The Colider and Roosevelt olcanic rocks (sw amazonian craton): geochemistry and sm-nd isotope characteristics of a silicic large igneous province

The volcanic rocks of the Colíder and Roosevelt formations are extensively exposed in the south-central portion of the Amazonian Craton where effusive and pyroclastic rocks have been mapped.Both units,topped by chemical sediments and oceanic facies as rhyolite and andesite lavas,rhyodacite,and porphyritic dacite,with frequent intercalations of pyroclastic and epiclastic deposits.Whole-rock geochemistry for 55 samples of rhyolitic to andesitic composition suggests the involvement of fertile mantle-derived components with E-MORB to OIB compositions.The analyzed rocks display calc-alkaline to shoshonitic affinity consistent with generation related to an active continental margin.The whole-rock Sm-Nd isotope data from selected felsic volcanic rocks of the Colíder and Roosevelt formations yield negative initial eNd values between–3 and–9,indicating the predominantly crustal nature of the parental magmas with early Archean to late Paleoproterozoic(ca.2.5–2.0 Ga)depleted mantle model ages.

Timing of Proterozoic magmatism in the Sunsas belt, Bolivian Precambrian Shield, SW Amazonian Craton

We present new U–Pb zircon and monazite ages from the Sunsas belt granitic magmatism in Bolivia, SW Amazonian Craton. The geochronological results revealed four major magmatic events recorded along the Sunsas belt domains. The older igneous event formed a granitic basement coeval to the Rio Apa Terrane(1.95–1.85 Ga) in the southern domain. The second magmatic episode is represented by 1.68 Ga granites associated to the Paraguá Terrane(1.69–1.66 Ga) in the northern domain. The 1.37–1.34 Ga granites related to San Ignacio orogeny represent the third and more pervasive magmatic event, recorded throughout the Sunsas belt. Moreover, magmatic ages of ~1.42 Ga revealed that the granitogenesis associated to the Santa Helena orogeny also affected the Sunsas belt, indicating that it was not restricted to the Jauru Terrane. Lastly, the 1.10–1.04 Ga youngest magmatism was developed during the Sunsas orogeny and represents the final magmatic evolution related to Rodinia assembly. Likewise, the 1.95–1.85 and 1.68 Ga inherited zircon cores obtained in the ~1.3 Ga and 1.0 Ga granite samples suggest strong partial melting of the Paleoproterozoic sources. The 1079 ± 14 Ma and 1018 ± 6 Ma monazite crystallization ages can be correlated to the collisional tectono-thermal event of the Sunsas orogeny, associated to reactions of medium-to high-grade metamorphism. Thus, the Sunsas belt was built by heterogeneous 1.95–1.85 Ga and 1.68 Ga crustal fragments that were reworked at 1.37–1.34 Ga and 1.10–1.04 Ga related to orogenic collages. Furthermore, the 1.01 Ga monazite age suggests that granites previously dated by zircon can bear evidence of a younger thermal history. Therefore, the geochronological evolution of the Sunsas belt may have been more complex than previously thought.

Prediction Equation of Body Weight of Amazonian Manatee (Trichechus inunguis) Calves in Captivity Using Biometry

The objective of the study was to determine a prediction equation of body weight of Amazonian manatee calves in captivity using their biometry. It was conducted out with 7 calves (4 males and 3 females) of approximately 8 months of age and average body weight of 29.94 ± 0.055 kg, arranged in pools of sufficient size. Biometry and weighing were performed periodically, with the following measurements: body weight (BW), total curved length (TCL), total length (TL), circumference (CIR), fin width (FW), tail width (TW) and peduncle (PED). Data were subjected to Pearson correlation analysis and linear regression, using the statistical software IBM SPSS 24.0. The results showed a significant correlation (P R2 = 0.855, R2aj = 0.852). In addition, three linear multiple regression equations of BW were calculated using the predictor variables previously analyzed by Person correlation analysis. The equation that used all biometric measurements (TCL, TL, FW, TW, CIR and PED) had the highest coefficient of determination and the lowest estimation error to predict BW. In conclusion, the biometric measurements of TCL, TL, FW, TW, CIR and PED showed a high correlation with the BW and can be used as predictive variables of BW of manatee calves, as they are easy to be measured.

