Download Structural models of the Mediterranean lithospehre

2373-4
Workshop on Geophysical Data Analysis and Assimilationn
29 October - 3 November, 2012
Structural models of the Mediterranean
lithospehre-asthenosphere system and volcanic activity
G. F. Panza
University of Trieste/ICTP
Trieste
Structural models of the Mediterranean lithosphere-­‐asthenosphere system and volcanic ac7vity G.F. Panza and the SAND group@ICTP Workshop on Geophysical Data Analysis and Assimila7on ICTP -­‐ Trieste, October 29 – November 3, 2012 1
The Italic region with studied cells sized 1°x1°. The main tectonic features and volcanoes are indicated. The colored polygons indicate the grouping of cells for which VS models will be presented in following figures. CELLULAR MODELS Cellular structural model for the Western Alps area. Yellow to brown colors represent crustal layers, blue to violet colors indicate mantle layers. Red dots denote all seismic events collected by ISC with M>3 (1904-­‐2006) For each layer VS variability range is reported. In the uppermost crustal layers the values of VS are omi_ed. The uncertainty on thickness is represented by texture. More details are given in the teaching material. Cellular structural model for the Eastern Alps area. Yellow to brown colors represent crustal layers, blue to violet colors indicate mantle layers. Red dots denote all seismic events collected by ISC with M>3 (1904-­‐2006). Cellular structural model for the Northern Tyrrhenian sea area. Yellow to brown colors represent crustal layers, blue to violet colors indicate mantle layers. Red dots denote all seismic events collected by ISC with M>3 (1904-­‐2006). Cellular structural model for the Dinarides area. Yellow to brown colors represent crustal layers, blue to violet colors indicate mantle layers. Red dots denote all seismic events collected by ISC with M>3 (1904-­‐2006) Cellular structural model for the Sothern Tyrrhenian sea area. Yellow to brown colors represent crustal layers, blue to violet colors indicate mantle layers. Red dots denote all seismic events collected by ISC with M>3 (1904-­‐2006) Cellular structural model for the Western Ionian sea area. Yellow to brown colors represent crustal layers, blue to violet colors indicate mantle layers. Red dots denote all seismic events collected by ISC with magnitude greater than 3 (1904-­‐2006) Our modeling results confirm some general well-­‐known features as the presence of deep lithospheric roots in western Alps down to 180-­‐200 km of depth while lithospheric roots are likely to be absent in the Jura mountains sector, where the lithosphere thickness is about 90 km. Lithospheric roots are also detected in the eastern Alps and south-­‐Alpine sector, across the Insubric line, where the lithosphere extends down to 200-­‐250 km depth, indica7ng a northward dipping. In the Po Valley, the lithosphere thickness ranges between 90 km and 120 km, with a prominent LVZ (VS about 4.00 km/s) marking the top of the asthenosphere below the Adria Plate. The main geodynamical features of the Apennines and Tyrrhenian basin are well delineated by the model, as the presence of rela7vely high-­‐velocity bodies along the Apennines indicates the subduc7on of the Adria lithosphere, and the shallow crust-­‐mantle transi7on beneath the Tyrrhenian Sea, with extended soe mantle layers (VS < 4 km/s) just below the Moho indica7ng a high percentage of melts and magmas. In general, the shallow asthenosphere beneath the Tyrrhenian supports the extension process in act following the eastward migra7on of Apenninic subduc7on, as a result of the global westward mo7on of the lithosphere with respect to the underlying mantle. The ac7ve part of the Tyrrhenian basin is characterized by an eastward emerging LVZ from a depth of about 150 km to 30 km. The considerable thickness of the LVZ may be explained not only by the presence of a wide front of basal7c magma, but more likely by the simultaneous presence of small frac7ons of vola7le elements (e.g. CO2). This hypothesis would support CO2 non-­‐volcanic emissions extended from the Tyrrhenian coast to the Apennines, in the zone of rela7vely low heat flow. We therefore interpret the central Tyrrhenian LVZ as induced by the presence of carbonate-­‐rich melts. The bo_om of the LVZ at a depth of 130-­‐150 km likely represents the beginning of a par7ally-­‐
