Search

The hydraulic system of Santa Catalina del Monte constitutes an ancient example of the relationships between the human being and the environment in the Bétic Range and Mediterranean semiarid climate, revealing the identity and characteristics of human interventions for the collection, storage and distribution of groundwater and natural spring water. [ABSTRACT FROM AUTHOR]

An interdisciplinary study of Miocene successions in the eastern External Betic Zone (South Iberian Margin) was carried out. Evidences of syn-sedimentary tectonic activity were recognized. The results enabled a better reconstruction of the stratigraphic architecture (with an improved chronostratigraphic resolution) in the framework of the Miocene foredeep evolution of the eastern EBZ. Two main depositional sequences were dated as uppermost Burdigalian-upper Serravallian p.p. and middle-upper Tortonian. p.p., respectively. The vertical and lateral diversification of lithofacies associations and thicknesses resulted from the syn-depositional tectonic complexity of the area. A great variety of sedimentary depositional realms is due to different subsidence rates, and the growing of anticlines and synclines during the Langhian p.p.-Serravallian. After a regression with an early Tortonian erosional gap, platform to hemipelagic realms developed during the middle Tortonian. The end of the sedimentation coincided with the emplacement of an important olisthostrome-like mass consisting of Triassic material related to either the development of thrust systems or diapirs emerged in the middle-late Tortonian, during the nappe emplacement. Correlations with other external sectors of the Betic Chain, and the external domains of the Rif, Tell, and northern Apennine Chains highlighted a similar Miocene foredeep evolution during the building of these orogens. [ABSTRACT FROM AUTHOR]

Sedimentological, paleobiological, mineralogical, and geochemical analyses of a sediment core retrieved on the seafront of Cartagena Bay were performed after high-resolution sampling. A wide series of dates obtained through radiocarbon and amino acid racemization proved that the Holocene record on the analyzed core began at ca. 7300 yr cal BP. Reinterpretation of the marine seismic profiles indicated that the beginning of this transgression was channeled along erosive paleochannels excavated on a coastal plain of, at least, MIS5c age. The Holocene paleoenvironmental evolution consisted of a first period marked by marine conditions with strong inputs from a fan delta linked to the reorganized fluvial network that occurred after the sudden rise of the base level, which caused a growing sedimentary prism. Later, the full marine environment was reflected in the development of a Posidonia - Cymodocea meadow hosting a rich biodiversity of marine species (mollusks, foraminifera, ostracoda). Around 3800 yr cal BP, the area underwent a profound change and a silting process started to alter the conditions, turning the area into a paucispecific brackish marsh environment in which mud deposition was dominant. Since Carthaginian times, arrangement works locally affected the record, allowing the arrival of some marine species due to port work (dredging) undertaken to gain depth and showing anthropic influence. [ABSTRACT FROM AUTHOR]

Sedimentological evidence for an abrupt dry spell in south-eastern Spain during the middle Holocene, from c. 4906 to 4384 cal. yr BP, is presented. This phase was determined primarily from halite beds deposited between muddy slimes in a lagoon system of Puerto de Mazarrón (Murcia province) with a peak phase from c. 4550 to 4400 cal. yr BP. A multi-core, multi-proxy study of 20 geotechnical drills was made in the lagoon basin to identify the main sedimentary episodes and depositional environments. The results suggest that this halite bed, more than 80 cm thick, was conditioned by climate change and was accompanied by a generalized drying-out of the basin. Halite precipitation was linked with palaeoecological changes, including forest and mesophyte depletions and increasing cover and diversity of xerophytic plant species. Archaeological evidence indicates a demise of the population at this period probably due to resource exhaustion. An overall picture of the biostratigraphy and palaeoclimates of the region is given in a broader geographical context. [ABSTRACT FROM AUTHOR]

