a sedimentological record of early miocene ice advance and retreat and 2a drill hole mcmurdo sound antarctica

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Hen Harrier Circus cyaneus nest sites on the Isle of Mull are associated with habitat mosaics and constrained by topography

This is an Accepted Manuscript of an article published by Taylor & Francis in Bird Study on 07/02/2018, available online: http://www.tandfonline.com/doi/full/10.1080/00063657.2017.1421611Capsule: Hen Harrier on the Isle of Mull, UK, are associated with habitat mosaics consisting of moorland, scrub and forestry but avoid grazed land, suggesting that forested habitats could be managed sympathetically for Hen Harrier in the future should the current UK population increase. Aims: To use distribution modelling to investigate nesting habitat associations using a long term dataset for Hen Harrier on Mull. Methods: We develop area-interaction models using a LASSO penalty to explore the distribution of 102 Hen Harrier nest sites in relation to habitat and topography. Our model is then successfully validated in tests using data for 70 nest sites from subsequent years. Results: Our model is effective in predicting suitable areas for Hen Harrier nest sites and indicates that Hen Harriers on Mull are found in habitat mosaics below 200 m asl. Hen Harrier nest intensity is positively associated with increasing proportions of moorland and scrub, open canopy forestry and closed canopy forestry. Nest intensity is negatively associated with increasing proportions of grazed land. Conclusion: Hen Harrier avoid grazed areas but are relatively tolerant of other habitat combinations. These findings are supported by previous observations of Hen Harrier habitat use and have implications for the recovery of some Hen Harrier SPA populations and future forest management. Open canopy forest and forest mosaics could potentially be incorporated into landscape-scale conservation plans for Hen Harriers using the population in Mull as an example

Early Jurassic palaeoenvironments in the Surat Basin, Australia - marine incursion into eastern Gondwana

Interpretations of palaeodepositional environments are important for reconstructing Earth history. Only a few maps showing the Jurassic depositional environments in eastern Australia currently exist. Consequently, a detailed understanding of the setting of Australia in Gondwana is lacking. Core, wireline logs, two‐dimensional and three‐dimensional seismic from the Precipice Sandstone and Evergreen Formation in the Surat Basin have been used to construct maps showing the evolution of depositional environments through the Early Jurassic. The results indicate the succession consists of three third‐order sequences (Sequence 1 to Sequence 3) that were controlled by eustatic sea level. The lowstand systems tract in Sequence 1 comprises braidplain deposits, confined to a fairway that parallels the basin centre. The strata were initially deposited in two sub‐basins, with rivers flowing in different orientations in each sub‐basin. The transgressive systems tract of Sequence 1 to lowstand systems tract of Sequence 3 is dominated by fluvio–deltaic systems infilling a single merged basin centre. Finally, the transgressive and highstand systems tracts of Sequence 3 show nearshore environments depositing sediment into a shallow marine basin. In the youngest part of this interval, ironstone shoals are the most conspicuous facies, the thickness and number of which increase towards the north and east. This study interprets a corridor to the open ocean through the Clarence–Moreton Basin, or the Carpentaria and Papuan basins, evidence of which has been eroded. These results challenge a commonly held view that eastern Australia was not influenced by eustasy, and propose a more dynamic palaeogeographic setting comprising a mixture of fluvial, deltaic and shallow marine sedimentary environments. This work can be used to unravel the stratigraphic relationships between Mesozoic eastern Australian basins, or in other basins globally as an analogue for understanding the complex interplay of paralic depositional systems in data poor areas

Incised valley paleoenvironments interpreted by seismic stratigraphic approach in Patos Lagoon, Southern Brazil

<div><p>ABSTRACT: The Rio Grande do Sul (RS) coastal plain area (33,000 km 2 ) had its physiography modified several times through the Quaternary, responding to allogenic and autogenic forcings. The Patos Lagoon covers a significant area of RS coastal plain (10,000 km 2 ), where incised valleys were identified in previous works. About 1,000 km of high resolution (3.5 kHz) seismic profiles, radiocarbon datings, Standard Penetration Test (SPT) and gravity cores were analyzed to interpret the paleoenvironmental evolution as preserved in incised valley infills. Seismic facies were recognized by seismic parameters. The sediment cores were used to ground-truth the seismic interpretations and help in the paleoenvironmental identification. Key surfaces were established to detail the stratigraphical framework, and seismic facies were grouped into four seismic units, which one classified in respective system tracts within three depositional sequences. The oldest preserved deposits are predominantly fluvial and estuarine facies, representing the falling stage and lowstand system tracts. The Holocene transgressive records are dominated by muddy material, mainly represented by estuarine facies with local variations. The transgression culminated in Late Holocene deposits of Patos Lagoon, representing the highstand system tract. The depositional pattern of the vertical succession was controlled by eustatic variations, while the autogenic forcing (paleogeography and sediment supply) modulated the local facies variation.</p></div