Access to the geochemical conditions of paleoenvironments is made through the analysis of the chemical composition of the hydroxyapatite of fossil bones. This is because the bones were able to incorporate chemical elements from adjacent fluids into their pores and channels during the fossildiagenesis process, and as a result, have their original apatite substituted. The main goal of the present study

The Mesozoic plate tectonic and paleogeographic history of the final break up of West Gondwana had a profound effect on the distribution of terrestrial vertebrates in South America. As the supercontinent fragmented into a series of large landmasses (South America, Antarctica, Australia, New Zealand, the Indian subcontinent, and Madagascar), particularly during the Late Jurassic and Cretaceous, its

The specimens herein studied were recollected in strata from the Paso Hondo Formation (lower-middle Permian), which are outcropping in the Chicomuselo region, southeast of Chiapas state, limiting with the frontier of Guatemala. The material studied consists of 13 species: four determined to a specific level (Bellerophon deflectus, Discotropis sulcifer, Omphalotrochus cochisensis, and Donaldospira geminocarinata)

Timing and ecological steps of the rise and expansion of grasslands differ not only geographically but also according to the type of available information. Patagonia (Argentina) was largely considered the region where grasslands and grazers early evolved in the Eocene, mostly based on functional morphology of mammals. However, recent paleobotanical studies question this traditional view and maintain

We mapped Plio-Pleistocene lake deposits in the Ixtlahuaca paleobasin in Central Mexico, located 51 km south of the Acambay Graben and 69 km west of Mexico City. Within the Acambay basin, Pleistocene to Holocene lake sediments record primary and secondary environmental effects of strong local earthquakes as a consequence of Quaternary activity of the major normal border faults. Likewise, the Ixtlahuaca

On the boundaries of the states of Coahuila and Zacatecas in northern Mexico, scarce outcrops of a Triassic subduction complex have been used to infer in several positions a tectonostratigraphic terranes boundary. This crustal boundary is covered by a pile of Jurassic volcanosedimentary rocks and a thick, folded, and thrusted Mesozoic sedimentary marine succession. We carried out detailed mapping,

Triassic beds from Argentina and Brazil provide the most relevant fossil record of early dinosauriforms in terms of numerical abundance and taxonomic diversity. This record currently represents the best source to understand the origin and early evolutionary radiation of dinosaurs. In the present paper we offer an updated review focused on the available evidence of Carnian dinosaurs from this continent

The Paleoproterozoic Araí continental rift, Central Brazil, hosts metabasaltic lava flows interbedded with a thick transgressive metasedimentary sequence at the basal portion of the Araí Group (Arraias Formation). The lava flows have basalt to basaltic andesite compositions, subalkaline, tholeiitic and within-plate geochemical signatures. These rocks still have low to moderate REEs content, negative

In the urban area of Rio Cuarto groundwater is used for domestic supply. The objective of the current research was to investigate the water dynamics and nitrate contamination in an unconfined aquifer system of Rio Cuarto River basin. Stable isotopes of water (δ18O and δ2H) and nitrate (δ15N–NO3 and δ18O–NO3) were used and combined with conventional chemical techniques and mixing modelling approaches

Los Molles Formation (Lower to Middle Jurassic), deposited under the first marine event above the synrift continental deposits of the Precuyo, is the second most important source rock of the Neuquén Basin after Vaca Muerta Formation. Los Molles Formation extends over more than 45,000 km2 and can be recognized in different geographic areas within the basin. Los Molles Formation, with a thickness that

The Preto River, located in the municipality of São Gonçalo do Rio Preto (Minas Gerais, Brazil), is one of the few perennial watercourses in the semi-arid region of northeastern Minas Gerais and is essential for the socio-environmental dynamics of the region. Its headwaters are located in the Southern Espinhaço Mountain Range, which is characterized by predominantly quartzite lithologies that form

The multi-proxy provenance analyses carried out in the Upper Pleistocene sediments of the La Primavera intra-caldera paleolake in western Mexico document the evolution of source areas. This lake formed a few thousand years after the caldera collapse (∼95 ka) and lasted until the intra-caldera resurgence process that ended 75 ka ago. Between 93.8 and 71 ka the sedimentary succession that filled the

The Upper Cretaceous M2 and U Sandstone members of the Napo Formation are prolific hydrocarbon producers in the Oriente Basin of eastern Ecuador. To understand the depositional origin of these reservoirs, an integrated sedimentologic, sequence-stratigraphic, and ichnologic study, using 490 ft (~149 m) of conventional core from six wells of oil fields located in the eastern part of the basin, was performed

Mafic volcanic rocks are typically formed by primitive magmas (MgO >8 wt.%) and are evidence of both a rapid magma ascent from the source and a negligible differentiation en route to the surface. Thus, mafic rocks on Earth are relatively close in composition to the primary magma. These rocks are common in intraplate and extensional tectonic environments, but not in subduction settings. At subduction

