Lamproitic rocks from Cabezo Negro de Zeneta: Brown micas as a record of magma mixing

Toscani, Lorenzo; Contini, Simona; Ferrarini, M.

doi:10.1007/bf01165122

Cited by 28 publications

(8 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2. K 2 O (wt.%) vs. SiO 2 classification diagram for orogenic magmatic rocks (Peccerillo and Taylor, 1976) with reported ultrapotassic, shoshonitic and calc-alkaline coeval rocks from Western Alps (Venturelli et al, 1984a), Corsica (Peccerillo et al, 1988), Murcia-Almeria (Venturelli et al, 1984b;Toscani et al, 1990Toscani et al, , 1995Venturelli et al, 1991a, b;Contini et al, 1993;Guarnieri, 2007), and Tuscany (Conticelli and Peccerillo, 1990;Conticelli et al, , 2001Ferrari et al, 1995;Conticelli, 1998;Perini et al, 2003Perini et al, , 2004Chelazzi et al, 2006;Conticelli's unpublished data). 2007), with data plotting on the potassium-rich basaltic andesite to rhyolite fields, partially overlapping high-K calc-alkaline rocks from Corsica and Murcia-Almeria (Fig. 2).…”

Section: Western Alpsmentioning

confidence: 69%

See 1 more Smart Citation

Trace elements and Sr–Nd–Pb isotopes of K-rich, shoshonitic, and calc-alkaline magmatism of the Western Mediterranean Region: Genesis of ultrapotassic to calc-alkaline magmatic associations in a post-collisional geodynamic setting

Conticelli

Guarnieri

Farinelli

et al. 2009

Lithos

280

206

View full text Add to dashboard Cite

High-MgO ultrapotassic rocks are found in four different areas of the Western Mediterranean basin associated in space and time with shoshonitic and calc-alkaline rocks. They represent different magmatic events at the active continental plate margin from Oligocene to Pleistocene. These rocks are found within the Western Alps (Northern Italy), in Corsica (France), in Murcia-Almeria (South-Eastern Spain), and in Southern Tuscany (Central Italy). Ultrapotassic terms are mostly lamprophyres, but olivine latitic lavas with a clear lamproitic affinity are also found. Lamproite-like rocks range from slightly silica under-saturated to silica over-saturated, and they are characterised by low Al 2 O 3 , CaO, and Na 2 O contents. They are plagioclase-free rocks, but K-feldspar is abundant beside other K-bearing phases. Shoshonitic and calc-alkaline rocks are invariably space associated to lamproites, and they either precede or follow them. High-Mg ultrapotassic rocks are characterised by strong enrichment of incompatible elements, which prevent further enrichment due to shallow level crustal contamination. K 2 O and incompatible element contents decrease passing from high-Mg ultrapotassic to high-Mg shoshonitic and calc-alkaline rocks suggesting that K and incompatible trace elements enrichments are a primary characteristic. Ultrapotassic to calc-alkaline rocks from Western Mediterranean regions, in spite of their different age of emplacement, are characterised by similar incompatible trace elements distribution. Depletion of High Field Strength elements with respect to Large Ion Lithophile elements is observed. Positive spikes at Th, U, and Pb, with negative spikes at Ba, Nb, Ta, Sr, P, and Ti, are common characteristics of ultrapotassic (lamproitic) to high-K calc-alkaline rocks. Ultrapotassic rocks are extremely enriched in radiogenic Sr and unradiogenic Nd with respect to the associated shoshonitic and calc-alkaline rocks. Different isotopic values are distinctive of the different magmatic provinces irrespective of magmatic affinities. 87 Sr/ 86 Sr i ranges between 0.71645 and 0.71759 for Western Alps lamproites, between 0.71226 and 0.71230 for Corsica lamproite, between 0.71642 and 0.72259 for Murcia-Almeria lamproites, and between 0.71578 and 0.71672 for Tuscany lamproites. Radiogenic Sr decreases along with K 2 O through shoshonitic to calc-alkaline rocks. Conversely 143 Nd/ 144 Nd i values increase with decreasing K 2 O, with the highest value of 0.51243 found for the one samples from Murcia-Almeria. Contrasting trends are observed among initial values of lead isotopes, but all falling well within the field of upper crustal rocks. Different trends of 207 Pb/ 204 Pb i and 208 Pb/ 204 Pb i vs. 206 Pb/ 204 Pb i for samples from the different provinces are observed. Several evidences indicate that most of the magmas of the different provinces have been generated in a depleted upper mantle (i.e., lithospheric) modified by metasomatism, but an asthenospheric component is also recognised in Corsica. At least two different s...

