Geochemistry and petrology of recycled orogen-derived sediments: a case study from Upper Precambrian siliciclastic rocks of the Central Iberian Zone, Iberian Massif, Spain

Ugidos, J. M.; Armenteros, Ildefonso Armenteros; Barba, Pedro; Valladares, M.I.; Colmenero, Juan Ramón

doi:10.1016/s0301-9268(97)00023-5

Cited by 52 publications

(42 citation statements)

References 28 publications

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“…5a,b) and the Ediacaran shales from Cantabrian Zone and NIBAS (Neoproterozoic 238 Iberian Average Shale. Ugidos et al 2010) show the same mean REE patterns and those 239 of the corresponding mean sandstones (Ugidos et al 1997b) are also the same (Fig. 5c).…”

Section: Ediacaran Shales and Sandstones 226supporting

confidence: 64%

The Ediacaran–Cambrian transition in the Cantabrian Zone (northern Spain): sub-Cambrian weathering, K-metasomatism and provenance of detrital series

Ugidos

Barba

Valladares

et al. 2016

JGS

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Ugidos, J.M., Barba, P., Valladares, M.I., Suarez, M., and Ellam, R.M. (2016) The Ediacaran-Cambrian transition in the Cantabrian Zone 1 (North Spain): sub-Cambrian weathering, K-metasomatism and provenance of detrital series. Journal of the Geological Society, 173(4), pp. 603-615. (doi:10.1144/jgs2016-004) This is the author's final accepted version.There may be differences between this version and the published version. You are advised to consult the publisher's version if you wish to cite from it.http://eprints.gla.ac.uk/115950/ Abstract: The Upper Ediacaran detrital succession in the Cantabrian Zone shows 9 geochemical and mineralogical changes resulting from sub-Cambrian weathering during 10 the Late Ediacaran worldwide sea-level fall. Relative to the unaltered rocks the altered 11 ones show crosscutting rubefaction of varying thickness a remarkable increase in illite, 12 K 2 O, Rb and Cs indicating K-metasomatism, and also depletion in MgO, CaO, Na 2 O, 13Be and Sr, but not in Zr, Nb, Y, Sc. The basal Cambrian siliciclastic rocks mostly 14 consist of detritus derived from the Ediacaran materials, as demonstrated by the 15 geochemical and Nd-isotope data [ Nd (t) ranges: -3.4 to -2.1, and -3.6 to -1.8, 16respectively)]. However, these geochemical features of the basal Cambrian change 17 upwards to more evolved compositions with lower  Nd (t) values (-4.9 to -5.8 Worldwide, the Ediacaran-Cambrian boundary corresponds to a major unconformity in 27 most sections, suggesting a possible eustatic fall in sea level (Bartley et al. 1998; Saylor 28 2003;Knoll et al. 2004;Pyle et al. 2004 Thomas et al. 2004;Soulaimani et al. 2004; 42 Álvaro et al. 2010). 43In the Cantabrian Zone (Fig. 1) which is an angular unconformity. In the Central Iberian Zone (Fig. 1A) in slope and base-of-slope environments (Valladares et al. 2000). 97The Herrería group (Fig. 2) predominantly consists of sandstones with some levels of 98 conglomerates, shales and carbonates, with a thickness varying between 900 m in 99Barrios de Luna (Fig. 1B) and 1500 m in the Cangas de Narcea-Mieldes areas (Comte 100 1959). The lower part of this group consists of conglomerates that locally displays 101 volcanic clasts, and have a lenticular geometry (Fig. 1B) followed by Rusophycus and Cruziana species, indicating that this member yielded 106 associations of ichnofossils suggestive of a Late Corduban age (Liñan et al. 2002). 107The Lower Cambrian begins with conglomerate and sandstone-shale alternations 108 deposited in alluvial and braided-channel environments at the base, which evolved 109 upwards to tidal environments. In a restricted area close to Mieldes (Fig. 1B) other Ediacaran outcrops are observable. In the IR and Sierra de la Demanda (Fig. 1A, 126 SD), the basal Lower Cambrian also has conglomerate beds but no volcanic clasts have 127 5 been reported; instead, subrounded clasts of white quartz prevail (Álvaro et al. 2008; 128 Ábalos et al. 2011). 129 Mineralogy 130XRD semi-quantitative data on the rock-forming minerals in the ru...

