Crustal xenoliths from Cenozoic volcanic fields of West Germany: Implications for structure and composition of the continental crust

Mengel, K.; Sachs, Peter M.; Stosch, H.-G.; Wörner, Gerhard; Loock, G.

doi:10.1016/0040-1951(91)90215-e

Cited by 56 publications

(22 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Metaigneous gneiss xenoliths from the Eifel volcanic field support this assumption (Mengel et al, 1991;Stosch et al, 1991;and references therein). A relatively thin layer of pyroxenite and hornblendite (Voll, 1983;Mengel et al, 1991;Stosch et al, 1991) (polygon 25, sections A and B and polygon 9, section C) represents the lower crust. The present-day thin lower crust is the result of delamination in geological times, during which the crust lost more than 15 km of its original thickness (Wittenberg et al, 2000;Ziegler et al, 2004).…”

Section: Structure Composition and Thermal Properties Of The Lithospsupporting

confidence: 52%

“…We interpret these velocities, which are typical of Palaeozoic middle crust, as representing metagranitoids (Rudnick and Fountain, 1995). Metaigneous gneiss xenoliths from the Eifel volcanic field support this assumption (Mengel et al, 1991;Stosch et al, 1991;and references therein). A relatively thin layer of pyroxenite and hornblendite (Voll, 1983;Mengel et al, 1991;Stosch et al, 1991) (polygon 25, sections A and B and polygon 9, section C) represents the lower crust.…”

Section: Structure Composition and Thermal Properties Of The Lithospmentioning

confidence: 69%

“…The present-day thin lower crust is the result of delamination in geological times, during which the crust lost more than 15 km of its original thickness (Wittenberg et al, 2000;Ziegler et al, 2004). The lithospheric mantle (polygon 26, sections A and B and polygon 10, section C) is likely made up of peridotite (spinel lherzolite and harzburgite) as indicated by xenoliths (Mengel et al, 1991;Shaw et al, 2005).…”

Section: Structure Composition and Thermal Properties Of The Lithospmentioning

confidence: 99%

“…In the latter two regions, i.e. underneath the Eifel and the Hunsrück, the succession is underlain by Proterozoic metasedimentary mica schist and gneiss (Mengel et al, 1991; attributed as crystalline upper crust in Table 7). The grey dash-dotted line within the crust ( The middle crust (polygon 24, sections A and B and polygon 8, section C) encompasses the depth realm between approximately 19 and 30 km characterized by a seismic velocity of 6.5-6.7 km s -1 (Mechie et al, 1983).…”

Section: Structure Composition and Thermal Properties Of The Lithospmentioning

confidence: 99%

“…2) is constrained from numerous seismic refraction (Mooney and Prodehl, 1978;Mechie et al, 1983;Meissner et al, 1983) and seismic reflection profiles farther east through the Eifel area (DEKORP Research Group, 1991;Oncken et al, 1999Oncken et al, , 2000. These seismic surveys allow a structural and to some point compositional subdivision of the crust in an upper part, largely composed of Palaeozoic rocks (known from the surface), and a lower part, consisting of Precambrian rocks known from xenolith samples of the Eifel volcanic field (e.g., Downes, 1993;Mengel et al, 1991;Stosch et al, 1991;Voll, 1983, Wörner et al, 1982. Simplified cross sections adapted to the geology of the study area (Wagner et al, 2012;Zitzmann and Grünig, 1987) were also considered.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Surface heat flow and lithosphere thermal structure of the Rhenohercynian Zone in the greater Luxembourg region

Schintgen

Förster

et al. 2015

Geothermics

View full text Add to dashboard Cite

Section: Structure Composition and Thermal Properties Of The Lithospsupporting

confidence: 52%

Section: Structure Composition and Thermal Properties Of The Lithospmentioning

confidence: 69%

Section: Structure Composition and Thermal Properties Of The Lithospmentioning

confidence: 99%

Section: Structure Composition and Thermal Properties Of The Lithospmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Surface heat flow and lithosphere thermal structure of the Rhenohercynian Zone in the greater Luxembourg region

