scholarly journals Magneto‐chemical signature of the Lower‐to‐Middle Siwaliks transition in the Karnali River section (Western Nepal): Implications for Himalayan tectonics and climate

2019 ◽  
Vol 55 (7) ◽  
pp. 4891-4904
Author(s):  
Pitambar Gautam ◽  
Pascale Huyghe ◽  
Jean‐Louis Mugnier ◽  
Kamal R. Regmi
Keyword(s):  
River Section ◽  
Chemical Signature ◽  
Himalayan Tectonics

scholarly journals Sedimentary facies analysis of the fluvial systems in the Siwalik Group, Karnali River section, Nepal Himalaya, and their significance for understanding the paleoclimate and Himalayan tectonics

2016 ◽  
Vol 51 ◽  
pp. 11-26 ◽  
Author(s):  
Ashok Sigdel ◽  
Tetsuya Sakai
Keyword(s):  
River System ◽  
Precipitation Pattern ◽  
Braided River ◽  
River Section ◽  
Meandering River ◽  
Braided Rivers ◽  
Facies Associations ◽  
Siwalik Group ◽  
Himalayan Tectonics ◽  
Flood Flow

Fluvial sediments of the Siwalik successions in the Himalayan Foreland Basin are one of the most important continental archives for the history of Himalayan tectonics and climate change during the Miocene Period. This study reanalyzes the fluvial facies of the Siwalik Group along the Karnali River, where the large paleo-Karnali River system is presumed to have flowed. The reinterpreted fluvial system comprises fine-grained meandering river (FA1), flood-flow dominated meandering river with intermittent appearance of braided rivers (FA2), deep and shallow sandy braided rivers (FA3, FA4) to gravelly braided river (FA5) and finally debris-flow dominated braided river (FA6) facies associations, in ascending order. Previous work identified sandy flood-flow dominated meandering and anastomosed systems, but this study reinterprets these systems as a flood-flow dominated meandering river system with intermittent appearance of braided rivers, and a shallow sandy braided system, respectively. The order of the appearance of fluvial depositional systems in the Karnali River section is similar to those of other Siwalik sections, but the timing of the fluvial facies changes differs. The earlier appearance (3-4 Ma) of the flood-flow dominated meandering river system in the Karnali River section at about 13.5 Ma may have been due to early uplift of the larger catchment size of the paleo-Karnali River which may have changed the precipitation pattern i.e. intensification of the Indian Summer Monsoon. The change from a meandering river system to a braided river system is also recorded 1 to 3 Ma earlier than in other Siwalik sections in Nepal. Differential and diachronous activities of the thrust systems could be linked to change in catchment area as well as diachronous uplift and climate, the combination of which are major probable causes of this diachronity.

Phytoepiphyton of the Main Riverbed of the River Section of the Kanev Reservoir

2017 ◽  
Vol 53 (6) ◽  
pp. 26-36 ◽  
Author(s):  
P. D. Klochenko ◽  
T. F. Shevchenko ◽  
O. S. Tarashchuk
Keyword(s):  
River Section

Seasonal and Interannual Dynamics of Phytoplankton, Phytomicroepiphyton, and Nutrients Content in the River Section of the Kanev Reservoir

2016 ◽  
Vol 52 (1) ◽  
pp. 49-61 ◽  
Author(s):  
V. I. Shcherbak ◽  
V. M. Yakushin ◽  
A. M. Zadorozhnaya ◽  
N. Ye. Semenyuk ◽  
M. I. Linchuk
Keyword(s):  
River Section ◽  
Seasonal And Interannual Dynamics ◽  
Interannual Dynamics

Light- or Dark-Colored, L-DOPA-Based Melanins

2018 ◽  
Author(s):  
Koen Vercruysse ◽  
Margaret M. Whalen
Keyword(s):  
Human Physiology ◽  
Ir Spectra ◽  
Immune Cells ◽  
Chemical Properties ◽  
Chemical Signature ◽  
Ft Ir

<p>This report is a continuation of previous research on the H<sub>2</sub>O<sub>2</sub>-mediated synthesis of melanin-like pigments. We synthesized and characterized L-DOPA-based pigments using air- or H<sub>2</sub>O<sub>2</sub>-mediated<sub> </sub>oxidation. We compared their physic-chemical properties and evaluated their capacity to affect the interleukin release from immune cells. The use of higher concentrations of H<sub>2</sub>O<sub>2</sub> resulted in melanin-like materials with a distinct chemical signature in their FT-IR spectra and a lighter color. All pigments enhanced the interleukin release from immune cells. The possibility that lighter-colored melanins can be generated is discussed in the context of the importance of melanin-based pigmentation in human physiology.</p>

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