The formation of passive margins: constraints from the crustal structure and segmentation of the deep Galicia margin, Spain

Boillot, G.; Beslier, Marie‐Odile; Krawczyk, Charlotte M.; Rappin, Didier; Reston, T. J.

doi:10.1144/gsl.sp.1995.090.01.04

Cited by 51 publications

(41 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It also agrees with late Kimmeridgian (prerift) extensional faulting documented on the western and southern Galicia Bank [Clark et al, 2007] (Figure 14). This latter extensional episode preceded Berramian (S4) continental breakup at N40°15 0 (segment 3) [Whitmarsh and Miles, 1995], $10 Ma before late Aptian breakup in segment 4 where a stretching maximum is recorded during the Valanginian [Groupe Galice, 1979;Murillas et al, 1990;Boillot et al, 1995] (Figures 14 and 15). Therefore, extension during the advanced rifting stage is interpreted to have occurred before the Valanginian in segments 2 and 3, thus correlating synrift successions on the outer proximal margin west of the Lusitanian Basin with equivalent synrift strata in the Jeanne D'Arc Basin [e.g., Sinclair, 1995].…”

Section: Stratigraphic Markers In Inner Proximal Basinsmentioning

confidence: 93%

“…Although it explains the greater thickness of synrift strata in outer proximal basins, this interpretation is incompatible with the age difference between the deposition of synrift strata in inner proximal basins (Oxfordian-Kimmeridgian in the Lusitanian and Porto basins [Alves et al, 2003b;C. Moita et al, Porto Basin: Seismic interpretation report, unpublished report, MILUPOBAS project, 1996]) and synrift units in outer proximal basins in segment 4, interpreted to span the late Berriasian -late Aptian [Boillot et al, 1995;Wilson et al, 2001]. Also, it does not fit with seismic reflection and well data from the entire west Iberian margin, in which a clear stratigraphic boundary separates prerift strata from synrift units on the outer proximal margin, i.e., dividing units deposited during the early rifting stage from strata accumulated in the advanced rifting stage [e.g., Groupe Galice, 1979;Boillot et al, 1989;Pinheiro et al, 1996] (Figure 5).…”

Section: Subsidence On the Outer Proximal Marginmentioning

confidence: 99%

See 1 more Smart Citation

Diachronous evolution of Late Jurassic–Cretaceous continental rifting in the northeast Atlantic (west Iberian margin)

et al. 2009

View full text Add to dashboard Cite

Regional (2‐D) seismic reflection profiles, outcrop, and borehole data are used to characterize the evolution of deep offshore sedimentary basins in southwest Iberia (Alentejo Basin). The interpreted data indicate the bulk of Late Jurassic–earliest Cretaceous subsidence occurred in the present‐day continental slope area, as shown by (1) significant thickening of synrift strata basinward from a slope‐bounding fault system (SFS), west of which the total thickness of sediment can reach more than 9.0 km, and (2) relatively thin Mesozoic strata east of the SFS, where thickening of synrift units against principal faults is limited. Five principal regressive events and their basal unconformities reflect tectonic uplift and relative emersion in proximal basins, which were located on the rift shoulder to subsiding tilt blocks west of the SFS. These regressive events are correlated with major rift‐related events occurring on the deeper margin. Direct comparisons with the Peniche Basin of northwest Iberia reveal that significant portions of the Iberian lower plate margin were uplifted and eroded during the last stages of continental rifting. This process was repeated at different times (and in different areas) as the locus of rifting and continental breakup migrated northward. As a result, two distinct rift axes are recognized in west Iberia, a first axis extending from the Porto Basin to the Alentejo Basin and a second axis located on the outer proximal margin north of 38°30N. In addition, the SFS delimited (1) prograding deposits of Cretaceous‐Paleogene age and (2) late Cenozoic deposits draping the modern continental slope. These latter facts demonstrate that on lower plate passive margins, the relative position of the continental slope is established during the final rifting episode(s) preceding continental breakup.

show abstract

Section: Stratigraphic Markers In Inner Proximal Basinsmentioning

confidence: 93%

Section: Subsidence On the Outer Proximal Marginmentioning

confidence: 99%

Diachronous evolution of Late Jurassic–Cretaceous continental rifting in the northeast Atlantic (west Iberian margin)

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The eastern Arabian Sea presents an intriguing case for the study of continental breakup between India and Madagascar, differing in important ways from both the classic nonvolcanic IberiaNewfoundland conjugate (Boillot et al, 1995;Whitmarsh et al, 2001) and the volcanic Norway-Greenland margin (Skogseid et al, 2000;Hopper et al, 2003). The northern Arabian Sea is characterized by the presence of large structural blocks located between the western continental shelf of India and the deep seafloor of the Arabian Basin.…”

