Upper Cisuralian palynology and palaeoclimate of Manuguru area Godavari basin,India and their global correlation     

Pauline Sabina K  Neerja Jha 《Journal of Earth System Science》2014,123(7):1681-1692

The Permian system of the Palaeozoic Erathem is divided into three series, the Early Permian Cisuralian Series, the Middle Permian Guadalupian Series, and the Late Permian Lopingian Series. The Cisuralian Series encompasses the Asselian to Kungurian stages which constitute the basal part of the Gondwana supersequence I. In India, they are represented lithostratigraphically by the Talchir, Karharbari, and Barakar formations. This paper presents the palynological results from the Barakar Formation of the Upper Cisuralian Series from Manuguru which lies in the southeastern part of the Godavari basin. The succession studied comprises 35 subsurface samples from bore hole 1007 represented by clay, shale, sandstone, and coal. The palynofloras in this sequence have a homogenous composition demonstrating that not many significant floral changes took place through the considered stratigraphic range. The entire sequence is characterized by the dominance of nonstriate bisaccate genus Scheuringipollenites and sub-dominance of striate bisaccate genus Faunipollenites(=Protohaploxypinus). The other pollen genera among the nonstriate bisaccates are Rhizomaspora, Primuspollenites, Ibisporites, and Platysaccus. The striate bisaccates include Striatites, Striatopodocarpites, and Stroterosporites. The taeniate taxa are represented by Lueckisporites and Lunatisporites. The common monosaccate genera include Caheniasaccites, Potoniesporites, and Barakarites. Spores are less common and include Latosporites, Brevitriletes, Horriditriletes, Microbaculispora, and Callumispora. They characterize the palynofloral composition of the Lower Barakar Formation. The correlation of this assemblage with some of the biostratigraphic palynozones proposed previously for the Cisuralian sequences of the Paraná Basin of South America, Kalahari Karoo Basin of South Africa, Ruhuhu Basin of Tanzania, East Africa as well as palynoassemblages from South Victoria Land and Dronning Maud Land, Antarctica and Collie Basin of west Australia point out to their Early Permian (Late Sakmarian–Early Artinskian) age. Palynomorphs such as Botryococcus sp., Tetraporinia sp., Balmeela sp. and Leiosphaeridia sp. are also recorded which suggest that these sediments were deposited during post-glacial near shore, cool and humid environment.  相似文献   

AGB Phase Transition in Globular Clusters: A Tool for Dating Starbursts     

Claudia Maraston  Markus Kissler-Patig  Jean Brodie  Pauline Barmby  John Huchra 《Astrophysics and Space Science》2002,281(1-2):137-138

A new method to detect and study young star clusters is presented. This is based on the knowledge that the light of stellar populations with ages between ∼ 200 Myr and ∼ 1/2 Gyr is dominated by very red, bright AGB stars. Star clusters undergoing this so-called ‘AGB phase transition’ are featured by very red V-K colours, like those of Magellanic Clouds clusters, while optical colours like B-V remain blue typical for young populations. The best channel for detecting star clusters in this age range is therefore the near IR. From the theoretical side, SSP models including properly the contribution of the bright AGB are required (Maraston, 1998). Using this strategy, we succesfully detected the AGB phase transition among the clusters of the merger remnant galaxy NGC 7252 (see Maraston etal., 2001). This revised version was published online in September 2006 with corrections to the Cover Date.  相似文献   

On the long-term context of the 1997–2009 ‘Big Dry’ in South-Eastern Australia: insights from a 206-year multi-proxy rainfall reconstruction     

Joëlle Gergis  Ailie Jane Eyre Gallant  Karl Braganza  David John Karoly  Kathryn Allen  Louise Cullen  Rosanne D’Arrigo  Ian Goodwin  Pauline Grierson  Shayne McGregor 《Climatic change》2012,111(3-4):923-944

