The complex impact structure Serra da Cangalha,Tocantins State,Brazil

Abstract– Serra da Cangalha is a complex impact structure with a crater diameter of 13,700 m and a central uplift diameter of 5800 m. New findings of shatter cones, planar fractures, feather features, and possible planar deformation features are presented. Several ring‐like features that are visible on remote sensing imagery are caused by selective erosion of tilted strata. The target at Serra da Cangalha is composed of Devonian to Permian sedimentary rocks, mainly sandstones that are interlayered with siltstone and claystones. NNE–SSW and WNW–ESE‐striking joint sets were present prior to the impact and also overprinted the structure after its formation. As preferred zones of weakness, these joint sets partly controlled the shape of the outer perimeter of the structure and, in particular, affected the deformation within the central uplift. Joints in radial orientation to the impact center did not undergo a change in orientation during tilting of strata when the central uplift was formed. These planes were used as major displacement zones. The asymmetry of the central uplift, with preferred overturning of strata in the northern to western sector, may suggest a moderately oblique impact from a southerly direction. Buckle folding of tilted strata, as well as strata overturning, indicates that the central uplift became gravitationally unstable at the end of crater formation.     

Two decadally resolved records from north‐west European peat bogs show rapid climate changes associated with solar variability during the mid–late Holocene

Two ¹⁴C accelerator mass spectrometry (AMS) wiggle‐match dated peat sequences from Denmark and northern England record changes in mire surface wetness reconstructed using plant macrofossil and testate amoebae analyses. A number of significant mid–late Holocene climatic deteriorations (wet shifts) associated with declines in solar activity were recorded (at ca. 2150 cal. yr BC, 740 cal. yr BC, cal. yr AD 930, cal. yr AD 1020, cal. yr AD 1280–1300, cal. yr AD 1640 and cal. yr AD 1790–1830). The wet shifts identified from ca. cal. yr AD 930 are concurrent with or lag decreases in solar activity by 10–50 years. These changes are replicated by previous records from these and other sites in the region and the new records provide improved precision for the ages of these changes. The rapidly accumulating (up to 2–3 yr cm^?1, ～1310 yr old, 34 ¹⁴C dates) Danish profile offers an unprecedented high‐resolution record of climate change from a peat bog, and has effectively recorded a number of significant but short‐lived climate change events since ca. cal. yr AD 690. The longer time intervals between samples and the greater length of time resolved by each sample in the British site due to slower peat accumulation rates (up to 11 yr cm^?1, ～5250 yr old, 42 ¹⁴C dates) acted as a natural smoothing filter preventing the clear registration of some of the rapid climate change events. Not all the significant rises in water table registered in the peat bog archives of the British and Danish sites have been caused by solar forcing, and may be the result of other processes such as changes in other external forcing factors, the internal variability of the climate system or raised bog ecosystem. Copyright © 2008 John Wiley & Sons, Ltd.     

Effect of Individual Phenolic Compounds and of their Mixtures on Luminous Bacteria. Part 5: Combined Action of Phenols and Heavy metals

Problems are discussed of the combined action of phenols and metals on luminous bacteria. It is shown that the toxic effect of a mixture was not always equal to the expected additive action. An assumption is made that during a combined action phenols and metals act on the principle of competing inhibition.     

Effect of Individual Phenolic Compounds and of their Mixtures on Luminous Bacteria. Part I.: Use of Bacterial Luminescence Extinguishing for Biotesting of Phenols

Data are presented that confirm the employment of the bacterial luminescence for evaluating the toxicity of phenolic compounds. High sensitivity and speed properties of the method are shown. Phenolic compound concentrations are determined that produce toxic effects on luminous bacteria cells. It is shown that hydroquinone possesses the highest toxicity.     

