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101.
The use of geophysical methods in metrology is a significant tool within the wide research topic of landscape archaeology context. Since 2011, the Ancient Appia Landscapes Project aims to recognize dynamics, shapes and layout of the ancient settlement located along the Appia road east of Benevento, and cyclical elements and human activities that influenced the choice of landscapes. The integration of geophysical data with an archaeological infra-site analysis allowed us to investigate the area of Masseria Grasso, about 6 km from Benevento (Campania region, Italy). In this framework, an archaeogeophysical approach (Geomagnetic and Ground Penetrating Radar) was adopted for detecting anomalies potentially correlated with buried archaeological evidences. The geomagnetic results have given a wide knowledge of buried features in a large survey highlighting significant anomalies associated with the presence of buildings, roads and open spaces. These geophysical results permitted us to define the first archaeological excavations and, successively, a detailed Ground Penetrating Radar approach has been provided highlighting the rooms and paved spaces. The overlap between archaeological dataset and geophysical surveys has also allowed recognizing the path of the ancient Appia road near the city of Benevento and hypothesize the settlement organization of the investigated area, which has been identified with the ancient Nuceriola.  相似文献   
102.
The sequence-stratigraphic investigation by Very High-Resolution (VHR) seismic profiles allowed recognition of the detailed architecture of the late Pleistocene and Holocene succession of the Venice area. In this way deposits previously known by the analyses of scattered cores, mainly taken along the lagoon margin and the littoral strips, have been correlated at regional scale including the near offshore sector and the result has pointed out the lateral variability of the stratal architecture. Late Pleistocene deposits consist of an aggrading floodplain and fluvial channel fills accumulated during decreasing eustatic sea level, and they are coeval with offlapping forced regressive marine wedges in the Central Adriatic basin. The Holocene sequence is composed of three main seismic units separated by major stratal surfaces. Unit 1 (up to 9 m thick) is formed by channelized deposits separated by areas showing sub-horizontal and hummocky reflectors, and is bounded at the base by a surface that records prolonged conditions of subaerial exposure and at the top by a flatter surface resulting from erosion by marine processes. Deposits of Unit 1 are interpreted as estuarine and distributary channel fills, and back-barrier strata. Unit 2 is well distinguishable from Unit 1 only in the offshore area and at the barrier island bounding the Venice Lagoon, and is composed of a prograding marine wedge (up to 10 m thick) that interacts laterally with ebb tidal deltas. Unit 3 consists of a tidal channel complex and inlet deposits, which testify the evolution of the lagoon area. Tidal channels are entrenched in the lagoon mud flat (coeval with Units 1–2) and cut the Pleistocene–Holocene boundary in several places.Following current sequence-stratigraphic concepts, the Holocene sequence is composed of a paralic transgressive systems tract (TST) (Unit 1) overlying a sequence boundary (the Pleistocene–Holocene boundary) and overlain by a marine highstand systems tract (HST) (Unit 2) in seaward locations and by highstand lagoonal deposits landwards. TST and HST are separated by a downlap surface that is amalgamated with a wave ravinement surface in several places. Unit 3 is coeval with the upper part of Unit 2, and its development has been favoured by human interventions, which led to a transgression limited to the lagoon area.Local factors during the deposition, i.e. subsidence, sediment supply, physiography, and current/wave regimes, led to a significant lateral variability in the architecture of the Holocene sequence, as evidenced by the extreme thickness variation of the TST along both depositional strike and dip. The HST, instead, shows less pronounced strike variations in the stratal architecture. Also, present data clearly evidence that the human impact has a great relevance in influencing the late Holocene sedimentation.  相似文献   
103.
This paper aimed to compare epiphyte assemblages of leaves and rhizomes of Posidonia oceanica exposed to different levels of concentration of nutrients. The same design including a potentially impacted meadow and two reference meadows was used in each of two locations, characterized by the presence of a city or of suspended cages of a fish farm, respectively. This allowed to test for the consistency of responses of epiphytic assemblages to different sources of eutrophication. In both studies, results documented differences in patterns of composition and abundance of epiphytic assemblages on leaves between disturbed and reference meadows, while assemblages on rhizomes did not appear sensitive to this kind of disturbance. Moreover, in potentially impacted meadows, both assemblages showed different patterns of spatial variability compared to reference assemblages. Species composition and abundance of epiphyte assemblages seemed suitable for detecting moderate nutrient increases, even if adequate sampling designs are needed to separate patterns related to the large natural spatial variability of these systems from those related to changes in environmental conditions.  相似文献   
104.