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Section: Ediacaran Shales and Sandstones 226supporting

confidence: 64%

The Ediacaran–Cambrian transition in the Cantabrian Zone (northern Spain): sub-Cambrian weathering, K-metasomatism and provenance of detrital series

Ugidos

Barba

Valladares

et al. 2016

JGS

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“…15,18 Provenance analysis of these rocks reveals a recycled orogen (sedimentary and metasedimentary lithic) source. Neither the petrology nor the geochemistry reveals any coeval volcanic contribution to the sediments 21,22 and no other volcanic rocks have been described in the region. The closest volcanic episodes are those related with the late Miocene to the recent alkaline intraplate volcanic field of Campo de Calatrava, 23 which are located in central Spain, approximately 250 km to the southeast of El Gasco.…”

Section: El Gasco Pumicementioning

confidence: 92%

Micro‐Raman spectroscopic study of El Gasco pumice, western Spain

Rull

Martínez‐Frías

Rodríguez-Losada

2006

J Raman Spectroscopy

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A micro-Raman spectroscopic study of pumice materials from El Gasco (Sierra de Gata, Spain) has been performed for the first time. The obtained spectra allow the precise identification of the minerals, quartz, haematite, magnetite, ilmenite, rutile and anatase, in general agreement with results obtained by complementary techniques of X-Ray Diffraction (XRD) and Electron Microprobe. Also, fayalite and ferroan ringwoodite have been identified. The presence of high-pressure polymorphs indicates that the pumice rocks were subjected to high-pressure conditions quite similar to those observed in shock-induced molten and recrystallised materials, such as some meteorites and impact-related rocks.

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“…Geochemical studies on the protolith show that Neoproterozoic-Lower Cambrian sandstones and shales [8][9][10][11][12]35] reveal a great homogeneity in the composition through the CIZ and WALTZ [7,36] as well as in areas of Central and Western Europe. These authors agree on the evidence that the sedimentary series record two provenance areas: a detrital material derived from recycled orogens and an important juvenile contribution, which governs their isotopic signature.…”

Section: Geochemical Featuresmentioning

confidence: 99%

“…[4][5][6][7][8][9][10][11][12]). It comprises Neoproterozoic -Lower Cambrian metasedimentary rocks considered as a possible protolith of the Peña Negra complex and many other granitic complexes in central Iberia [3,13].…”

Section: Introductionmentioning

confidence: 99%

Evidence of Protolith Contamination in the Generation of an Anatectic Complex: Peña Negra, Central Spain

Pereira¹,

Alonso²,

Salman³

2008

TOMJ

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Abstract:The Peña Negra complex, in central Spain, provides a superb opportunity for the study of Variscan partial melting processes. The heat source for the anatexis has been controversial. The presence of mafic rocks in the vicinity has given rise to the suggestion that mafic magmas of mantle origin provided the requisite heat for the generation of the anatectic granites. Experimental petrology can be used to support this concept, but the volumes of mafic magma necessary for the anatexis appear improbably large. Geophysical models for Central Iberia do not support the presence of such large basic complexes at depth. Furthermore radiometric dating of the scarce mafic outcrops indicates that they are too old to have been involved in the granitic magma genesis. The alternative interpretation is that melting of the protolith was promoted by the radioactive decay of K, U and Th. Anatexis was enhanced by the existence of a fertile protolith and by the presence of shear structures that permitted volatile fluxing. The situation is believed to have been analogous to that in other European Variscan terrains.

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Geochemistry and petrology of recycled orogen-derived sediments: a case study from Upper Precambrian siliciclastic rocks of the Central Iberian Zone, Iberian Massif, Spain

Cited by 52 publications

References 28 publications

The Ediacaran–Cambrian transition in the Cantabrian Zone (northern Spain): sub-Cambrian weathering, K-metasomatism and provenance of detrital series

The Ediacaran–Cambrian transition in the Cantabrian Zone (northern Spain): sub-Cambrian weathering, K-metasomatism and provenance of detrital series

Micro‐Raman spectroscopic study of El Gasco pumice, western Spain

Evidence of Protolith Contamination in the Generation of an Anatectic Complex: Peña Negra, Central Spain

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