Enhancement of volcanic eruption in mid-ocean ridge during the last deglaciation: New sedimentary evidence in the middle part of Central Indian Ridge

2021 ◽  
pp. 106574
Author(s):  
Dhongil Lim ◽  
Jihun Kim ◽  
Jonguk Kim ◽  
Dongsung Kim ◽  
Dohyun Jeong ◽  
...  
Keyword(s):  
Volcanic Eruption ◽  
Middle Part ◽  
Last Deglaciation ◽  
Central Indian Ridge ◽  
Mid Ocean Ridge ◽  
The Last Deglaciation ◽  
Indian Ridge ◽  
Ocean Ridge

Investigation into the influence of the Réunion plume on the Central Indian Ridge

2020 ◽  
Author(s):  
Clément Vincent ◽  
Jung-Woo Park ◽  
Sang-Mook Lee ◽  
Jonguk Kim ◽  
Sang-Joon Pak
Keyword(s):  
High Resolution ◽  
Leading Edge ◽  
Middle Part ◽  
Geochemical Data ◽  
Long Distance ◽  
Transform Faults ◽  
Central Indian Ridge ◽  
Mid Ocean Ridge ◽  
Indian Ridge ◽  
Ocean Ridge

<p>Plume-ridge interaction is an important thermal and geological process, which results in various physical and chemical anomalies along a significant length of the global mid-ocean ridge system. Despite numerous studies, some remaining questions to be solved are the origin and mechanisms of geochemical variations and their possible correlation with the morphology of mid-ocean ridges.</p><p>The Central Indian Ridge, with a slow to intermediate spreading rate, provides an ideal opportunity to explore the long-distance plume-ridge interactions. Presently, the ridge is moving away from the Réunion hotspot which is located 1000 km away from the Central Indian Ridge at Réunion Island. Paleogeographic reconstruction suggests that the hotspot crossed the middle part of the Central Indian Ridge (MCIR) between 8°S and 17°S at ~34 Ma. Previous studies argue that the plume material currently flows into the Central Indian Ridge at around 19°S, south of Marie Celeste Fracture Zone (MCFZ) and geochemical enrichments of the mid-ocean ridge basalts (MORB) from the MCIR 14°S and 19°S segments can be attributed to a fossil Réunion plume component. However, a recent geophysical study has suggested that the geochemical anomalies along the Rodrigues segment (18-21°S) can be ascribed to the asthenospheric flow from the Réunion plume, reopening the debate about the origin of the enriched anomalies along the MCIR (14-19°S).</p><p>In this study, we revisited the MCIR from 14°S to 17°S with new geochemical data obtained based on high-resolution sampling and ship-board high-resolution bathymetry data to constrain the influence of the Réunion plume on geochemistry and bathymetry of the MCIR. The results show that trace element ratios and isotopic compositions of on-axis MORB vary in association with ridge discontinuities such as transform faults and non-transform fault discontinuities. The MORB from the northern parts of segments display substantially enriched geochemical features and the enrichments correspond to a shallower axial bathymetry. We attribute the chemical and morphological anomalies along the ridge to the influence of a Réunion plume component focussed by a hotspot leading edge effect. The hotspot leading segments are offset in the direction of the plume and are more efficiently affected by the enriched plume materials. These findings suggest that lithospheric discontinuities such as transform faults and fracture zones may control the flow of mantle plume material into the ridge and the geometry of the ridge coupled to its hotspot proximity may play an important role, particularly in the long-distance plume-ridge interaction.</p>

scholarly journals Mantle heterogeneity in the source region of mid-ocean ridge basalts along the northern Central Indian Ridge (8°S-17°S)

2017 ◽  
Vol 18 (4) ◽  
pp. 1419-1434 ◽  
Author(s):  
Jonguk Kim ◽  
Sang-Joon Pak ◽  
Jai-Woon Moon ◽  
Sang-Mook Lee ◽  
Jihye Oh ◽  
...  
Keyword(s):  
Source Region ◽  
Mantle Heterogeneity ◽  
Central Indian Ridge ◽  
Mid Ocean Ridge ◽  
Indian Ridge ◽  
Ocean Ridge

scholarly journals Petrology and Geochemistry of Mid-Ocean Ridge Basalts from the Southern Central Indian Ridge

2014 ◽  
pp. 163-175
Author(s):  
Hiroshi Sato ◽  
Kentaro Nakamura ◽  
Hidenori Kumagai ◽  
Ryoko Senda ◽  
Tomoaki Morishita ◽  
...  
Keyword(s):  
Central Indian Ridge ◽  
Mid Ocean Ridge ◽  
Southern Central ◽  
Petrology And Geochemistry ◽  
Indian Ridge ◽  
Ocean Ridge

