Person:
Canales Fernández, María Luisa

First Name

María Luisa

Last Name

Canales Fernández

URI

https://hdl.handle.net/20.500.14352/75214

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Geológicas

Department

Geodinámica, Estratigrafía y Paleontología

Area

Paleontología

Identifiers

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Now showing 1 - 10 of 26

El mar subtropical del Jurásico en Guadalajara
(Geología de Guadalajara, 2008) Gómez Fernández, Juan José; Canales Fernández, María Luisa; Calonge García, María Amelia; Rodríguez Martínez, Marta
Integrated biostratigraphy (Ammonoidea, Foraminiferida) of the Aalenian of the Lusitanian Basin (Portugal): A synthesis
(Episodes,Journal of International Geoscience, 2016) Henriques, Maria Helena; Canales Fernández, María Luisa; Silva, Silvia Clara; Figueiredo, Vera
This work reports a synthesis of biostratigraphic outputs resulting from over two decades of comprehensive analysis on the expressive stratigraphic record of the Aalenian of the Lusitanian Basin (Western Iberian Margin; Portugal). The rich and diverse ammonite record studied from ten marly and marlylimestones sections, outcropping in different sectors of the basin ranging from distal to proximal facies, has enabled the establishment of a detailed ammonite-based biostratigraphical framework correlated with other basins located around the Iberian Plate. The study of the benthic foraminiferal assemblages occurring in the basin at the same time interval has allowed the establishment of a biostratigraphic scale based on microfossils accurately calibrated with the ammonite record, an important tool in log interpretation in the context of hydrocarbon exploration activities in sedimentary basins of Jurassic age. The corresponding biostratigraphic units are characterized, as well as the bioevents recognized in the benthic foraminiferal record, which represent another additional proxy of local and/or regional rank that can be used to determine both the age and depositional environment assigned to core samples.
High resolution ammonite–benthic foraminiferal biostratigraphy across the Aalenian–Bajocian boundary in the Lusitanian Basin (Portugal)
(Geological Journal, 2015) Silva, S. C.; Henriques, M. H.; Canales Fernández, María Luisa
This work describes the ammonite and benthic foraminiferal assemblages recorded across the Aalenian–Bajocian boundary of the Serra da Boa Viagem II section, located about 6 km to the east of the Bajocian GSSP (Murtinheira, Portugal), and calibrated to the standard ammonite zonation previously established for the Lusitanian Basin. A total of 220 ammonite specimens referred to 30 fossiliferous levels were collected and identified throughout the section, enabling the recognition of the Concavum Zone (Concavum and Limitatum subzones) of the upper Aalenian, and the Discites Zone of the lower Bajocian. A total of 2356 foraminifers were obtained from the 16 samples collected along the section, corresponding to 4 suborders, 8 families, 16 genera and 44 species. The occurrence of Lenticulina quenstedti (Gümbel) has enabled the recognition of the Lenticulina quenstedti Zone, ranging from the Bradfordensis Zone (middle Aalenian) to the lower Discites Zone (lower Bajocian). The first record of Ramulina spandeli Paalzow, whose occurrence, up to now, was limited in the Lusitanian Basin to the Murtinheira section (the Bajocian GSSP), highlights the usefulness of the Ramulina spandeli Zone, with its lower boundary referred to the lower Discites Zone (lower Bajocian). Other bioevents displaying local, basinal or regional biostratigraphic interest have also been identified. The benthic foraminiferal record here presented, accurately calibrated with the ammonite record, aims at contributing to support the recognition of the Lenticulina quenstedti Zone and the Ramulina spandeli Zone as formal biostratigraphic units integrating the biostratigraphic scale based on benthic foraminifers for the Aalenian–Bajocian boundary in the Lusitanian Basin (Portugal).
Ammonite-benthic Foraminifera turnovers across the Lower-Middle Jurassic transition in the Lusitanian Basin (Portugal)
(Geobios, 2013) Paiva Henriques, María Helena; Canales Fernández, María Luisa
