000064513 001__ 64513
000064513 005__ 20200221144303.0
000064513 0247_ $$2doi$$a10.1180/claymin.2016.051.5.03
000064513 0248_ $$2sideral$$a103913
000064513 037__ $$aART-2016-103913
000064513 041__ $$aeng
000064513 100__ $$aCampo, M. do
000064513 245__ $$aSEM and TEM evidence of mixed-layer illite-smectite formed by dissolutioncrystallization processes in continental Paleogene sequences in northwestern Argentina
000064513 260__ $$c2016
000064513 5060_ $$aAccess copy available to the general public$$fUnrestricted
000064513 5203_ $$aIn the northernmost Calchaquí Valley (Salta, Argentina), the Paleogene continental sediments show a transition from smectite, at the top, to R3 I-S (>90% illite) through R1 I-S (65–80% illite), in contrast to the remaining sectors, containing smectite up to the bottom. Samples at the base of the succession were characterized by high-quality step-scan X-ray diffraction (XRD), scanning electron microscopy (SEM) and analytical high-resolution transmission electron microscopy (HRTEM). Analysis by SEM demonstrated dissolution of primary phases (feldspars, micas and quartz) and crystallization of illite, I-S and kaolinite. As this alteration is not pervasive, an intermediate fluid/rock ratio could be inferred. The lattice-fringe images of the samples from upper parts of the sequence show abundant I1-rich areas, whereas in the lower parts of the sequence, illite packets and I3 I-S coexist and compositions evolve towards muscovite (tetrahedral-charge increase, principally compensated by Mgby-Al substitution in octahedral sites and by a slight decrease in Ca in interlayer sites). As burial temperatures were probably similar in all the samples, depth was not responsible for the illite formation at the bottom. The TEM textures suggest that illitization proceeded mainly by dissolution-crystallization. The active faults close to the northern Calchaquí Valley probably promoted the circulation of hot, deep fluids, favouring illitization.
000064513 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/CGL2011-30153-C02-01$$9info:eu-repo/grantAgreement/ES/MINECO/CGL2013-46169-C2-1-P
000064513 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/
000064513 590__ $$a1.052$$b2016
000064513 591__ $$aMINERALOGY$$b17 / 29 = 0.586$$c2016$$dQ3$$eT2
000064513 591__ $$aCHEMISTRY, PHYSICAL$$b119 / 145 = 0.821$$c2016$$dQ4$$eT3
000064513 591__ $$aGEOSCIENCES, MULTIDISCIPLINARY$$b143 / 188 = 0.761$$c2016$$dQ4$$eT3
000064513 592__ $$a0.364$$b2016
000064513 593__ $$aGeochemistry and Petrology$$c2016$$dQ3
000064513 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000064513 700__ $$0(orcid)0000-0002-4970-6333$$aBauluz, B.$$uUniversidad de Zaragoza
000064513 700__ $$aNieto, F.
000064513 700__ $$aPapa, C. del
000064513 700__ $$aHongn, F.
000064513 7102_ $$12000$$2120$$aUniversidad de Zaragoza$$bDpto. Ciencias de la Tierra$$cÁrea Cristalografía Mineralog.
000064513 773__ $$g51, 5 (2016), 723-740$$pClay miner.$$tCLAY MINERALS$$x0009-8558
000064513 8564_ $$s960990$$uhttps://zaguan.unizar.es/record/64513/files/texto_completo.pdf$$yVersión publicada
000064513 8564_ $$s62930$$uhttps://zaguan.unizar.es/record/64513/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000064513 909CO $$ooai:zaguan.unizar.es:64513$$particulos$$pdriver
000064513 951__ $$a2020-02-21-13:33:33
000064513 980__ $$aARTICLE