Details

Autor(en) / Beteiligte

• Laubscher, H
• Meissner, Rolf
• Brown, Larry
• Franke, Wolfgang
• Seifert, Friedrich
• Dürbaum, Hans‐Jürgen
• Fuchs, Karl

Titel

Seismic Data from the Alps and their Bearing on the Formation of Granulite and Eclogite Nappes

Ist Teil von

• Continental Lithosphere: Deep Seismic Reflections, 1991, p.207-212

Ort / Verlag

Washington, D. C: American Geophysical Union

Erscheinungsjahr

1991

Quelle

Wiley Online Library All Obooks

Beschreibungen/Notizen

• Several models for the uplift to the surface of deep‐seated masses have been proposed in the past, largely on surface evidence. Geophysical data from the deeper parts of young collision zones had been scant, but recent seismic surveys through Alpine ranges provided important information. Although these data emphasize Neogene tectonics which severely disrupted older structures that contain eclogitic to granulitic bodies, they suggest various ways for the submergence, deep‐seated metamorphism, and re‐emergence of originally surficial rocks. In a section through central Switzerland, three modes of the localized uplift of deep‐seated masses may be surmised: (1) Delamination of lower crust and its wedging into the middle crust of the opposite plate; (2) partition of transpression into dip‐slip‐ and strike‐slip‐dominated structures, with locally continued underthrusting along the latter; (3) crustal brachyanticlines (“flower structures”) associated with transpression and uplift of slivers along steep shear zones. The transpressive scenarios (2) and (3) are probably important for eclogitic rocks from the early Cretaceous when according to plate tectonics models strike‐slip predominated. Transpression‐induced localized depression and uplift of both oceanic and continental crustal slivers may explain a number of otherwise puzzling features such as the juxtaposition as exotic terranes of eclogitic slivers of Austroalpine, Piemontese, and European affinities.