Pedro Callapez

Micropaleontología y Estratigrafía del límite Cenomaniense/Turoniense en la Cuenca Lusitánica, Portugal

En este trabajo se describe la sucesion de naturaleza carbonatica de edad Cretacico medio expuesta en la region del valle del Rio Mondego (Cuenca Lusitanica, Margen Occidental de Iberia, Portugal) y su contenido microfosil. La mayoria de las secciones del limite Cenomaniense-Turoniense descritas en la bibliografia registran facies de ambientes marinos de mayor rofundidad, mientras que la seccion que se presenta en este trabajo muestra dicha transicion en depositos formados en un ambiente marino de aguas poco profundas. Los escasos foraminiferos benticos que han sido hallados en esta sucesion no habian sido estudiados en detalle previamente en relacion al evento de extincion del fi nal del Cenomaniense. En la sucesion del Rio Mondego ha sido analizado tambien el “horizonte de ejecta”, expuesto en el litoral de Praia da Vitoria, 10 km al norte de Nazare.

Holocene interplay between a dune field and coastal lakes in the Quiaios– Tocha region, central littoral Portugal

Coastal dune fields and dune-body associated lakes were studied through sedimentological, malacological and palynological analyses. Lake deposits and palaeosoil horizons gave new information about phases of aeolian activity and dune building, coastline and sea level, vegetation history and cultural impact. After a period of intense aeolian activity (Late Pleistocene) that limited soil-forming processes, a wet aeolian field, recorded by podzolized sands and interdune wetland deposits, was present in the region. Around 5000 to 4000 yr BP sea level reached the current level and the coastline was situated c. 1 km further inland compared with the present situation. Subsequently lagoon-barrier island systems developed c. 4000 yr BP. Vegetation in the region during this time was a pine/oak forest. Between 4000 and 1600 yr BP the forest was replaced by a semi-natural heathland. Later the heathland was degraded, allowing dune migration and finally formation of a desert-like landscape. This process was probably a consequence of a combination of deteriorating climate during the ‘Little Ice Age’ (LIA) and overgrazing. To counteract sand invasion, reforestation efforts were initiated in the region c. 300 years ago and locally along the coastal margin between 1924 and 1940. Formation of the row of freshwater lakes bordering the dune field at present was contemporaneous with the initial reforestation phase. A close relation between lake formation and accumulation of sand dunes was found. Various types of dunes were identified, truncated dunes, parabolic dunes and transverse/oblique dunes. Dune migration caused an eastward displacement of lakes.

Palaeoenvironmental significance of clay minerals in Upper Cenomanian–Turonian sediments of the Western High Atlas Basin (Morocco)

Abstract Upper Cenomanian-Turonian clay mineral assemblages of sediments cropping out in the Western High Atlas basin are studied in four sections. Smectite and mixed-layer illite-smectite (I-S) have been identified as major constituents of the deposits. The composition of clay associations in black shales and associated sediments varies considerably according to age, but usually depends either on the general lithology, the abundance of organic matter, or the depth of burial. A distinct correlation is evident between clay mineral distribution and sea-level. Smectite and mixed-layer I-S with greater percentages of smectite layers increase in sediments deposited during transgressive periods, whereas they decrease progressively in the shallower facies deposited during regression in favouij of illite and mixed-layer I-S with a greater percentage of illite. The vertical evolution and lateral distribution of clay assemblages and their relationships with sea-level as well as the palaeogeographic conditions prevailing during the Late Cenomanian-Turonian period (flattened topography and arid climate), indicate a detrital origin of the smectite minerals and a distribution pattern controlled by differential settling processes.