show abstract

Section: Western Alpsmentioning

confidence: 69%

“…2). MgO ranges from 1.73 to 16.7 wt.% (e.g., Venturelli et al, 1984bVenturelli et al, , 1991aVenturelli et al, , 1991bContini et al, 1993;Toscani et al, 1995;Guarnieri, 2007), showing a bell shaped differentiation pattern on a K 2 O vs. silica diagram (Fig. 2).…”

Section: Murcia-almeriamentioning

confidence: 99%

Trace elements and Sr–Nd–Pb isotopes of K-rich, shoshonitic, and calc-alkaline magmatism of the Western Mediterranean Region: Genesis of ultrapotassic to calc-alkaline magmatic associations in a post-collisional geodynamic setting

Conticelli

Guarnieri

Farinelli

et al. 2009

Lithos

280

206

View full text Add to dashboard Cite

show abstract

“…Previous studies have shown that fractionation coupled with assimilation, and/or mixing with crust-derived magma(s) operated during Mediterranean lamproite genesis (Van Bergen et al, 1983;Toscani et al, 1995;Conticelli, 1998;Prelević et al, 2004b;Duggen et al, 2005). Many of the previous studies, however, have convincingly excluded the possibility that assimilation of crustal material may have been principally responsible for the main geochemical signatures Conticelli and Peccerillo, 1992;Conticelli, 1998).…”

Section: Process Identificationmentioning

confidence: 91%

Mediterranean Tertiary lamproites derived from multiple source components in postcollisional geodynamics

Prelević

Foley

Romer

et al. 2008

Geochimica et Cosmochimica Acta

246

191

View full text Add to dashboard Cite

“…The coexistence of phlogopite and biotite, which is an important characteristic of these rocks, has already been reported from many areas where mixing of magmas had occurred (e.g. Carlier et al, 1994;Prelević et al, 2004;Toscani et al, 1995;Venturelli et al, 1984). Phlogopite is often found as 300 μm long microphenocrysts that commonly show effects of incomplete growth (or dissolution?)…”

Section: Rock Classification Petrography and Mineral Chemistrymentioning

confidence: 96%

Oligocene shoshonitic rocks of the Rogozna Mts. (Central Balkan Peninsula): Evidence of petrogenetic links to the formation of Pb–Zn–Ag ore deposits

Šoštarić

Cvetković

Neubauer

et al. 2012

Lithos

View full text Add to dashboard Cite

Lamproitic rocks from Cabezo Negro de Zeneta: Brown micas as a record of magma mixing

Cited by 28 publications

References 23 publications

Trace elements and Sr–Nd–Pb isotopes of K-rich, shoshonitic, and calc-alkaline magmatism of the Western Mediterranean Region: Genesis of ultrapotassic to calc-alkaline magmatic associations in a post-collisional geodynamic setting

Trace elements and Sr–Nd–Pb isotopes of K-rich, shoshonitic, and calc-alkaline magmatism of the Western Mediterranean Region: Genesis of ultrapotassic to calc-alkaline magmatic associations in a post-collisional geodynamic setting

Mediterranean Tertiary lamproites derived from multiple source components in postcollisional geodynamics

Oligocene shoshonitic rocks of the Rogozna Mts. (Central Balkan Peninsula): Evidence of petrogenetic links to the formation of Pb–Zn–Ag ore deposits

Contact Info

Product

Resources

About