The South Atlantic coast in Argentine Patagonia is an area where semi-arid to arid conditions predominate and coastal populations present serious water supply problems. The aim of the work was to evaluate the factors that condition the salinization processes of coastal aquifers from a hydrochemical and isotopic analysis of the groundwater located in Pleistocene and Holocene littoral ridges in the northern

In central-western Argentina, a mafic-ultramafic belt occurs throughout the western margin of the Precordillera. This belt is interpreted as the suture zone between the Cuyania terrane and the Chilenia terrane, both accreted onto the Gondwana margin during the Early Paleozoic. The belt comprises rocks from different setting and age and can be divided into a northern (28-32°S, present coordinates) and

This work aimed to investigate the ichnofossiliferous sites in Nioaque and surrounding region, Mato Grosso do Sul state, Brazil, analyzing their paleontological, stratigraphic and paleoenvironmental context, because dinosaur tracks were found in an area previously mapped as Permo–Carboniferous age. Some sedimentary facies previously assigned to the glacial Aquidauana Formation were herein reinterpreted

The Devonian succession in Paraná Basin encompasses marine deposits bearing fossils representative of the Malvinokaffric Realm, corroborated by sedimentological and ichnological data. Although the trace fossil assemblage preserved in these beds is archetypal of fully marine conditions, signs of environmental stressing conditions can be observed locally in the Givetian beds. This study aims to provide

U–Pb geochronology on detrital zircons from the Neogene sediments of San Carlos Basin in Costa Rica, yielded a wide range of ages, from Paleoproterozoic to Cenozoic. The most representative is the Miocene population, constrained to a maximum depositional age of 6.9 ± 0.2 Ma. It reflects the local volcanic activity of the evolving island arc and late Miocene to Pliocene basin sedimentation. Cenozoic

The Morro del Cobre porphyry (Cu-Mo-Au) deposit, genetically linked to the upper Miocene magmatism (~9–10 Ma), is located at the eastern margin of the Andean Frontal Cordillera of San Juan, Argentina, over the Pampean flat-slab segment (28–33°S) of the Central Andes. The petrogenetic analysis of these rocks reveals an arc affinity and an adakite-like signature with the source magmas evolving under

Carbonates of the Salitre Formation, Irecê Basin, Brazil, have been the focus of extensive stratigraphic and structural studies for several decades. Besides hosting phosphorites deposits, these rocks are analogues to fractured and certified oil reservoirs, such as those of the Cretaceous pre-salt oil system offshore Brazil. The present study presents an integration of X-Ray Diffraction (XRD), Quantitative

Copahue volcano is an active stratovolcano located in the Southwest of the Agrio-Caviahue depression in the Province of Neuquén at the border between Argentina and Chile, and the most recent eruptive activity involved five cycles between 1992 and 2016. The Moderate Resolution Imaging Spectroradiometer (MODIS) is an instrument onboard the satellites Terra and Aqua that provides, on average, four images

The late Miocene Urumaco Formation of Venezuela has one of the richest and ecologically diverse crocodylian fossil faunas of the Cenozoic of South America. This diversity includes several different genera and species of crocodylians that held many distinct ecological niches, such as those of generalist predators, durophagous predators, giant predators and longirrostrine piscivorous, among others. This

The Pará-Maranhão/Barreirinhas margin, North Brazil, is a pull-apart passive margin, with two strike-slip borders, formed during the opening of the Equatorial Atlantic Ocean during Cretaceous time. Its geometry and evolution are speculative due to the lack of information on the crustal structure and the crustal nature. We present here the E-W profiles of the MAGIC (Margins of brAzil, Ghana and Ivory

Quantifying the effects of drilling predation on juvenile and adult gastropods is important for understanding the paleoecology of communities. Although numerous studies have examined predation on adult shells, virtually no reports cover juvenile specimens. We compare predation frequency and prey effectiveness between juvenile and adult gastropods in a Pliocene assemblage from the eastern Pacific of

During the last decades, provenance studies have proven to be an invaluable tool to evaluate modern and ancient sedimentary environments and to reconstruct the paleogeography and evolution of different tectonic settings. Whereas in the past provenance studies were mainly based on qualitative comparisons of whole-rock sandstone detrital modes, the advance and implementation of microanalytical techniques

The structure and taphonomy of araucarian stumps and logs from the Jurassic of Patagonia are analyzed. Density measurements of these trees indicate that they were organized into woodlands that occupied extensive paleosurfaces affected by repetitive volcanism from nearby areas. At least two episodes of araucarian woodlands were identified, both terminated by explosive volcanism. As a result, fallen

