Cuenca De Research Articles

New teeth of a basal Macronarian (Sauropoda) from the Jurassic–Cretaceous transition of Spain

In this work, a dentary, and several teeth from the Valdepalazuelos-Tenadas del Carrascal site (Burgos, Spain) are studied. Geologically,this site is situatedat the base of the Rupelo Formation (Cuenca de Cameros), of Tithonian–Berriasian age. This formation has been interpreted as lacustrine-palustrine deposits with low gradient margins and with periodic changes in the water level. MDS-VPCR,851 is a fragment of the rostral symphyseal zone of a right dentary, a robust bone with a rostral ridge on its lingual surface, large diameter foramina on the lingual surface, a wide Meckelian canal extending from the rostroventral margin, semicircular symphysis arranged rostrolingually, and with two alveoli preserving two erupting teetheach. Although the functional teeth have not been preserved, each alveolus could contain one active tooth and at least two replacement teeth. Eight maxillary and mandibular teeth are described, with a spatulate crown, a rough enamel surface, a D-shaped croos-section, and a very marked cingulum. The dentary and teeth from this site have evident differences with those of other taxa and specimens described in the Kimmeridgian-Berriasian of the Iberian Peninsula. Its greatest similarities are with Camarasaurus, but in the specimens from Valdepalazuelos there are characters that seem to be unique and differ from that taxon. Consequently. the specimens described here are identified as belonging to a basal macronarian, close to Camarasaurus. This work points to the existence of two macronarian sauropods in the Tithonian–Berriasian transit of the Cameros Basin, and increases the diversity of the Iberian record of that time period.

Geophysical model of Cuenca de la Independencia aquifer

Cuenca de la Independencia (CI) is a semi-arid basin in Central Mexico, subdivided into four administrative hydrogeological regions, and comprised of two hydrogeological units: a granular aquifer of lacustrine origin overlying a fractured acidic igneous aquifer. Although many geophysical soundings were carried out within the basin, no geophysical data exceeding 500 m of depth has ever been reported; the actual conceptual models were generated only from shallower geophysical studies, geological and hydrogeochemical mapping. We performed a geophysical survey in CI to determine the geometry of the hydrogeological units through Audio-Magnetotellurics (AMT), Time Domain Electromagnetics (TDEM), and Vertical Electrical Soundings (VES). Since the acquired data set from the different applied geophysical methods are multidimensional and band-limited, some well-known empirical relations between the applied methods were used to improve the subsurface imaging, turning data into broadband-integrated and space-time scaled into the MT frequency domain. We present a methodology on how to handle this integrated information through a 2-D inversion approach.The results reveal that, even though there are two hydrogeological units, they could not be vertically distinguished, thus is not possible to refute the previous idea of direct vertical communication between the two aquifers. Moreover, a clear lateral transition in resistivity models was not found, so the administrative division of CI would only obey political-administrative purposes.

Escribiendo en los márgenes: las cartas de doña Ana Zurita Ochoa en Cuenca de las Indias, siglo XVII

Doña Ana Zurita Ochoa es una mujer española que hace su vida en Cuenca de las Indias en la primera mitad del siglo XVII. Pertenece a la élite étnica, social y económica por lo que ocupa un lugar “privilegiado” con relación a los indígenas, negros y mestizos que forman parte de la urbe. En su cotidianeidad, también se relaciona con sus iguales, hace negocios, convive y se defiende de sus afrentas. Sus cartas (manuscritos inéditos que reposan en el Archivo Nacional de Historia-Núcleo del Azuay) dirigidas a su esposo, don Salvador de Poveda, son el testimonio de su existencia. En estas, por medio de la escritura, doña Ana construye y proyecta imágenes de sí misma como madre, esposa, amante, y vecina de Cuenca dentro del contexto de la Audiencia quiteña. Escribe en y desde el margen del papel de la carta; de este modo, ocupa este espacio como una “treta” que reafirma su centralidad. Es decir, manifiesta su voz y se hace presente en la historia de las mujeres.

Metales y metalurgia en la <em>Abdera</em> fenicia. Datos isotópicos sobre la procedencia e intercambio de materias primas

The first results of isotopic analyses are presented from a selection of samples of a galena nodule, lead droplets and copper-based objects from the Phoenician settlement of Abdera (Adra, Almeria). According to the lead isotope data, there are two different areas of mineral supply, which can be located at the Sierra de Gador and the Cuenca de Vera (probably from Cerro Minado or Herrerias), mining areas in the province of Almeria (Spain). The results stress unknown and interesting aspects on the trade of metals between the western Phoenicians.