molten mantle, while its upper margin, at about 30 km depth, represents the upper limit of the melt's ascent. To the east the LVZ vanishes, where a 7ck LID (VS about 4.70 km/s) between 90 km and 160 km of depth represents the subduc1ng Ionian slab, whose presence is also supported by deep seismicity. Evidence of subduc7ng slab is clear along all the Calabrian Arc. The Hellenic subduc1on is well delineated by an eastward thickening lithosphere, somewhere even doubling. In general, the arc-­‐shaped Ionian-­‐Adria lithosphere supports a strong connec7on between Hellenic subduc7on and Ionian-­‐Tyrrhenic subduc7on, possibly endorsing an upduc7on-­‐subduc7on counterflow mechanism in the upper mantle. SEISMICITY CAN HELP THE IDENTIFICATION OF CRUST-­‐MANTLE TRANSITION IF SHARP MOHO IS ABSENT IN CELLULAR MODELS Plots of seismicity can help in defining crust mantle transi7on when sharp Moho is absent. Plots of seismicity can help in reducing ambiguity of inverse problem. Cellular VS structure in cell C5 and related seismicity distribu7on obtained grouping hypocentres in 10-­‐
km intervals: (a)  the unconstrained model selected by LSO; (b)  the representa7ve cellular model; (c)  logN-­‐ h; (d)  logE–h; (e)  log∏E-­‐h. SELECTED CROSS-­‐
SECTIONS BASED ON CELLULAR MODELS (VS, Density, Heat flow) Study area, showing the geographical loca7on of the considered sec7ons. The cellular grid is omi_ed for sake of clarity. Main tectonic lineaments are shown: comb lines indicate compressive fronts and single lines indicate transfer zones. (1)  ECORS; (2)  TRANSALP; (3)  Northern Adria7c; (4)  Crop03; (5)  Adria42; (6)  Tyrrhenian I; (7)  Sardinia– Balkans; (8)  Tyrrhenian II. Top: Cellular model of the sec7on along ECORS profile. Yellow to brown colors represent crustal layers, blue to violet colors indicate mantle layers. Red dots denote all seismic events collected by ISC with M>3 (1904-­‐2006). For each layer VS variability range is reported. The uncertainty on thickness is represented by texture. Centre: Interpreta7on of the model. The VS value reported may not necessarily fall in the centre of the VS range gained from inversion. Bo>om: Heat flow (mWm-­‐2,red full circles) and gravimetric anomaly (mGal, green triangles) data. Top: Cellular model of the sec7on along TRANSALP profile. Yellow to brown represent crustal layers, blue to violet indicate mantle layers. Red dots denote all seismic events collected by ISC with M>3 (1904-­‐2006). For each layer VS variability range is reported. The uncertainty on thickness is represented by texture. Centre: Interpreta7on of the model. The VS value reported may not necessarily fall in the centre of the VS range gained from inversion. Bo>om: Heat flow (mWm-­‐2,red full circles) and gravimetric anomaly (mGal, green triangles). Top: Cellular model of the sec7on across Northern Adria1c. Yellow to brown represent crustal layers, blue to violet indicate mantle layers. Red dots denote all seismic events collected by ISC with M>3 (1904-­‐2006). For each layer VS variability range is reported. The uncertainty on thickness is represented by texture. Centre: Interpreta7on of the model. The VS value reported may not necessarily fall in the centre of the VS range gained from inversion. Bo>om: Heat flow (mWm-­‐2,red full circles) and gravimetric anomaly (mGal, green triangles) data. ASYMMETRY BETWEEN WEST-­‐DIRECTED (Apennines) and EAST-­‐
DIRECTED (Dinarides) SUBDUCTIONS IS A ROBUST FEATURE EVIDENCED BY CELLULAR MODELS Asymmetry between west-­‐directed (Apennines) and east-­‐directed (Dinarides) subduc7ons is a robust feature of the central values of the velocity model NO EVIDENCES OF SLAB PULL ECORS sec7on from Flumet (western Alps) to Euganei Hills: VS and density model (3D inversion). Striking feature of the sec7on is the subduc7on of the European plate below the Adria7c plate, with deep lithospheric roots below Milan and surroundings, represented by high-­‐velocity lid, well in agreement with Mueller and Panza (1986). In contrast to Apennines subduc7on, no intermediate depth seismicity is observed in western Alps. To the West the LVZ is found at a depth of about 180 km. To the East, a prominent LVZ marks the Euganei Hills magma7c zone below a depth of about 130 km. The subduc1ng lid is characterized by nega1ve density anomaly, whereas a posi7ve density anomaly is seen beneath Euganei Hills, as shallow as 30 km. TRANSALP : VS and density model from Bavarian Alps to Northern Apennines. The low-­‐angle subduc7on of the European plate below the Adria7c plate is fairly well evidenced by gently N–S dipping high-­‐velocity lid and in accordance with scarce shallow seismicity and almost absent intermediate depth seismicity, as seen in ECORS sec7on. A