The Bom Santo Cave (Lisbon, Portugal): Catchment, Diet, and Patterns of Mobility of a Middle Neolithic Population

The study of the Bom Santo Cave (central Portugal), a Neolithic cemetery, indicates a complex social, palaeoeconomic, and population scenario. With isotope, aDNA, and provenance, analyses of raw materials coupled with stylistic variability of material culture items and palaeogeographical data, light is shed on the territory and social organization of a population dated to 3800–3400 cal BC, i.e. the Middle Neolithic. Results indicate an itinerant farming, segmentary society, where exogamic practices were the norm. Its lifeway may be that of the earliest megalithic builders of the region, but further research is needed to correctly evaluate the degree of this communitys participation in such a phenomenon.

Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)

A clear relationship exists between eustatic sea-level rises and falls recorded as cyclical depositional sequences and ammonite faunas during the Cenomanian-Santonian in the Iberian and West Portuguese basins. Most of the faunal turnovers correlate with stratigraphic intervals related to marine transgressions, maximum flooding of the shelf (locally associated to anoxic events), and marine regressions. Specifically, within each depositional sequence, three distinct and identical events of morphological change occur, involving ammonoids belonging to different groups. Transgressive sediments are characterized by moderately ornamented, inflated and evolute morphologies, which are replaced by smooth, involute and compressed oxycones (the most hydrodynamic shells) during maximum flooding (and to a lesser extent at the early highstand) of the sequences. The latter morphologies in turn are replaced by coarsely ornamented and evolute shells during late highstands. We conclude that ammonoid faunal analysis can be used to trace sea-level changes and provides an additional tool for sequence stratigraphy.

Fossil assemblages and palaeoenvironments in the Cenomanian vertebrate site of Nazaré (West Central Portugal)

 References  Citations  Supplementary Data  Article Media  Metrics  Suggestions  

Paleoenvironmental and Paleobiogeographical Implications of a Middle Pleistocene Mollusc Assemblage from the Marine Terraces of Baía Das Pipas, Southwest Angola

Abstract Quaternary raised marine terraces containing the remains of diverse, shallow water marine invertebrate faunas are widespread across the coast of Angola. These deposits and faunas have not been studied in the same detail as contemporaneous features in northwest and southernmost Africa. We analyzed the fossil assemblages and sedimentology of two closely spaced middle Pleistocene marine terrace deposits in Baía das Pipas, southwest Angola. This revealed 46 gastropod and 29 bivalve species, along with scleractinian corals, encrusting bryozoans, polychaete tubes, barnacles, and echinoids. The fauna is characteristic of intertidal and nearshore rocky substrates and sandy soft-bottom habitats. Sedimentological analysis is consistent with faunal data and indicates an upper shoreface paleoenvironment along a gravel coast. This diverse fauna stands out as a rare example of a marine Pleistocene assemblage from over 6,000 km of the West African coast. The assemblage is dominated by extant tropical West African molluscs, including species from the “Senegalese fauna” that colonized northern Africa and beyond during Pleistocene interstadials. Additionally, as along the modern coast of the Namibe Desert, the influence of the cool-water Benguela Current is apparent in the paleofauna by the occurrence of a few temperate species. The distribution and thermal tolerances of extant species identified in the Pipas fauna indicate that this region experienced similar climatic and oceanographic conditions as that of the present during this interstadial. Seasonal temperature varied between ∼20 and 28°C and resulted from upwelling in this tropical setting.

Revision and new data on the Coniacian ammonite genus Hemitissotia in the Iberian Peninsula (Spain and Portugal)

