The Westernmost Tethys Blog Geology mapping, basin analysis and 3D modeling

01/17/2020

Latest Chattian-Langhian Volcano- Sedimentary Event

Filed under: oligocene,Tethys — Tags: , — messinianalicante @ 10:09 AM

High amounts of Chattian-Langhian orogenic magmatism have generated volcaniclastic deposits that are interbedded within the penecontemporaneous sedimentary marine successions in several central-western peri-Mediterranean chains. These deposits are widespread in at least 41 units of different basins located in different geotectonic provinces: (1) the Africa-Adria continental margins (external units), (2) the basinal units resting on oceanic or thinned continental crust of the different branches of the western Tethys, (3) the European Margin (external units), and (4) the Western Sardinia zone (Sardinia Through units). The emplacement of volcaniclastic material in marine basins was controlled by gravity flows (mainly turbidites; epiclastites) and fallout (pyroclastites). A third type comprises volcaniclastic grains mixed with marine deposits (mixed pyroclastic-epiclastic). Calc-alkaline magmatic activity is characterized by a medium- to high-potassium andesite-dacite-rhyolite suite and is linked to complex geodynamic processes that affected the central-western Mediterranean area in the ∼26 to 15 My range. The space/time distribution of volcaniclastites, together with a paleogeographic reconstructions, provide keys and constraints for a better reconstruction of some geodynamic events. Previous models of the central-western Mediterranean area were examined to compare their compatibility with main paleotectonic and paleogeographic constraints presented by the main results of the study. Despite the complexity of the topic, a preliminary evolutionary model based on the distribution of volcaniclastites and active volcanic systems is proposed.

Paleogeographic and paleotectonic evolutionary model of the central-western Mediterranean region sketched in three steps (modified from Schettino and Turco 2006, 2011; Guerrera and Martín-Martín 2014). A, Late Oligocene. B, Early Miocene. C, Middle Miocene p.p. (Langhian). The relationships between sedimentary basins and volcaniclastites, and the distribution of active volcanic systems during the late Oligocene-middle Miocene p.p. (Langhian) are shown.

Cite as: Martín-Martín, M., Guerrera, F., and Tramontana, M. (in press): Geodynamic Implications of the Latest Chattian-Langhian Central-Western Peri-Mediterranean Volcano-Sedimentary Event: A Review.  The Journal of Geology 128:1, 29-43. doi: 10.1086/706262

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