Holocene cooling events have been reconstructed for the southern Adriatic Sea (central Mediterranean) by means of analyses of organic walled dinoflagellate cysts, planktonic foraminifera, oxygen isotopes, calcareous nanoplankton, alkenones and pollen from a sediment core. Two cooling events have been detected, during which sea‐surface temperatures (SSTs) were ca. 2°C lower. Unravelling the SST signal into dominant seasonal components suggests maximum winter cooling of 2°C at around 6.0 ka, whereas the cooling at ca. 3.0 ka might be the result of a spring temperature cooling of 2–3°C. The events, lasting several hundred years, are apparently synchronous with those in the Aegean Sea, where they have been related to known cooling events from the Greenland ice‐core record. A distinct interruption in Adriatic Sea sapropel S1 is not clearly accompanied by a local drop in winter temperatures, but seems to be forced by ventilation, which probably occurred earlier in the Aegean Sea and was subsequently transmitted to the Adriatic Sea. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
105.
Abstract— In this edition of The Meteoritical Bulletin, 1394 recognized meteorites are reported, 27 from specific locations within Africa, 133 from Northwest Africa, 1227 from Antarctica (from ANSMET, PNRA, and PRIC expeditions), and 7 from Asia. The Meteoritical Bulletin announces the approval of four new names series by the Nomenclature Committee of the Meteoritical Society, two from Africa and one from Asia, including Al Haggounia, from Al Haggounia, Morocco, which is projected to be on the order of 3 metric tons of material related to enstatite chondrites and aubrites. Approved are two falls from Africa, Bassikounou (Mauritania) and Gashua (Nigeria). Approved from areas other than Antarctica are one lunar, two Martian, 32 other achondrites, three mesosiderites, two pallasites, one CM, two CK, one CR2, two CV3, one CR2, and four R chondrites. The Nomenclature Committee of the Meteoritical Society announces 48 newly approved relict meteorites from two new name series, Österplana and Gullhögen (both from Sweden).  相似文献   
106.
The standard thermodynamic properties at 25°C, 1 bar (ΔG fo, ΔH fo, S o, C Po, V o, ω) and the coefficients of the revised Helgeson–Kirkham–Flowers equations of state were evaluated for several aqueous complexes formed by dissolved metals and either arsenate or arsenite ions. The guidelines of Shock and Helgeson (Geochim Cosmochim Acta 52:2009–2036, 1988) and Sverjensky et al. (Geochim Cosmochim Acta 61:1359–1412, 1997) were followed and corroborated with alternative approaches, whenever possible. The SUPCRT92 computer code was used to generate the log K of the destruction reactions of these metal–arsenate and metal–arsenite aqueous complexes at pressures and temperatures required by the EQ3/6 software package, version 7.2b. Apart from the AlAsO4o and FeAsO4o complexes, our log K at 25°C, 1 bar are in fair agreement with those of Whiting (MS Thesis, Colorado School of Mines, Golden, CO, 1992). Moreover, the equilibrium constants evaluated in this study are in good to fair agreement with those determined experimentally for the Ca–dihydroarsenate and Ca–hydroarsenate complexes at 40°C (Mironov et al., Russ J Inorg Chem 40:1690, 1995) and for Fe(III)–hydroarsenate complex at 25°C (Raposo et al., J Sol Chem 35:79–94, 2006), whereas the disagreement with the log K measured for the Ca–arsenate complex at 40°C (Mironov et al., Russ J Inorg Chem 40:1690, 1995) might be due to uncertainties in this measured value. The implications of aqueous complexing between dissolved metals and arsenate/arsenite ions were investigated for seawater, high-temperature geothermal liquids and acid mine drainage and aqueous solutions deriving from mixing of acid mine waters and surface waters. Electronic Supplementary Material The online version of this article () contains supplementary material, which is available to authorized users.  相似文献   
107.