The types of the species of the Coniacian ammonite genus Hemitissotia Peron, 1897, identified in the Iberian Peninsula (Spain and Portugal), which are currently held in the Wiedmann (Universität Tübingen, Germany) and Choffat (Instituto Geológico e Mineiro, Portugal) collections, have been revised and refigured. New specimens of the taxa Hemitissotia ceadouroensis Choffat, 1898, Hemitissotiaceltiberica Wiedmann, 1975b, Hemitissotiaturzoi Karrenberg, 1935, Hemitissotiadullai (Karrenberg 1935) and Hemitissotialenticeratiformis Wiedmann in Wiedmann and Kauffman, 1978 have also been presented. As results, H. celtiberica has been considered as a junior synonym of H. ceadouroensis, and the lectotype of this species and the neotypes of H. turzoi and H. dullai have been designated and figured. Additionally, the geographical and stratigraphical distributions of all of these species have been determined with precision, and several phylogenetic relationships between them have been identified, revealing morphologies that become progressively smaller and more depressed and ornamented (hydrodynamically less efficient), interpreted as an adaptative response to sea-level changes.KurzfassungDie Typen der Arten der Ammoniten-Gattung Hemitissotia Peron, 1897 aus dem Coniacium der Iberischen Halbinsel (Spanien und Portugal) wurden neu bearbeitet und abgebildet. Sie befinden sich heute in den Sammlungen von Wiedmann (Universität Tübingen, Deutschland) und Choffat (Instituto Geológico e Mineiro, Portugal). Neue Exemplare von Hemitissotia ceadouroensis Choffat, 1898, Hemitissotia celtiberica Wiedmann, 1975b, Hemitissotia turzoi Karrenberg, 1935, Hemitissotia dullai (Karrenberg 1935) und Hemitissotia lenticeratiformis Wiedmann in Wiedmann and Kauffmann, 1978, werden ebenfalls dargestellt. Dabei zeigt sich, dass H. celtiberica ein jüngeres Synonym von H. ceadouroensis ist. Der Lectotyp dieser Arten sowie die Neotypen von H. turzoi und H. dullai werden definiert und abgebildet. Die geographische und stratigraphische Verbreitung der erwähnten Arten werden detailliert dargestellt, wie auch die phylogenetischen Beziehungen. Sie weisen eine zunehmend kleinere, flachere und stärker verzierte Morphologie auf, was hydrodynamisch weniger effizient ist und scheinbare eine Anpassung an Änderungen des Meeresspiegels darstellen.

The oldest turtle from Portugal corresponding to the only pre-Kimmeridgian plesiochelyid (basal Eucryptodira) recognized at the generic level

Abstract: A shell coming from an upper Oxfordian section of the Lusitanian Basin located in Alqueidão da Serra (Municipality of Porto de Mós, West Central Portugal) is here presented. It corresponds to the oldest remain of a turtle identified in Portugal. In fact, the record of Jurassic turtles identified in pre-Kimmeridgian levels of Europe is very scarce. The new specimen represents the second worldwide identification of a Plesiochelyid turtle (basal Eucryptodira) performed in pre-Kimmeridgian levels, being the only one recognized at generic level. Therefore, this specimen corresponds to the oldest identification of Craspedochelys, a genus well-represented in Kimmeridgian and Tithonian levels of several European countries. This finding contributes the first evidence on the synchronous coexistence of more than a member of Plesiochelyidae in pre-Kimmeridgian levels, which provides arguments to justify the relatively wide diversity known for this exclusively Jurassic clade during the Kimmeridgian and the Tithonian.

The Cape Mondego Mining District and Ernest Fleury’s (1878‑1958) technical contribution to the extractive industry and the local cement factory: a 1923 unpublished geological report

This paper focuses on the report produced by Ernest Fleury (1878-1958), professor at the “Instituto Superior Técnico” of Lisbon, following an early invitation of the conhttps://doi.org/10.14195/1645-2259_16_15 Versão integral disponível em digitalis.uc.pt R EV I STA D E H I STÓ R I A DA SO CI E DA D E E DA CU LT U R A | 16 344 cessionaire and a visit in April 1923 to the clay pits and quarries opened near Buarcos, Tavarede and in the mining district of Cape Mondego (Figueira da Foz). These open-pits supplied raw materials to the local ceramic, hydraulic lime and cement factories, which manufactured flagship products well received on the national market, but faced a serious and growing competition. The report describes the main characteristics of the explored deposits and gives an expert opinion about their potential, as part of a long collaboration that this important geologist had with the Cape Mondego industries. In this scope, besides its technical aura, this document should be read within a temporal context and as a contribution to the history of Applied Geology in Portugal, in which Fleury was a pioneer.