Section: Background Geological Settingmentioning

confidence: 99%

Untitled

Pandey

Clift

Kulhanek

et al. 2015

International Ocean Discovery Program Preliminary Report

View full text Add to dashboard Cite

The Indian (southwest) summer monsoon is one of the most intense climatic phenomena on Earth. Its long-term development has been linked to the growth of high topography in South and Central Asia. The Indian continental margin, adjoining the Arabian Sea, offers a unique opportunity to investigate tectonic-climatic interactions and the net impact of these processes on weathering and erosion of the western Himalaya. During International Ocean Discovery Program Expedition 355, two sites (U1456 and U1457) were drilled in Laxmi Basin in the eastern Arabian Sea to document the coevolution of mountain building, weathering, erosion, and climate over a range of timescales. In addition, recovering basement from the eastern Arabian Sea provides constraints on the early rifting history of the western continental margin of India with special emphasis on continental breakup between India and the Seychelles and its relationship to the plume-related volcanism of the Deccan Plateau.Drilling and coring operations during Expedition 355 recovered sediment from Sites U1456 and U1457 in the Laxmi Basin, penetrating 1109.4 and 1108.6 m below seafloor (mbsf ), respectively. Drilling reached sediment dated to 13.5-17.7 Ma (late early to early middle Miocene) at Site U1456, although with a large hiatus between the lowermost sediment and overlying deposits dated to <10.9 Ma. At Site U1457, a much longer hiatus occurs near the base of the cored section, spanning from 10.9 to ~62 Ma. At both sites, hiatuses span ~8.2-9.2 and ~3.6-5.6 Ma, with a possible condensed section spanning ~2.0-2.6 Ma, although the total duration for each hiatus is slightly different between the two sites.A major submarine fan draining the western Himalaya and Karakoram must have been supplying sediment to the eastern Arabian Sea since at least ~17 Ma. Sand mineral assemblages indicate that the Greater Himalayan Crystalline Sequence was fully exposed to the surface by this time. Most of the recovered sediment appears to be derived from the Indus River and includes minerals that are unique to the Indus Suture Zone, in particular glaucophane and hypersthene, most likely originating from the structural base of the Kohistan arc. Pliocene sandy intervals at Site U1456 were deposited in lower fan "sheet lobe" settings, with intervals of basin plain turbidites separated by hemipelagic muddy sections deposited during the Miocene. Site U1457 is more distal in facies, reflecting its more marginal setting. No major active lobe appears to have affected the Laxmi Basin since the Middle Pleistocene (~1.2 Ma).We succeeded in recovering sections spanning the 8 Ma climatic transition, when monsoon intensity is believed to have changed strongly, although the nature of this change awaits postcruise analysis. We also recovered sediment from a large mass transport deposit measuring ~330 and ~190 m thick at Sites U1456 and U1457, respectively. This section includes an upper sequence of slump-folded muddy and silty rocks, as well as underlying calcarenites and limestone breccias, to...

show abstract

“…In many cases, these systems, when subparallel to the extension direction, have been interpreted as transfer faults of the normal faults, such as at the North Sea [Gibbs, 1984], the Atlantic margin of Brazil [Milani and Davison, 1988], of Newark [Schlische, 1992], Galicia [Boillot et al, 1995], West Africa [Clemson et al, 1997;Watts and Stewart, 1998], Norway [Dorè et al, 1997;Tsikalas et al, 2001], the Suez Rift [McClay and Khalil, 1998], the Basin and Range [Martin et al, 1993;Duebendorfer and Black, 1992], and the East African Rift System [Rosendahl, 1987;Faulds and Varga, 1998]. In other cases, three-dimensional strain [Reches, 1978;Krantz, 1989] and viscosity or density instabilities [Watterson et al, 2000] have been proposed to explain the development of transverse faults under a constant extensional regime.…”

Section: Introductionmentioning

confidence: 99%

Transverse systems along the extensional Tyrrhenian margin of central Italy and their influence on volcanism

2006

View full text Add to dashboard Cite

[1] The Tyrrhenian margin of central Italy has undergone Plio-Quaternary extension, developing NW-SE normal faults and NE-SW faults. The NE-SW faults decrease in frequency toward NE with the stretching factor b, becoming negligible for b < 1.3. Plio-Quaternary volcanoes, aligned NW-SE, formed at the intersection among NE-SW and NW-SE faults; fissure eruptions are mostly controlled by NE-SW faults. Structural field data show normal motions for 76% of NW-SE Quaternary faults and transtensive for 73% of NE-SW Quaternary faults. Analogue experiments simulating the NE-SW Tyrrhenian extension show that transverse transtensive faults form with differential extension Db > 0.21. These data suggest that the NE-SW transtensive structures are transfer faults of the NW-SE normal faults due to relevant differential extension (Db > 0.21) within a stretched crust (b > 1.3). The minor dip-slip and strikeslip components of the NE-SW and NW-SE faults, respectively, possibly result from the NW-SE extension due to the southeastward slab retreat beneath the Calabrian arc. The NE-SW and NW-SE extensions in the central southern Tyrrhenian Sea account for the composite kinematics of the NE-SW structures, which, in turn, exert a twofold role in controlling volcanism. Where their dip-slip component forms basins, the associated decompression induces magma accumulation (developing central volcanoes) at the intersection among NW-SE and NE-SW systems. Where transfer faults are mainly strike slip, their inferred subvertical attitude enhances their permeability to magma, accounting for the observed NE-SW fissure eruptions. Regional extension, forming NW-SE faults, enhances the overall generation and rise of magma along the margin, but NE-SW structures focus magma rise and emplacement at shallower levels. Citation: Acocella, V., and R.

show abstract

The formation of passive margins: constraints from the crustal structure and segmentation of the deep Galicia margin, Spain

Cited by 51 publications

References 39 publications

Diachronous evolution of Late Jurassic–Cretaceous continental rifting in the northeast Atlantic (west Iberian margin)

Diachronous evolution of Late Jurassic–Cretaceous continental rifting in the northeast Atlantic (west Iberian margin)

Untitled

Transverse systems along the extensional Tyrrhenian margin of central Italy and their influence on volcanism

Contact Info

Product

Resources

About