An Overview of the Amazonian Craton Evolution: Insights for Paleocontinental Reconstruction

The Amazonian craton major accretionary and collisional processes may be correlated to supercontinent assemblies developed at several times in the Earth history. Based on geologic, structural and paleomagnetic evidence paleocontinent reconstructions have been proposed for Archean to younger times. The oldest continent (Ur) was formed probably by five Achaean cratonic areas (Kaapvaal, Western Dhawar, Bhandara, Singhhum and Pilbara cratons). Geologic evidences suggest the participation of the Archaean rocks of the Carajás region in the Ur landmass. Supercontinental 2.45 Ga Kenorland amalgamation is indicated by paleomagnetic data including Laurentia, Baltica, Australia, and Kalahari and Kaapvaal cratons. There is no evidence indicating that Amazonian craton was part of the Kenorland supercontinent. From 1.83 Ga to 1.25 Ga Columbia and Hudsonland supercontinents including Amazonian craton were proposed based on NE portion of the Amazonian craton (Maroni/Itacaiunas province) connection with West Africa and Kalahari cratons. Rodinia supercontinent reconstructions show Amazonia joined to Laurentia-Baltica as result of 1.1 Ga to 1.0 Ga fusion based on the Sunsas-Aguapei belts and Greenville and Sveconorwegian belts, respectivelly. The large Late Mesoproterozoic landmass included also Siberia, East Antartica, West Nile, Kalahari, Congo/Sao Francisco and Greenland. The 750 - 520 Ma Gondwana assembly includes most of the continental fragments rifted apart during the break-up of Rodinia followed by diachronic collisions (Araguaia, Paraguay and Tucavaca belts). The supercontinent Pangea is comprised of Gondwana and Laurentia formed at about 300 - 180 Ma ago. The Amazonian craton margins probably were not envolved in the collisional processes during Pangea because it was embebed in Neoproterozoic materials. As consequence, Amazonian craton borders have no record of the orogenic processes responsible for the Pangea amalgamation.

Influences of Amazonian White and Black Waters on the Hematological and Biochemical Plasma Features of Arapaima gigas （Osteoglossiformes）

The Arapaima gigas, despite being an air breather, its gill structure is quite close to water breathers, especially in early stages of development. The effects of Amazonian waters is well notices in other Teleostei expose to BW （black water）, and WW （white water）. However, information about hematological adjustments and its implications to ionic regulation patters are scarce. Therefore, our aim was to analyzed A. gigas hematological parameters when exposed to BW and WW providing suitable hematological data concerning about physiological responses in Amazonian waters. Fish were acclimated in three separated ponds containing BW, WW and well water as control （C）. Blood samples were taken from the caudal vessel in order to perform measurement assays on levels of hemoglobin, hematocrit, mean corpuscular volume, corpuscular hemoglobin, corpuscular hemoglobin concentration, glucose, cholesterol and protein. Our findings corroborate the hypothesis stating that BW does interfere on fish adaptation specialy in smallfish （-100 g）. However in largefish （-1,000 g） neither WW or BW can interfere on plasma profile of analysed fish. Despite black water systems being considered a barrier constraining the dispersion of several species, this seems not to be a problem for this specie which has kept its ion-regulatory mechanisms even in black waters.

Origin of the Amazonian Rainforest

In the last 30 ma, the passive continental margin of South America and the Amazonian basin experienced three periods of major sea level inundation;viz. at around 20 ma, at around 10 ma and at around 3 ma. The establishment of the immense Amazonian rainforest ecosystem covering some 6 million square km can neither have occurred during the periods of high sea level nor at the intermediate periods of arid or semi-arid climatic conditions. Therefore, the origin of the Amazonian rainforest of present-day dimensions must be set at the Late Miocene. The establishment of the Amazonian rainforest implied the withdrawal of enormous quantities of water from the global hydrological cycle. The drastic increase in evaporation leading to the Messinian salinity crisis in the Mediterranean occurred at the same time as the Amazonian rainforest (sensu hodierno) establishment suggesting a causal linkage.

