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The use of foraminiferal tests as bio-drifters: a new tool to define longshore sediment flows. An example from Pisa coast (Tuscany, Italy)
No full textThe planning of every defense project in a sandy coast demands to know how
dynamic pro."rró. affecting the coast act and, particularly, how the sedimentary supply,
cómirrg from fluvial input,-is distributed along the coast by littoral drifts' Beside welltestedLethodologies
turned to the definition of the longshore sediment-flow (e.g.
petrographic and ìextural analysis ofthe sands or artificial drifter-launch) less traditional
meth;ds, like geochemical analysis of the sediment and the study of bio-drifters can be
used.
This paper presents the preliminary results of a research carried out on the coast of
pisa and ruipori"a by Provincia of Pisa. Fossil foraminifers, picked from sandy samples,
were used às natural drifters in order to define longshore sediment flows. Samples were
collecteda t severald epthsa long transectsn ormal to the shore,f rom the foreshorez one to
the shoreface zone up to the isobate of -10 meters. The costal area between Arno and
CalambroneR iversw as samPled.
Two main groups of fòraminfera were distinguished: i) well preserved pliocenic
foraminifers without any evidence of recrystal\zation and ii) bad preserved and
recrystallizedp re-pliocenicf oramiferers.
The first assemblageis characterizedby the presenceo f Globorotalia puncticulata
andG lobigerinoides, lb"r-elongotus gr. while Paleocene-Eocen(ee g. Morozovella and
Acarininal and Miocene (eg. Gtobigerinoides spp., Dentoglobigerina altispira gt) taxa
prevail within the second assemblage.
The preliminary resultsi ndicatet hat the first group exclusivelyc haracterizesth e seaareab
etweenS colamatoreR iver and Calambronev illage while the secondo ne develops
along the coastal zone between Arno River and Tirrenia village.
In order to know the feed area of these two foraminiferal assemblagesa dditional
samples were collected in Amo and calambrone rivers. The acquired data indicate that
the Èliocenicf oramifersa re carriedb y CalambroneR iver while pre-Pliocenica ssociations
are typical of the sandst ransportedb y Arno River. Therefore,t he presenceo f a northward
drift'(from Calambrone Riveì to Calmbrone village) and of a southward drift (from Arno
Rivei to Tirrenia village) can be infened and reveals a drift-convergence zone, in
agreemenwt ith the resuliso f previousw orks basedo n different methodologies'
In conclusion,t he use ofloramiferal assemblagetso define longshores ediment-flows
seemst o be a very promisingt ool, particularly in coastalz onesf ed by fluvial systemst hat
drain different alimentation areas
Relative chronology and kinematics of the NW and NE trending faults of the Sorrento Peninsula (Southern Apennines)
No full textRelative chronology and kinematics of the NW and NE trending faults of the Sorrento Peninsula (Southern Apennines)
No full textStratigraphy of selected wells along the CROP-04 transect
Full text linkSeveral wells drilled in the Campania-Lucania Apennines and in the Apulia foreland have been used to interpret and calibrate the CROP - 04 seismic profile. Among these wells, San Fele 1 (TD 3515 m), Monte Foi 1 (TD 5755 m), San Gregorio Magno 1 + 1bis (TD 3976 m), Contursi 1 (TD 3479.70 m), and Acerno 1 (TD 4625 m) have provided very important constraints and suggestions that have strongly influenced the interpretation of the line. In this paper we present a revision of the well stratigraphy based on the analysis of the cutting samples (thin-section analysis, microfossil and nannofossil analysis) and on the interpretation of the gamma ray/SP and resistivity logs
Provenance of modern littoral sands of Pisa coast (Tuscany, Italy)
No full textThe studies concern ing longshore drift carried out on Pisa coast go back to the
end of Seventies and are antecedent to the construction of most part of the
coastal defence systems. The subsequent construction of protection structures
has probably modified coastal dynamics.
