Using environmental isotopes along with major hydro-geochemical compositions to assess deep groundwater formation and evolution in eastern coastal China

2018 ◽  
Vol 208 ◽  
pp. 1-9 ◽  
Author(s):  
Naizheng Xu ◽  
Jianshi Gong ◽  
Guoqiang Yang
Keyword(s):  
Environmental Isotopes ◽  
Deep Groundwater ◽  
Formation And Evolution ◽  
Coastal China

scholarly journals Environmental isotopes and noble gas ages of the deep groundwater with coupled flow modelling in the Baltic artesian basin

2021 ◽  
Vol 61 (1) ◽  
Author(s):  
R. Mokrik ◽  
V. Samalavičius ◽  
M. Gregorauskas ◽  
M. Bujanauskas
Keyword(s):  
Noble Gas ◽  
Sedimentary Cover ◽  
Regional Scale ◽  
Environmental Isotopes ◽  
Age Dating ◽  
Coupled Flow ◽  
Deep Groundwater ◽  
Artesian Basin ◽  
Deep Aquifers ◽  
The Baltic

In this study, modelled groundwater actual flow times in intermediate and deep aquifers, covered by regional scale impermeable aquitards, were compared with 4He and 81Kr age dating results. To improve the reliability of the steady state 3D groundwater flow model, the isotopic ages of deep groundwater were compared to the MODPATH modelled travel times. The highest helium values in groundwater reservoirs coincide with fault zones in the crystalline basement and sedimentary cover near Rapakivi granite massifs. Insights into isotope-geochemical anomalies of the Baltic Artesian Basin intermediate and deep groundwater support their main distribution peculiarities in the flow path towards the Baltic Sea coast lowland and seabed depression as the regional groundwater discharge area.

Case study: methane gas in a groundwater system located in a dolerite ring structure in the Karoo Basin; South Africa

2019 ◽  
Vol 122 (3) ◽  
pp. 357-368 ◽  
Author(s):  
D. Hohne ◽  
F. de Lange ◽  
S. Esterhuyse ◽  
B. Sherwood Lollar
Keyword(s):  
Meteoric Water ◽  
Shallow Groundwater ◽  
Environmental Isotopes ◽  
Ring Structure ◽  
Deep Groundwater ◽  
Methane Gas ◽  
Karoo Basin ◽  
Close Proximity ◽  
Local Municipality

Abstract In the past few years numerous assumptions were made on groundwater in the Karoo Basin and related shale gas development, but not many baseline studies were conducted on groundwater and on boreholes where methane currently occurs. This article focuses on one of these boreholes (BHA) in the Ubuntu Local Municipality area, located close to a dolerite ring structure, which is releasing methane gas. Water samples were analysed for macro and trace elements, environmental isotopes and methane concentrations. Chemical analyses results indicate that groundwater at this borehole may be a mixture between deep groundwater, shallow groundwater and meteoric water. A rise in the groundwater level and subsequent flowing artesian conditions that was observed, support the theory that mixing between deeper groundwater from the Ecca Group and shallower water from the Beaufort Group is taking place. These water level reactions could be due to possible seismic activity within close proximity to the dolerite ring structure and/or due to recharge and interflow to BHA.

Investigation of paleoclimate signatures in Sfax deep groundwater (Southeastern Tunisia) using environmental isotopes and noble gases

2020 ◽  
Vol 547 ◽  
pp. 208-219 ◽  
Author(s):  
Rim Trabelsi ◽  
Takuya Matsumoto ◽  
Kamel Zouari ◽  
Mahdi Trabelsi ◽  
Bhishm Kumar
Keyword(s):  
Noble Gases ◽  
Environmental Isotopes ◽  
Deep Groundwater

scholarly journals Environmental Isotope Study (14C, 13C, 18O, D, Noble Gases) on Deep Groundwater Circulation Systems in Hungary With Reference to Paleoclimate