The Cenozoic Malaguide Basin from Sierra Espuña (Internal Betic Zone, S Spain) due to the quality of outcropping, areal representation, and continuity in the sedimentation can be considered a key-basin. In the last 30 years, a large number of studies with very different methodological approaches have been done in the area. Models indicate an evolution from passive margin to wedge-top basin from Late Cretaceous to Early Miocene. Sedimentation changes from limestone platforms with scarce terrigenous inputs, during the Paleocene to Early Oligocene, to the deep basin with huge supplies of turbidite sandstones and conglomerates during the Late Oligocene to Early Miocene. The area now appears structured as an antiformal stack with evidence of synsedimentary tectonics. The Cenozoic tectono-sedimentary basin evolution is related to three phases: (1) flexural tectonics during most of the Paleogene times to create the basin; (2) fault and fold compartmentation of the basin with the creation of structural highs and subsiding areas related to blind-fault-propagation folds, deforming the basin from south to north during Late Oligocene to Early Aquitanian times; (3) thin-skin thrusting tectonics when the basin began to be eroded during the Late Aquitanian-Burdigalian. In recent times some works on the geological heritage of the area have been performed trying to diffuse different geological aspects of the sector to the general public. A review of the studies performed and the revisiting of the area allow proposing different key-outcrops to follow the tectono-sedimentary evolution of the Cenozoic basin from this area. Eight sites of geological interest have been selected (Cretaceous-Cenozoic boundary, Paleocene Mula Fm, Lower Eocene Espuña-Valdelaparra Fms, Middle Eocene Malvariche-Cánovas Fms, Lowermost Oligocene As Fm, Upper Oligocene-Lower Aquitanian Bosque Fm, Upper Oligocene-Aquitanian Río Pliego Fm, Burdigalian El Niño Fm) and an evaluation has been performed to obtain four parameters: the scientific value, the educational and touristic potential, and the degradation risk. The firsts three parameters obtained values above 50 being considered of "high" or "very high" interest ("very high" in most of the cases). The last parameter shows always values below 50 indicating a "moderate" or "low" risk of degradation. The obtained values allow us considering the tectono-sedimentary evolution of this basin worthy of being proposed as a geological heritage. [ABSTRACT FROM AUTHOR]

Here we reconstructed the evolution of the Mazarrón Basin during the Pleistocene and Holocene. In this regard, we studied 9 cores with the aim to: 1) define a chronological framework; 2) obtain data on the palaeoenvironment; and 3) establish the relationship with recent tectonics. A total of 158 samples were recovered for amino acid racemization (AAR) dating, 4 for radiocarbon dating (14C), and 332 for sedimentological and palaeontological determination, and 110 for determination of the mineralogical content. These approaches allowed us to elucidate the evolutionary phases of the palaeo-landscape of the Mazarrón Basin, a fault-controlled graben affected by diverse faults, mainly those of Las Moreras and Rella. The ages of the records and the facies correlation indicate that Las Moreras Fault controlled sedimentation during Marine Isotope Stage (MIS) 7, whereas the Rella Fault was strongly active during the Middle Holocene. During MIS7, a brackish lagoon developed in the western area, overlying alluvial fan deposits. Later, the area was uplifted, thereby becoming exposed to erosion. The activity of the Rella Fault allowed sedimentation in the western part of the Mazarrón Basin during the Middle Holocene, while in the Upper Holocene sedimentation occurred in the eastern part. The Holocene transgression was reflected in a temporarily floodable marsh in the hinterland, with changing salinity conditions, from brackish to euhaline waters. Along the sea front, the marine influence was evident but not dominant. Thus, the Mazarrón Basin during the Holocene was brackish to highly euhaline, with variable biological diversity linked to a narrow and probably discontinuous communication with the sea, with restricted circulation and long flushing times, which was reflected by the significant presence of halite. The record ended with recent alluvial/anthropic sediments. [ABSTRACT FROM AUTHOR]

Here, we sought to reconstruct the Pleistocene and Holocene evolution of Cartagena Bay. Therefore, 16 borehole cores were analysed with the following aims: (1) to define a chronological framework; (2) to obtain data on the palaeoenvironment; and (3) to establish the relationship with human activities, especially focused on the reconstruction of the Carthago Nova (also known as Qart Hadasht) conquest. A total of 147 samples were recovered for amino acid racemisation (AAR) dating; 32 for radiocarbon dating (14C); and 159 for sedimentological, palaeontological, and biomarker determination. These approaches allowed us to elucidate the evolutionary phases of the palaeolandscape in Cartagena. The simultaneous use of AAR and 14C dating allowed the discrimination of spurious ages and the establishment of a chronological scale. During the Marine Isotope Stages (MIS) 7 and 5, the sea level (SL) in Cartagena Bay was almost the same as today. An alluvial plain developed in the northern area, and a delta was formed by an ephemeral river. In contrast, during MIS4, after a fall in SL, a wide sandy coastal plain emerged, leading to the accumulation of colluvial and aeolian deposits. The Holocene transgression was reflected in the hinterland in a late and temporarily floodable marsh fed by alluvial fans and creeks, producing a salinity gradient from freshwater to brackish and saline waters. Along the sea front, the marine influence was evident but not dominant, grading up and landwards to saline and freshwater marshes. Therefore, at the time of Scipio's conquest, the geography of Carthago Nova was quite different from that described by Polybius. The Roman's sudden attack seized Qart Hadasht from the south-west, avoiding the marshy area and not crossing a fast and deep ebb stream as it never existed on the Mediterranean Iberian coast. [ABSTRACT FROM AUTHOR]

