Natural History of the Lutz`s Frog Cycloramphus lutzorum Heyer, 1983 (Anura: Cycloramphidae) in the Brazilian Atlantic Forest: Description of the Advertisement Call, Tadpole, and Karyotype

We describe the advertisement call, tadpole, karyotype, and additional information on the natural history of Cycloramphus lutzorum from southern Brazil. Sonograms were generated from digitally recorded calls. Tadpoles were collected in the field for description in the lab, and an adult was collected for karyotyping. Data on seasonal activity were gathered monthly from November 2005 to November 2007. All tadpoles (N = 21), juveniles (N = 18), and adults (N = 52) were found exclusively in streams. Reproduction, as identified by calling frogs, occurred from July through November. Frogs call all day long, but mostly at dusk, from rock crevices inside the stream edges near the splash zone. The call is short and loud, with 11 pulsed notes, of 491-641 ms, with a dominant frequency of 0.98-1.39 kHz. We describe the exotrophic and semiterrestrial tadpoles, always found in constantly humid vertical rock walls in the stream. Tadpoles of C. lutzorum are recognized by differences in labial tooth row formula, eye diameter, body shape, position of nares, and development of tail. Like congeneric species, the karyotype of C. lutzorum comprises 26 metacentric and submetacentric chromosomes. Cycloramphus lutzorum is restricted to and adapted for living in fast flowing streams, many of which are threatened by deforestation, pollution, and habitat loss. Therefore, we recommend the status of C. lutzorum be changed from its current ""Data Deficient"" to ""Near Threatened (NT)"" in the IUCN species red list.

Untangling associations between chironomid taxa in Neotropical streams using local and landscape filters

1. Analyses of species association have major implications for selecting indicators for freshwater biomonitoring and conservation, because they allow for the elimination of redundant information and focus on taxa that can be easily handled and identified. These analyses are particularly relevant in the debate about using speciose groups (such as the Chironomidae) as indicators in the tropics, because they require difficult and time-consuming analysis, and their responses to environmental gradients, including anthropogenic stressors, are poorly known. 2. Our objective was to show whether chironomid assemblages in Neotropical streams include clear associations of taxa and, if so, how well these associations could be explained by a set of models containing information from different spatial scales. For this, we formulated a priori models that allowed for the influence of local, landscape and spatial factors on chironomid taxon associations (CTA). These models represented biological hypotheses capable of explaining associations between chironomid taxa. For instance, CTA could be best explained by local variables (e.g. pH, conductivity and water temperature) or by processes acting at wider landscape scales (e.g. percentage of forest cover). 3. Biological data were taken from 61 streams in Southeastern Brazil, 47 of which were in well-preserved regions, and 14 of which drained areas severely affected by anthropogenic activities. We adopted a model selection procedure using Akaike`s information criterion to determine the most parsimonious models for explaining CTA. 4. Applying Kendall`s coefficient of concordance, seven genera (Tanytarsus/Caladomyia, Ablabesmyia, Parametriocnemus, Pentaneura, Nanocladius, Polypedilum and Rheotanytarsus) were identified as associated taxa. The best-supported model explained 42.6% of the total variance in the abundance of associated taxa. This model combined local and landscape environmental filters and spatial variables (which were derived from eigenfunction analysis). However, the model with local filters and spatial variables also had a good chance of being selected as the best model. 5. Standardised partial regression coefficients of local and landscape filters, including spatial variables, derived from model averaging allowed an estimation of which variables were best correlated with the abundance of associated taxa. In general, the abundance of the associated genera tended to be lower in streams characterised by a high percentage of forest cover (landscape scale), lower proportion of muddy substrata and high values of pH and conductivity (local scale). 6. Overall, our main result adds to the increasing number of studies that have indicated the importance of local and landscape variables, as well as the spatial relationships among sampling sites, for explaining aquatic insect community patterns in streams. Furthermore, our findings open new possibilities for the elimination of redundant data in the assessment of anthropogenic impacts on tropical streams.

