, it has been demonstrated that the code measurements collected onboard the CHAMP satellite are notably affected by multipath errors in the aft-looking hemisphere, which can be attributed to cross-talk between the occultation antenna string and the primary precise orbit determination antenna. For carrier smoothed 10 s normal points, the code noise itself varies between a minimum of 5 cm at high elevations and 0.5 m (C/A) to 1.0 m (P₁, P₂) at 10° elevation. Carrier-phase data exhibit representative errors of 0.2 to 2.5 mm. The results of the CHAMP GPS data analysis contribute to a better understanding and possible improvement of the BlackJack receiver and support the design of optimal data editing and weighting strategies in precise orbit determination applications.     

A description of how metal pollution occurs in the Tinto-Odiel rias (Huelva-Spain) through the application of cluster analysis

In the last few decades, the study of space-time distribution and variations of heavy metals in estuaries has been extensively studied as an environmental indicator. In the case described here, the combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel Rivers, located in the southwest of the Iberian Peninsula.Based on the statistical treatment of the data from the analysis of the water samples from this system, which has been affected by processes of industrial and mining pollution, the 16 variables analyzed can be grouped into two large families. Each family presents high, positive Pearson r values that suggest common origins (fluvial or sea) for the pollutants present in the water analyzed and allow their subsequent contrast through cluster analysis.