Therefore, through an agreement between Provincia an d University of Pisa a
multidisciplinary study has been pianned in order to define and widen the
knowledge about the Pisa coasta zone. O ne of these regards the study of
provenance of littoral sands by compositional analysis.
The Pisa coastal area, about 26 km long, belongs to the physiographic unit
comprised between Punta Bianca and Livornesi Mounts and is mainly made by
sand beaches fed from north to south by Magra, Serchio, Arno and Scolmatore
rivers. The last three and particu larly the Arno River feed the pisa n coast even
if in an insufficient way. Beginning from the second half of the nineteenth
century the Arno delta underwent rapid erosion because of severa l factors,
which strongly changed sedimentary budgets.
The petrography of recent sands from the Pisa coast is used to determine their
provenance and thus how their longshore transport and distribution occur.
In respect to previous works the step of sampling has been increased a long
transects norma l to the shore up to the 10 m isobath in order to a better
estimati o n of longshore behaviour.
The modal analysis has allowed us to recognize two petrographic provinces,
from north to the south, which reflect distinct provenances. The northern
province includes lithoquartzose sands, fed largely by the Arno River and, in
small quantities, by the Serchio River. The southern province consists of
quartzolithic sands, less quartzose than sands belonging to the former
province. The moda l analysis and the petrographical characterization of the latter indicate a northward sediment drift. These sands are perhaps supplied
from Secche della Mel oria and/or from Scolmatore River.
Detrital modes of the sands a long transects show some compositional changes .
within a few of these, which may indicate a major complexity in longshore
transport and distribution.
Besides, in arder to evaluate whether the provenance of sands has changed
their characteristics both in space and time, during the last 3000 yr B. P, the
compositional study of sands forming the coastal dune was a Iso carried aut,
sin ce coastal dune alignment represents the position of an ancient shorelin
New stratigraphical data and sedimentological observations on the Plio-Pleistocene deposits of the lower Valdarno (Tuscany, Italy)
No full textThe Plio-Pleistocene successions of the lower Valdarno have been studi ed since the XIX century
prevalently for the presence of numerous mamma] fossi! remains. Most of the previous
studies focused on biostratigraphical and paleontological observations (e.g. Bossio et al. , 1993)
whereas the stratigraphical and depositional aspects were only seldom investigated (Benvenuti
& Dominici, 1992, Benvenuti et al., 1997).
To obtain new data on these topics, the present research considers, from a multidisciplinary
geologica! standpoint, some successions cropping out in the lower Valdarno between the villages
ofMontopoli and Pontedera. These successions ranging in age from the Middle Pliocene and the
Middle Pleistocene, are affected by important unconformity surfaces (Zanchetta et al. , 1998).
One of the most important unconformity separates the middle Pliocene deposits from the Pleistocene
sediments.
The middle Pliocene deposits, mainly constituted by sands and bioclastic sands, are predominantly
accumulated in a coastal marine-paralic environment. They record a high sedimentary
ciclicity controlled by relative marine fluctuations, and thus by the subtraction or addition
of accomodation space, in relation to increase or diminution of sedimentary supply.
The lower Pleistocene sediments, mainly represented by clay and silty clay in the lower part
of the succession and by sands and silty sands in the upper part, are stili related to a coastal
marine-paralic environment. During the middle Pleistocene, a widespread continental sedimentation
took piace. Two major events of fluvial erosion related to grave! bed-load rivers followed
by a phase of alluvial plain aggradation in a mixed-load river type are detected.