Impactos económicos del aprovechamiento de los yacimientos de gas natural de la Cuenca de Burgos mediante el esquema de contratos de obra pública financiada / Economic Impacts of Intensification in the Exploitation of Natural Gas Deposits of Cuenca de Bur

Mediante la construcción de un modelo interregional de insumo producto se analizan los impactos sobre la producción, el empleo, los salarios y el valor agregado relacionados con el programa de aprovechamiento de los yacimientos de gas natural de la Cuenca de Burgos por medio del esquema denominado contratos de obra pública financiada (modalidad de participación de la inversión privada en la explotación de ese recurso energético). AbstractUsing an interregional input-output model, this paper examines the impacts in production and employment associated with the program of exploitation of natural gas deposits of Cuenca de Burgos (located in the northeast region of Mexico) using the scheme of Public Investment Financing Contracts (modality of private capital participation in the production of natural gas).

Playa‐lake sedimentation and organic matter accumulation in an Andean piggyback basin: the recent record from the Cuenca de Pozuelos, North‐west Argentina

AbstractExpansive playa‐lake systems situated in high‐altitude piggyback basins are important and conspicuous components of both modern and ancient cordilleran orogenic systems. Extant playa lakes provide vital habitat for numerous endemic species, whereas sediments from these deposystems may record signals of climate change or develop natural resources over geological time. Laguna de los Pozuelos (North‐west Argentina) provides the opportunity for an actualistic sedimentological and geochemical assessment of a piggyback basin playa lake in an area of critical interest for understanding Quaternary palaeoclimate dynamics. Silty clays and diatom ooze are the dominant playa‐lake centre microfacies, with concentrations of total organic carbon and biogenic silica commonly exceeding 1·5 wt% in this sub‐environment. Elemental and stable isotopic analyses point to a mixed organic matter composition in the playa‐lake centre, with substantial contributions from algae and transported aquatic macrophytes. Bulk sediment and organic mass accumulation rates in the southern playa‐lake centre approach 0·22 g cm−2 year−1 and 2·89 mg cm−2 year−1, respectively, indicating moderately rapid deposition with negligible deflation over historic time. Playa margin facies contain higher percentages of fragmented biogenic carbonate (ostracods and charophytes) and inorganically precipitated aragonite crusts due to seasonal pumping and evaporation of ground water. Organic matter accumulation is limited along these heavily bioturbated wet and dry mud flats. Fluvial–lacustrine transitional environments, which are key waterbird habitats, are either silty terminal splay (northern axis) or sandy deltas (southern axis) containing highly oxidized and partially allochthonous organic matter. Modern analogue data from Laguna de los Pozuelos provide key insights for: (i) environmental reconstructions of ancient lake sequences; and (ii) improving facies models for piggyback basins.

Archeological Evidence for Dietary Use of Bigfoot Leopard Frog (Lithobates megapoda) in Postclassic and Colonial Central Mexico