Trace Element and Isotopic Evidence for Recycled Lithosphere from Basalts from 48 to 53°E, Southwest Indian Ridge

2020 ◽  
Author(s):  
Jixin Wang ◽  
Huaiyang Zhou ◽  
Vincent J M Salters ◽  
Henry J B Dick ◽  
Jared J Standish ◽  
...  
Keyword(s):  
Trace Element ◽  
Southwest Indian Ridge ◽  
Isotopic Compositions ◽  
Depleted Mantle ◽  
Bone Segment ◽  
Mid Ocean Ridge ◽  
Mantle Component ◽  
Indian Ridge ◽  
Basalt Glasses ◽  
Ocean Ridge

Abstract Mantle source heterogeneity and magmatic processes have been widely studied beneath most parts of the Southwest Indian Ridge (SWIR). But less is known from the newly recovered mid-ocean ridge basalts from the Dragon Bone Amagmatic Segment (53°E, SWIR) and the adjacent magmatically robust Dragon Flag Segment. Fresh basalt glasses from the Dragon Bone Segment are clearly more enriched in isotopic composition than the adjacent Dragon Flag basalts, but the trace element ratios of the Dragon Flag basalts are more extreme compared with average mid-ocean ridge basalts (MORB) than the Dragon Bone basalts. Their geochemical differences can be explained only by source differences rather than by variations in degree of melting of a roughly similar source. The Dragon Flag basalts are influenced by an arc-like mantle component as evidenced by enrichment in fluid-mobile over fluid-immobile elements. However, the sub-ridge mantle at the Dragon Flag Segment is depleted in melt component compared with a normal MORB source owing to previous melting in the subarc. This fluid-metasomatized, subarc depleted mantle is entrained beneath the Dragon Flag Segment. In comparison, for the Dragon Bone axial basalts, their Pb isotopic compositions and their slight enrichment in Ba, Nb, Ta, K, La, Sr and Zr and depletion in Pb and Ti concentrations show resemblance to the Ejeda–Bekily dikes of Madagascar. Also, Dragon Bone Sr and Nd isotopic compositions together with the Ce/Pb, La/Nb and La/Th ratios can be modeled by mixing the most isotopically depleted Dragon Flag basalts with a composition within the range of the Ejeda–Bekily dikes. It is therefore proposed that the Dragon Bone axial basalts, similar to the Ejeda–Bekily dikes, are sourced from subcontinental lithospheric Archean mantle beneath Gondwana, pulled from beneath the Madagascar Plateau. The recycling of the residual subarc mantle and the subcontinental lithospheric mantle could be related to either the breakup of Gondwana or the formation and accretion of Neoproterozoic island arc terranes during the collapse of the Mozambique Ocean, and is now present beneath the ridge.

scholarly journals Landscape Dynamics in the Caspian Lowlands Since the Last Deglaciation Reconstructed From the Pedosedimentary Sequence of Srednaya Akhtuba, Southern Russia

Geosciences ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 492 ◽  
Author(s):  
Marina Lebedeva ◽  
Alexander Makeev ◽  
Alexey Rusakov ◽  
Tatiana Romanis ◽  
Tamara Yanina ◽  
...  
Keyword(s):  
Clay Mineralogy ◽  
Fine Sand ◽  
Middle Part ◽  
Source Material ◽  
Last Deglaciation ◽  
Soil Horizons ◽  
Aeolian Transport ◽  
Southern Russia ◽  
Buried Soil ◽  
The Last Deglaciation

Surface Kastanozem of the Lower Volga area was first studied as a part of the pedocomplex, with the lower part (148–160 cm) formed in Early Khvalynian Chocolate clays (13–15 ka), the middle part (100–148 cm) in a mixed clay-loess sediment sand, and the upper part (0–100 cm) in loess. This resulted from local aeolian transport, with the source material derived from the rewinding of marine sediments. They are enriched in aggregates of Chocolate clays and glauconitic grains of a fine sand-course silt size and have similar contents of clay minerals. The high salinity of similar types evidences marine genesis for both Chocolate clays and source material for loess sediments. Clay fragments of a sand and silt size are responsible for the heavy texture and high gypsum content of loess. The study of soils with the focus on micromorphology and clay mineralogy allows the identification of the complex character of a shift from marine to sub-areal sedimentation. This shift was accompanied by short breaks in sedimentation, allowing the development of synlithogenic soil horizons of Late Khvalynian, after-Khvanynian, and Boreal time. The features of shallowly buried soil horizons confirm increased aridity after the last deglaciation. Surface Calcic Kastanozem is a full Holocene soil reflecting the present environment. However, it is deeply influenced by shallow buried soil horizons and Chocolate clays.

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