transitional environment
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Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7445
Author(s):  
Leifu Zhang ◽  
Qun Zhao ◽  
Sizhong Peng ◽  
Zhen Qiu ◽  
Congjun Feng ◽  
...  

In the Carboniferous–Permian period, several organic-rich black shales were deposited in a marine–continental transitional environment in the Linfen area on the eastern margin of the Ordos Basin. Integrated sedimentological and organic geochemical analyses are performed on an outcrop in order to clarify the relationship between paleoenvironment and organic matter accumulation. The results of this study show that the marine–continental transitional strata of the Upper Carboniferous Benxi Formation to Lower Permian Taiyuan and Shanxi Formation exposed in the Linfen area are composed of sandstone, shale, coal, and limestone. Total organic carbon (TOC) contents of the studied samples were mainly distributed in the range of 0.59%–35.4%, with an average of 7.32%. From Benxi Formation to Shanxi formation, the humidity gradually increased, and the climate gradually changed from hot and humid to warm and humid during Carboniferous to Permian. The deposition of the Shanxi Formation ended with the climate returning to hot and humid, having an oxic-suboxic conditions and a high paleoproductivity. Paleoredox conditions and paleoproductivity are the two vital factors controlling the formation of organic matter in black shales. The transitional environment characterized by oxic-suboxic, relatively high deposition rate, and various source of organic matter, although different from the marine environment, provides a good material basis for the deposition of organic-rich shales.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marco Pansera ◽  
Elisa Camatti ◽  
Anna Schroeder ◽  
Giacomo Zagami ◽  
Alessandro Bergamasco

AbstractThe Venice lagoon (VL) has been recognized as a hot spot of introduction of non-indigenous species (NIS), due to several anthropogenic factors and environmental stressors that combined may facilitate NIS invasions. In the last decades an increasing number of zooplankton NIS have been observed in the VL. This work aims to provide a picture of the annual cycle and distribution of the recently recorded non-indigenous copepod Oithona davisae, considering the coexistence patterns with the congeneric resident Oithona nana. Therefore, zooplankton samplings were carried out monthly from August 2016 to July 2017 at five Long-Term Ecological Research LTER stations in the VL. Oithona davisae showed a persistent occurrence throughout the year with the highest abundances in the warm season and in the inner areas, while the congeneric O. nana, showing a different distribution pattern, resulted more abundant near the inlets of the Lagoon, where O. davisae reached the minimum density. Oithona davisae seems to find local conditions that promote its settlement and distribution, especially in the inner and more trophic lagoon sites. In other European coastal embayments or transitional waters, O. davisae occupied the niche left by the indigenous O. nana or can replace this congeneric species through competitive exclusion mechanisms. Our data indicate that, for now, such species replacement has not occurred in the VL. One of the causes is the extreme variety of habitats and niches offered by this environment allowing a balanced coexistence with O. nana and in general with the resident copepod community.


2021 ◽  
Author(s):  
Elisabete Castro D'oliveira ◽  
Lucio Fábio Lourencato ◽  
Camila Rodrigues e Silva ◽  
ANDRESSA CRISTHY BUCh ◽  
Eduardo Duarte Marques ◽  
...  

Abstract Peatlands are a transitional environment between terrestrial and aquatic ecosystems that provide essential hydrological, ecological, and biogeochemical. Peatlands have been recognized as important environmental matrices in the storage of organic carbon and water. However, little is known in the literature about the influence of peatlands on the quality of surface water. Therefore, this study aims to evaluate the water quality from peatlands in the spring of the Rio Campo Belo, in Itatiaia National Park, Itatiaia-Brazil. The spring water quality from peat profiles was based on the determinations of the temperature, dissolved oxygen (DO), electrical conductivity, pH, turbidity, dissolved organic carbon (DOC), total organic carbon (TOC), silica, ions, and trace elements (Al, Sb, As, Cd, Co, Cu, Cr, Sn, Fe, Mn, Mo, Ni, V, Ga, Rb, Sr, and Zn) on spring water and peat core samples. The highest DO values ​​observed in the spring waters that leachate water and may be related to the lower water temperature, as well as the movement of water. The DOC values were relatively low suggesting no difference between the spring water and the water leached (1.6 and 1.7 mg l-1, respectively). Higher values of ions and trace elements in the leaching water from core peat demonstrate a greater contribution of the peatland to the concentration of these ions in spring water. An increase in TOC peatland did not cause an increase in pH, however, the removal of organic matter promoted an increase in pH.


Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 648
Author(s):  
Natalia Stefania Piotrowska ◽  
Stanisław Zbigniew Czachorowski ◽  
Mariusz Jerzy Stolarski

In a short period, we have observed the rapid expansion of bioenergy, resulting in growth in the area of energy crops. In Europe, willow and poplar growing in short-rotation coppices (SRC) are popular bioenergy crops. Their potential impact on biodiversity has not yet been fully investigated. Therefore, there are many uncertainties regarding whether commercial production can cause environmental degradation and biodiversity impoverishment. One of the aspects examined is the impact of these crops on entomofauna and ecosystem services. The best-studied insect group is ground beetles from the Carabidae family. This work gathers data on biodiversity and the functions of carabids in willow and poplar energy plants. The results of these investigations show that energy SRC plants and Carabidae communities can create a synergistic system of mutual benefits. Willow and poplar plants can be a valuable habitat due to the increased biodiversity of entomofauna. Additionally, SRC creates a transitional environment that allows insect migration between isolated populations. On the other hand, ground beetles are suppliers of ecosystem services and make a significant contribution to the building of sustainable agriculture by pest control, thereby ameliorating damage to field crops.


2020 ◽  
Vol 30 (1) ◽  
pp. 31-44
Author(s):  
William Moura ◽  
João Carlos Araujo ◽  
Thales Lucio ◽  
João Adauto Souza Neto

Paleoenvironmental conditions from cretaceous black shales of Ipubi Formation (Araripe Basin-NE Brasil) are continuously debated. The main point of controversy is if these rocks were deposited in a lacustrine or restricted marine environment. The present study was developed in these black shales, by saturated biomarkers analyses (n-alkanes and isoprenoids) to discuss about the paleoenvironment of deposition of those shales. The n-alkanes predominance between n-C13 and n-C19 reveal algalic contribution. However an influence of terrestrial organism is also observed by the presence of n-C27, n-C28, and n-C29. The Pr/Ph ratio and Pr/Ph vs. (Pr+n-C17)/(Fi+n-C18) diagram indicated both anoxic and hypersaline conditions during the deposition of those shales. The Pr/n-C17 vs. Ph/n-C18 diagram also suggests reducing conditions, and classify an algalic contribution as marine-transitional source. Thus, this study indicates that the investigated shales were deposited in reducing and hypersaline conditions in a restricted marine to transitional environment.


2020 ◽  
Vol 1 (1) ◽  
pp. 40-47
Author(s):  
Diah Wully Agustine

“Athran” field is an active field for hydrocarbon exploration with trending northeast-southwest and focus on the reservoir zone is the Talang Akar Formation with A-C layer intervals. The method used in this research is electrofacies, delta deposition system, formation evaluation, static reservoir modeling, and multi-attribute linear regression. The distribution of reservoir modeling is done by using the stochastic variogram method to make modeling lithofacies and depositional facies. Identification of lithofacies in the study area obtained two units, namely sandstone and shale facies. The depositional facies analysis was carried out using the electrofacies approach, showing that the research target was in a transitional environment with a delta deposition system, namely the distributary channel, delta front and prodelta. The deposition process. Sandstones and shales affect the distribution of porosity which functions as a reservoir property. The data integration of the distribution of lithofacies, gamma ray and porosity was carried out using the multi-attribute linear regression method to predict data both vertically and horizontally. The results of this study are used to help determine the distribution direction and direction of sediment deposition as a good reservoir zone for exploration activities.


2020 ◽  
Vol 42 (3) ◽  
pp. 205-226
Author(s):  
Alejandra Manco-Garcés ◽  
Maria Isabel Marín-Cerón ◽  
Carlos Javier Sánchez-Plazas ◽  
Luis Carlos Escobar-Arenas ◽  
Alejandro Beltrán-Triviño ◽  
...  