Characterization of the mechanisms underlying the inflammatory response to Polistes lanio lanio (paper wasp) venom in mouse dorsal skin

Stings by Polistes wasps can cause life-threatening allergic reactions, pain and inflammation. We examined the changes in microvascular permeability and neutrophil influx caused by the venom of Polistes lanio a paper wasp found in southeastern Brazil. The intradermal injection of wasp venom caused long-lasting paw oedema and dose-dependently increased microvascular permeability in mouse dorsal skin. SR140333, an NK(1) receptor antagonist, markedly inhibited the response, but the NK(2) receptor antagonist SR48968 was ineffective. The oedema was reduced in capsaicin-treated rats, indicating a direct activation of sensory fibres. Dialysis of the venom partially reduced the oedema and the remaining response was further inhibited by SR140333. Mass spectrometric analysis of the venom revealed two peptides (QPPTPPEHRFPGLM and ASEPTALGLPRIFPGLM) with sequence similarities to the C-terminal region of tachykinin-like peptides found in Phoneutria nigniventer spider venom and vertebrates. Wasp venom failed to release histamine from mast cells in vitro and spectrofluorometric assay of the venom revealed a negligible content of histamine in the usual dose of P.l. lanio venom (1 nmol of histamine/7 mu g of venom)that was removed by dialysis. The histamine H(1) receptor antagonist pyrilamine, but not bradykinin B(1) or B(2) receptor antagonists, inhibited venom-induced oedema. In conclusion, P. l. lanio venom induces potent oedema and increases vascular permeability in mice, primarily through activation of tachykinin NK(1) receptors by substance P released from sensory C fibres, which in turn releases histamine from dermal mast cells. This is the first description of a neurovascular mechanism for P. l. lanio venom-mediated inflammation. The extent to which the two tachykinin-like peptides identified here contribute to this neurogenic inflammatory response remains to be elucidated. (c) 2008 Elsevier Ltd. All rights reserved.

Detection of metallo-beta-lactamases-encoding genes in environmental isolates of Aeromonas hydrophila and Aeromonas jandaei

Aims: To determine the prevalence and expression of metallo-beta-lactamases (MBL)-encoding genes in Aeromonas species recovered from natural water reservoirs in southeastern Brazil. Methods and Results: Eighty-seven Aeromonas isolates belonging to Aeromonas hydrophila (n = 41) and Aer. jandaei (n = 46) species were tested for MBL production by the combined disk test using imipenem and meropenem disks as substrates and EDTA or thioglycolic acid as inhibitors. The presence of MBL genes was investigated by PCR and sequencing using new consensus primer pairs designed in this study. The cphA gene was found in 97.6% and 100% of Aer. hydrophila and Aer. jandaei isolates, respectively, whereas the acquired MBL genes bla(IMP), bla(VIM) and bla(SPM-1) were not detected. On the other hand, production of MBL activity was detectable in 87.8% and 10.9% of the cphA-positive Aer. hydrophila and Aer. jandaei isolates respectively. Conclusions: Our results indicate that cphA seems to be intrinsic in the environmental isolates of Aer. hydrophila and Aer. jandaei in southeastern Brazil, although, based on the combined disk test, not all of them are apparently able to express the enzymatic activity. Significance and Impact of the Study: These data confirm the presence of MBL-producing Aeromonas species in natural water reservoirs. Risk of water-borne diseases owing to domestic and industrial uses of freshwater should be re-examined from the increase of bacterial resistance point of view.