In this paper, we conduct a palynological analysis of a high-resolution Holocene record from Cartagena Bay, southeast of the Iberian Peninsula, to establish paleoenvironmental variability of coastal areas in the western Mediterranean region at a centennial-scale over the last 7300 years. Statistical analysis of four palynozones allows reconstruction of paleotemperature and paleohumidity conditions. Pinus , steppic, xerophilous, and Mediterranean taxa persisted continuously through the record, and only during periods of increased humidity did deciduous and Mediterranean taxa expand (Zones II, subzone IIIb). Cooler and dry conditions favored the development of Cupressaceae and scrubs between 7300 and 7000 yr cal BP. The mid-Holocene (Northgrippian) mesophytic optimum took place between 6800 and 4000 yr cal BP during which time a Mediterranean climate was present and open forest developed, predominantly consisting of Mediterranean taxa and deciduous trees. The gradual rise in aridity in the Meghalayan (4000–1700 yr cal BP) led to Mediterranean forest being replaced by steppic and xerophilous vegetation, a change related mostly to a decrease in summer insolation, with superimposed centennial-scale variability in humidity. In parallel with forest degradation caused by increasing aridity, the record shows marked evidence of human influence since 4000 yr cal BP, which accelerated the progression of open landscapes from the Chalcolithic onwards, this change being especially marked during the Roman period. Significant denudation of the landscape can be attributed to the use of fire, as well as due to agriculture and grazing, with a major contributor being intense metallurgical and mining activity in the area. The Cartagena Bay record reported herein shows centennial-scale oscillations in humidity and temperature that correlate with well-known climatic events during the late Holocene in the western Mediterranean region, synchronous with variability in solar and atmospheric dynamics. The alternation of persistent North Atlantic Oscillation modes is likely to have played a key role in regulating humid–arid periods. • Pollen content allowed the paleoenvironmental reconstruction during the Holocene. • Centennial-scale oscillations in humidity & temperature correlate with climatic events. • The mid-Holocene mesophytic optimum took place between 6800 and 4000 yr cal BP. • Aridity and xerophytization occurred between 4000 and 1700 yr cal BP. • Human influence accelerated the progression of open landscapes since the Chalcolithic. [ABSTRACT FROM AUTHOR]

Abstract: Cueva Negra del Estrecho del Río Quípar (Caravaca de la Cruz, Murcia, Spain), hereinafter Cueva Negra, is a key-site for understanding the early peopling of Europe. Since 1990, systematic excavation has revealed an intriguing assemblage of lithic and faunal remains, and hominin teeth. It was deposited 0.99–0.78 Ma according to palaeomagnetic and biostratigraphical data; pollen data indicate warm moist conditions. Recently, possible evidence of thermal alteration was detected in a deep part of the deposit. We report here on our revision of the Cueva Negra stratigraphy, and offer information on site formation processes, based on new field observations and preliminary data from soil micromorphology. The Cueva Negra succession comprises three main stratigraphical complexes. Complex 1 is late Holocene. Complexes 2 and 3 are Pleistocene and are formed mainly of alluvial sediment, with subordinate inputs from the cave walls. Complexes 2 and 3 were accumulated almost without interruption, being separated by an erosive surface truncating a thin alluvial soil developed at the top of Complex 3. Our initial micromorphological findings indicate that anthropic inputs are mostly in derived positions, very likely having undergone inward displacement from the mouth of the rock-shelter. [Copyright &y& Elsevier]

Abstract: At Sima de las Palomas del Cabezo Gordo (Murcia, Spain) remains of several Neanderthals have been excavated recently. From about 50,000 years ago articulated parts of 3 adult skeletons (including skulls with mandibles, vertebral column, rib cages, shoulder blades, hip bones, upper and lower limbs, hands and feet, often in anatomical connexion) were excavated from the lower part of a cemented accumulation of scree and large stones (éboulis) sloping downwards and inwards into the cavity, along with burnt bones of large mammals and Mousterian implements. The excavation of the skeletons is the subject of this paper (palaeoanthropological skeletal descriptions are soon to be published elsewhere). Behind the cemented scree there accumulated a layer of finer sediment containing burnt animal bones, followed by more fine sediment that filled the cavity up to the overhanging rock roof and contained isolated teeth and unburnt bone fragments of Neanderthals, including 3 mandibles, as well as Mousterian implements and faunal remains, all dating from before 40,000 years ago. Altogether, at least 9 Neanderthals are represented by finds from the site (including 3 unstratified mandibles), ranging from babies to adults. Dating methods include radiocarbon, uranium-series, and optical luminescence. Pollen analysis implies conditions less severe than those of the Heinrich 4 cold oscillation at 40,000 years ago. [Copyright &y& Elsevier]