Marine diagenesis of ikaite: Implications from the isotopic and geochemical composition of glendonites and host concretions (Palaeogene–Neogene sediments, Sakhalin Island)

Sedimentology ◽  
2021 ◽  
Author(s):  
Kseniia Vasileva ◽  
Oleg Vereshchagin ◽  
Victoria Ershova ◽  
Mikhail Rogov ◽  
Irina Chernyshova ◽  
...  
Keyword(s):  
Sakhalin Island ◽  
Geochemical Composition ◽  
Neogene Sediments

Hydrogeological responses in tropical mountainous springs

2019 ◽  
Author(s):  
Ricardo Sánchez-Murillo
Keyword(s):  
Costa Rica ◽  
Isotope Composition ◽  
Central Valley ◽  
Distribution Functions ◽  
Geochemical Composition ◽  
Transit Times ◽  
Management Plans ◽  
Best Fit ◽  
Term Data

This study presents a hydrogeochemical analysis of spring responses (2013-2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2H in rainfall resulted in a highly significant meteoric water line: δ2H = 7.93×δ18O + 10.37 (r2=0.97). Rainfall isotope composition exhibited a strong dependent seasonality. The isotopic variation (δ18O) of two springs within the Barva aquifer was simulated using the FlowPC program to determine mean transit times (MTTs). Exponential-piston and dispersion distribution functions provided the best-fit to the observed isotopic composition at Flores and Sacramento springs, respectively. MTTs corresponded to 1.23±0.03 (Sacramento) and 1.42±0.04 (Flores) years. The greater MTT was represented by a homogeneous geochemical composition at Flores, whereas the smaller MTT at Sacramento is reflected in a more variable geochemical response. The results may be used to enhance modelling efforts in central Costa Rica, whereby scarcity of long-term data limits water resources management plans.

Prevalence of Killer Whale Tooth Rake Marks on Gray Whales off Sakhalin Island, Russia

2018 ◽  
Vol 44 (6) ◽  
pp. 643-652
Author(s):  
David W. Weller ◽  
Amanda L. Bradford ◽  
Aimée R. Lang ◽  
Alexander M. Burdin ◽  
Robert L. Brownell, Jr.
Keyword(s):  
Killer Whale ◽  
Sakhalin Island ◽  
Gray Whales

Features of the Mongi oil-gas-condensate field development (Sakhalin Island)

2020 ◽  
pp. 104-108
Author(s):  
R.R. Haliulin ◽  
◽  
S.N. Zakirov ◽  
A.H. Kha ◽  
N.E. Vedernikov ◽  
...  
Keyword(s):  
Sakhalin Island ◽  
Gas Condensate ◽  
Field Development ◽  
Oil Gas

New cryptogamic records. 4

2019 ◽  
Vol 53 (2) ◽  
pp. 431-479 ◽  
Author(s):  
I. V. Czernyadjeva ◽  
O. M. Afonina ◽  
D. V. Ageev ◽  
E. Z. Baisheva ◽  
T. M. Bulyonkova ◽  
...  
Keyword(s):  
Sakhalin Island ◽  
Diatom Species ◽  
Altai Republic ◽  
Lichenicolous Fungi ◽  
Magadan Region ◽  
Novosibirsk Region ◽  
Republic Of Bashkortostan ◽  
Khanty Mansi Autonomous

First records of diatom species from the Barents and East-Siberian seas, of Myxomycetes for the Khanty-Mansi Autonomous Area — Yugra, Novosibirsk Region, Trans-Baikal Territory, Basidiomycetes for the Arkhangelsk, Novosibirsk, Rostov and Volgograd regions, Altai Republic, Altai Territory, lichens, calicioid and lichenicolous fungi for the Murmansk, Novgorod and Tver regions, bryophytes for the Lipezk, Voronezh and Volgograd regions, St. Petersburg, Stavropol Territory, Caucasus, Republic of Bashkortostan, Yamal and Gydan peninsulas, Trans-Baikal Territory, Magadan Region, Sakhalin Island, Republic of Uzbekistan are presented. Data on localities, habitats, distribution of recorded species are provided.

Distribution of Mercury in Lake St. Clair and the St. Clair River Sediments

1989 ◽  
Vol 24 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Alena Mudroch ◽  
K. Hill
Keyword(s):  
Organic Matter ◽  
Sediment Cores ◽  
River Sediments ◽  
Size Fraction ◽  
Mineralogical Composition ◽  
Recent Sediment ◽  
Geochemical Composition ◽  
Visual Appearance ◽  
Decaying Wood ◽  
Relationship Of

Abstract Sediment cores were collected in Lake St. Clair in 1985 and in the St. Clair River in 1986 to investigate the horizontal and vertical distribution and association of Hg in the sediments. A layer of recent sediment up to about 35 cm thick was differentiated by the geochemical composition and visual appearance from the underlying glacial-lacustrine deposits. The concentration of Hg in the surficial sediments in Lake St. Clair was lower in 1985 (<0.025 to 1.200 µg/g) than that found in 1974 (<0.20 to 3.00 µg/g). Up to 8.30 µg/g of Hg were found in the sediments collected from the nearshore area at Sarnia, Ontario, in the St. Clair River in 1986. The concentrations of Hg ranged from 5.05 to 16.00 µg/g in different sand-sized fractions (0.063 to 0.350 mm) of the sediment. The concentration of Hg was 17.80 µg/g in the silt-clay size fraction (<0.063 mm). No relationship was found between the concentration of organic matter and Hg, and the concentration of silica and Hg in the St. Clair River sediments. The results indicated a relationship of Hg with particles of different mineralogical composition. Up to 3.72 µg/g Hg was found in the surface sediment in Chenal Ecarte. The greatest concentration of Hg (13.15 µg/g) existed in the 0.350 mm particle size fraction, which consisted mainly of small pieces of decaying wood. A good relationship was found between the concentration of Hg and organic matter in the sediment at this area.

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