Schintgen

Förster

et al. 2015

Geothermics

View full text Add to dashboard Cite

USArray Imaging of Continental Crust in the Conterminous United States

Lowry

2017

Tectonics

View full text Add to dashboard Cite

The thickness and bulk composition of continental crust provide important constraints on the evolution and dynamics of continents. Crustal mineralogy and thickness both may influence gravity anomalies, topographic elevation, and lithospheric strength, but prior to the inception of EarthScope's USArray, seismic measurements of crustal thickness and properties useful for inferring lithology are sparse. Here we improve upon a previously published methodology for joint inversion of Bouguer gravity anomalies and seismic receiver functions by using parameter space stacking of cross correlations of modeled synthetic and observed receiver functions instead of standard H‐κ amplitude stacking. The new method is applied to estimation of thickness and bulk seismic velocity ratio, vP/vS, of continental crust in the conterminous United States using USArray and other broadband network data. Crustal thickness variations are reasonably consistent with those found in other studies and show interesting relationships to the history of North American continental formation. Seismic velocity ratios derived in this study are more robust than in other analyses and hint at large‐scale variations in composition of continental crust. To interpret the results, we model the pressure‐/temperature‐dependent thermodynamics of mineral formation for various crustal chemistries, with and without volatile constituents. Our results suggest that hydration lowers bulk crustal vP/vS and density and releases heat in the shallow crust but absorbs heat in the lowermost crust (where plagioclase breaks down to pyroxene and garnet resulting in higher seismic velocity). Hence, vP/vS variations may provide a useful proxy for hydration state in the crust.

show abstract

Geodynamic Setting of the Tertiary Hocheifel Volcanism (Germany), Part II: Geochemistry and Sr, Nd and Pb Isotopic Compositions

View full text Add to dashboard Cite

Major and trace element as well as isotopic compositions on 26 volcanic rocks from the Tertiary Hocheifel volcanic field and for comparison from Upper Rhine Graben occurrences (western Central European Volcanic Province) were measured in order to provide geochemical evidence for the geodynamic setting of the Tertiary Eifel volcanism. Except for a few differentiated lavas there are mainly basanitic compositions. These rocks were produced by low degree partial melting of a previously metasomatized garnet peridotite source at pressures and temperatures corresponding to depths of about 75 to 90 km. In contrast to the differentiated lavas, most of the basanites are not significantly affected by crustal contamination. In the Hocheifel, the crustally contaminated basanites and the differentiated lavas form an older age group (ca. 44-39 Ma). In contrast, the basanites not affected by crustal contamination belong to a younger age group (ca. 37-35 Ma) indicating a change in the petrogenetic style of evolution with time. Low-radiogenic Sr together with high-radiogenic Nd and Pb of the Hocheifel lavas show isotope characteristics similar to LVC (Low Velocity Composition) or FOZO (Focal Zone) mantle sources. Since FOZO is con-208 Fekiacova Z, Mertz DF, Hofmann AW sidered to be a common component in the entire mantle, a contribution from the deep mantle can be neither confirmed nor excluded. Plate reconstruction modelling indicates that the Hocheifel volcanic field at its time of activity ca. 40 m.y. ago was located ~1000 km southwest relative to its recent position, and therefore a relation to a mantle-stationary Quaternary Eifel plume is not plausible. Integrating evidence from geochronology, geochemistry, isotopic compositions and plate reconstruction, we conclude that the Tertiary Hocheifel volcanism is not genetically related to a mantle plume but is caused by Middle to Upper Eocene pre-rift extensional decompression related to the Rhine Graben taphrogenetic evolution.

show abstract

Crustal xenoliths from Cenozoic volcanic fields of West Germany: Implications for structure and composition of the continental crust

Cited by 56 publications

References 16 publications

Surface heat flow and lithosphere thermal structure of the Rhenohercynian Zone in the greater Luxembourg region

Surface heat flow and lithosphere thermal structure of the Rhenohercynian Zone in the greater Luxembourg region

USArray Imaging of Continental Crust in the Conterminous United States

Geodynamic Setting of the Tertiary Hocheifel Volcanism (Germany), Part II: Geochemistry and Sr, Nd and Pb Isotopic Compositions

Contact Info

Product

Resources

About