Alkaline magmatism in the Amambay area, NE Paraguay: The Cerro Sarambi complex

The Early Cretaceous alkaline magmatism in the northeastern region of Paraguay (Amambay Province) is represented by stocks, plugs, dikes, and dike swarms emplaced into Carboniferous to Triassic-Jurassic sediments and Precambrian rocks. This magmatism is tectonically related to the Ponta Pora Arch, a NE-trending structural feature, and has the Cerro Sarambi and Cerro Chiriguelo carbonatite complexes as its most significant expressions. Other alkaline occurrences found in the area are the Cerro Guazu and the small bodies of Cerro Apua, Arroyo Gasory, Cerro Jhu, Cerro Tayay, and Cerro Teyu. The alkaline rocks comprise ultramafic-mafic, syenitic, and carbonatitic petrographic associations in addition to lithologies of variable composition and texture occurring as dikes; fenites are described in both carbonatite complexes. Alkali feldspar and clinopyroxene, ranging from diopside to aegirine, are the most abundant minerals, with feldspathoids (nepheline, analcime), biotite, and subordinate Ti-rich garnet; minor constituents are Fe-Ti oxides and cancrinite as the main alteration product from nepheline. Chemically, the Amambay silicate rocks are potassic to highly potassic and have miaskitic affinity, with the non-cumulate intrusive types concentrated mainly in the saturated to undersaturated areas in silica syenitic fields. Fine-grained rocks are also of syenitic affiliation or represent more mafic varieties. The carbonatitic rocks consist dominantly of calciocarbonatites. Variation diagrams plotting major and trace elements vs. SiO(2) concentration for the Cerro Sarambi rocks show positive correlations for Al(2)O(3), K(2)O, and Rb, and negative ones for TiO(2), MgO, Fe(2)O(3), CaO, P(2)O(5), and Sr, indicating that fractional crystallization played an important role in the formation of the complex. Incompatible elements normalized to primitive mantle display positive spikes for Rb, La, Pb, Sr, and Sm, and negative for Nb-Ta, P, and Ti, as these negative anomalies are considerably more pronounced in the carbonatites. Chondrite-normalized REE patterns point to the high concentration of these elements and to the strong LRE/HRE fractionation. The Amambay rocks are highly enriched in radiogenic Sr and have T(DM) model ages that vary from 1.6 to 1.1 Ga. suggesting a mantle source enriched in incompatible elements by metasomatic events in Paleo-Mesoproterozoic times. Data are consistent with the derivation of the Cerro Sarambi rocks from a parental magma of lamprophyric (minette) composition and suggest an origin by liquid immiscibility processes for the carbonatites. (C) 2011 Elsevier Ltd. All rights reserved.

Related changes in biodiversity, insolation and climate in the Atlantic rainforest since the last interglacial

The long-term Colonia record is located in the Atlantic rainforest domain in Brazil (23 degrees 52`S 46 degrees 42`20 `` W 900 m a.s.l.). The 780 cm long core CO3 provides a coverage of a complete interglacial/glacial cycle for the first time in a neotropical rainforest. Information on the behavior of tropical climates compared to global changes in temperatures indicates specific climate responses in terms of precipitation at these latitudes. Winter extratropical circulation was very active during the last interglacial and most of the glacial. Floristic composition of the rainforest changed several times in each phase of expansion, twice during the interglacial, and three times during glacial episodes. Araucaria was well developed in the area of Sao Paulo until the beginning of the first dry phase of the glacial at ca. 50,000 yr B.P. Changes in insolation controlled the expansion of the rainforest and the tropical hydrological cycle as evidenced by a strong precession signal. However precession had no impact on regional climatic features. The two interglacials (MIS 5e and Holocene) showed completely different patterns attesting to the continuous evolution of the forest. The biodiversity index (Shannon-Wiener Index) remained high during both the interglacial and glacial attesting to the permanence of small patches of rainforest refugia during drier phases. The lowest Shannon-Wiener Indexes were recorded between 23,000 and 12,000 yr B.P. and 40,000 and 30,000 yr B.P. and characterize two marked phases of stress for the rainforest. (C) 2008 Elsevier B.V. All rights reserved.

Thermal history versus sedimentary history: OSL sensitivity of quartz grains extracted from rocks and sediments

The optically stimulated luminescence (OSL) sensitivity of quartz has a significant influence on luminescence dating procedures. Furthermore, identifying the natural controls of quartz OSL sensitivity is an important step towards new applications of OSL in geology such as provenance tracing. We evaluate the OSL sensitivity (total and the proportion of the informally assigned fast, medium and slow components) of single grains of quartz extracted from 10 different igneous and metamorphic rocks with known formation conditions; and from fluvial and coastal sediments with different sedimentary histories and known source rocks. This sample suite allows assessment of the variability of the OSL sensitivity of single quartz grains with respect to their primary origin and sedimentary history. We observed significant variability in the OSL sensitivity of grains within all studied rock and sediment samples, with the brightest grains of each sample being those dominated by the fast component. Quartz from rocks formed under high temperature (> 500 degrees C) conditions, such as rhyolites and metamorphic rocks from the amphibolite facies, display higher OSL sensitivity. The OSL sensitivity of fluvial sediments which have experienced only a short transport distance is relatively low. These sediments show a small increase in OSL sensitivity downstream, mainly due to a decreasing fraction of ""dim"" grains. The quartz grains from coastal sands present very high sensitivity and variability, which is consistent with their long sedimentary history. The high variability of the OSL sensitivity of quartz from coastal sands is attributed more to the mixture of grains with distinct sedimentary histories than to the provenance from many types of source rocks. The temperature of crystallization and the number of cycles of burial and solar exposure are suggested as the main natural factors controlling the OSL sensitivity of quartz grains. The increase in OSL sensitivity due to cycles of erosion and deposition surpasses the sensitivity inherited from the source rock, with this increase being mainly related to the sensitization of fast OSL components. The discrimination of grains with different sedimentary histories through their OSL sensitivities can allow the development of quantitative provenance methods based on quartz. (C) 2010 Elsevier B.V. All rights reserved.

