English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/131663
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:


Chabazite and dolomite formation in a dolocrete profile: An example of a complex alkaline paragenesis in Lanzarote, Canary Islands

AuthorsAlonso-Zarza, Ana María ; Bustamante, Leticia; Huerta, Pedro; Rodríguez-Berriguete, Álvaro ; Huertas, María José
Canary Islands
Issue Date10-Mar-2016
CitationSedimentary Geology, 337: 1–11 (2016)
AbstractThis paper studies the weathering and soil formation processes operating on detrital sediments containing alkaline volcanic rock fragments of the Mirador del Río dolocrete profile. The profile consists of a lower horizon of removilised weathered basalts, an intermediate red sandy mudstones horizon with irregular carbonate layers and a topmost horizon of amalgamated carbonate layers with root traces. Formation occurred in arid to semiarid climates, giving place to a complex mineralogical association, including Mg-carbonates and chabazite, rarely described in cal/dolocretes profiles. Initial vadose weathering processes occurred in the basalts and in directly overlying detrital sediments, producing (Stage 1) red-smectites and dolomicrite. Dominant phreatic (Stage 2) conditions allowed precipitation of coarse-zoned dolomite and chabazite filling porosities. In Stages 3 and 4, mostly pedogenic, biogenic processes played an important role in dolomite and calcite accumulation in the profile. Overall evolution of the profile and its mineralogical association involved initial processes dominated by alteration of host rock, to provide silica and Mg-rich alkaline waters, suitable for chabazite and dolomite formation, without a previous carbonate phase. Dolomite formed both abiogenically and biogenically, but without a previous carbonate precursor and in the absence of evaporites. Dominance of calcite towards the profile top is the result of Mg/Ca decrease in the interstitial meteoric waters due to decreased supply of Mg from weathering, and increased supply of Ca in aeolian dust. Meteoric origin of the water is confirmed by C and O isotope values, which also indicate lack of deep sourced CO2. The dolocrete studied and its complex mineral association reveal the complex interactions that occur at surface during weathering and pedogenesis of basalt-sourced rocks.
Publisher version (URL)http://dx.doi.org/10.1016/j.sedgeo.2016.02.018
Appears in Collections:(IGEO) Artículos
Files in This Item:
File Description SizeFormat 
SG_2016_337_1.pdf3,13 MBAdobe PDFThumbnail
Show full item record
Review this work

Related articles:

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.