Maria Angeles Garcia del Cura

Concepción Bonet Muñoz (1916-2014) fue la primera mujer que se incorporó a la geología profesional y, además contribuyó en la implementación de la fotogeología en España. Cursó Ciencias Naturales en Madrid, graduándose en 1943. Se dedicó a la enseñanza, y en 1950 obtuvo una beca del CSIC para especializarse como paleontóloga. Entre 1953 y 1954, realizó una estancia en la Universidad de Heerlen (Holanda) para estudiar las megasporas carboníferas. Defendió su Tesis Doctoral en 1955. Entre 1954 y 1956 dió clases en la Facultad de Ciencias Naturales. Se especializó en Fotogeología y entre 1956 y 1973 impartió clases de fotogeología. En 1957 ingresó en la Junta de Energía Nuclear, dónde creó el Departamento de Fotogeología y realizó varias estancias de especialización en el extranjero. En 1964 entró en la Dirección General de Carreteras del Ministerio de Obras Públicas, donde permaneció hasta que se jubiló en 1984. Trabajó en el desarrollo del Plan General de Carreteras y participó en los Estudios Geológicos Previos de las principales carreteras, donde influyó en la metodología de trabajo, incluyendo los fotoplanos geológicos como herramienta fundamental de trabajo, tanto por su aportación al conocimiento de la geomorfología como por su utilidad para buscar materias primas para la obra pública.

This paper compares different experimental methods for measuring water permeability in 17 different porous building rocks. Both commercial apparatus and specially made designed permeameters are used for characterising intrinsic permeability and hydraulic conductivity, k, of rocks in the range of 10−12 to 10−4 m/s (~ 10−19−10−11 m2 or ~ 10−4−104 mD). We use both falling head and constant head permeameter methods including the triaxial and modified triaxial tests and a classical constant head permeameter. Results showed that for very low and low permeability samples (k< 10−6 m/s), triaxial conditions were found the most accurate procedures and they provided similar or slightly lower permeability values than constant and falling head methods. The latter techniques were highly recommended for permeable and high permeable porous building materials. Water permeability values were also linked to effective porosity and interpreted in terms of interparticle and vugs porosity. Finally, some modifications in the apparatus and procedures were carried out in order to assess water permeability in soft materials, which involve the use of non-saturated samples.

This article reports evidence for biologically mediated precipitation of dolomite in a fresh water spring in the south‐east of Spain. Build‐ups in the spring consisted of calcite, minor dolomite, barite and gypsum crystals formed by the mineralisation of microbial biofilms and bryophytes. A detailed microscopic study, coupled with geochemical analysis of the dolomite‐precipitating biofilms, showed that dolomite crystals occurred in association with living coccoid micro‐organisms, providing strong evidence that micro‐organisms play a fundamental role in the precipitation of this mineral. Many of the calcite crystals observed were associated with extracellular polymeric substances. Moreover, microbial involvement in the precipitation of calcite was further supported by the presence of living cyanobacteria within the calcite crystals. Two different types of build‐up were found in the spring: soft spongy moss tufa and laminated crusts. Two types of crusts were identified as follows: simple pink crusts and laminated crusts, the latter forming in both sub‐aquatic and sub‐aerial environments. Sub‐aquatic accumulation of simple detached pink crust fragments occurred sporadically. Both tufa and the carbonate crusts hosted cyanobacterial‐dominated biofilms with different bacteria and diatoms and their extracellular polymeric substances. The δ¹³C values of calcite showed some biogenic involvement in the origin of this mineral. The δ¹⁸O values were similar in the tufa and carbonate crusts and corresponded to current climatological characteristics. The occurrence of different groups of minerals (carbonates and sulphates) in close spatial association with micro‐organisms suggests the presence of different macro‐environmental and micro‐environmental conditions that facilitate mineral precipitation within biofilms. These findings extend the known range of aerobic microbial dolomites to include springs, and show that the precipitation of both dolomite and calcite carbonates occurs while organisms are alive.

Shoreline gypsiferous sediments of an inland lake in central Spain furnishes valuable insight into reconstructions of early sedimentary changes related to shore fly–microbial mat interactions in fossil gypsum precipitating saline lake systems. The association of adult and larval forms of Ephydra (Diptera) with microbial matgrounds overlying the lake margin results in the formation of gypsiferous meniscate back‐filled burrows that provide an analogue for recurring, extensively developed trace fossils that occur in Cenozoic, but not older, lacustrine gypsum rocks. In this setting, sediment burrowing by ephydridae hinders significant preservation of microbialites. The overwhelming rise of Diptera at the onset of the Cenozoic resulted in extensive feeding and dwelling activity and contributed to reshape the saline aquatic habitat where microbial mats thrived, thus leading to the formation of specific trace fossils that are illustrative of the existence of microbes in the paleoenvironment.