The Northern Andes of Ecuador contain some of the most active volcanic systems in the Andes and extend over a broad region from the Western Cordillera to the Subandean Zone. While it is known that the arc straddles a range of basement compositions, from accreted mafic oceanic terranes in the west to silicic continental terranes in the east, the details of the crustal structure beneath the arc is unclear

Richly fossiliferous upper Oligocene to lower Miocene Patagoniense marine deposits constitute a conspicuous feature of the sedimentary record of most basins in Patagonia. Patagoniense meaning and subdivisions have been confusing, and correlation and elucidation of factors controlling sedimentation in a region as extensive as Patagonia are still highly debated. Our revision of the distribution, correlation

The Lajas Formation of the Neuquén Basin (Argentina) was deposited mainly during the Middle Jurassic but with a highly diachronic pattern. The exact time elapsed in the deposition of this unit remains controversial and depends on the location within the basin. Particularly in the Portada Covunco locality, north of the Huincul High, the debate on the age of the Lajas Formation persists. The age of the

The Archean nucleus of the Amazonian Craton, represented by the Carajás Mineral Province (northern Brazil), crops out as a broad exposition of igneous, sedimentary, and metamorphic rocks showing a complex polyphase geologic history. A succession of orthogneisses (metagranitoids), amphibolites, and metavolcano-sedimentary rocks that show greenstone belt characteristics occur in Tancredo Neves Village

The Caviahue-Copahue Volcanic Complex (CCVC, 37° 51’ S-71° 05′ W) is located in the central segment of the South Volcanic Zone, ~30 km eastward from the main Andean volcanic arc. Within a complex tectonic setting, it has developed under the influence of the northern transtensional Liquiñe-Ofqui Fault Zone, to the south and the Copahue-Antiñir Fault Zone to the northeast. The onset of volcanic activity

The Aptian Crato Member of the Araripe Basin is a 50-m-thick succession of laminated limestones alternated with siliciclastic rocks. This unit has been receiving attention worldwide mainly because it is one of the most famous fossil Konservat-Lagerstätten, where were identified well-preserved paleofauna and paleoflora. Clay mineralogy and lithogeochemical data have been widely used in paleoenvironmental

Here we present aptychi and one perisphinctid ammonite from a 2.23 km-thick sedimentary section along the Aztlán Creek, Hidalgo state (East Central Mexico). The sedimentary sequence is predominantly build-up by basinal carbonates and is assigned to the Tepexic/Cahuasas (partim) formations, which are of Bathonian to Callovian in age and were deposited in the proto-Atlantic Basin at the western Tethys

Representative locomotion types in lizards include terrestrial, arboreal, grass swimmer, sand swimmer and bipedal. Few studies explain the locomotion habit of extinct lizards, and even less asses those of bipedal ones. Here, we use quantitative methods to infer the type of locomotion of two Albian Mexican lizards (Lower Cretaceous) and three Cretaceous lizards from Brazil, North America and Spain,

First low-temperature thermochronology data across the central Patagonia and thermal modeling provide information on the thermal history of the intraplate San Bernardo fold and thrust belt (44–46 °S). Apatite (U–Th-Sm)/He (AHe), fission tracks (AFT) ages and inverse thermal modeling indicate that the sedimentary rocks presently at the surface of the southwestern San Bernardo FTB have experienced a

Interdisciplinary concepts have been used to manage the environmental crisis of the 21st century. Ecological problems and solutions require an increasingly comprehensive soil study and this has been carried out in order to consider the entire regolith profile. Regoliths are the entire column of materials above the fresh rock, whether this is saprolite (literally “rotten rock”) or soil, material with

The continental early-middle Miocene Santa Cruz Formation (SCF) in Austral Patagonia contains the best record of South American mammalian faunas prior to the Great American Biotic Interchange (GABI) and is of particular interest because it is the best preserved high-latitude continental biotic record in the Southern Hemisphere spanning the mid-Miocene Climatic Optimum. Through intensive fieldwork we

The study area is in the southern Pernambuco–Alagoas Domain, Borborema Province Southern sub province, northeastern Brazil. The Maravilha orthogneiss comprise an elongated intrusion of ∼200 km2, with an ESE-WNW major axis, ranging in composition from tonalite to sienogranite, emplaced into metasedimentary rocks of the Inhapi sequence, in the southern part of the Pernambuco - Alagoas Domain. Diorite

The NNE-directed tectonic escape of the North Andean block (NAB) or sliver (NAS) with respect to South America (SA) is generally accepted now. NAS is detached from continental South America (SA) by a 2000-km-long, NE-SW-trending dominant dextral fault system, known as the Eastern Frontal Front System (EFFS; Pennington's name and acronym kept for simplicity) that extends from the gulf of Guayaquil-Tumbes