Use of the mini nutritional assessment tool in elderly people from long-term institutions of southeast of Brazil

Background: the Mini Nutritional Assessment (MNA) is a multidimensional method of nutritional evaluation that allows the diagnosis of malnutrition and risk of malnutrition in elderly people, it is important to mention that this method has not been well studied in Brazil. Objective: to verify the use of the MNA in elderly people that has been living in long term institutions for elderly people. Design: transversal study. Participants: 89 people (>= 60 years), being 64.0% men. The average of age for both genders was 73.7 +/- 9.1 years old, being 72.8 +/- 8.9 years old for men, and 75.3 +/- 9.3 years old for women. Setting: long-term institutions for elderly people located in the Southeast of Brazil. Methods: it was calculated the sensibility, specificity, and positive and negative predictive values. It was data to set up a ROC curve to verify the accuracy of the MNA. The variable used as a ""standard"" for the nutritional diagnosis of the elderly people was the corrected arm muscle area because it is able to provide information or an estimative of the muscle reserve of a person being considered a good indicator of malnutrition in elderly people. Results: the sensibility was 84.0%, the specificity was 36.0%, the positive predictive value was 77.0%, and the negative predictive value was 47.0%; the area of the ROC curve was 0.71 (71.0%). Conclusion: the MNA method has showed accuracy, and sensibility when dealing with the diagnosis of malnutrition and risk of malnutrition in institutionalized elderly groups of the Southeastern region of Brazil, however, it presented a low specificity.

The energy cycle and structural evolution of cyclones over southeastern South America in three case studies

In this paper, the Lorenz energy cycle over a limited area was applied for three cyclones with different origins and evolutions, where each of them was formed in an important cyclogenetic region near southeastern South America. The synoptic conditions and energetics were analyzed during each system`s life cycle and showed important relationships between their energy cycle and the evolution of their vertical structure. In the case of the weak baroclinic cyclone which formed on Brazil`s south-southeastern coast, the analysis showed that it originated through a midlevel cutoff low with contribution from barotropic instability. Its evolution would indicate potential transition to a hybrid system if the convective activity were stronger. The system that occurred in the La Plata River mouth had features of an oceanic bomb-type cyclogenesis and showed an important contribution from the available potential energy generation term through the latent heat release by the convection. Meanwhile, the system of the southern Argentina coast presented a classical baroclinic development of extratropical cyclogenesis in the energy cycle, from the wave amplification up to the final occlusion of the associated frontal system. These analyses revealed that the development of some cyclones that occur in eastern South America can present different mechanisms that are not related to the classical extratropical cyclogenesis.

Bathymetric distribution of the shrimp Rimapenaeus constrictus (Stimpson, 1874) (Decapoda, Penaeidae) in two locations off the southeastern Brazilian coast

The distribution of benthic organisms is directly or indirectly associated with the physical and chemical properties of the water and sediment. This study analysed the spatial and temporal distribution of Rimapenaeus constrictus in unconsolidated sublittoral sediments of two areas off the northern coast of the state of Sao Paulo, Brazil. We also analysed the association of environmental factors with the occurrence of this species. Shrimp were collected monthly from July 2001 to June 2003, with a fishing boat equipped with two double-rig nets, in the regions of Ubatuba (UBA) and Caraguatatuba (CA). The collections were made during the day, along five transects with mean depths of 5, 10, 15, 20, 25, 30, and 35 m. We obtained a total of 5478 individuals, 3403 (UBA = 2025 and CA = 1378) during the first year, and 2075 (UBA = 875 and CA = 1200) during the second year. Significant differences in abundance were observed in relation to depth, season of the year, and also in the interaction between region and depth. Higher abundances occurred in fall and winter, independently of the sampling year. The largest numbers of shrimp were caught on the 20-m transect in UBA and the 25-m transect in CA. It is concluded that the distribution pattern of this species is closely related to environmental factors, and the temperature of the bottom water and the sediment texture were the most significant variables affecting the distribution.