The Colíder Paleoproterozoic felsic volcanism:New insights into stratigraphy and petrogenesis in the southern Amazonian Craton

The eastern side of Alta Floresta Mineral Province(AFMP)(União do Norte region)comprises an effusive/-subvolcanic phase,explosive phase,and epiclastic rocks.The effusive/subvolcanic phase comprises massive porphyritic rhyolite with different degrees of crystallinity,porphyritic rhyolite with flow structure,and microcrystalline rhyolite.The explosive phase is characterized by welded lapilli tuff,lapilli tuff with flow structure,stratified lapilli tuff,and tuff with accretionary lapilli.Sandstones and siltstones characterize epiclastic rocks.There are porphyritic rhyolite dikes that cut the volcanic sequence.The rocks of the Colíder Group are rhyolites(>70%SiO2)with calcic-alkaline to alkaline-calcic affinity.A rhyolitic rock is predominantly ferroan and metaluminous,while a pyroclastic rock is predominantly magnesian to ferroan and meta-to peraluminous in composition.The rocks have a high LREE content,and slight fractionation of HREE suggests they have hybrid geochemical characteristics of high potassium calc-alkaline,shoshonitic,and suggestive affinities of A-type magmas,probably produced in a post-collisional orogenic environment.These rocks have a relatively high level of Ba and Rb and a negative anomaly for Sr,P,Nb,Ta,and Ti,suggesting an intra-plate mantle source with contributions from a metasomatized mantle edge.The rocks do not have adakitic characteristics nor fertility for Cu-Au(Sr/Y<1.9 and LaN/YbN<38.0)as in other regions of the AFMP.The welded lapilli tuff rocks show U-Pb age of 1838±17 Ma and 1817±2 Ma and are the older explosive phases.The effusive/subvolcanic phase has U-Pb ages of 1800±3 Ma and 1792±3 Ma obtained in the massive porphyritic rhyolite.The age interval of approximately 46 Ma(1838–1792 Ma)suggests the presence of two or more volcanic cycles or distinct volcanic events.Based on the interpretation of volcanic and epiclastic deposits and remote sensing products,the paleoenvironmental reconstruction includes subaerial with effusive/subvolcanic and explosive stages in a probable eroded volcanic caldera system with epiclastic rocks from a fluvial depositional system.This volcanic scenario provides more information about the Colíder–Teles Pires volcano-plutonic event,uniquely mapped in AFMP,and offers new insights into the tectonic frame of the Amazonian craton.

Deciphering the fiber quality of Gossypium barbadense L.var.brasiliensis in La Convención,Cusco,Perú

Background The quality of cotton fiber determines its value in the textile market,influencing agricultural profitability and the efficiency of textile processing.The selection of genotypes with superior fibers is a key factor for genetic improvement programs seeking adaptability and sustainability in the face of climate change.This demonstrates the strategic importance of this plant for sustainable agriculture and the global textile industry.The objective of this research was to decipher the fiber quality of Gossypium barbadense var.brasiliensis in the native Amazonian communities of La Convención,Cusco-Perú,and to evaluate other critical aspects of native cotton that have not yet been identified.The methodology included non-probability sampling for accessibility,qualitative and quantitative analyses,and multivariate analyses.The fiber length(mm),micronaire index(maturity/fineness),fiber strength(gf/tex),length uniformity index(%),fiber elongation(%),maturation index(%),and short fiber index(%)were the fiber characteristics evaluated using the HVI method in cotton genotypes.Results Cotton accessions collected from Koribeni(Gossypium spp.)and Shivankoreni(Gossypium barbadense var.brasiliensis)stood out for their fiber quality properties,especially length,strength,and uniformity,which highlights their relevance for advanced textile applications and potential for use in plant genetic improvement programs.Conclusion These findings reinforce the need to conserve and study these native cotton accessions from the Peruvian Amazon region,which can offer promising perspectives for the textile industry and agricultural biodiversity.

Medicinal plants from the Brazilian Amazonian region and their antileishmanial activity:a review

Leishmaniasis, a neglected disease caused by Leishmania protozoans, primarily affects people in tropical and subtropical areas. Chemotherapy based on the use of pentavalent antimonials, amphotericin B, paromomycin, miltefosine and liposomal amphotericin B is currently the only effective treatment. However, adverse effects, long-term treatment and the emergence of parasite resistance have led to the search for alternative treatments. Natural products used in traditional medicine provide an unlimited source of molecules for the identification of new drugs, and the Amazon region has abundant biodiversity that includes several species of plants and animals, providing a rich source of new products and com- pounds. Although the literature describes numerous promising compounds and extracts for combating Leishmania protozoans, the results of such research have not been embraced by the pharmaceutical industry for the development of new drugs. Therefore, this review focused on the antileishmanial activity of extracts, isolated compounds and essential oils commonly used by the local population in the Brazilian Amazonian region to treat several illnesses and described in the literature as promising compounds for combating leishmaniasis.