rela7vely low velocity lid is found beneath Dolomites, just below the Moho. The bo_om of the lid is found at about 120–140 km of depth and overlies a well-­‐marked LVZ in the asthenosphere. In the southernmost part of the sec7on, Apennines subduc7on is delineated by high seismicity that reaches intermediate depth. The prominent high-­‐density body, as shallow as 40 km of depth, below Vene7an plain, may be a signature of the Euganei Hills magma7c ac7vity. Adria43-­‐46 sec7on (Northern Adria1c): VS and density model from Capraia Island to Julian Alps. The pronounced high-­‐velocity, almost ver7cal, slab represents Apennines subduc7on consistent with significant seismicity at intermediate depth. To the West, a low-­‐velocity asthenospheric mantle wedge, mainly aseismic, is present. To the East, a high velocity lid about 100 km thick extends towards the NE-­‐dipping Alpine subduc7on, marked by the shallow to intermediate depth seismicity in the right part of the sec7on. The bo_om of the lid is well marked by a LVZ. Striking features of density model are the nega1ve density anomaly beneath Apennines and Julian Alps, with the excep1on of the rela1vely high-­‐density value found beneath Tuscany, probably related to mantle wedge. Po plain and Northern Adria1c are instead characterized by rela1vely high-­‐ density mantle at depths ranging from 60 to 200 km. Asymmetry between west-­‐directed (Apennines) and east-­‐directed (Alps, Dinarides) subduc7ons is a robust feature of the velocity model, while the density model reveals that slabs are not denser than the ambient mantle, thus supplies no evidence for slab pull. EVIDENCES OF UPDUCTION (EXUMATION) IN THE EASTERN MEDITERRANEAN TransMed profiles, VII and VIII, cuqng Hellenic and Cyprian arcs overlaying the heat flow map of the Region (Global heat flow online database www.hearlow.und.edu) with fault plane solu7ons of major events and mean tectonic scheme. The grey cells are the inverted cells. N.B.: The low heat flow in Anatolia can be a graphic ar7fact due to lack of data. Transmed VII Smoothed VS sec7on along Transmed VII. Stars represent hypocenters within a 100 Km wide band centered around the profile (1908-­‐2009 -­‐ ISC catalogue). Density sec7on, obtained by linear inversion of gravity data, keeping fixed the geometry as indicated by the central VS values obtained by non-­‐linear inversion of surface waves tomography. Heat flow curve is dashed while gravity curve is solid. Transmed VIII Smoothed VS sec7on along Transmed VIII. Stars represent hypocenters within a 100 Km wide band centered around the profile (1908-­‐2009 -­‐ ISC catalogue). Density sec7on, obtained by linear inversion of gravity data, keeping fixed the geometry as indicated by the central VS values obtained by non-­‐linear inversion of surface waves tomography. Heat flow curve is dashed while gravity curve is solid. Simplified carton showing schema7cally the upducted slab and the exuma7on of the mantle material along Transmed VII (lee) and the Cyprian arc (right). The focal mechanisms of the largest earthquakes occurred in the period 1970-­‐2009 are plo_ed from side view. The modeled profiles exhibit a con7nental crust type overlain by a thick sedimentary cover and underlain by a thick lithospheric mantle. The lithosphere-­‐
asthenosphere system exhibits features which suggests the presence of upducted asthenosphere exhumed to the north of the Hellenic arc, where the slab extension is limited to depths of about 220 Km. With respect to the mantle, Africa is moving away from Greece, but Greece is overriding Africa since it moves faster (Doglioni et al., 2007), hence upduc7on (exuma7on) is a preferable term to describe the process going on in the eastern Mediterranean and pictured in Transmed VII. The convex asthenosphere interface below the profile is consistent with the flow of a por7on of lower mantle material, sucked from below in the wake lee by the upduc7on (exuma7on) of the African Plate (Doglioni et al., 2009). This is consistent with the down-­‐dip extension evidenced by the earthquake mechanisms. In the Cyprian arc the mantle structure (VS and density) seems to indicate a less advanced process of upduc7on than in the Hellenic arc, well in agreement with the direc7on of mo7on of the Anatolian plate rela7ve to the African and Hellenic plates, both in the deep and shallow hot spot reference frameworks. Along both sec7ons the stress pa_ern inferred from fault plane solu7ons (see also Papazachos et al., 2000) is well consistent with down-­‐dip extension. FROM VS TO TEMPERATURE IN THE MANTLE a) Distribu7on of Plio-­‐Quaternary magma7sm. Open symbols indicate seamounts. Ages (in Ma) are given in parentheses. Inset: schema7c distribu7on of orogenic and anorogenic volcanism: arrows (red) show migra7on of orogenic magma7sm with 7me (Peccerillo, 2005); b) the study area. Main tectonic lineaments are shown. Major volcanoes and seamounts are indicated by triangles, while stars indicate main mantle xenolith locali7es. Diamond (blue) indicates Finero's perido7te complex. The cell's alphanumerical label is given as well with the loca7on of the cross-­‐