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 902-918 ◽  
Author(s):  
Martin Stute ◽  
Jozsef Deak
Keyword(s):  
Cross Sections ◽  
Isotope Ratio ◽  
Noble Gases ◽  
Environmental Isotopes ◽  
Carbonate Dissolution ◽  
Deep Groundwater ◽  
Α Decay ◽  
Groundwater Circulation ◽  
Groundwater Samples ◽  
Isotope Study

We have studied environmental isotopes and noble gases in groundwater samples from various locations in the Great Hungarian Plain along two selected hydrogeological cross-sections of ca 100km. The 14C groundwater ages were corrected hydrochemically and compared with age information derived from excess helium due to 4He from α-decay of U and Th and their daughter nuclides within the aquifer and to He accumulation from the crustal (and mantle) He flux. In correcting the 14C groundwater ages, we considered carbonate dissolution under open and closed system conditions in the infiltration areas. Non-radioactive reduction of the 14C/12C isotope ratio also plays an important role due to the addition of “dead” carbon species to groundwater along its subsurface pathway. High (corrected) 14C ages, which fall into the last global cold period, are supported by significantly lower heavy stable isotope values as well as lower temperatures derived from the noble gases Ne, Ar, Kr and Xe.

AFM study of the dynamics of α-alumina surface faceting during high-temperature processing

1995 ◽  
Vol 53 ◽  
pp. 334-335 ◽  
Author(s):  
Michael W. Bench ◽  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
High Temperature ◽  
Thin Foil ◽  
Sem Analysis ◽  
Conductive Coatings ◽  
Force Microscopy ◽  
Minimal Sample ◽  
Atomic Force ◽  
Formation And Evolution ◽  
High Temperature Processing ◽  
Nominal Surface

To gain a better understanding of the surface faceting that occurs in α-alumina during high temperature processing, atomic force microscopy (AFM) studies have been performed to follow the formation and evolution of the facets. AFM was chosen because it allows for analysis of topographical details down to the atomic level with minimal sample preparation. This is in contrast to SEM analysis, which typically requires the application of conductive coatings that can alter the surface between subsequent heat treatments. Similar experiments have been performed in the TEM; however, due to thin foil and hole edge effects the results may not be representative of the behavior of bulk surfaces.The AFM studies were performed on a Digital Instruments Nanoscope III using microfabricated Si3N4 cantilevers. All images were recorded in air with a nominal applied force of 10-15 nN. The alumina samples were prepared from pre-polished single crystals with (0001), , and nominal surface orientations.

Molecular Identification of Stranded Cetaceans in Coastal China

2019 ◽  
Vol 45 (5) ◽  
pp. 525-532
Author(s):  
Ting Li ◽  
Hao Wu ◽  
Caiwen Wu ◽  
Guang Yang ◽  
Bingyao Chen
Keyword(s):  
Molecular Identification ◽  
Coastal China

The First Galaxies in the Universe

2013 ◽  
Author(s):  
Abraham Loeb ◽  
Steven R. Furlanetto
Keyword(s):  
Galaxy Evolution ◽  
Big Bang ◽  
First Stars ◽  
Distant Galaxies ◽  
Formation And Evolution ◽  
Early Galaxies ◽  
First Galaxies ◽  
Large Telescopes ◽  
New Generation ◽  
The Big Bang

This book provides a comprehensive, self-contained introduction to one of the most exciting frontiers in astrophysics today: the quest to understand how the oldest and most distant galaxies in our universe first formed. Until now, most research on this question has been theoretical, but the next few years will bring about a new generation of large telescopes that promise to supply a flood of data about the infant universe during its first billion years after the big bang. This book bridges the gap between theory and observation. It is an invaluable reference for students and researchers on early galaxies. The book starts from basic physical principles before moving on to more advanced material. Topics include the gravitational growth of structure, the intergalactic medium, the formation and evolution of the first stars and black holes, feedback and galaxy evolution, reionization, 21-cm cosmology, and more.

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