The paper deals with the implementation of a levelling and Global Positioning System (GPS) network to control land subsidence in the coastal area north of the Venice Lagoon. About 480 km of levelling lines with 527 benchmarks, 45 of which suited for Differential GPS measurements, were established in 2004. A complete survey of the net was carried out in 2004 soon after its establishment. The 2004 records have been compared with previous scattered data obtained by the use of levelling surveys, DGPS and SAR interferometry. The results show a trend in land settlement that increases from the lagoon margin to the north and jeopardize the Venice coastland. Groundwater withdrawals for domestic, agricultural, and health spas uses, peat oxidation of reclaimed marshlands for farming, natural consolidation of the Holocene deposits, and tectonics of the pre-Quaternary basement are the causes of land subsidence in the study area. Since most of the area lies below the mean sea level and on account of the expected sea level rise due to global change, a detailed monitoring of land displacements in the near future will be of paramount importance to plan necessary works for coastland protection.  相似文献   
108.
Abstract— The Frontier Mountain (FRO) 93001 meteorite is a 4.86 g fragment of an unshocked, medium‐ to coarse‐grained rock from the acapulcoite‐lodranite (AL) parent body. It consists of anhedral orthoenstatite (Fs13.3 ± 0.4Wo3.1 ± 0.2), augite (Fs6.1 ± 0.7Wo42.3 ± 0.9; Cr2O3 = 1.54 ± 0.03), and oligoclase (Ab80.5 ± 3.3Or3.1 ± 0.6) up to >1 cm in size enclosing polycrystalline aggregates of fine‐grained olivine (average grain size: 460 ± 210 μm) showing granoblastic textures, often associated with Fe,Ni metal, troilite, chromite (cr# = 0.91 ± 0.03; fe# = 0.62 ± 0.04), schreibersite, and phosphates. Such aggregates appear to have been corroded by a melt. They are interpreted as lodranitic xenoliths. After the igneous (the term “igneous” is used here strictly to describe rocks or minerals that solidified from molten material) lithology intruding an acapulcoite host in Lewis Cliff (LEW) 86220, FRO 93001 is the second‐known silicate‐rich melt from the AL parent asteroid. Despite some similarities, the silicate igneous component of FRO 93001 (i.e., the pyroxene‐plagioclase mineral assemblage) differs in being coarser‐grained and containing abundant enstatite. Melting‐crystallization modeling suggests that FRO 93001 formed through high‐degree partial melting (≥35 wt%; namely, ≥15 wt% silicate melting and ?20 wt% metal melting) of an acapulcoitic source rock, or its chondritic precursor, at temperatures ≥1200 °C, under reducing conditions. The resulting magnesium‐rich silicate melt then underwent equilibrium crystallization; prior to complete crystallization at ?1040 °C, it incorporated lodranitic xenoliths. FRO 93001 is the highest‐temperature melt from the AL parent‐body so far available in laboratory. The fact that FRO 93001 could form by partial melting and crystallization under equilibrium conditions, coupled with the lack of quench‐textures and evidence for shock deformation in the xenoliths, suggests that FRO 93001 is a magmatic rock produced by endogenic heating rather than impact melting.  相似文献   
109.
A model for the calculation of a representative complete elastic tensor of a geologic body is presented here, in order to fill the gap between the small scale sample and the complex structural and lithological association of a geologic body, which may be of the same large scale as the wavelength used on the seismic survey. The major problems arising during the modelling are discussed, namely the representativity of a suite of hand samples and the evaluation of the volume fraction of the different lithologies comprising a formation. An application example is presented of a metapelitic sequence spanning the tectonic boundary of the Ivrea-Verbano zone with the Serie dei Laghi in Valle Cannobina (N. Italy). It is shown that the effective formation anisotropy is drastically reduced relative to that of hand samples when the structure is averaged over a large area, except for the sheared and mylonitic sub-areas comprising the tectonic contact zone (the Cossato-Mergozzo-Brissago- and Pogallo lines). In these subareas the effective anisotropy is slightly reduced (a few points of a percent) from the hand sample scale to that of the geologic formation. Moreover, because the polarization of the fastest shear wave and the plane of maximum shear wave splitting of the most common crustal rock types coincide with the foliation, there is an opportunity to infer the structure of deep rock formations from teleseismic shear waves.  相似文献   
110.
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