Effect of Individual Phenolic Compounds and of their Mixtures on Luminous Bacteria. Part 6: On Possibilities of Using o- and p-Diphenols as Pesticides

A brief discussion is suggested of a possibility of employing in the practice of the analyses results on the combined action of phenols described in the preceeding parts of the work and of the interaction of the increased toxicity of phenolic compounds with the processes of their oxidation.     

Further notes on the geology of the betic of Málaga,the Subbetic,and the zone between these two units,in the region of Vélez Rubio (southern Spain)

The stratigraphy of Betic of Málaga and of Subbetic near Vélez Rubio is given. No major tectonic movement took place between Paleozoic and Oligo-Miocene in the area of deposition of the Betic of Málaga and neighbourhood. The geology and formations of the narrow zone between Betic of Málaga and Subbetic are described. Nappe movement of the Betic of Málaga is older than the thrusting of Subbetic over Prebetic. Age of the former movement and origin of major tectonic units are tested on the characteristics of a pre-Orbulina marl formation and on the distribution of the detritus contained in this formation.

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Zusammenfassung Die Stratigraphie des Betikums von Málaga, des Subbetikums und der zwischen beiden Einheiten liegenden Zone wird aus dem Gebiet von Vélez Rubio beschrieben.Größere tektonische Bewegungen haben zwischen Paläozoikum und OligoMiozän im Ablagerungsgebiet des Betikums von Málaga und in der näheren Umgebung nicht stattgefunden. Die Deckenbewegung des Betikums von Málaga ist älter als die Überschiebung des Subbetikums über das Präbetikum. Das Alter der Deckenbewegung und der Ursprung der größeren tektonischen Einheiten werden an Hand der Merkmale einer Prä-Orbulina Mergel-Einheit und an Hand der Verbreitung des in dieser Einheit enthaltenen Schutts überprüft.

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Résumé Les auteurs exposent la stratigraphie du Bétique de Málaga et du Subbétique dans les environs de Vélez Rubio. Aucun mouvement tectonique important n'a eu lieu entre le Paléozoïque et l'Oligo-Miocène dans l'aire sédimentaire du Bétique de Málaga et les régions limitrophes. Les formations de l'étroite zone comprise entre Bétique de Málaga et Subbétique sont étudiées, ainsi que leur relations mutuelles. Le mouvement de nappe du Bétique de Málaga est plus ancien que le chevauchement du Subbétique sur le Prébétique. L'âge de celui-là, ainsi que l'origine des unités tectoniques principales sont examinés en utilisant les caractéristiques d'une formation d'âge pré-Orbulina ainsi que la répartition des débris dérivés de ces unités tectoniques qu'elle contient.

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Photo-identification and habitat use of Atlantic humpback dolphins Sousa teuszii around the Río Nuñez Estuary in Guinea,West Africa

Ecological data for the Atlantic humpback dolphin Sousa teuszii are scant. Six on-effort Sousa teuszii sightings were recorded during 817.6?km of boat-based effort in the Río Nuñez region of Guinea during October and November 2013. Two incidental sightings were also reported. Groups comprised 1–25 animals. Photo-identification produced a minimum population estimate of 47 animals. Most sightings (n = 5) were located close (<1?km) to shore along a 5.7?km stretch of coast on the west side of Île de Taïdi, primarily over shallow, sand–mud habitat. Two very distinctive individuals were present in all four Taïdi photo-identification encounters, suggesting high site fidelity and stable associations. Two sightings occurred in the outer Río Nuñez Estuary much farther from the coast (5–12?km) but in relatively shallow water (≤15?m) over sand–mud sediment. Focal follows (n = 5: 0.2–3.8?h duration) produced 9.02?h of behavioural data. Travel (51%), foraging (39%) and feeding (9.2%) dominated, with Taïdi dolphins spending more time foraging and feeding than the outer estuary groups. Three individuals had linear-severed dorsal fins consistent with injuries from fishing line. Some management implications of variation in habitat, site fidelity and movements of Sousa teuszii groups are discussed.