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| Main Authors: | , , |
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| Format: | Dataset Open Access |
| Language: | en |
| Published: |
PANGAEA
1998
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| Subjects: | |
| Online Access: | https://doi.org/10.1594/PANGAEA.438923 |
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| _version_ | 1867171611898019840 |
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| author | Passchier, Sandra Wilson, Terry Paulsen, Timothy S |
| author_facet | Passchier, Sandra Wilson, Terry Paulsen, Timothy S |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | CoreScan images were examined to determine the origin of breccias in the CRP-1 core. Breccias occur throughout the core. but are dominant deformation features in the upper 85 m. Breccia textures, boundaries and texture arrangements suggest that in situ fracturing and horizontal planar shearing are important deformation mechanisms in the upper part of the Miocene section. Forceful injections of silt and clay into fractures point to dewatering of overpressurised sediment. Breccias located below 55 metres below the sea floor (mbsf) occur associated with soft-sediment deformation, which is absent in younger intervals of the core. Deformation styles interpreted from the breccia textures, their downcore distribution, and the relations of breccias with sequence boundaries and lithologies, such as diamictites and graded beds, suggest brecciation occurred as a result of subglacial shearing and mass-movement processes. These mechanisms were also proposed for breccias and soft sediment deformation features observed in other McMurdo Sound cores. Subglacial shearing was a possible cause for the development of two thick brecciated intervals at ~44 and at ~79 mbsf, whereas slope failure and redeposition was probably the cause of brecciation below ~85 mbsf. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_438923 |
| institution | PANGAEA |
| language | en |
| publishDate | 1998 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Characterisation of breccias in sediment core CRP-1 (Table 1) Passchier, Sandra Wilson, Terry Paulsen, Timothy S 16 km ENE Cape Roberts; Boundary description; Cape Roberts Project; Core wireline system; CRP; CRP-1; CRP-1__Campaign; CWS; Deformation structure, type; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Description; Interpretation; Lithology/composition/facies; off Cape Roberts, Ross Sea, Antarctica; Sampling/drilling ice; Texture; Visual description CoreScan images were examined to determine the origin of breccias in the CRP-1 core. Breccias occur throughout the core. but are dominant deformation features in the upper 85 m. Breccia textures, boundaries and texture arrangements suggest that in situ fracturing and horizontal planar shearing are important deformation mechanisms in the upper part of the Miocene section. Forceful injections of silt and clay into fractures point to dewatering of overpressurised sediment. Breccias located below 55 metres below the sea floor (mbsf) occur associated with soft-sediment deformation, which is absent in younger intervals of the core. Deformation styles interpreted from the breccia textures, their downcore distribution, and the relations of breccias with sequence boundaries and lithologies, such as diamictites and graded beds, suggest brecciation occurred as a result of subglacial shearing and mass-movement processes. These mechanisms were also proposed for breccias and soft sediment deformation features observed in other McMurdo Sound cores. Subglacial shearing was a possible cause for the development of two thick brecciated intervals at ~44 and at ~79 mbsf, whereas slope failure and redeposition was probably the cause of brecciation below ~85 mbsf. |
| title | Characterisation of breccias in sediment core CRP-1 (Table 1) |
| topic | 16 km ENE Cape Roberts; Boundary description; Cape Roberts Project; Core wireline system; CRP; CRP-1; CRP-1__Campaign; CWS; Deformation structure, type; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Description; Interpretation; Lithology/composition/facies; off Cape Roberts, Ross Sea, Antarctica; Sampling/drilling ice; Texture; Visual description |
| url | https://doi.org/10.1594/PANGAEA.438923 |