Constraints on water activity at the Zhurong landing site in Utopia Planitia,Mars

Mineralogical evidence of water–rock interactions is a strong indicator of the presence of liquid water on ancient Mars.Previous observations have found widely distributed hydrated minerals in the southern highlands,whereas such discoveries have been rare in the younger northern lowlands.China’s first Mars exploration mission successfully landed a rover(Zhurong)in southern Utopia Planitia,providing an opportunity to analyze the exposed rocks in the northern lowlands.Using data from the short-wave infrared(SWIR)spectrometer and the laser-induced breakdown spectrometer(LIBS)onboard the Zhurong rover,we found evidence for the widespread presence of hydrated minerals(probably sulfates or silica)around the landing site.The basaltic-like elemental compositions of the targeted samples further indicated that hydrated minerals are likely minor components.The results from Zhurong suggest that active aqueous activities occurred during the overall cold and dry Amazonian era on Mars.However,further evaluations are needed on the duration and scale of these activities.

温度对大瓶螺心率与卵孵化速率的影响

水温对大瓶螺心率的影响,在7～38℃之间心率随温度上升而加快,超过40℃心率下降.致死温度的上、下限为47℃和3 ℃.卵发育的生物学零度为15.4℃,孵化的有效积温为161.3℃,孵化的最适温度范围25～30℃,温度≥34℃,孵化速度为零.

Zircon U-Pb and Lu-Hf isotope constraints on Archean crustal evolution in Southeastern Guyana Shield

The southeastern Guyana Shield,northeast Amazonian Craton,in the north of Brazil,is part of a widespread orogenic belt developed during the Transamazonian orogenic cycle(2.26-1.95 Ga)that includes a large Archean continental landmass strongly reworked during the Transamazonian orogeny,named Amapa Block.It consists mainly of a high-grade metamorphic granulitic-migmatitic-gneiss complex,of Meso-to Neoarchean age and Rhyacian granitoids and supracrustal sequences.For the first time,coupled U-Pb and Lu-Hf isotope data were obtained on zircon by LA-ICP-MS from five tectono-stratigraphic units of the Archean basement and one Paleoproterozoic intrusive rock,in order to investigate the main episodes of crustal growth and reworking.Whole-rock Sm-Nd isotope data were compared to the zircon Lu-Hf data.Three main magmatic episodes were defined by U-Pb zircon dating,two in the Mesoarchean(~3.19 Ga and 2.85 Ga)and one in the Neoarchean(~2.69-2.65 Ga).SubchondriticεHf(t)values obtained for almost all investigated units indicate that crustal reworking processes were predominant during the formation of rocks that today make up the Amapa Block.Hf-TDMC model ages,ranging from2.99 Ga to 3.97 Ga,indicate that at least two important periods of mantle extraction and continental crust formation occurred during the Archean in southeastern Guyana Shield,an older one in the Eoarchean(~4.0 Ga)and a younger one in the Mesoarchean(~3.0-3.1 Ga).The latter is recognized as an important period of crustal accretion worldwide.The recognition of an Eoarchean episode to the southeastern most part of the Guyana Shield is unprecedented and was not recorded by whole-rock Sm-Nd data,which were restricted to the Meso-Paleoarchean(2.83 Ga to 3.51 Ga).This finding reveals t hat continental crust generation in the Amazonian Craton began at least 500 Ma earlier than previously suggested by the SmNd systematics.

茶皂素对福、寿螺纤维素酶的影响研究

从苦茶粕中提取茶皂素,用离体的方法测定它对福寿螺中消化酶—纤维素酶活性的影响.结果表明,在所测定的10-150μg/ml的浓度内,茶皂素对内切β-1,4葡聚糖酶(EG)的作用表现为先激活,后抑制;对外切β-1,4葡聚糖纤维二糖水解酶(CBH)的作用表现为激活作用,基本上不表现抑制作用.

REE Distribution Pattern in Plants and Soils from Pitinga Mine—Amazon,Brazil

The rare earth element contents of plant specimens of the families Rhamnaceae, Ampelozizyphus amazonicus Ducke (local name: Saracura-Mirá) and of Pteridófitas from genus Gleichenia sp. e Adiantum sp. (ferns) were determined and compared to those of the soils, in the Pitinga Mine area, Amazon, Brazil. The Pitinga mine district has large tin reserves genetically related to two granite bodies, Agua Boa e Madeira, both intrusive in volcanic rocks included in the Iricoumé Group. This deposit contains, also, bodies of cryolite and rare metals, such as Zr, Nb, Ta, Y and REE. The REE biogeochemical signatures, shown by the collected plants, reflect the patterns of the respective soils. The Eu and Ce anomalies shown by some plant samples are inherited from soils, as well. The higher contents of REE observed in fern samples confirm they are accumulators and reflect the abundance of REE in the soils of Pitinga Mine region. Additionally, that supports their potential use in geochemical exploration and bioremediation. The results of this study stress the importance of biogeochemical research integrated with geochemistry of soils, rocks and minerals.