This paper describes and characterises the co-occurrence of ammonite and benthic foraminiferal assemblages across the Sao Giao outcrop (Central Portugal), a reference section for the Lower-Middle Jurassic boundary in the Lusitanian Basin. The upper Toarcian-lower Aalenian marls and marlylimestones in this section provide a precise and detailed ammonite-based biostratigraphic zonation, with a mixed assemblage of northwest European and Mediterranean faunal elements, associated with benthic foraminifera assemblages with northern hemisphere affinities, both correlatable with the Aalenian GSSP at the Fuentelsaz section (Iberian Cordillera, Spain). A total of 447 well-preserved ammonite specimens and 13.116 foraminifera have been studied; no evidence was detected of any taphonomic processes that could have changed the original assemblages. From a biostratigraphic point of view, the ammonite record has enabled four biostratigraphic units to be recognised (the Mactra and Aalensis subzones of the Aalensis Biozone in the upper Toarcian, and the Opalinum and Comptum subzones of the Opalinum Biozone in the lower Aalenian). With regard to the benthic foraminifera, the taxa identified have enabled the Astacolus dorbignyi Zone and 11 bioevents to be identified, most of which representing local biostratigraphic proxies. However, the increase in the relative abundance of Lenticulina exgaleata Dieni from the upper part of the Opalinum Subzone to the lower part of the Comptum Subzone has a regional value. The constant and continuous ammonite record of northwest European taxa, together with typical Mediterranean taxa – namely Grammoceratinae – throughout the section, the high relative abundance of Miliolina representatives – generally interpreted as foraminifers typical of shallow waters – and the absence of foraminiferal forms typical of cool waters, do not support the inference of cool seawater temperatures attributed to the Early Aalenian, or the global character of the ‘‘Comptum cooling event’’, at least with reference to the Lusitanian Basin.
Foraminiferal assemblages from the bajocian global stratotype section and point (GSSP) at Cape Mondego (Portugal)
(Journal of Foraminiferal Research, 2013) Canales Fernández, María Luisa; Paiva Henríques, Maria Helena
A detailed study of the benthic foraminiferal assemblages at the Bajocian Global Stratotype Section and Point (GSSP— Murtinheira section, Lusitanian Basin, western Portugal) presented herein increases the correlation potential of this relevant global geological time reference. The recorded assemblages are relatively abundant and diverse, and are composed of wellpreserved taxa typical of the Boreal Realm. The most abundant suborders are Lagenina and Spirillinina. Representatives of the Suborder Textulariina are also abundant in some assemblages, while those of the suborders Robertinina and Rotaliina are scarce. Lenticulina specimens are the most abundant in all assemblages, but at the specific level, there are differences between Aalenian and Bajocian assemblages, with Lenticulina muensteri being most abundant in the former and Spirillina orbicula in the latter. Two biozones, based on calcareous foraminifers, have been established and calibrated to the standard ammonite zonation: 1) the Lenticulina quenstedti Zone, ranging from the upper part of the Gigantea Subzone, Bradfordensis Biozone, upper Aalenian, to the lower part of the Discites Biozone, lower Bajocian, and 2) the Ramulina spandeli Zone, beginning at the top of the preceeding zone and having an undefined upper boundary. In addition, 11 bioevents are defined on first occurrences, last occurrences, changes in abundances of some taxa, or changes in assemblage diversity. After a severe impoverishment at the Aalenian–Bajocian transition, an important foraminiferal turnover takes place in the early Bajocian, where some Lower Jurassic and Aalenian forms are replaced by typical Middle Jurassic taxa
Foraminifera of the Toarcian-Aalenian boundary from the Lusitanian Basin (Portugal): a paleoecological analysis
(Journal of iberian geology, 2014) Figueiredo, V.; Canales Fernández, María Luisa; Henriques, M.H.
A detailed study carried out on 37 well preserved benthic foraminiferal assemblages sampled throughout the upper Toarcian-middle Aalenian in two well calibrated sections representing different facies within the Lusitanian Basin (Portugal) - the Maria Pares and the Zambujal de Alcaria sections - allows interpreting the past environmental conditions. Several mathematical indexes related to diversity, which enable establishing the particular conditions to which the assemblages were submitted, were applied. All the studied assemblages are characteristic of the Jurassic carbonate platforms of the Boreal Realm, in which the genus Lenticulina usually dominates. The suborder Lagenina is the most abundant, but taking the second more abundant suborder into account, the comparison between coeval sections in the Lusitanian Basin allows the recognition of a regional gradient ranging from the distal part of the platform (Murtinheira) towards the transitional and proximal parts of the shelf (sections of Maria Pares and Zambujal de Alcaria respectively). The relative abundance values, as well as the obtained data from the diversity indexes indicate that the studied assemblages are relatively abundant and diverse, reflecting general appropriate paleoenvironmental conditions for their development. The detailed analysis of the data allows the identification in both sections of three different episodes, traducing particular environmental conditions: unstable (Mactra Subzone-lower part of the Opalinum Subzone), favorable and stable (lower part of the Opalinum Subzone-upper part of the Comptum Subzone), and unfavorable (upper part of the Comptum Subzone-lower Bradfordensis Subzone). These data are consistent with previous results obtained in the sections of Murtinheira and São Gião, located in the Northern Lusitanian Basin and corresponding to the distal and transitional parts of the platform respectively, and they aimed at contributing to a better understanding of the paleoecological conditions prevailing within the Lusitanian Basin during the Early-Middle Jurassic times.