How does a riverine setting affect the lifestyle of shellmound builders in Brazil?

The contact of inland and coastal prehistoric groups in Brazil is believed to have been restricted to regions with no geographical barrier, as is the case in the Ribeira de Iguape valley. The inland osteological collection from the riverine shellmound Moraes (5800-4500 BP) represents a unique opportunity to test this assumption for this region. Despite cultural similarities between riverine and coastal shellmounds, important ecological and site distribution differences are expected to impact on lifestyle. The purpose of this study is thus to document and interpret health and lifestyle indicators in Moraes in comparison to coastal shellmound groups. Specifically we test if the rare evidence of fish and mollusc remains in the riverine shellmound led to (a) higher caries rates and (b) lower auditory exostosis frequency and (c) if the small size of the riverine shellmound translates into reduced demographic density and thus rarity of communicable infectious diseases. Of the three hypotheses, (a) was confirmed, (b) was rejected and (c) was partly rejected. Bioanthropological similarities between Moraes and coastal shellmounds include auditory exostoses with equally high frequencies; significantly more frequent osteoarthritis in upper than in lower limbs; cranial and dental morphological affinities and low frequencies of violent trauma. However, there are also important differences: Moraes subsisted on a much broader protein diet and consumed more cariogenic food, but showed a stature even shorter than coastal groups. Thus, despite the contact also suggested by treponematoses in both site types, there was enough time for the people at the riverine site to adapt to local conditions. (c) 2008 Elsevier GmbH. All rights reserved.

The invasive hydromedusae Blackfordia virginica Mayer, 1910 (Cnidaria: Blackfordiidae) in southern Brazil, with comments on taxonomy and distribution of the genus Blackfordia

The invasive brackish-water hydrozoan Blackfordia virginica is reported from estuaries and harbours in southeastern and southern Brazil. Medusae of the species were collected for the first time in Cananeia, Guaratuba Bay, and Babitonga Bay. They were also found in Paranagua Bay where they were previously known to occur. Based on material examined here, a comparative redescription is given of B. virginica, and its distribution worldwide is reviewed. The three nominal species of Blackfordia are assessed.

New and little-known cheilostomatous Bryozoa from the south and southeastern Brazilian continental shelf and slope

The present paper reports on 22 species collected by the Brazilian Program of Living Resources in the Exclusive Economic Zone (REVIZEE). A new genus and species of Cribrilinidae, Corbuliporina crepida n. gen. et sp., is described, along with seventeen other new species: Chaperia brasiliensis n. sp., Amastigia aviculifera n. sp., Isosecuriflustra pinniformis n. sp., Cellaria subtropicalis n. sp., Melicerita brasiliensis n. sp., Arachnopusia haywardi n. sp., Smittina migottoi n. sp., Hippomenella amaralae n. sp., Rogicka joannae n. sp., Malakosaria atlantica n. sp., Turbicellepora winstonae n. sp., Rhynchozoon coalitum n. sp., Stephanollona angusta n. sp., Stephanollona arborescens n. sp., Aulopocella americana n. sp., Conescharellina cookae n. sp. and Conescharellina bocki n. sp. Chorizopora brongniartii (Audouin, 1826) is recorded for the first time in Brazilian waters and a new combination for Rhynchozoon arborescens Canu & Bassler, 1928 is established. New illustrations and taxonomic remarks are included for two little-known species from Brazil, Rogicka scopae (Canu & Bassler, 1928) and Fenestrulina ampla Canu & Bassler, 1928. A compilation of species recorded from deeper waters of the Brazilian coast is included.

