Deformational structures associated with gravitational block gliding; examples from sedimentary olistoliths in the Kalvag Melange, western Norway

Steen, Øyvind; Andresen, Arild

doi:10.2475/ajs.297.1.56

Cited by 14 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5b) giving rise to a chocolate tablet structure in plan view. Similar three-dimensional block shapes have been described in block-inmatrix units and interpreted as broken formations during slumping by Steen and Andresen (1997) and Alonso et al (2006). A weak cleavage developed in the shale matrix, which resembles what some authors have called scaly cleavage in other block-in-matrix formations (Pini, 1999;Vannucchi et al, 2003).…”

Section: Structure Of the Western Precordillerasupporting

confidence: 72%

Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera

et al. 2008

View full text Add to dashboard Cite

The paper describes ubiquitous extensional structures developed in a passive margin of Ordovician age in the Argentine Precordillera. These extensional structures include normal faults and boudinaged sequences. In some places the boudinage reaches very high extension values, giving rise to block-in-matrix formations. Most of these extensional structures developed when sediments were not well lithified, as recorded by hydroplastic fractures, slump folds and pinch-and-swell structures. The presence of slump folds coeval with the extensional deformation, the variable extension directions obtained from the kinematic analysis and a weak cleavage recording layer-perpendicular shortening support the interpretation that gravitational collapse related to submarine sliding was the cause for extensional deformation. Well-consolidated rocks, located at the lower part of the stratigraphic sequence, also display scarce extensional faults. These extensional faults predate folding because they were breached by flexural-slip faults and, as a result of their passive rotation in fold limbs, these initial normal faults may now appear as reverse faults, particularly in steep and overturned limbs. The truncation of extensional faults by flexural-slip faults produces typical bed thickness changes across the extensional faults, giving rise to apparent synsedimentary faults. These normal faults can be attributed to the crustal extension that generated the passive continental margin or may represent deep parts of faults related to gravitational collapse.

show abstract

Section: Structure Of the Western Precordillerasupporting

confidence: 72%

Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Most giant submarine landslides have been described from the Recent on the basis of bathymetric and geophysical data (e.g. Collot et al, 2001;Huvenne et al, 2002;Ha£idason et al, 2004Ha£idason et al, , 2005Frey-Mart|¤ nez etal., 2005 but ancient examples of such phenomena are scarce (Martinsen & Bakken, 1990;Steen & Andresen, 1997;Payros et al, 1999;Graziano, 2001;Floquet & Hennuy, 2003;Lucente & Pini, 2003;Vernhet et al, 2006;Sp˛rli & Rowland, 2007) and their anatomy has been rarely described at scales 4100 km. This paper deals with the Ayabacas Formation of southern Peru, an interesting rock unit that has received a puzzling variety of interpretations.…”

Section: Introductionmentioning

confidence: 99%

Giant submarine collapse of a carbonate platform at the Turonian–Coniacian transition: The Ayabacas Formation, southern Peru

et al. 2008

View full text Add to dashboard Cite

The Ayabacas Formation of southern Peru is an impressive unit formed by the giant submarine collapse of the mid‐Cretaceous carbonate platform of the western Peru back‐arc basin (WPBAB), near the Turonian–Coniacian transition (∼90–89 Ma). It extends along the southwestern edge of the Cordillera Oriental and throughout the Altiplano and Cordillera Occidental over >80 000 km2 in map view, and represents a volume of displaced sediments of >10 000 km3. The collapse occurred down the basin slope, i.e. toward the SW. Six zones are characterised on the basis of deformational facies, and a seventh corresponds to the northeastern ‘stable’ area (Zone 0). Zones 1–3 display increasing fragmentation from NE to SW, and are composed of limestone rafts and sheets embedded in a matrix of mainly red, partly calcareous and locally sandy, mudstones to siltstones. In contrast, in Zones 4 and 5 the unit consists only of displaced and stacked limestone masses forming a ‘sedimentary thrust and fold system’, with sizes increasing to the southwest. In Zone 6, the upper part of the limestone succession consists of rafts and sheets stacked over the regularly bedded lower part. The triggering of this extremely large mass wasting clearly ensued from slope creation, oversteepening and seismicity produced by extensional tectonic activity, as demonstrated by the observation of synsedimentary normal faults and related thickness variations. Other factors, such as pore pressure increases or lithification contrasts probably facilitated sliding. The key role of tectonics is strengthened by the specific relationships between the basin and collapse histories and two major fault systems that cross the study area. The Ayabacas collapse occurred at a turning point in the Central Andean evolution. Before the event, the back‐arc basin had been essentially marine and deepened to the west, with little volcanic activity taking place at the arc. After the event, the back‐arc was occupied by continental to near‐continental environments, and was bounded to the southwest by a massive volcanic arc shedding debris and tuffs into the basin.

show abstract

“…Location shown in figure 5. duplex system Steen and Andresen (1997). described such kinds of structures in slump-deformed olistoliths of the Kalvag mélange.…”

mentioning

confidence: 99%

Anatomy and emplacement mechanism of a large submarine slide within a Miocene foredeep in the northern Apennines, Italy: A field perspective

Lucente¹

2003

American Journal of Science

149

158

View full text Add to dashboard Cite

The Casaglia Monte della Colonna (CMC) body, from the middle Miocene Marnoso-arenacea Formation of the Northern Apennines, covering more than 350 square kilometers, provides a rare opportunity to study the geometry and the internal deformation of a large, basin-wide submarine landslide. Although the head zone of the landslide has not been preserved, the body has a transitional zone, a contractional ramp cutting off more than 200 meters of the footwall stratigraphic succession, and a very wide lobe spilling over onto. the adjoining basin plain deposits. The extent of the body, the depth of the ramp cut-off and the widening of the lobe are comparable with the largest present-day submarine landslides, not often observed in fossil examples. Internal deformation structures are distributed differently in the ramp and lobe zones. The ramp zone has antiformal stacking of duplexes and steeply inclined folds. The lobe has a well-defined strain partition: the upper part of the body is affected by extensional structures such as listric normal faults and extensional duplexes; the lower part is de formed by recumbent folds, boudinage and stacking of blocks, which are compatible with flow-induced, heterogeneous simple shear. This distribution is consistent with a kinematic model of extrusion-spreading, implying rear compression in the ramp zone with thickening and shortening of the body, and spreading in the lobe with thinning and stretching. The localized buckling present in the distal part of the lobe may be related to the onset of lateral confinement,, due to local topographic features of the basin plain (synsedimentary intrabasinal high). The various degrees and styles of stratal disruption in the mass wasting body depend on the different combination of progressive simple shear, layer-parallel extension and shortening. Different structural associations occur in well-defined parts of the body due to kinematics of emplacement (spreading, flow and buckling). These associations may be diagnostic of. gravitational mass wasting processes rather than shallow-level tectonic deformation

show abstract

Deformational structures associated with gravitational block gliding; examples from sedimentary olistoliths in the Kalvag Melange, western Norway

Cited by 14 publications

References 0 publications

Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera

Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera

Giant submarine collapse of a carbonate platform at the Turonian–Coniacian transition: The Ayabacas Formation, southern Peru

Anatomy and emplacement mechanism of a large submarine slide within a Miocene foredeep in the northern Apennines, Italy: A field perspective

Contact Info

Product

Resources

About