sec7ons analysed in the following, shown by (color) lines. The seismic velocity–temperature rela7onship is strongly nonlinear and it is influenced by several perturbing factors, such as the variable mantle composi1on, the presence of melt material and of fluids in the upper mantle, the anelas1c behaviour of the propaga7on medium at the high temperatures in the mantle (Karato, 1993; Tsumura et al., 2000; Nakajima and Hasegawa, 2003; Priestley and McKenzie, 2006). The seismic velocity–temperature conversion formulated by Goes et al. (2000) for the shallow mantle, is extended to account for (a) the effect of composi1onal varia1ons and correc1ons for the effect of anelas1city, and for (b) the melt and water presence in the mantle rocks. The variability of mantle composi7on has been evaluated through average physical parameters for a given composi7on, as a func7on of the volumetric propor7on of each individual mineral, using the Voight–Reuss–Hill (VRH) averaging scheme. The upper mantle is assumed to be composed of three main minerals (olivine, orthopyroxene, clinopyroxene), plus minor garnet/spinel and accessory phlogopite and amphiboles as shown in the following tables. TEMPERATURE IN THE MANTLE In the upper mantle above 400 km of depth, the uncertain7es in the elas7c and anelas7c proper7es of mantle minerals translate into an error in the temperatures inferred from seismic veloci7es of about ±100 °C (Cammarano et al., 2003). Further informa7on about temperature uncertain7es can be obtained through parametric tests. VS model of cell A7 (a) sensi7vity to varia7on of DVC (deriva7ve of VS with respect to the melt content) of: (b) temperature and (c) melt frac7on. Here and in the following LVZ marks the bo_om of the low velocity zone in the asthenosphere. sensi7vity to the water content (wt.%) of the temperature (b), derived from VS (a) and the melt percentage (c). The result of our parametric tests indicates that while there is li_le effect on the inferred temperature, the melt frac1on is strongly influenced by DVC (deriva7ve of VS with respect to the melt content) values. Thus, an increase of the VS sensi7vity to the presence of melt by approximately 6 and 11 7mes leads to a decrease of the melt frac7on by about 5 and 9 7mes, respec7vely. This result is not surprising since the applied correc7on for the presence of melt is introduced in such a way to decrease the anelas7c seismic velocity by an amount propor7onal to the product of DVC by Melt Frac7on (MF). With fixed DVC, the results obtained for cell A7 indicate that large water content (0.45 wt.%), in the mantle rocks, lowers the calculated temperature values by 12–22%, and increases the melt frac7on values by more than 47%. Smaller water content (0.1 wt.%) in the mantle rocks reduces the calculated temperature values by around 9% and increases the melt frac7on values by more than 26%. In the anhydrous case, parameteriza7ons developed by McKenzie and Bickle (1988) and Katz et al. (2003) give similar results about the inferred temperatures and melt frac7ons. VS model of cell a2: (b) sensi7vity to varia7on of mantle composi7on of the temperature derived from Vs and (c) of the melt percentage. Three different composi7ons have been adopted in the parametric tests. The temperatures for cell a2, located in the Roman Province, are obtained with a mantle composi7on constant with depth, without hydrous phases and with the two variable mantle composi7ons, that differ, among others, in the amounts of hydrous phases (phlogopite and amphiboles). The crust, about 25 km thick, lies on a thin hot mantle layer (VS ∼ 3.9 km/s) that reaches the depth of about 38 km; a fast LID (VS ∼ 4.6 km/
