000057804 001__ 57804
000057804 005__ 20170327111900.0
000057804 0247_ $$2doi$$a10.1111/sed.12053
000057804 0248_ $$2sideral$$a89076
000057804 037__ $$aART-2014-89076
000057804 041__ $$aeng
000057804 100__ $$0(orcid)0000-0002-4212-0524$$aArenas, C.$$uUniversidad de Zaragoza
000057804 245__ $$aSedimentology and depositional architecture of tufas deposited in stepped fluvial systems of changing slope: Lessons from the quaternary añamaza valley (Iberian Range, Spain)
000057804 260__ $$c2014
000057804 5060_ $$aAccess copy available to the general public$$fUnrestricted
000057804 5203_ $$aThe Pleistocene and Holocene tufas of the Añamaza valley (stepped build-ups, up to 70 m thick, along the valley) consist of several depositional stages separated by erosional surfaces. Eight associations of tufa and related carbonate facies, plus minor polygenic detrital facies, represent the processes that occurred in different fluvial and related environments. The bedrock lithology and structure controlled the location of the knickpoints along the valley and allowed separation of two stepped stretches with distinct conceptual facies models. The moderate-slope model includes extensive standing-water areas dammed by barrage-cascades. In the lakes, bioclastic silts, sands and limestones along with phytoclastic and marly, at places peaty, sediments formed. Abundant stem phytoherms account for extensive palustrine areas. The high-slope model consists of smaller dammed areas between close-up cascades and barrage-cascades, which were composed primarily of moss phytoherms and phytoclastic tufas. An outstanding feature is the extensive steep reach with phytoclastic and polygenic detrital sediments, and stepped cascades consisting of stromatolitic and moss phytoherms. There, the steep slope limited the preservation of stem phytoherms and favoured erosion. The geometry and thickness of the sedimentary fill (wedge-shaped units composed of cascade and barrage-cascade deposits downstream, and dammed and gentle-sloped channel deposits upstream) are therefore different for each model. Multi-storey wedges are a distinctive feature of the high-slope model. The initial knickpoint geometry and the tufa aggradation/progradation ratio on such steep surfaces (for example, related to changes in discharge) controlled the growth style of the cascades or barrage-cascades and, hence, the extent, thickness and vertical evolution of the upstream deposits. The sedimentological attributes and stable-isotope composition of the carbonate facies suggest a higher and more variable precipitation/evaporation ratio during the Pleistocene than during the Holocene, consistent with an overall decrease in the river discharge. This evolution was coupled with warm conditions, which prevailed during the stages of tufa formation. These results may help to assess architectural patterns in interpreting other basins, and underscore the significance of tufas as records of past hydrology and climate.
000057804 536__ $$9info:eu-repo/grantAgreement/ES/REN2002-03575-CLI$$9info:eu-repo/grantAgreement/ES/MINECO/CGL2009-09216-BTE$$9info:eu-repo/grantAgreement/ES/MICINN/CGL2006-05063-BTE
000057804 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000057804 590__ $$a2.948$$b2014
000057804 591__ $$aGEOLOGY$$b6 / 44 = 0.136$$c2014$$dQ1$$eT1
000057804 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000057804 700__ $$aVázquez-Urbez, M.
000057804 700__ $$0(orcid)0000-0001-6082-5301$$aPardo G.$$uUniversidad de Zaragoza
000057804 700__ $$0(orcid)0000-0002-1304-2264$$aSancho, C.$$uUniversidad de Zaragoza
000057804 7102_ $$12000$$2427$$aUniversidad de Zaragoza$$bDepartamento de Ciencias de la Tierra$$cGeodinámica Externa
000057804 7102_ $$12000$$2280$$aUniversidad de Zaragoza$$bDepartamento de Ciencias de la Tierra$$cEstratigrafía
000057804 773__ $$g61, 1 (2014), 133-171$$pSedimentology$$tSEDIMENTOLOGY$$x0037-0746
000057804 8564_ $$s6373730$$uhttp://zaguan.unizar.es/record/57804/files/texto_completo.pdf$$yVersión publicada
000057804 8564_ $$s97731$$uhttp://zaguan.unizar.es/record/57804/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000057804 909CO $$ooai:zaguan.unizar.es:57804$$particulos$$pdriver
000057804 951__ $$a2016-12-21-12:51:28
000057804 980__ $$aARTICLE