Both fragmental scientific quotations and misquotations can contribute to the spread of mistakes and cast confusion upon future research. We discuss several erroneous or conflictive statements and some misquotations found in an article published in GEODERMA. Many of the flaws are related with the occurrence of gypsum in soils and with the use of the term 'equivalent' in the designation of analytical results. Our reading of the subject article raises concerns about its validity, with practical implications on the future use of the concepts and data. The subject article by Badía et al. (2013) contains several erroneous or contradictory statements and misrepresentations of information from the published literature. Many of the above flaws occur in their discussions related to the occurrence of gypsum in soils and with use of the term "equivalent" in analytical results. Guerra and Monturiol (1970) do not use the "French taxonomy system", as stated by Badía et al. (2013) in their Introduction. This system is not mentioned in Guerra and Monturiol (1970), and their earlier publication (Guerra et al., 1968, page ix) states that most of the adopted

lavado de los materiales paleozoicos que atraviesa (Formación Bádenas), ricos en sulfuros metálicos dispersos. En los puntos de confluencia de este arroyo con afluentes de aguas neutras-alcalinas se producen espectaculares procesos de floculación de coloides ricos en aluminio y hierro que tapizan el fondo del arroyo. En este trabajo se presentan los primeros resultados obtenidos sobre las concentraciones de tierras raras (REE) de estas aguas ácidas (en muestras filtradas a través de mallas de 0,1 I-tm) y en los coloides asociados.Las pautas de tierras raras (normalizadas frente a NASC) de las aguas ácidas analizadas presentan globalmente un enriquecimiento relativo de las tierras taras pesadas (HREE) respecto a las ligeras (LREE), con relaciones Lun/La n = 2. No obstante, lo más llamativo de estas pautas es el considerable enriquecimiento en las tierras raras intermedias (IREE) representadas por Eu, Gd y Tb. Ello provoca que, en detalle, las pautas obtenidas para estas aguas puedan caracterizarse por un enriquecimiento en las tierras raras más pesadas desde La a Gd y por un empobrecimiento, también respecto a las más pesadas, entre Gd y Lu.Los contenidos de REE de los geles analizados son considerablemente superiores a los determinados en las aguas, presentando enriquecimientos de hasta tres y cuatro órdenes de magnitud. Las pautas de REE obtenidas para estos geles, tomados en distintos puntos del curso del Arroyo del Val, son considerablemente diferentes. La del coloide muestreado en el mismo punto que las aguas analizadas es similar a la de las soluciones, con una marcada convexidad para los IREE; la del otro gel, tomado aguas abajo respecto al anterior, presenta un perfil mucho más plano aunque todavía ligeramente convexo para los IREE.Aparentemente, el proceso de floculación coloidal observado en la primera confluencia del Arroyo del Val con un afluente de aguas neutras provoca una considerable disminución de las REE transportadas por las aguas ácidas (hasta un SO %). Yen ese punto, el coloide floculado presenta un enriquecimiento relativo en HREE respecto al observado en las aguas antes y en el punto de floculación.Palabras clave: Tierras raras, aguas ácidas, floculación, coloides. ABSTRACTAcidic waters of the «Arroyo del Val» stream are naturally generated by oxidation of sulfide minerals dispersed in the sedimentary materials of the drainage basin. Mixing of this acidic stream with neutral-alkaline tributaries yields spectacular iron and aluminium rich flocculants that precipitate at the confluences. Previous analysis of rare earth element (REE) concentrations of sorne 0.1 I-tm-filtered water samples and colloids are shown.The shale-normalized REE patterns of acidic waters show significant HREE enrichments in terms of Lun/La n (= 2) and they are tipically enriched in the intermediate REEs (IREEs, Eu-Gd-Tb). So, in detail, these patterns are characterized by HREE enrichments between La and Gd and HREE depletions between Gd and Lu.

In this study, the methodology of geochemical prospecting has been applied to the study of cadmium, lead, copper and zinc dispersion in the fine sediments of the upper course of the Huerva River (Iberian Range, NE Spain). The survey was organised in two stages: (1) general sampling along the river and its tributary channels, aimed at selecting the sections with the highest contents of the target elements, and (2) detailed study of those sections, aimed at an interpretation of possible positive geochemical anomalies and identification of their sources. The results of this study prove the existence of multiple and complex sources, with a significant influence of sources related to anthropogenic activity. However, the system shows a good ability to depurate itself under current conditions.

Solutions coming from two natural playa-lake saline systems located in Central Ebro Basin (NE Spain) have been evaporated in the laboratory, in order to obtain the precise path of chemical evolution followed until high concentration stages. The lakes belong to two chemically different neutral brines: La Playa (with Na-Cl solutions) and La Salada (Na-Mg-SO 4 type). Experimental evaporation has been carried out at 25 8C until total dryness, and samples collected along the experiment have been analysed for their major components. Application of geochemical modelling techniques allowed calculation of the saturation indexes for the main saline minerals using the PHRQPITZ program, which incorporates Pitzer's model. The mineral precipitation sequence for La Playa brines following the saturation data is: gypsum, halite, thenardite and epsomite. Brines reach saturation almost simultaneously with respect to both halite and thenardite, but halite precipitates more massively and hence the solid samples collected after total desiccation were composed mainly of halite. In the case of La Salada brines, the order of precipitation is somewhat different and is as follows: gypsum, mirabilite, thenardite and bloedite. Solid samples here consisted of bloedite and thenardite, this latter formed after subaquatic dehydration of mirabilite when brines attained a peritectic point. The evolution of saturation indexes is in good agreement with mineral determinations carried out on the solid experimental samples, and it allowed us to interpret the evaporative evolution of both La Playa and La Salada brines.

El análisis de diferentes factores físico-químicos que condicionan la solubilización del yeso-anhidrita, señala la importancia de la textura de la roca yesífera y de la presencia de NaCl en disolución. Procesos geomorfológicos tales como el escarpe y domo de Remolinos o el desarrollo de depresiones en El Castellar son el resultado de fenómenos de disolución de materiales evaporíticos en el Valle del Ebro. SUMMARYThe analysis of different physical-chemical factors for the solubilitation of the system gypsum-anhydrite remark the significance of textures and contents of NaCl in solutíon. Geomorphologíc processes such as the escarp and the dome of Remolinos or the depressions in El Castellar are effects of disolution phenomena for evaporitic materials in the Ebro Valley.El tema objeto de este trabajo pretende destacar algunos fenómenos concretos, muy espectaculares, de una región poco extensa: el borde meridional de los Montes de El Castellar, limitado al sur por el cauce del Ebro, haciendo hincapié en los fenómenos producidos en el área de Remolinos. Indicaremos algunos puntos que, a nuestro juicio, presentan alguna interpre-