Abstract Analysis of archaeofaunal remains recovered fromseveral geographically and culturally linked postclassicsites in the Laguna de Magdalena Basin, Jalisco, Mexico,reveals that indigenous agrarian people of this areaincorporated substantial quantities of the robust bigfootleopard frog (Lithobates megapoda) (Taylor 1942) in theirdiet during both prehispanic and colonial occupations. Eventhough residents of this area combined hunting and fishingwith cultivation of both native and colonially introducedflora and fauna, more frog remains were recovered than anyother small species. Furthermore, it appears that exploita-tion of the frog was most intensive during the colonialoccupation. As in modern cuisine, the hindlimbs were thepreferred portion. Mortuary frog effigies suggest that thefrog may also have had iconic value. [Keywords: DietaryLithobates megapoda, postclassic Etzatla´n, Jalisco] Introduction In the early 1960s a team of archeologists based atthe University of California, Los Angeles (UCLA),excavated a cluster of sites in the Cuenca de Laguna deMagdalena or Etzatla´n Basin of western central Mexico.This is the westernmost lake basin of the Mesa Central,located at an elevation of about 14 hundred meters(4,593 feet), about eighty kilometers (50 miles) west ofGuadalajara and about one hu ndred kilometers (62 miles)east of the Pacific coast. Prehistorically and at the timeof Spanish contact, numerous native communitieswere situated around the margins of an expansivelake and on islands within the lake (Figure 1). Thislake was one of many volcanic endorheic freshwatersources in Central Mexico; that is, it was a closeddrainage basin with no direct outflow, losing wateronly by evaporation and seepage.Laguna de Magdalena has been pictured asextending from the present community of Etzatla´non the south to El Arenal on the north (Bell 1974, plateI accompanying Nicholson and Meighan 1974). In1892, the lake was reported to have been about twentymiles long and several miles wide (Goldman 1951) andsupported a thriving local fishery. Although the lake isnow considered extinct (having been drained in theearly 1900s) (Weigand 1985), residual stands of waterin the basin currently provide habitat for some fish(Dominguez-Dominguez et al. 2007; Smith and Miller1980) and aquatic birds (Williams 1982).Early Spanish reports note that Etzatla´n had anable-bodied adult male population of about sixhundred. Weigand, however, estimates a much largerpopulation, possibly several thousand individualsoccupying several hundred hectares (Nance et al.n.d.).

Meles iberica n. sp., a new Eurasian badger (Mammalia, Carnivora, Mustelidae) from Fonelas P-1 (Plio-Pleistocene boundary, Guadix Basin, Granada, Spain)

This paper reports a new species of ancient badger – Meles iberica n. sp. – discovered at the Fonelas P-1 Plio-Pleistocene site (Cuenca de Guadix, Granada, Spain). The anatomical features of its fossils, which identify it as a new species of Meles, include: the great robustness and small size of the specimens found, orbits nearly closed by well-developed zygomatic processes of the frontal bone, very small and rounded infraorbital foramens that open above the fourth upper premolar metacone, upper carnassial teeth with a concave linguodistal outline, the reduction of the talon of the first upper molar, a very deep masseteric fossa, whose anterior margin reaches the mesial limit of the second lower molar, an extensive horizontal platform at the base of this fossa, and a very long and narrow angular apophysis. This species is the most ancient of the genus recorded for the Iberian Peninsula.

Oda a la ambigüedad Crónica

“Oda a la ambigüedad Crónica” is part of a short series of meditative, playful and sensual texts Susana wrote as a contribution to the series of research and creative symposia on Regimes of the Senses, housed at the Institute for International Studies, UTS, which began in 2006. The chronicle will also be included in her next book project, Letters a los Musos: Scenes from la Cuenca de Los Angeles y otros Natural Disasters.

(1703) Proposal to reject the name Euthrixia salsoloides (Compositae)