s) extends down to about 50 km of depth; below, the asthenosphere, whose top is marked by a LVZ (VS ∼ 4.1 km/s and 4.4 km/s) seems to extend to depths as large as 300 km.In the modelling, the weight frac7ons of bulk water content have the same value of 0.45 wt.% and remain constant with depth. VS model of cell a2: (b) sensi7vity to varia7on of mantle composi7on of the temperature derived from Vs and (c) of the melt percentage. The results illustrate a clear tendency in the differences between the temperatures es7mated for constant and variable (Torre Alfina) composi7onal models to increase with increasing seismic velocity. The same effect is seen if a variable composi7on containing larger amount of hydrous phases (like Finero composi7on) is used. Composi1onal variability produces differences in the temperatures, as high as ∼370 °C. In both tests, the melt frac7on has the tendency to decrease by an amount between 0.3% and 1%. At 250 km of depth (and deeper), outside the stability limit for phlogopite, the temperatures es1mated for constant and variable composi1onal models are prac1cally the same. This emphasizes the importance of a realis1c choice of the amount and type of hydrous phases composing the upper mantle. TEMPERATURE PROFILES ALONG SELECTED SECTIONS In each cell the composi7on is laterally homogeneous, but the it may differ from cell to cell. For cells located in front of the present-­‐day convergence fronts temperature and melt frac7on values in the upper mantle are obtained using the Finero type reference mantle composi7on, DVC=4 and variable depth water content (a large value of 0.45 wt.% in the depth interval from Moho to the stability limit of phlogopite, taken equal to 200 km, and a small value of 0.1 wt.% at depths larger than 200 km). In case of cells located in foreland areas, the mantle composi7on remains fixed with depth and a smaller value of water content of 0.1 wt.% is assumed (but DVC is kept equal to 4). In all cross-­‐sec7ons the (colour) scale of temperatures starts at 11 °C, assumed as average surface temperature in Italy. Temperature (color scale) and melt frac7on (isolines) distribu7on along cross-­‐sec7on 1. Temperature (color scale) and melt frac7on (isolines) distribu7on along cross-­‐sec7on 2. Temperature (color scale) and melt frac7on (isolines) distribu7on along cross-­‐sec7on 3. Temperature (color scale) and melt frac7on (isolines) distribu7on along cross-­‐sec7on 4. Some of the features seen so far are rather obvious, fit current models of the evolu7on of the Tyrrhenian Sea area and therefore represent a posi7ve test of the validity of the enhanced procedure. Others are more problema7c, and deserve some in-­‐depth discussion. EFFECT OF COMPOSITION ON MANTLE TEMPERATURUES temperature and melt frac7on (isolines) distribu7on for Sec7on 1, obtained using reference composi7onal model. Variant of the temperature and melt frac7on (isolines) distribu7on for Sec7on 1, obtained using (variable) Torre Alfina type composi7on for the back-­‐arc area. ? Sec1on 2: Published thermal model (Tumanian et al. 2012) – upper figure. Variant of thermal model, obtained with improved mantle models, all other parameters being fixed (lower figure). Remnants of subduc7on effects (cooling) encircled by ellipse; under cell A6 cold spot not easily explained (?). Variant of thermal model for sec1on 2, which points out the effect of the assump7on that cell A6 belongs to foreland (as cells A7-­‐A8), Remnants of subduc7on effects (cooling) are robust features of the thermal model with respect to uncertain7es in VS. The thermal structure of the shallow upper mantle inferred by Vs–T conversion indicates temperature values geqng above 1600 °C at the bo_om of the sec7ons (300 km). These results seem to be in accordance with the LLAMA (Laminated Lithologies with Aligned Melt Accumula7ons) model proposed by Anderson (2010), who concludes that temperature can be as high as 1600 °C at the base of the boundary layer (BL) and ~200 °C ho_er than the ridge geotherm. Our thermal evalua7ons do not support the assump7ons by McKenzie and Bickle (1988) who presume a subsolidus poten7al temperature of 1280 °C ± 20 °C for ‘ambient mantle’ beneath the plate. In the model the ambient mantle temperatures (inferred from MORB temperatures obtained by petrological experiments) are forced to approach the ridge geotherm and the mantle cannot retain the melt. Consequently, the seismic low-­‐velocity layer (LVL) is subsolidus and controlled by high temperature gradients with no par7al mel7ng (e.g. Priestley and McKenzie, 2006) If mid-­‐ocean ridges exemplify the ‘ambient mantle’, the mid-­‐plate magmas seem to require temperatures more than 200 °C higher than the assumed ambient temperatures. Moreover, an upper mantle kept isothermal and homogeneous below the