Paleo-and Mesoarchean TTG-sanukitoid to high-K granite cycles in the southern São Francisco craton,SE Brazil

The generation of the continental crust is widely accepted to have taken place predominantly in the Archean,when TTG magmatism associated with greenstone-belt supracrustal succession development was typically followed by emplacement of high-K granites before crustal stabilization.This study focuses on the Campos Gerais complex(CGC),which is an Archean granite-greenstone belt lithological association in a tectonic window located in the southwesternmost portion of the São Francisco craton(SFC).The CGC is an important segment of Paleo-to Mesoarchean continental crust to be integrated into paleogeographic reconstructions prior to the transition into the Paleoproterozoic.This investigation reports field relationships,28 major and trace element compositions,U–Pb(zircon)geochronological results,and Hf and Sm–Nd isotope data for orthogneiss and amphibolite samples.The results indicate that the CGC records a complex Archean crustal evolution,where voluminous 2.97 Ga TTG tonalites and trondhjemites(ε_(Nd)(t)=-4.7;T_(DM)=3.24 Ga)were followed by 2.89 Ga sanukitoid tonalite production(ε_(Nd)(t)=-1.9;T_(DM)=3.02 Ga),broadly coeval with the development of the Fortaleza de Minas and Pitangui greenstone-belts.These events are interpreted to represent the initial stage of an important subduction-accretion tectonic cycle,which ended with the emplacement of 2.82–2.81 Ga high-K leucogranites and migmatization of the TTG-sanukitoid crust,with hybrid and two-mica,peraluminous compositions(ε_(Nd)(t)=-8.0 to-8.6;T_(DM)=3.57–3.34 Ga).The presence of inherited zircons with207Pb/206Pb ages of 3.08 Ga,3.29 Ga,3.55 Ga and 3.62 Ga indicates that the Mesoarchean tectonic processes involved reworking of Meso-to Eo-archean crust.Renewed TTG magmatism took place at ca.2.77 Ga represented by juvenile tonalite stocks(ε_(Nd)(t)=+1.0 to-1.5;T_(DM)=2.80–2.88 Ga)which intrude the TTG-greenstone belt association.Crustal stabilization was attained by 2.67 Ga,allowing for the emplacement of within-plate tholeiitic amphibolites(ε_(Nd)(t)=-3.1;T_(DM)=2.87 Ga).The CGC shows important tectonic diachronism with respect to other Archean terrains in the southern São Francisco craton,including an independent Meso-to Neoarchean crustal evolution.

Moving beyond Wastewater:Perspectives on Environmental Surveillance of Infectious Diseases for Public Health Action in Low-Resource Settings

Although testing wastewater for public health surveillance has recently received significant attention in the United States,researchers and public health professionals have long realized the tremendous promise of environmental surveillance(ES),defined as tracking pathogens of interest in fecally contaminated surface waters,soil,or fomites,in low-resource settings for public health action.1,2 The power of ES in lowresource settings is most clearly illustrated with the over 30 years of well-established and standardized polio surveillance.As part of the Global Polio Eradication Initiative,the World Health Organization(WHO)has accredited 146 laboratories within the Global Polio Lab Network(GPLN).These facilities across 92 countries process over 8,000 wastewater or fecally contaminated surface water samples per year,in addition to over 220,000 stool samples annually.3 The data generated from the GPLN are closely linked to clear public health action related to targeted vaccination campaigns.The investment and adoption of ES for polio eradication efforts serves as a use-case for other targets of interest.To explore the current state of the field,the National Science Foundation-funded Research Coordination Network(RCN)on Wastewater Based Epidemiology for SARS-CoV-2 and Emerging Public Health Threats held a workshop in December 2023 to discuss the opportunities and challenges for ES in low-resource settings(Figure 1).Discussions during the workshop highlighted knowledge gaps,best-practices,target selection,academic/government/private partnerships and overall public health action and sustainability of these programs.