A further aim of this study is the better understanding of the stratigraphic relationships between
the succession cropping out north to the Arno river, in the Lucca basin, and those surveyed south
of the Amo river, in the Elsa and Era basins. The correlati o n between these successions represent
matter of debate stili far to a definitive solution (Sarti et al., 200 l; Cantini et al., 2001)
Calcareous plankton biostratigraphy of the fiume Orte section (Abruzzo, central apennines, Italy)
No full textThe uppermost Rupelian-Messinian portion of the Montagna della Maiella carbonate succession (Bolognano Fm. of Crescenti et al., 1969) outcrops extensively in the northern sector of
the mass if. Most of the previous studies mainly dea! with facies analysis and sequence stratigraphy
of these deposits (Accarie, 1988; Yecsei & Sanders, 1999), but their biostratigraphy is sti li
poor investigated. The aim of thi s study is to improve the biostratigraphy of the hemipelagic
marly deposits of the middle-upper portion of the Bolognano Fm .. These deposits are well
exposed along the Fiume Orta valley, between Salle and Piano d'Orta villages.
The section studi ed is located o n the right si de of the valley, 2 Km south-east of Piano d'Orta
village. The lower portion of the section, which corresponds to the Briozoi superiori member of
the Bolognano Fm. (Yecsei, 1991 ; Bellatalla, 1992), is made up of 35 meters of inner-ramp
skeletal limestones arranged into stacked subaqueous dunes with cross-stratification associated
with bed-concordant and bed-di scordant lamination. They are biocl as tic grain stones and packstones
with abundant bryozoans, echinoderm debris and benthic foramjnifers, among which
Nephrolepidina morgani and Miogypsina globulina were determined. These depos its are capped
by a phosphorite hardground, 25-30 cm thick, rich in glauconite gra in s, phosphatized lithoclasts
and bioclasts and fish teeth. Rare specimens of the nautiloid Aturia are al so present. The hardground
is fol lowed by almost 80 meters of li mestones and marls rich in planktic foraminifers
deposited in an outer ramp environment (Marn.e ad Orbulina member of the Bolognano Fm;
Bellatall a, 1992). The interval starts with 2,5 meters of fine- gra ined bioclastic packstones, that
up-section pass to 68 meters of cyclically bedded and thoroughly bioturbated hemipelagic marly
limestones and calcareous marls. They are wackestones and subordinate packstones with abundant
planktic foraminifers. The last IO meters of this interval consist of very fine to fine-grained
biocla tic packsto nes, which show a clear shallowing-upward depositional trend characteri sed
by both abundant benthic debris input (benthic foraminifers, echinoid remains, pelecypod fragments)
and consistent decrease in planktic foraminifer content. The section ends with 10 meters
of inner ramp thick-bedded bioclastic limestones. This portion belongs to the Calcari a litotamni
member of the Bolognano Fm. (Crescenti et al., 1969).
The biostratigraphic study presented here is focused on the Marn.e ad Orbulina member of
the Bolognano Fm., that in this area shows the maximum thickness. The integrated study of
planktic fo raminifers and calcareous nannofossil s, based on the analyses of 100 samples, indicate
a Langhian to early Tortonian age for this interval. Praeorbulina glomerosa s. I. to Jower
portion of Neogloboquadrina acostaensis planktic foraminifers Zones of Foresi et al. ( 1998),
and the MNN5 to MNN7 calcareous nannofoss il Zones of Fornaci ari et al. ( 1996) were recognized.
The Langhian l Serravallian and Serravallian l Tortonian boundaries were identified as
well.ln agreement with Fornaciari et al. (1996), the Langhian l Serravallian boundary has been
recognized by the LO of Sphenolithus heteromorphus. It is worth mention ing that the LO of
Globorotalia peripheroronda occurs l ,5 meters above this boundary. Following Foresi et al.
(1998), the Serravall ian l Tortonian boundary has been placed at the LO of Paragloborotalia
siakensis. This bioevent predates the FO of Neogloboquadrina atlantica s.s. which occurs about
3 meters above.
The section studied, characterised by severa! calcareous plankton bioevents, can be considered
a reference section for the middle Miocene carbonate successions of the Maiella massif.
Besides, the data coll ected allowed to state some biostratigraphic constrains useful for a better
understanding of the sequence stratigraphic evolution of the Maiella un i t during Miocene times
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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