Camu-Camu (<i>Myrciaria dubia</i>HBK): Yogurt Processing, Formulation, and Sensory Assessment

The objective of this study is to formulate and assess technologies for producing yogurt with camu-camu pulp, which has market potential and can be included in school meals, providing the general population with a nutritious and functional product. Three formulations of yogurt with camu-camu pulp were prepared, F1 10%, F2 13%, and F3 15%, with the following ingredients: whole UHT (Ultra High Temperature) milk, camu-camu pulp, dairy culture, and sugar. The micro-biological characteristics of the final products were within the standards recommended by ANVISA. Regarding sensory assessment, formulation 1 achieved the highest acceptability. The chemical, physical, and microbiological parameters were within the limits established by the legislation, and the acceptability of the formulation containing 10% camu-camu pulp was satisfactory. This is a more quality food option for the Amazonian and Brazilian population.

Paying for Environmental Services

The Amazonian economic occupation over the last forty years has been extremely harmful to the environment and to the traditional populations. One of the strategies to overcome this difficulty, dealing with sustainable development, is the development of productive units—starting with non-timber forest products (NTFP)—and the Payment for Environmental Services (PES) for the residents and/or owners of forest areas. The main problem which the literature demonstrates is that the estimated values paid for the PES are rather high, because they use the opportunity cost as reference, not considering the family reproduction social cost. The main aim of this study is to provide an alternative forecast of the value to be paid for the environmental services (PES) for the Amazon forest, based on the real costs of the forest communities maintenance, as based on the real economic needs of rural family production in the “Chico Mendes” Extractive Reserve (RESEX), in Xapuri (Acre state), Brazil. It was used a specific methodology, developed regionally, which measured and provided indicators to evaluate and to analyze the economic evolution of those families over the last decade. Based on the needs of family reproduction, the calculations require that the minimum value for PES should be US$13 per hectare, a far lower and more appropriate value than the literature’s average propositions that is around US$50 per hectare. The present paper estimates that the costs of the PES in the Chico Mendes RESEX would be approximately US$5,767,000 per year—taking into account the average area per family.

Mining Threats to Ancient Anthropogenic Soils and other Resources Associated to Indigenous Food Security in the Middle Caqueta River, Colombia

Mining is encroaching upon Protected Areas and Indigenous Reserves in the Colombian Amazon. In the Middle Caqueta region small-scale, illegal gold mining is eroding riverbanks, affecting water quality, and jeopardizing the livelihoods of indigenous peoples. In addition, mining also threatens the integrity of pre-Columbian anthropogenic soils （terra preta） created between 500 years to 2,000 years B.P. on the bluffs of the Caqueta . River. These soils are the only, non-flooded fertile soils present in the region, and as such are important for local indigenous communities. In Colombia, there is little knowledge about Terra Preta soils. This work assesses the present and potential dangers artisanal mining has for terra preta soils and other natural resources that are central to indigenous peoples＇ food security. Results posit that more knowledge is needed about the way terra preta soils are related to the livelihoods of indigenous people so that informed policy decisions can be made about the desirability of mining in the region.

The Amazon Anthropology

This study aims to demonstrate who the Amazon man is, where he came from, how he used to live and how he lives nowadays. The Amazon scenario in the past, when it was almost untouchable compared with the present situation, after the economic, social, political, and environmental challenges. The methodology used was the reading of the books of authors and articles that made possible a better interpretation and development of the present work, through the interweaving of the authors＇ ideas.

热带福寿螺的引种养殖与气候适应性区划

在分析比较原产地气候条件和福寿螺生物学特性的基础上,确定福寿螺养殖的生态因子指标,划分适宜养殖区域并进行分区综合评价.为这一新兴的水产珍品养殖业的迅速合理发展提供科学依据.

稻田福寿螺发生为害的特点及综合防治技术

福寿螺对水稻的为害十分严重。文章介绍福寿螺的特征特性及发生规律,并在调查试验的基础上,总结出一套农业防治和药物防治相结合的综合防治福寿螺的办法。