plate could be in disagreement with the VS heterogeneity in the upper 200 km of the upper mantle, which could exceed 7%, implying temperature varia7ons of 700 °C. Recent geophysical data, like: (a)  observa7ons on the maximum depths of mel7ng and inferred temperatures of the mid-­‐plate magmas, (b)  the models for bathymetry data, (c)  the mantle poten7al temperatures derived from petrology for dry back-­‐arc basin basalts by Kelley et al. (2006), indicate a mean mantle temperature higher than that assumed by McKenzie and Bickle (1988) and confirm that MORB-­‐source mantle and mid-­‐plate mantle temperatures differ by ~200 °C. MODELLED MELT DISTRIBUTION IS ROUGHLY CORRELATED WITH THE AGE OF MAGMATISM Correla7on between the melt frac7on (evaluated for the main volcanic areas) with the age of the magma7sm. Cell numbers of different centres (Fig. 1b) are given in parentheses. CONCLUSIONS Basic assump1on: the upper mantle seismic structure is controlled both by temperature and composi1on. The obtained results confirm the possibility to interpret the upper-­‐mantle seismic models in terms of temperature and composi7on, and offer an enhanced insight into the geodynamic evolu7on, s7ll in debate, of one of the most studied and geodynamically complex regions of Europe. Based on the thermal structure and melt distribu7on obtained, the following conclusions may be drawn. (a) The ongoing subduc7on process of the Ionian/Adria7c plate (beneath Umbria, Calabria and the Aeolian arc), (b) the latest episode of con7nental convergence (beneath Tuscany) and (c) the thermal effect of the remnant of the Adria7c plate (Campania) leave dis7nc7ve signatures in the temperature's field of the shallow upper mantle. Despite the epistemic uncertain7es in the T–VS conversion, which affect the thermal es7ma7ons, the temperature field characteris7cs seems to be in agreement with independent studies about the change of the slab structure along the Apennines chain, from north to south, due to fragmenta7on of Apennines' lithosphere with the gradual termina7on of ac7ve subduc7on. In the Northern Apennines the slab is almost horizontal, and underlies the chain and the uplie of Apennines is the result of the isosta7c adjustment. In the Central Apennines the slab is almost ver7cally dipping and reaches depths of around 130 km. Beneath the Southern Apennines the slab reaches larger depths, its dynamics being controlled by roll-­‐back and tearing processes. Temperature values at Moho are, in general, correlated with surface heat flow values in the Tyrrhenian Sea area and surroundings, even if most of the provinces of the study area (like Tuscan-­‐Tyrrhenian area, Apennines and Adria7c trough) have not yet reached the steady-­‐state thermal regime. The thermal gradients evaluated in Adria foreland are higher in comparison with those of the back-­‐arc area (Tyrrhenian Sea) and they could be an effect of the eastward mantle flow (Panza et al., 2007) beneath Adria lithosphere or a consequence of the presence of a low frac7on of melts ≤1 wt.%, which cannot rise in the compressive regimes, or both. Melt frac7on distribu7on in the back-­‐arc area, corresponding to the inferred temperatures, is roughly correlated with the age of the magma7sm, the highest abundance occurring in the most ac7ve volcanism area in the southern Tyrrhenian Sea. The use of refined models obtained aeer publica7on of Tumanian et al. (2012) permits to clearly outline the remnants of subduc7on effects (cooling) and to be_er define the posi7on of the transi7on from foreland to Tyrrhenian back-­‐arc domain. The capability of inferring plausible temperatures by the developed conversion technique depends on how precisely are evaluated input parameters, like DVC values, weight frac7on of water dissolved in the melt and mantle composi7on variability and this requires a truly interdisciplinary approach. These lectures are based on the following papers (and references therein); the contribu7on of all co-­‐authors is gratefully acknowledged Brandmayr, E., Raykova, R., Zuri, M., Romanelli, F., Doglioni, C. and Panza, G.F., (2010). The lithosphere in Italy: structure and seismicity. In: (Eds.) Marco Beltrando, Angelo Peccerillo, Massimo Ma_ei, Sandro Con7celli and Carlo Doglioni, The Geology of Italy, Journal of the Virtual Explorer, Electronic Edi7on, ISSN 1441-­‐8142, volume 36, paper 1. Brandmayr E., Marson I., Romanelli F. and Panza G.F., (2011). Lithosphere density model in Italy: no hint for slab pull. Terra Nova, vol 23, pp. 292-­‐299; doi: 10.1111/j.