During revision of the South American Compositae genus Chaetanthera (Mutisieae) by the author (in prep.), the name Euthrixia salsoloides D. Don (I.e.) was unearthed, a name that has never been in common usage. Instead, the later name Chaetanthera linearis Poepp. ex Less. (Syn. Gen. Compos. 112. Jul-Aug 1832) has, from the time of its publication, been accepted and widely used in the literature pertaining to Chaetanthera. The species in question is one of the most widespread in Chile, and is one of the most commonly collected taxa in the genus. David Don (I.e. 257-259) published an unusually detailed descriptio generico-specifica for his Euthrixia D. Don and its single species Euthrixia salsoloides, based on material collected by Ruiz & Pav?n in the Lambert Herbarium. However, tracing the type material has not been successful. With sale of the Lambert Herbarium, Ruiz & Pav?n collections were sold/sent principally to BM, B, and OXF, but some were later dis persed to other herbaria (Miller in Taxon 19: 489-656. 1970; Stafleu & Cowan, Taxon. Lit, Ed. 2,4: 981.1983). There is a collection in G that has a clear, handwritten summary of Don's protologue in A. P. de Candolle's handwriting, but the collection does not have any labels that might suggest a collection of Ruiz and/or Pav?n. Lessing (I.e.) published Chaetanthera linearis with a clear protologue citing widely distributed and well-pre served syntype collections (Syntype 1 : Poeppig (1) Diar. 414 [BM! G! microfiche]; Poeppig (111) D. 414 [BM! G! MO! W! F!]; Syntype 2: Bertero 474 [BM(2)! F! M! NY! P! W!]). This name was immediately taken up (e.g. Hooker & Arnott in Companion Bot. Mag. 1: 104. 1835; Candolle, Prodr. 7(1): 30. 1838) and has, almost without exception, remained in use. Chaetanthera linearis has been widely cited in the literature including Reiche (Fl. Chile 4: 335. 1904), Cabrera's revision of the genus (in Revista Mus. La Plata, Secc. Bot. 1: 178. 1937), Navas's Flora de la Cuenca de Santiago de Chile (3: 275. 1979), Marticorena & Quezada's Cat?logo de la Flora Vascular de Chile (in Gayana, Bot. 42: 30. 1985), and the Libro Rojo: Regi?n de Coquimbo (Squeo & al. (Eds.), Edic. Univ. de La Serena 7: 110. 2001). The protologue of Euthrixia clearly describes an annual with sessile, linear, glabrous leaves with glandu lar teeth; the scales [involucral bracts] are obtuse, mem braneous with scarious margins and the ray and disk flo rets are yellow. This description, together with the assumption that Euthrixia really is closely associated to the other genera Don (l.c.) believed it to be (Proselia, p. 234; Tylloma, pp. 238, 301), establishes that Euthrixia salsoloides is almost certainly the taxon more common ly known as Chaetanthera linearis. This entity is one of a group of three annual Chilean Chaetanthera taxa unit ed by their linear, sessile, glabrous leaves. The two key taxa involved here are C. linearis, with yellow rays and obtuse inner involucral bracts, and Chaetanthera micro phylla (Cass.) Hook. & Arn. (I.e.; based on Cherina microphylla Cass. in Cuvier, Diet. Sei. Nat. 8: 438. 1817), with brick-red rays and acute inner involucral bracts.

Groundwater flow regime under natural conditions as inferred from past evidence and contemporary field observations in a semi-arid basin: Cuenca de la Independencia, Guanajuato, México

This study was carried out in the Cuenca de la Independencia, a semi-arid basin in Central Mexico. The objective is to describe the main features of a groundwater flow regime under natural conditions, based on groundwater discharge manifestations. Information obtained from paleoecological, paleontological, archaeological and historical data suggests that, prior to heavy development (starting in the 1950s), the hydrogeologic regime was characterized by a larger groundwater availability in a more humid and colder climate. Manifestations associated to groundwater discharges are springs, lagoons, wetlands, saline soils, chalcedony deposits, phreatophytes, thermalism, and artesianism. The different types of manifestations and their position in the basin indicate the influence of groundwater flow systems hierarchically nested, forming concentric zones at ground level. The groundwater flow regime corresponds to a classical gravity-induced flow system with generation of local, intermediate and regional patterns. Integrating several types of data to establish the flow geometry and its dynamics has proven a useful tool to increase understanding of the original groundwater regimes. This approach can also be applied in other over-exploited semi-arid basins.

Late Quaternary lacustrine paleoenvironments in the Cuenca de México

A late Quaternary paleolimnological history from the Mexican highlands has been obtained by diatom analysis of short cores and stratigraphic sections of lake and marsh sediments from the Cuenca de México, the large, endorheic, graben basin that holds Mexico City. The records, dated by radiocarbon and tephrochronologic methods, extend back to about 30 ka BP and document the presence of extensive, saline lakes in the basin until 25 ka BP. Thereafter, lake levels fell and marginal sites became shallow and fresh under the influence of surficial drainage and (especially) spring discharge. A shallow, saline lake existed 18 ka BP in Texcoco, the central and lowest basin in the system, reflecting moderately increased effective moisture at that time. By 16 ka BP, Lake Texcoco had become so shallow that diatoms were no longer preserved. However, marginal sites nourished by spring flow recorded changes in the local hydrologic balance resulting from increased infiltration at higher elevations. These changes appear to coincide with glacial advances between about 14 and 10 ka BP on the volcanic mountains surrounding the basin. Dry climates with reduced infiltration characterized the early Holocene, but by 5 ka BP a modest increase in precipitation established the modern climatic regime. These lacustrine records offer important insights for evaluating the paleoenvironmental history of the Cuenca de México based on other evidence. They confirm glaciological, stratigraphic and palynologic data that suggest dry climates and the absence of large pluvial lakes in the Cuenca de México during and after the full glacial, but document climates of significantly increased precipitation at least 10 ka prior to 18 ka BP.