This study presents the first multi-proxy reconstruction of rainfall variability from the mid-latitude region of south-eastern Australia (SEA). A skilful rainfall reconstruction for the 1783–1988 period was possible using twelve annually-resolved palaeoclimate records from the Australasian region. An innovative Monte Carlo calibration and verification technique is introduced to provide the robust uncertainty estimates needed for reliable climate reconstructions. Our ensemble median reconstruction captures 33% of inter-annual and 72% of decadal variations in instrumental SEA rainfall observations. We investigate the stability of regional SEA rainfall with large-scale circulation associated with El Niño–Southern Oscillation (ENSO) and the Inter-decadal Pacific Oscillation (IPO) over the past 206 years. We find evidence for a robust relationship with high SEA rainfall, ENSO and the IPO over the 1840–1988 period. These relationships break down in the late 18th–early 19th century, coinciding with a known period of equatorial Pacific Sea Surface Temperature (SST) cooling during one of the most severe periods of the Little Ice Age. In comparison to a markedly wetter late 18th/early 19th century containing 75% of sustained wet years, 70% of all reconstructed sustained dry years in SEA occur during the 20th century. In the context of the rainfall estimates introduced here, there is a 97.1% probability that the decadal rainfall anomaly recorded during the 1998–2008 ‘Big Dry’ is the worst experienced since the first European settlement of Australia.  相似文献   

Guidelines on the use of structure-from-motion photogrammetry in geomorphic research     

Mike R. James  Jim H. Chandler  Anette Eltner  Clive Fraser  Pauline E. Miller  Jon P. Mills  Tom Noble  Stuart Robson  Stuart N. Lane 《地球表面变化过程与地形》2019,44(10):2081-2084

As a topographic modelling technique, structure-from-motion (SfM) photogrammetry combines the utility of digital photogrammetry with a flexibility and ease of use derived from multi-view computer vision methods. In conjunction with the rapidly increasing availability of imagery, particularly from unmanned aerial vehicles, SfM photogrammetry represents a powerful tool for geomorphological research. However, to fully realize this potential, its application must be carefully underpinned by photogrammetric considerations, surveys should be reported in sufficient detail to be repeatable (if practical) and results appropriately assessed to understand fully the potential errors involved. To deliver these goals, robust survey and reporting must be supported through (i) using appropriate survey design, (ii) applying suitable statistics to identify systematic error (bias) and to estimate precision within results, and (iii) propagating uncertainty estimates into the final data products. © 2019 John Wiley & Sons, Ltd.  相似文献   

Georisks in the Mediterranean and their mitigation     

D&#;Amico  Sebastiano  Galea  Pauline  Borg  Ruben P.  Bonello  Marc 《Natural Hazards》2017,86(2):199-202

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Dose-dependent response of a benthic system to biodeposition from suspended blue mussel (Mytilus edulis) culture     

Pauline Robert  Christopher W. Mckindsey  Gwénaëlle Chaillou  Philippe Archambault 《Marine pollution bulletin》2013,66(1-2):92-104

This study reports the results of a field experiment using benthic mesocosms that examined dose-dependent effects of mussel biodeposition on the benthic environment. Mesocosms were placed in the natural sea bottom and subjected to one of eight levels of biodeposition (from 0 to 1400 mussels m^?2). Most analyses indicated non-linear (i.e., threshold) effects. Sediment characteristics changed significantly between 200 and 400 mussels m^?2 as did multivariate community structure. Community structure effects were characterised by changes in abundances of species that are very sensitive or tolerant to organic loading. The multivariate AZTI Marine Biotic Index (M-AMBI) indicated that the benthic status changed from High to Good in all mesocosms receiving biodeposits. Sediments acted as a sink for oxygen (O₂), but results suggest O₂ sediment demand was not sensitive enough to evaluate organic loading impacts. Results from this and improved experiments can be used to determine the environmental carrying capacity of sites for bivalve culture.  相似文献   

Social Mix and the Problematisation of Social Housing     

Rupert H. Doney  Pauline M. McGuirk 《The Australian geographer》2013,44(4):401-418

Social housing in Australia is at a significant juncture. High levels of housing stress, increasing levels of socio-spatial polarisation and reduced government funding are posing complex policy challenges. Social mix policies are one response to these challenges, arising from the problematisation of social housing estates as socially excluded. This problematisation is examined through case studies of two Sydney social housing renewal projects: Telopea and Riverwood North. Drawing on interviews with government, private-sector and not-for-profit housing practitioners, the paper identifies two distinct discourses of social exclusion within this problematisation—culture of poverty discourse and equity discourse—that shape the implementation of social mix. These discourses reveal that implementing social mix is more complex than simply managing the cohabitation of residents in different tenures. Rather, the practice of social mix is embedded within discourses about the nature and causes of social exclusion. These discourses, in their turn, inform the multiple and sometimes conflicting aspirations pursued through social mix policies.  相似文献   