1365-­‐3121.2011.01012.x. ElGabry M.N., Panza G.F. ,Badawy A.A. and Korrat I.M. Imaging a relic of complex tectonics: the lithosphere-­‐asthenosphere structure in the Eastern Mediterranean, Terra Nova, in press Tumanian M., Frezzoq M. L., Peccerillo A., Brandmayr E. and Panza G.F. (2012). Thermal structure of the shallow upper mantle beneath Italy and neighbouring areas: Correla7on with magma7c ac7vity and geodynamic significance. Earth-­‐Science Reviews. Elsevier, 369-­‐385. Panza, G. F., Raykova, R.B., Carmina7, E. and Doglioni, C., (2007). Upper mantle flow in the western Mediterranean. EPSL, 257, 200-­‐214. ADDITIONAL SELECTED REFERENCES Anderson, D.L., 2010. Hawaii, boundary layers and ambient mantle — geophysical constraints. First published online: December 2, Journal of Petrology, h_p://dx.doi.org/ 10.1093/petrology/egq068. Cammarano, F., Goes, S., Vacher, P., Giardini, D., 2003. Inferring upper mantle temperatures from seismic veloci7es. Physics of the Earth and Planetary Interiors 139, 197–222. Doglioni, C., Carmina7, E., Cuffaro, M. and Scrocca, D. 2007. Subduc7on kinema7cs and dynamic constraints. Earth Science Reviews, Vol. 83, 125-­‐175. Doglioni, C., Tonarini, S. and Innocen7, F., 2009. Mantle wedge asymmetries and geochemical signatures along W-­‐ and E-­‐NE-­‐directed subduc7on zones. Lithos, doi:10.1016/j.lithos.2009.01.012 Goes, S., Govers, R., Vacher, P., 2000. Shallow mantle temperatures under Europe from P and S wave tomography. Journal of Geophysical Research 105 (B5), 11153–11169. Karato, S., 1993. Importance of anelas7city in the interpreta7on of seismic tomography. Geophysical Research Le_ers 20, 1623–1626. Katz, R.F., Spiegelman, M., Langmuir, C.H., 2003. A new parameteriza7on of hydrous mantle mel7ng. Geochemistry, Geophysics, Geosystems 4 (9), h_p://dx.doi.org/ 10.1029/2002GC000433. Kelley, K.A., Plank, T., Grove, T.L., Stolper, E.M., Newman, S., Hauri, E., 2006. Mantle mel7ng as a func7on of water content beneath back-­‐arc basins. Journal of Geophysical Research 111, B09208, h_p://dx.doi.org 10.1029/2005JB003732. McKenzie, D., Bickle, M.J., 1988. The volume and composi7on of melt generated by extension of the lithosphere. Journal of Petrology 29, 625–679. Nakajima, J., Hasegawa, A., 2003. Es7ma7on of thermal structure in the mantle wedge of northeastern Japan from seismic a_enua7on data. Geophysical Research Le_ers 30 (14), 1760, h_p://dx.doi.org/10.1029/2003GL017185. Papazachos, B.C., Karakostas, V.G., Papazachos, C.B. and Scordilis, E.M., 2000. The geometry of the Wada7-­‐Benioff zone and lithospheric kinema7cs in the Hellenic arc. Tectonophysics, 319, pp. 275-­‐300. Priestley, K., McKenzie, D., 2006. The thermal structure of the lithosphere from shear wave veloci7es. Earth and Planetary Science Le_ers 244, 285–301. Tsumura, N., Matsumoto, S., Horiuchi, S., Hasegawa, A., 2000. Three-­‐dimensional a_en-­‐ ua7on structure beneath the northeastern Japan arc es7mated from spectra of small earthquakes. Tectonophysics 319 (4), 241–260.