Deformation and geochronology of syntectonic granitoids emplaced in the Major Gercino Shear Zone, southeastern South America

The Major Gercino Shear Zone is one of the NE-SW lineaments that separate the Neoproterozoic Dom Feliciano Belt, of Brazil and Uruguay, into two different domains: a northwestern supracrustal domain from a southeastern granitoid domain. The shear zone, striking NE, is composed of protomylonites to ultramylonites with mainly dextral kinematic indicators. In Santa Catarina State, southern Brazil, the shear zone is composed of two mylonite belts. The mylonites have mineral orientations produced under greenschist fades conditions at a high strain rate. Strong flattening and coaxial deformation indicate the transpressive character, while the role of pure shear is emphasized by the orientation of the mylonite belts in relation to the inferred stress field component. The quartz microstructures point out that different dynamic recrystallization regimes and crystal plasticity were the dominant mechanisms of deformation during the mylonitization process. Additionally, the fabrics suggest that the glide systems are activated for deformation conditions compatible with the metamorphism in the middle greenschist facies. Elongated granitoid intrusions belonging to two petrographically, geochemically and isotopically distinct rock associations occur between the two mylonite belts. The structures observed in the granites result from a deformation range from magmatic to solid-state conditions points to a continuum of magma straining during and just after its crystallization. Conventional U-Pb analysis of multi-crystal zircon fractions yielded essentially identical ages of 609 +/- 16 Ma and 614 +/- 2 Ma for the two granitic associations, and constrain the transpressive phase of the shear zone. K-Ar ages of biotites between 585 and 560 Ma record the slow cooling and uplift of the intrusions. Some K-Ar ages of micas in regional mylonites are similar, suggesting that thermo-tectonic activity was intense up to this time, probably related to the agglutination of the granite belt to the supracrustal belt NW of the MGSZ. (C) 2009 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

THE RIO APA CRATON IN MATO GROSSO DO SUL (BRAZIL) AND NORTHERN PARAGUAY: GEOCHRONOLOGICAL EVOLUTION, CORRELATIONS AND TECTONIC IMPLICATIONS FOR RODINIA AND GONDWANA

The Rio Apa cratonic fragment crops out in Mato Grosso do Sul State of Brazil and in northeastern Paraguay. It comprises Paleo-Mesoproterozoic medium grade metamorphic rocks, intruded by granitic rocks, and is covered by the Neoproterozoic deposits of the Corumbi and Itapocurni Groups. Eastward it is bound by the southern portion of the Paraguay belt. In this work, more than 100 isotopic determinations, including U-Pb SHRIMP zircon ages, Rb-Sr and Sm-Nd whole-rock determinations, as well as K-Ar and Ar-Ar mineral ages, were reassessed in order to obtain a complete picture of its regional geological history. The tectonic evolution of the Rio Apa Craton starts with the formation of a series of magmatic arc complexes. The oldest U-Pb SHRIMP zircon age comes from a banded gneiss collected in the northern part of the region, with an age of 1950 +/- 23 Ma. The large granitic intrusion of the Alumiador Batholith yielded a U-Pb zircon age of 1839 +/- 33 Ma, and from the southeastern part of the area two orthogneisses gave zircon U-Pb ages of 1774 +/- 26 Ma and 1721 +/- 25 Ma. These may be coeval with the Alto Terere metamorphic rocks of the northeastern corner, intruded in their turn by the Baia das Garcas granitic rocks, one of them yielding a zircon U-Pb age of 1754 +/- 49 Ma. The original magmatic protoliths of these rocks involved some crustal component, as indicated by the Sm-Nd TDm model ages, between 1.9 and 2.5 Ga. Regional Sr isotopic homogenization, associated with tectonic deformation and medium-grade metamorphism occurred at approximately 1670 Ma, as suggested by Rb-Sr whole rock reference isochrons. Finally, at 1300 Ma ago, the Ar work indicates that the Rio Apa Craton was affected by widespread regional heating, when the temperature probably exceeded 350 degrees C. Geographic distribution, age and isotopic signature of the fithotectonic units suggest the existence of a major suture separating two different tectonic domains, juxtaposed at about 1670 Ma. From that time on, the unified Rio Apa continental block behaved as one coherent and stable tectonic unit. It correlates well with the SW corner of the Amazonian Craton, where the medium-grade rocks of the Juruena-Rio Negro tectonic province, with ages between 1600 and 1780 Ma, were reworked at about 1300 Ma. Looking at the largest scale, the Rio Apa Craton is probably attached to the larger Amazonian Craton, and the actual configuration of southwestern South America is possibly due to a complex arrangement of allochthonous blocks such as the Arequipa, Antofalla and Pampia, with different sizes, that may have originated as disrupted parts of either Laurentia or Amazonia, and were trapped during later collisions of these continental masses.