Volcaniclastic rocks and volcaniclastic facies in the Middle Precambrian (Aphebian) Belcher Group, Northwest Territories, Canada

1982 ◽  
Vol 19 (6) ◽  
pp. 1275-1294 ◽  
Author(s):  
B. D. Ricketts ◽  
Michael J. Ware ◽  
J. Allan Donaldson
Keyword(s):  
Volcanic Rocks ◽  
Source Area ◽  
Early Growth ◽  
Rapid Quenching ◽  
Immature Stage ◽  
Island Arc ◽  
Growth Stages ◽  
Accretionary Lapilli ◽  
Volcaniclastic Rocks ◽  
Volcanic Facies

The Middle Precambrian Flaherty Formation consists of a thick sequence of volcanic rocks of both effusive and explosive origin, derived from a source area west of the Belcher Islands. The effusive volcanic facies are made up of thick, massive lava flows, some of which are compound, that are intercalated with thick lenticular units of pillowed lava. Facies of explosive origin, the volcaniclastic rocks, are a product of phreatic and phreatomagmatic eruptions. A variety of volcaniclastic facies are recognized on the basis of bed geometry, sedimentary structures, and textural characteristics, and include: thinly bedded tuffs and lapillistones that were deposited by fallout from vertical ash columns (some tuffs contain accretionary lapilli and hence originated from subaerial eruption columns); pillow talus deposits (hyaloclastites) resulting from the rapid quenching of lava in water; volcaniclastic turbidites representing relatively deep-water resedimented tephra; and a single massive pyroclastic flow that was emplaced during a single depositional event, and may have been derived from a Plinian eruption or series of Surtseyan eruptions. Systematic variations in these volcaniclastic facies, for example an increase in the proportion of turbidite units towards eastern Belcher Islands, indicate that water depth increased eastward.Based on physical volcanological aspects, the Flaherty Formation is compared with some modern and ancient analogues. The style of volcanism envisaged for the Flaherty is similar to that of Iceland, or possibly to an immature stage of island arc development. From a tectonic viewpoint, the comparison with Iceland is problematical because it is part of an oceanic regime, whereas the Flaherty Formation is more closely related to an ensialic regime. Direct comparison with an island arc also is difficult because little is known about volcanic facies relationships in the early growth stages of such arcs.

scholarly journals THE LOWER SILURIAN TERRIGENOUS DEPOSITS OF THE LAOELING-GRODEKOVO TERRANE (SOUTH PRIMORYE): MATERIAL COMPOSITION AND FORMATION SETTINGS

2021 ◽  
pp. 25-44
Author(s):  
A.I. Malinovsky ◽  
◽  
V.V. Golozubov ◽  
Keyword(s):  
Sedimentary Basin ◽  
Volcanic Rocks ◽  
Source Area ◽  
Island Arc ◽  
Material Composition ◽  
Recycling Rate ◽  
Composition Analysis ◽  
Rock Composition ◽  
South Primorye ◽  
Genetic Interpretation

This paper studies the original results of the material composition analysis of the Early Silurian terrigenous deposits of the Kordonka formation of the Paleozoic – Early Mesozoic Laoeling-Grodekovo terrane of the South Primorye. The research is aimed at reconstructing paleogeodynamic setting of the deposition of sediments of the formation, and determining the type and mother rock composition of the feed sources based on the complex genetic interpretation of the material composition of rocks. It was established that mineralogically and geochemically formation of the rocks correspond to the typical graywackes and represent petrogenic or “first cycle” rocks formed mainly through the source rock failure. They are characterized by a low maturity, low lithodynamic recycling rate of mother rocks and their rapid burial. The interpretation of the results of the complex study of the material composition of the rocks was carried out on the basis of its comparison with the compositions of ancient rocks and modern sediments formed in the well-known geodynamic settings. The obtained data indicate that deposits of the Kordonka formation accumulated in a sedimentary basin connected with an oceanic island arc. Being built by basic and intermediate volcanic rocks as well as by igneous and sedimentary rocks that constituted its base, this island arc was the source area that supplied clastic material to the aforementioned sedimentary basin.

Lithogeochemistry of volcano-plutonic assemblages of the southern Hanson Lake Block and southeastern Glennie Domain, Trans-Hudson Orogen: evidence for a single island arc complex

1999 ◽  
Vol 36 (2) ◽  
pp. 209-225 ◽  
Author(s):  
Ralf O Maxeiner ◽  
Tom II Sibbald ◽  
William L Slimmon ◽  
Larry M Heaman ◽  
Brian R Watters
Keyword(s):  
Volcanic Rocks ◽  
Volcanic Belt ◽  
Oceanic Island ◽  
Island Arc ◽  
Island Arcs ◽  
Calc Alkaline ◽  
East Central ◽  
South Central ◽  
Volcaniclastic Rocks ◽  
Flin Flon