Palynological dating and correlation of surface and subsurface sediments from Wardha valley coalfield,Maharashtra     

Neerja Jha  Pauline Sabina  K. Rajni Tewari  N. C. Mehrotra 《Journal of the Geological Society of India》2011,77(2):137-148

42 genera of palynomorphs have been reported from the qualitative and quantitative analysis of the palynoflora from both open cast mine and bore holes viz., Ballarpur open cast mine, Durgapur open cast mine and Bore hole CMWNM-57 on barrier between Kawadi/Majri open cast and Hindustan Lalpeth Colliery from the Wardha valley coalfield of Wardha basin. Two palynoassemblages have been recorded i.e., an Upper Karharbari palynoassemblage comprising dominance of radial monosaccate genus Parasaccites and subdominance of nonstriate disaccate genus Scheuringipollenites and a Lower Barakar palynoassemblage consisting of dominance of Scheuringipollenites and subdominance of striate disaccates chiefly Faunipollenites, suggesting an Early Permian age (Late Sakmarian to Early Artinskian) to the sediments. It is further authenticated by the occurrence of palynotaxa viz., Crucisaccites, Caheniasaccites, Indotriradites and Tiwariasporis. Upper Karharbari Formation has been demarcated for the first time in lithologically designated Barakar Formations in Ballarpur, Durgapur, Majri and Hindustan Lalpeth Colliery while the sample 57/2 of bore hole CMWNM from Kawadi area may belong to the Kamthi Formation on the basis of pinkish yellowish coarse grained to medium grained sandstone. An attempt has been made to correlate these palynoassemblages with other Lower Gondwana basins of Early Permian affinity.  相似文献   

Trace elements in the shallow ground water of The Netherlands. A geochemical and statistical interpretation of the national monitoring network data     

Giuseppe Frapporti  Simon P. Vriend  Pauline F. M. Van Gaans 《Aquatic Geochemistry》1996,2(1):51-80

Concentration levels of the trace elements Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Li, Mo, Ni, Pb, Sr, V, Y, and Zn in the shallow Dutch ground water were studied. Data were extracted from the data base of the Dutch National Ground Water Quality Monitoring Network, a network set up to monitor the diffuse contamination. The network contains over 350 sites at a low density of about 1 per 100 km². The sites are sampled once a year at two depths (approx. 10 and 25 m below surface). A two-step multivariate statistical approach was used, in which the major element chemistry was used to define water types. Within each water type, trace element behavior could be coupled to distinct geochemical processes: dilution, acidification and weathering, carbonate dissolution, oxidation/reduction, and ion exchange. In recently infiltrated acid rain water in low buffering capacity sands, the anthropogenic influence indirectly caused mobilization of Al (median 430 g/l), Cd (0.6 g/l), Co (14 g/l), Cu (2.7 g/l), Ni (16 g/l), Y (11 g/l), and Zn (50 mg/l). In carbonate bearing sediments the acidification is neutralized, and the mentioned trace elements remain immobile. Arsenic and Cr have higher concentrations levels in ground waters with a slightly reducing character and are possibly governed by the dissolution of iron-manganese hydroxides. Boron, Li, and Sr have high concentrations (respectively 875, 80, 2700 g/l) in the water type related to a seawater source. Strontium is related to carbonate dissolution in all other water types (medians ranging from 100 to 1000 g/l). Barium shows a complex behaviour. It is concluded that the high Al, Cd, Co, Cr, Ni, and Zn concentrations are anthropogenically induced. High Ba and Cr concentrations are inferred to be due to natural processes.  相似文献   

Erratum to: 3D thermal history and maturity modelling of the Levant Basin and its eastern margin,offshore–onshore Lebanon     

Samer Bou Daher  Mathieu Ducros  Pauline Michel  Nicolas Hawie  Fadi H. Nader  Ralf Littke 《Arabian Journal of Geosciences》2016,9(9):550

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