A stratigraphic section in the San Jacinto fold and thrust belt located at northwestern Colombia was studied. This section displays part of the Oligocene-Early MioceneCiénagade Oro Formation(COF).This work analyses thesedimentsprovenance usinga multi-tool approach which include: (I)conglomerate and sandstonecounting clastwith mesh,(II)heavy mineralsassemblages, (III)paleocurrents and (IV) U/Pb detrital zircon ages.The sedimentary sequence was deposited in deltaic to transitional environment deposition, with reduction in the waves and tidal effect, and increase in the dominance of transitional river processes upward the section. Two main source areas have been identified from a dissected arc province: a main granitic to pegmatitic and a secondary basic igneous source rocks, located to the east and southwest of the current position. Detrital zircon U-Pb geochronology analysis display four age populations: (I) Devonian-Permian, (II) Permian-Triassic, (III) Jurassic and (IV) Cretaceous, with maximum deposition ages of 75.2±0.9 Ma in the lower part of the section, 68.9±0.6 Ma in the middle and 74.5±0.7 Ma for the upper part. It is proposed that COF was sediment-supplied by a south-to-north fluvial system, which drained exposed basement blocks and their late Cretaceous to Paleogene sedimentary cover during the Oligocene. This fluvial system carried sediments from late Cretaceous plutonslike the AntioqueñoBatholith and mafic/ultramafic rocks, which make up the basement of the Western and Central Cordilleras


2020 ◽  
Vol 8 (9) ◽  
pp. 628
Author(s):  
Michele Arienzo ◽  
Francesco Bolinesi ◽  
Giuseppe Aiello ◽  
Diana Barra ◽  
Carlo Donadio ◽  
...  

A multidisciplinary survey was carried out on the quality of water and sediments of the estuary of the Sele river, an important tributary of the Tyrrhenian Sea, to assess anthropogenic pressures and natural variability. Nine sediment sites were monitored and analyzed for granulometry, morphoscopy, benthic foraminifera and ostracod assemblages, heavy metals, and polycyclic aromatic hydrocarbons. Surface water was assayed for ionic composition and phytoplankton biomass. Total organic carbon (TOC) and total nitrogen (TN) in sediments were higher in the inner part of the estuary (IE), up to 12.7 and 0.7% because of anthropic influence. In waters, N-NH4, N-NO3, and Ptot. were high, with loads of Ptot in IE exceeding ~fourfold the limit. Here, it was also observed that the highest primary production was Chl-a, 95.70 µg/L, with cryptophytes, 37.6%, and diatoms, 33.8%, being the main phytoplanktonic groups. The hierarchical analysis split the estuary into two areas, with marked differences in anthropic pollution. Waters were classified as poor–bad level with respect to the content of nutrients. Sedimentological assay reveals littoral erosion and poor supply of river sandy sediments. The erosion environment is confirmed by the presence of meiobenthic recent marine forms intrusion inside the river. All these data reveal the fragility of the estuary and the need of urgent remediation actions.


2020 ◽  
Vol 18 (1/2020) ◽  
pp. 109-124
Author(s):  
Dejan Bursac

The study is designed to empirically test the effects which different ruling party ideologies have on spending for public order and safety budget component in Central and Eastern European countries. The transitional environment and especially post-Cold War security context have altered the concept of security in former socialist societies. Our assumption, based not just on theoretical concepts of left and right ideologies, but also on studies examining this matter in more developed Western democracies, was that right-leaning cabinets will have higher levels of budget consumption for law and order than leftist governments. The empirical model confirmed this hypothesis, albeit only partially. A number of other political, economic, and contextual variables connected with transitional setting, which usually have effect on general levels of spending or certain budget areas, have demonstrated a low significance when comes to law and order spending.


2020 ◽  
Vol 12 (3) ◽  
pp. 279-288
Author(s):  
K. E. Aweto

The study area Burutu lies within the transitional environment of the Niger delta. The area is sectioned by a compact network of rivers and creeks, which maintain a fragile but dynamic balance between saline, estuarine and freshwater surface bodies. Twenty direct current resistivity soundings were carried out to provide adequate information on the spatial lithological variation and groundwater conditions in Burutu. Resistivity contrasts and water analysis were used as a means of characterizing probable lithology and water type present within the pore spaces of aquiferous units. The results revealed spatial development of the aquifer architectural facies that follows a trend of mostly sand with little clay in the south to sand with abundant of clayey facies in the north near the Forcados River. The groundwater conditions indicated that salty/brackish water constituting about 4 % of water present was confined to the bank of the Forcados River and extend laterally landwards to about 120 m. Further away from the river bank, the water was mostly poor to good quality freshwater. The depth to the freshwater constituting about 96 % groundwater present varied from about 49.0 – 63.3 m near the Forcados River and became as shallow as 1.6 m in inland areas.


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