Compositional heterogeneity of the continental mantle: Evidence from ultramafic xenoliths in cenozoic basalts from Northern Eurasia

2015 ◽  
Vol 15 (1) ◽  
pp. 1-13
Author(s):  
A. F. Grachev
Keyword(s):  
Northern Eurasia ◽  
Compositional Heterogeneity ◽  
Ultramafic Xenoliths

Mantle xenoliths from Tertiary lavas and dykes on Ubekendt Ejland, West Greenland

1998 ◽  
pp. 152-154
Author(s):  
Stefan Bernstein ◽  
C. Kent Brooks
Keyword(s):  
Field Work ◽  
Mantle Xenoliths ◽  
Alkaline Basalt ◽  
Basalt Flow ◽  
Volcanic Province ◽  
East Greenland ◽  
Original Series ◽  
West Greenland ◽  
Ultramafic Xenoliths ◽  
Extensive Collection

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Bernstein, S., & Brooks, C. K. (1998). Mantle xenoliths from Tertiary lavas and dykes on Ubekendt Ejland, West Greenland. Geology of Greenland Survey Bulletin, 180, 152-154. https://doi.org/10.34194/ggub.v180.5099 _______________ Mantle xenoliths were found in Tertiary alkaline (basanitic) lavas on Ubekendt Ejland in West Greenland in the mid 1970s by J.G. Larsen. Microprobe analyses of olivine, pyroxene and spinel in two mantle xenoliths, suggested that the xenoliths on Ubekendt Ejland are highly depleted and have high modal olivine contents, and low modal orthopyroxene and clinopyroxene (Larsen 1982). In this respect the mantle xenoliths from Ubekendt Ejland are very similar to the spinel harzburgites from Wiedemann Fjord, in the Tertiary volcanic province of East Greenland (Brooks & Rucklidge 1973; Bernstein et al. 1998). Larsen (1981) also reported dykes containing mantle nodules and a varied suite of cumulates and megacrysts, one of which has subsequently been dated to 34.1 ± 0.2 Ma (Storey et al. 1998) The basalt flow that carries the xenoliths is from what is defined as the Erqua Formation which occurs at the top of the lava succession in western Ubekendt Ejland (Fig. 1; Drever & Game 1948; Larsen 1977a, b). The basalts have not been dated, but are younger than 52.5 Ma, which is the date obtained for the underlying formation (Storey et al. 1998). During July 1997, we spent three weeks collecting xenoliths and prospecting for xenolith-bearing dykes in the Uummannaq district of central West Greenland. The field work resulted in an extensive collection of xenoliths from an alkaline basalt flow described by Larsen (1977a, b), as well as the discovery of a dyke carrying a large number of ultramafic xenoliths of various origins. 

V International symposium 'Steppes of Northern Eurasia'

2010 ◽  
Vol 2 (2) ◽  
pp. 1-7
Author(s):  
A. A. Chibilev ◽  
A. G. Ryabukha
Keyword(s):  
International Symposium ◽  
Northern Eurasia

COMPOSITIONAL HETEROGENEITY OF THE JOSEPHINE MOUNTAIN INTRUSION

2020 ◽  
Author(s):  
Patrick B. Oliver ◽  
◽  
Zachary Levenson ◽  
Roger L. Putnam
Keyword(s):  
Compositional Heterogeneity

Devonian Radiolarian Ecozones of Northern Eurasia

2020 ◽  
Vol 54 (9) ◽  
pp. 947-1093
Author(s):  
M. S. Afanasieva
Keyword(s):  
Northern Eurasia

Legumes of Northern Eurasia. A Checklist

Kew Bulletin ◽  
1996 ◽  
Vol 51 (3) ◽  
pp. 622
Author(s):  
Brian Schrire ◽  
G. P. Yakovlev ◽  
A. K. Sytin ◽  
Yu. R. Roskov
Keyword(s):  
Northern Eurasia

scholarly journals Unraveling the compositional heterogeneity and carrier dynamics of alkali cation doped 3D/2D perovskites with improved stability

2021 ◽  
Author(s):  
Ming-Chun Tang ◽  
Siyuan Zhang ◽  
Timothy J. Magnanelli ◽  
Nhan V. Nguyen ◽  
Edwin J. Heilweil ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Comprehensive Analysis ◽  
Carrier Dynamics ◽  
Alkali Cation ◽  
Compositional Heterogeneity ◽  
Improved Stability

A comprehensive analysis of the compositional heterogeneity and carrier dynamics in novel rubidium-doped 3D/2D perovskites is investigated, showing a PCE over 20% and improved stability at ≈50% relative humidity without encapsulation.

scholarly journals Anthropogenic climate change has changed frequency of past flood during 2010-2013

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yukiko Hirabayashi ◽  
Haireti Alifu ◽  
Dai Yamazaki ◽  
Yukiko Imada ◽  
Hideo Shiogama ◽  
...  
Keyword(s):  
Climate Change ◽  
South America ◽  
Radiative Forcing ◽  
Water Cycle ◽  
Flood Frequency ◽  
Anthropogenic Climate Change ◽  
Climate Change Signal ◽  
Northern Eurasia ◽  
Large Ensemble ◽  
The Impact

AbstractThe ongoing increases in anthropogenic radiative forcing have changed the global water cycle and are expected to lead to more intense precipitation extremes and associated floods. However, given the limitations of observations and model simulations, evidence of the impact of anthropogenic climate change on past extreme river discharge is scarce. Here, a large ensemble numerical simulation revealed that 64% (14 of 22 events) of floods analyzed during 2010-2013 were affected by anthropogenic climate change. Four flood events in Asia, Europe, and South America were enhanced within the 90% likelihood range. Of eight snow-induced floods analyzed, three were enhanced and four events were suppressed, indicating that the effects of climate change are more likely to be seen in the snow-induced floods. A global-scale analysis of flood frequency revealed that anthropogenic climate change enhanced the occurrence of floods during 2010-2013 in wide area of northern Eurasia, part of northwestern India, and central Africa, while suppressing the occurrence of floods in part of northeastern Eurasia, southern Africa, central to eastern North America and South America. Since the changes in the occurrence of flooding are the results of several hydrological processes, such as snow melt and changes in seasonal and extreme precipitation, and because a climate change signal is often not detectable from limited observation records, large ensemble discharge simulation provides insights into anthropogenic effects on past fluvial floods.

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