+ Site Statistics
+ Resolve Accession
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
Submit PDF Full TextSubmit PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Multiple stages of continental subduction during India/Asia convergence; insight from seismic tomography and tectonic reconstructions

, : Multiple stages of continental subduction during India/Asia convergence; insight from seismic tomography and tectonic reconstructions. Congres Geologique International, Resumes 33

We use tomographic images of mantle structure down to 1600 km depth beneath the India/Asia collision zone to identify several slab fragments of Indian or Asian continental lithosphere. Their positions and their lateral extent are properly estimated, giving a better insight into the complex 3D mantle structure. At a given depth, a high-wavespeed anomaly zone is interpreted as the record of a subduction process, which occurred at the age associated with that depth. The reconstructed location of major faults through time allows us to discuss the tectonic context associated with these subduction processes. We infer a major slab breakoff process occurring at the early stage of the collision, probably around 45 Ma. We were able to draw the geometry of India after the breakoff, and to follow its evolution in the following collision process. We propose that India/Asia convergence between approximately 45 and 30 Ma was absorbed by southward subduction of the Asian lithosphere along the proto-Red River fault, whereas Indian lithosphere was moving horizontally, without subducting. In contrast, convergence from approximately 30 Ma to at least 15 Ma was likely accommodated by subduction along the proto-Karakorum fault of a portion of the northwestern margin of India. During the same period, the northeastern portion of India was probably cut and extruded eastwards with the Indochina block. The central part was likely affected by a combination of both subduction and extrusion mechanisms that caused a forward motion of the convergent boundary, resulting in an overturned geometry of the slab. We therefore infer a very heterogeneous behaviour of northern India from west to east along the collision zone. This lateral heterogeneity implies that the Indian continent was torn perpendicularly to its northern boundary during the collision process. Along most convergent margins where oceanic plates subduct into the mantle, the upper plate deforms little. Relating the dynamics of the subducting plate to tectonic shortening within the upper plate is then a second order problem. This is not the case, however, for the India/Asia collision zone, where the crust of upper plate shortened several hundreds of kilometres and extruded eastward. We used our knowledge of the crustal deformation during the collision to relate surface deformations to the dynamics of sinking lithospheric material and unravel this relationship. We infer that lateral advection in the mantle is small and that the sinking rate was about 2 cm/yr in the lower mantle and about 4 cm/yr above the transition zone.

(PDF 0-2 workdays service)

Order PDF Full Text


Click here to order any other PDF Full Text

Accession: 037110700

PDF Full Text: Submit

Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:

Other references

FORSSBERG, A.; NORDLANDER, S., 1950: Experiences of the polarographic serum protein reaction in cancer diagnosis. Acta Radiologica 33(2): 165-186

Britt, Adam., 1999: Encouraging natural feeding behavior in captive Varecia variegata variegata. Laboratory Primate Newsletter. April; 382: 19-20

Shen, Q-jie.; Liu, Y-bin.; Jin, S., 2013: Analyses of relevant influencing factors in the treatment of tibial pilon fractures. To explore the relevant influencing factors of surgical outcomes for closed tibial pilon fractures. From April 2005 to May 2011, 52 consecutive closed tibial pilon fractures were treated by the same surgical team. There were 35 males and 17 female...

Han, L.; Pei, H.; Hu, W.; Han, F.; Song, M.; Zhang, S., 2015: Nutrient removal and lipid accumulation properties of newly isolated microalgal strains. In this work, four microalgae including Chlorella sp. SDEC-10, Chlorella ellipsoidea SDEC-11, Scenedesmus bijuga SDEC-12 and Scenedesmus quadricauda SEDC-13 isolated from a local lake have been investigated for the properties of growth, nutrient r...

Ossoinig, K.; Seher, K.; Kaufmann, F., 1967: Echographic studies of fine tissue structure. II. On one of the phenomenan noticed by ultrasonic studies of citrated blood. Albrecht Von Graefes Archiv für Klinische und Experimentelle Ophthalmologie. Albrecht Von Graefe's Archive for Clinical and Experimental Ophthalmology 173(4): 327-338

Jordan, F.L.; Sandrin, S.K.; Frye, R.J.; Brusseau, M.L.; Maier, R.M., 2004: The influence of system complexity on bacterial transport in saturated porous media. A series of miscible-displacement column experiments were conducted under saturated flow conditions to systematically investigate the influence of physical and biological complexity on bacterial activity and fate in the presence and absence of a n...

Lance, R.; Costabile, R.A.; Albo, M.; Steers, W., 1995: Oral trazodone for erectile dysfunction. Journal of Urology 153(4 SUPPL ): 473A

Rutstein R.P.; Eskridge J.B., 1982: The clinical evaluation of vertical fixation disparity. American Journal of Optometry & Physiological Optics 59(10): 77P

Machatschek Fritz, 1935: Niveauveraenderungen des Eiszeitalters. Changes in level during the ice age.

Schurko, A.M.; Mendoza, L.; Lévesque, C.André.; Désaulniers, N.L.; de Cock, A.W.A.M.; Klassen, G.R., 2003: A molecular phylogeny of Pythium insidiosum. Sequence analysis of the ribosomal DNA internal transcribed spacers (ITS) was used to establish phylogenetic relationships among 23 isolates of Pythium insidiosum, the etiological agent of pythiosis in mammals. The isolates were divided into three...