This paper describes the geology, geochemistry, and age of two amphibolite facies volcano-plutonic assemblages in the southern Hanson Lake Block and southeastern Glennie Domain of the Paleoproterozoic Trans-Hudson Orogen of east-central Saskatchewan. The Hanson Lake assemblage comprises a mixed suite of subaqueous to subaerial dacitic to rhyolitic (ca. 1875 Ma) and intercalated minor mafic volcanic rocks, overlain by greywackes. Similarly with modern oceanic island arcs, the Hanson Lake assemblage shows evolution from primitive arc tholeiites to evolved calc-alkaline arc rocks. It is intruded by younger subvolcanic alkaline porphyries (ca. 1861 Ma), synvolcanic granitic plutons (ca. 1873 Ma), and the younger Hanson Lake Pluton (ca. 1844 Ma). Rocks of the Northern Lights assemblage are stratigraphically equivalent to the lower portion of the Hanson Lake assemblage and comprise tholeiitic arc pillowed mafic flows and felsic to intermediate volcaniclastic rocks and greywackes, which can be traced as far west as Wapawekka Lake in the south-central part of the Glennie Domain. The Hanson Lake volcanic belt, comprising the Northern Lights and Hanson Lake assemblages, shows strong lithological, geochemical, and geochronological similarities to lithotectonic assemblages of the Flin Flon Domain (Amisk Collage), suggesting that all of these areas may have been part of a more or less continuous island arc complex, extending from Snow Lake to Flin Flon, across the Sturgeon-Weir shear zone into the Hanson Lake Block and across the Tabbernor fault zone into the Glennie Domain.

scholarly journals Osmotic Stress or Ionic Composition: Which Affects the Early Growth of Crop Species More?

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 435
Author(s):  
Agnieszka Ludwiczak ◽  
Monika Osiak ◽  
Stefany Cárdenas-Pérez ◽  
Sandra Lubińska-Mielińska ◽  
Agnieszka Piernik
Keyword(s):  
Osmotic Stress ◽  
Stress Responses ◽  
Ionic Composition ◽  
Degradation Process ◽  
Early Growth ◽  
Cultivated Plants ◽  
C3 Plants ◽  
Growth Stages ◽  
Crop Species ◽  
Ionic Salt

Salinization is a key soil degradation process. An estimated 20% of total cultivated lands and 33% of irrigated agricultural lands worldwide are affected by high salinity. Much research has investigated the influence of salt (mainly NaCl) on plants, but very little is known about how this is related to natural salinity and osmotic stress. Therefore, our study was conducted to determine the osmotic and ionic salt stress responses of selected C3 and C4 cultivated plants. We focused on the early growth stages as those critical for plant development. We applied natural brine to simulate natural salinity and to compare its effect to NaCl solution. We assessed traits related to germination ability, seedlings and plantlet morphology, growth indexes, and biomass and water accumulation. Our results demonstrate that the effects of salinity on growth are strongest among plantlets. Salinity most affected water absorption in C3 plants (28% of total traits variation), but plant length in C4 plants (17–27%). Compensatory effect of ions from brine were suggested by the higher model plants’ growth success of ca 5–7% under brine compared to the NaCl condition. However, trait differences indicated that osmotic stress was the main stress factor affecting the studied plants.

scholarly journals Coastal Mangrove Response to Marine Erosion: Evaluating the Impacts of Spatial Distribution and Vegetation Growth in Bangkok Bay from 1987 to 2017

2020 ◽  
Vol 12 (2) ◽  
pp. 220 ◽  
Author(s):  
Han Xiao ◽  
Fenzhen Su ◽  
Dongjie Fu ◽  
Qi Wang ◽  
Chong Huang
Keyword(s):  
Spatial Distribution ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Mangrove Ecosystem ◽  
Early Growth ◽  
Growth Stages ◽  
Human Disturbances ◽  
Vegetation Growth ◽  
Two Parameters ◽  
The Impact

Long time-series monitoring of mangroves to marine erosion in the Bay of Bangkok, using Landsat data from 1987 to 2017, shows responses including landward retreat and seaward extension. Quantitative assessment of these responses with respect to spatial distribution and vegetation growth shows differing relationships depending on mangrove growth stage. Using transects perpendicular to the shoreline, we calculated the cross-shore mangrove extent (width) to represent spatial distribution, and the normalized difference vegetation index (NDVI) was used to represent vegetation growth. Correlations were then compared between mangrove seaside changes and the two parameters—mangrove width and NDVI—at yearly and 10-year scales. Both spatial distribution and vegetation growth display positive impacts on mangrove ecosystem stability: At early growth stages, mangrove stability is positively related to spatial distribution, whereas at mature growth the impact of vegetation growth is greater. Thus, we conclude that at early growth stages, planting width and area are more critical for stability, whereas for mature mangroves, management activities should focus on sustaining vegetation health and density. This study provides new rapid insights into monitoring and managing mangroves, based on analyses of parameters from historical satellite-derived information, which succinctly capture the net effect of complex environmental and human disturbances.

scholarly journals Effect of sodium silicate on early growth stages of wheat under drought stress

2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Sang Gyu Lee ◽  
Hyeri Lee ◽  
Byung Cheon Lee ◽  
Hojoung Lee ◽  
Jun Cheol Moon ◽  
...  
Keyword(s):  
Drought Stress ◽  
Sodium Silicate ◽  
Early Growth ◽  
Growth Stages
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