Accessible Geoparks in Iberia: a Challenge to Promote Geotourism and Education for Sustainable Development
(Geoheritage, 2019) Henriques, María Helena Paiva; Canales Fernández, María Luisa; García Frank, Alejandra; Gómez Heras, Miguel
This work aims at providing an overview regarding accessibility conditions for people with functional diversity among the 15 UNESCO Global Geoparks (UGGs) located in the Iberian Peninsula—4 in Portugal and 11 in Spain—from the point of view of a disabled user wishing to visit a geopark. Website information and a questionnaire composed of closed and multiple choice questions directly administrated to the geopark managers were used aiming at inquiring about facilities provided to people requiring adapted access conditions, including mobility, vision, hearing and cognitive dimensions of access both under the aim of geotourism activities or in the frame of educational programmes. Results show that Iberian UGGs display several facilities for the development of geotourism and education that meet the needs of people with functional diversity. Accessibility facilities to receive people with physical impairments are common, but sensory and communication access facilities are scarce. Geoparks’ websites generally lack information concerning facilities for special groups, and the web design does not meet the needs of people that have difficulties with written word and speech. The constraints on implementation of programmes aimed at disabled visitors can be partially overcome if geoparks’ leaders seek to integrate partners that currently develop activities for persons with disabilities. Geodivulgar (an innovation project from the Complutense University) and Science without Barriers (an association; Ciencia sin Barreras in Spanish) are pioneer initiatives for the outreach of geology among people with functional diversity in Spain, which currently develops activities and resources that can be of great help to enlarge the geoparks’ offer about geotouristic tours and/or educational programmes for disabled visitors. The acquired experience at the Basque Coast UGG can be of great help for other partners of the UGG Network to fully fulfil their roles as agents of sustainable development through geotourism and education for all.
Foraminifera from the Aalenian and the Bajocian GSSP (Middle Jurassic) of Murtinheira section (Cabo Mondego, West Portugal): Biostratigraphy and paleoenvironmental implications
(Marine micropaleontology, 2008) Canales Fernández, María Luisa; Henriques, María Helena Paiva
The detailed study of benthic foraminifera in 28 samples from Late Toarcian–Aalenian–Early Bajocian hemipelagic sediments of the Murtinheira section (Cabo Mondego, Lusitanian Basin, West Portugal), has permitted the recognition of the assemblage composition and the analysis of their evolution throughout this time interval. The representatives of the Suborder Lagenina dominate all the assemblages and, in the majority of them, the most abundant species is Lenticulina münsteri. The Late Toarcian and Early Aalenian assemblages are very similar. From the Comptum Subzone, a gradual replacement of the Early Jurassic forms by characteristic Middle Jurassic taxa takes place. During the Late Aalenian–Early Bajocian interval, a significant number of last occurrences (LOs) of taxa are recorded. The assemblages composition, the estimation of the relative taxa abundances and the data obtained from the calculation of several diversity indexes, together with the previous sedimentological and paleontological works in this area, indicate that these assemblages were developed in a shelfal basin environment. This platform showed normal marine salinity values, good oxygenation and was always located above calcite compensation depth (CCD). However, the environmental conditions were not always the best for the development of rich and diverse foraminiferal assemblages. These conditions were probably unstable during the Late Toarcian (Aalensis Subzone)–Early Aalenian (lower part of the Comptum Subzone). From the Comptum Subzone to the lower part of the Limitatum Subzone (Late Aalenian), conditions were more stable and more favourable for the development of foraminiferal communities. However, in the Aalenian–Bajocian transition the environmental conditions changed again and affected the development of this group. In the Limitatum Subzone a decrease in the diversity of the assemblages was recorded. This fact seems to be related to a global perturbation in the carbon-cycle that could have affected the foraminifera, together with other marine and continental organism groups.
