The effect of décollement dip on geometry and kinematics of model accretionary wedges.
2003 (English)In: Journal of Structural Geology, ISSN 0191-8141, Vol. 25, no 9, 1445-1450 p.Article in journal (Refereed) Published
We conducted a series of sand-box models shortened asymmetrically above a frictional-plastic de´collement to study the influence ofamount and sense of the de´collement dip on the geometry and kinematics of accretionary wedges. Model results illustrate that the amount anddirection of de´collement dip strongly influence the geometry and mode of deformation of the resulting wedge. In general, for models havingsimilar de´collement frictional parameters, the resulting wedge is steeper, grows higher and is shorter when shortened above a de´collementthat dips toward the hinterland. At 42% bulk shortening, the length/height ratio of wedges formed above a 58-dipping de´collement was equalto 2.4 whereas this ratio was equal to 3 for wedges shortened above a horizontal de´collement. Moreover, models with a hinterland dippingde´collement undergo larger amounts of layer parallel compaction (LPC) and area loss than models shortened above a non-dippingde´collement. The effect of de´collement dip on wedge deformation is most pronounced when basal friction is relatively high (mb ¼ 0.55),whereas its effect is less significant in models where the basal de´collement has a lower friction (mb ¼ 0.37). Model results also show thatincreasing basal slope has a similar effect to that of increasing basal friction; the wedge grows taller and its critical taper steepens.
Place, publisher, year, edition, pages
2003. Vol. 25, no 9, 1445-1450 p.
Accretionary wedges, Sand-box models, De´collement dip, basal friction
IdentifiersURN: urn:nbn:se:uu:diva-47208OAI: oai:DiVA.org:uu-47208DiVA: diva2:75115