Up to date, at least 50 species of Crocodylomorpha are known in Brazil. Those species are distributed in a temporal range from the Triassic to the present day. However, Crocodylomorpha records from the Brazilian Jurassic are quite scarce, and they have been often considered as lacking enough information for a proper systematic identification. In this study, we describe new Crocodylomorpha specimens

The Apure river is the largest tributary of the Orinoco river basin in the Venezuelan plains, it transports considerable amounts of sediments in the range of coarse sand to clay, and its distribution is fundamental to understand the processes of sedimentation in the different fluvial environments. However, little attention has been given to its sedimentary features. We present a field investigation

The Vitória Seamount (VTS), distant ~300 km from the Brazilian coastline at latitude 20°S, is the second closest offshore volcanic complex of the Vitória-Trindade Ridge (VTR) which corresponds to a ca. 1200 km long ridge of seamounts and islands composed of SiO2-undersaturated magmatic rocks commonly considered to be the volcanic track of the Trindade mantle plume in the South American Plate. Based

A review on the findings of chaetetid sponges in Mexico is made. Up to date, two localities house the whole diversity of Mesozoic chaetetids in the country consisting of three species, all of them from the Cretaceous. The studied localities are Arroyo La Cruz, in the state of Oaxaca, and El Gorrión, in the state of San Luis Potosí. At Arroyo La Cruz, outcrops from the San Isidro Formation (of a Hauterivian-Barremian

The present work gives a detailed analysis of the metamorphic and deformational evolution of the back-arc portion of the Famatinian Orogen exposed in the southern Sierra de Aconquija (Cuesta de La Chilca segment) in the Eastern Pampean Sierras. The Eastern Pampean Sierras include from north to south the Aconquija, Ambato and Ancasti mountains. They are mainly composed of middle to high grade metasedimentary

The up to 3000 m thick Mesoproterozoic and Neoproterozoic sedimentary succession exposed at the southern border of the São Francisco Craton, São João del Rei region (southern Minas Gerais State, Brazil), records the stacking of five sedimentary basins. These basins evolved due to multiple rifting episodes related to the southernmost Espinhaço rift system and were deformed around 600 Ma during the evolution

Strata containing the Iniyoo Local Fauna (LF) crop out in the outskirts of Santiago Yolomécatl in the Yolomécatl Subbasin of the southeastern Tlaxiaco Basin in northwestern Oaxaca, southern Mexico. The assemblage is from a 325-m-thick fluviolacustrine unit previously assigned to the Yanhuitlán Formation and then the Yolomécatl Formation, which was restricted to the Yolomécatl Subbasin and its immediate

The volcano-sedimentary succession of the Cerro Piche Graben, Río Negro province, Patagonia (Argentina), was studied U–Pb and Lu–Hf in zircon. As well, a stratigraphic, sedimentological, palynology and a review of the paleoflora content was made. The combined stratigraphic and geochronological study on the volcano-sedimentary succession indicates that the Cerro Piche Graben was developed during the

The Novo Gosto amphibolites represent the oldest unit of the Canindé domain, a Neoproterozoic sequence located in the NW Sergipano Belt, southern Borborema Province, Brazil. The domain comprises an association of metavolcano-sedimentary rocks, gabbroic intrusions, bimodal magmatic rocks, and syn-to post-tectonic granitoids. Due to the lithostratigraphic and geochemical complexity of this domain, several

Solid mine wastes can be dispersed in river systems by fluvial processes contaminating distant areas. This process has been previously reported in rivers of the Atacama Desert impacted by mining. The removal of waste in these rivers is a complex environmental scenario that involves (i) mining operation plans, (ii) the spatio-temporal variability of precipitation events and, (iii) the sediment-transport

One new species of Plakolana Bruce, 1993 and three new species of Cirolana Leach (1818), from the Lower Cretaceous (Aptian) Sierra Madre Formation dolomites at El Espinal quarries (Central-East Chiapas, SE Mexico) are reported and described and compared with other fossil species Cirolanidae from around the world. The specimens consist of the body and a few moults, with showing various degrees of decay

The Triassic Period was the setting for the origin and early diversification of Mesozoic ecosystems after the end-Permian mass extinction. The study of the Triassic is essential to understand the evolution of non-marine Mesozoic ecosystems, particularly the vertebrate components and their climatic context. During this time, the configuration of the supercontinent Pangea, which was unique (e.g., the

New ichthyosaur remains from the Upper Jurassic of Antarctica, recovered from the Ameghino (=Nordenskjöld) Formation are described. These three new specimens represent the first unambiguous records of ichthyosaurs in this continent. Based on the morphology of the humerus, we refer one of the specimens to Ophthalmosauridae, the dominant ichthyosaur forms from the Middle Jurassic until the extinction