Response of benthic foraminiferal assemblages to contrasting environments during the Aalenian–Bajocian in the Iberia: a case study from the Talveila section (Iberian Range) and Murtinheira section (Lusitanian Basin)
(Journal of Iberian Geology, 2018) Hernández, L.; Canales Fernández, María Luisa; Henriques, María Helena Paiva
This paper analyses the composition of the foraminiferal assemblages recorded in two different depositional contexts located in Iberia for the lower Aalenian–lower Bajocian stratigraphical interval: the Talveila section, corresponding to proximal facies within the Iberian Basin (NE Spain), and the Murtinheira section representing distal facies within the Lusitanian Basin (Western Portugal). The obtained specimens (10,736 in total) correspond to 6 suborders, 10 superfamilies, 16 families and 30 genera in Talveila, and 6 suborders, 9 superfamilies, 14 families and 26 genera in Murtinheira. Several biostratigraphic units based on the foraminiferal record and accurately calibrated with the ammonite record were recognized in both sections. Moreover, bioevents based on the first or last appearances of a taxon, significant changes in the abundance of one or several taxa or noticeable changes in diversity of the assemblages were also identified. The palaeoecological analysis shows that the foraminiferal assemblages from both sections were developed in a well-oxygenated and normal salinity shelf environment. The application of diversity indexes indicates that the paleoenvironmental conditions did not remain constant throughout the studied stratigraphic interval; changes recognized in both sections are similar, coeval and correspond to three intervals representing paleoenvironmental conditions more or less favourable for the development of the foraminiferal assemblages. As so, despite the different paleogeographical locations, the development of the assemblages in both sections during the Early Aalenian–Early Bajocian seem to have been conditioned by environmental changes of regional scale, which affected at the same time both the Iberian and the Lusitanian basins.
Abrupt diatom responses to recent climate and land use changes in the Cantabrian Mountains (NW Spain)
(Journal of paleolimnology, 2022) Gardoki, Jon; Morellón Marteles, Mario; Leira, Manel; Ezquerra, F. Javier; Remondo, Juan; Tinner, Willy; Canales Fernández, María Luisa; van der Horst, Anouk; Morales Molino, César
The multi-proxy study of sediment cores from Lake Isoba (43° 02′ N, 5° 18′ W; 1400 m a.s.l.) allows a detailed assessment of the past hydrological and environmental dynamics in north-western Iberia resulting from the interplay between climate variability and anthropogenic impact. The combination of diatom stratigraphy, sedimentology and high-resolution elemental geochemistry along with a robust chronological framework (established by 210Pb, 137Cs and 14C dating) provides a detailed environmental reconstruction for the past ~ 500 years. Abrupt changes in the fossil diatom assemblages indicate a high sensitivity of this small lake to past environmental change and allow identifying four major stages related to the main climate fluctuations of the Little Ice Age (LIA) and recent warming. High lake levels, enhanced runoff and higher productivity characterised the middle phase of the LIA (~ 1550 to 1630 CE), indicating an overall wet climate. Conversely, shallow lake levels, decreased runoff and relatively low productivity prevailed during the last phase of the LIA and the onset of the Industrial Era (~ 1630 to 1925 CE), likely due to colder and drier conditions. High lake levels and higher carbonate input occurred after ~ 1925 CE until the 1980s CE, when our data show an abrupt drop in lake levels probably caused by a regional negative rainfall anomaly related to climate warming during the past decades. Finally, since ~ 1997 CE a remarkable and abrupt increase in the lake nutrient load and turbidity is detected, probably associated with the replacement of transhumant sheep flocks with staying cattle. The main environmental changes reconstructed at Lake Isoba mostly agree with other palaeoclimatic records from northern Spain. However, the hydrological patterns reconstructed are opposed to those observed on the northern slopes of the Cantabrian Mountains. The recent and strong impact of land-use changes on the lake, causing more ecological disruptions than previous climate changes, is noteworthy and demonstrates the high sensitivity of mountain lakes to human activities in a global change context.