Paleoecological Studies at Lake Patzcuaro on the West-Central Mexican Plateau and at Chalco in the Basin of Mexico

AbstractA 1520-cm sediment core from Lake Patzcuaro, Michoacan, Mexico, is 44,000 yr old at the base. All parts of the core have abundant pollen ofPinus(pine),Alnus(alder), andQuercus(oak) with frequentAbies(fir). The interval dated from 44,000 to 11,000 yr ago has a homogeneous flora characterized by abundantJuniperus(juniper) pollen and frequentArtemisia(sagebrush). It is believed to represent an appreciably drier and colder climate than at present. The Holocene at Lake Patzcuaro is characterized by a moderate increase inPinuspollen and the loss ofJuniperuspollen, as the modern type of climate succeeded.Alnuswas abundant until about 5000 yr ago; its abrupt decrease with the first appearance of herbaceous weed pollen may reflect the cutting of lake-shore and stream-course alder communities for agricultural purposes, or it may simply reflect a drying tendency in the climate. Pollen ofZea(corn) appears at Lake Patzcuaro along with low peaks of chenopod and grass pollen at 3500 yr B.P. apparently recording a human population large enough to modify the natural environment, as well as the beginning of agriculture. A rich aquatic flora in this phase suggests eutrophication of the lake by slope erosion. In the most recent period corn is absent from the sediments, perhaps reflecting a change in agricultural practices. The environment changes at Lake Patzcuaro are similar to and correlate with those in the Cuenca de Mexico, where diatom stratigraphy from the Chalco basin indicates fluctuations in lake levels and lake chemistry in response to variations in available moisture. Before 10,000 yr ago climates there were cool and dry, and the Chalco basin was occupied by a shallow freshwater marsh that drained north to Lake Texcoco, where saline water accumulated by evaporation. Increases in effective moisture and possible melting of glaciers during the Holocene caused lake levels to rise throughout the Cuenca de Mexico, and Lake Texcoco flooded the Chalco basin with brackish water. After 5000 yr ago such flooding decreased, and shallow freshwater ponds and marshes were restored in the Chalco basin. This environmental change coincides with the appearance ofZeapollen and suggests cultural control of lake levels and salinity.

PALYNOLOGY IN SOUTHERN NORTH AMERICA

The sediments of the Cuenca de Mexico fall into two classes—transported materials from the surrounding highlands and residual materials deposited as a result of limnological processes, in situ . The latter include inorganic and organic constituents as well as microfossils. Studied together these components reflect events influenced or controlled by changing climates, by volcanic and tectonic activity, and by erosion whether natural or accelerated by man. Changes in percentage composition of upland forest pollen reflect changes in available moisture, and thus in climate. Changes in the density or abundance of recoverable pollen are closely related to changes in sedimentary zones and in water content of the sediments. High pollen density is associated with slow sedimentation and high water content of the sediments, whereas stages of rapid sedimentation and low water content are marked by sparseness or absence of pollen. As upland forest pollen composition is chiefly a function of climate, pollen density is a function of volcanic and other physiographic processes. Pollen and spores from lowland communities reflect swamp conditions and changes in vegetation caused by disturbance of habitat by volcanism, tectonic activity, and human occupation. Temporary disturbance from fresh ash fall and tectonic activity tends to be followed by a brief period of heavy density of ruderal pollen (composite, amaranth, grass) and by prompt restoration of the prevailing upland forest communities. Maize pollen was recovered throughout the archeological period and at a depth of 9 m, predating the presence of agricultural man in the basin. It was again recovered at 70m, a depth which represents considerable antiquity for maize; which is evidence in favor of the American origin of this plant. Contemporary pollen gathered from a site comparable to the Mexico City basin indicates relatively short distance of upland pollen transport. Therefore, the sparse spruce pollen found at various horizons in the Mexican cores probably came from the vicinity during times cooler than the present. Exceptionally heavy spruce pollen in samples from a recent horizon appears to be the result of redeposition of older sediments from the surrounding highlands. Correlation of the sedimentary components involves a complex of climatic, tectonic, volcanic and biotic factors; evidence from every possible source, in addition to conventional pollen analysis, is required for proper interpretation.