On the cratonization of the Arabian-Nubian Shield: Constraints from gneissic granitoids in south Eastern Desert, Egypt

The Shaitian granite complex(SGC)spans more than 80 Ma of crustal growth in the Arabian–Nubian Shield in southeast Egypt.It is a voluminous composite intrusion(60 km2)comprising a host tonalite massif intruded by subordinate dyke-like masses of trondhjemite,granodiorite and monzogranite.The host tonalite,in turn,encloses several,fine-grained amphibolite enclaves.U-Pb zircon dating indicates a wide range of crystallization ages within the SGC(800±18Ma for tonalites;754±3.9 Ma for trondhjemite;738±3.8 Ma for granodiorite;and 717±3.2 Ma for monzogranite),suggesting crystallization of independent magma pulses.The high positiveεNdi(+6–+8)indicate that the melting sources were dominated by juvenile material without any significant input from older crust.Application of zircon saturation geothermometry indicates increasing temperatures during the generation of melts from 745±31℃ for tonalite to 810±25℃ for trondhjemite;840±10℃ for granodiorite;and 868±10℃ for monzogranite.The pressure of partial melting is loosely constrained to be below the stability of residual garnet(<10 kbar)as inferred fromthe almost flat HREE pattern((Gd/Lu)N=0.9–1.1),but>3 kbar for the stability of residual amphibole as inferred from the significantly lower NbN and TaN compared with LREEN and the sub-chondrite Nb/Ta ratios exhibited by the granitic phases.The inverse relation between the generation temperatures and the ages estimates of the granitoid lithologies argue against a significant role of fractional crystallization.The major and trace element contents indicate the emplacement of the SGC within a subduction zone setting.It lacks distinctive features for melt derived from a subducted slab(e.g.high Sr/Y and high(La/Yb)N ratios),and the relatively low MgO and Ni contents in all granite phases within the SGC suggest melting within the lower crust of an island arc overlying a mantlewedge.Comparisonwith melts produced during melting experiments indicates an amphibolite of basaltic composition is the best candidate as source for the tonalite,trondhjemite and granodiorite magmas whereas the monzogranite magma is most consistent with fusion of a tonalite protolith.Given the overlapping Sm-Nd isotope ratios as well as several trace element ratios between monzogranite and tonalite samples,it is reasonable to suggest that the renewed basaltic underplating may have caused partialmelting of tonalite and the emplacement ofmonzogranite melt within the SGC.The emplacement of potassic granite(monzogranite)melts subsequent to the emplacement of Na-rich granites(tonalitetrondhjemite-granodiorite)most likely suggests major crustal thickening prior arc collision and amalgamation into the over thickened proto-crust of the Arabian-Nubian shield.Eventually,after complete consolidation,the whole SGC was subjected to regional deformation,most probably during accretion to the Saharan Metacraton(arc–continent collisions)in the late Cryogenian-Ediacaran times(650–542 Ma).

Interaction of carbonaceous nanomaterials with wastewater biomass

Increasing production and use of carbonaceous nanomaterials （NMs） will increase their release to the sewer system and to municipal wastewater treatment plants. There is little quantitative knowledge on the removal of multi-walled carbon nanotubes （MWCNTs）, graphene oxide （GO）, or few-layer graphene （FLG） from wastewater into the wastewater biomass. As such, we investigated the quantification of GO and MWCNTs by UV-Vis spectrophotometry, and FLG using programmable thermal analysis （PTA）, respectively. We further explored the removal of pristine and oxidized MWCNTs （O- MWCNTs）, GO, and FLG in a biomass suspension. At least 96% of pristine and O-MWCNTs were removed from the water phase through aggregation and 30-min settling in presence or absence of biomass with an initial MWCNT concentration of 25mg.L-1. Only 65% of GO was removed with biomass concentration at or above 1,000 mg. L-1 as total suspended solids （TSS） with the initial GO concentration of 25 mg. L-1. As UV-Vis spectrophotometry does not work well on quantification of FLG, we studied the removal of FLG at a lower biomass concentration （50mg TSS-L-1） using PTA, which showed a 16% removal of FLG with an initial concentration of 1 mg ·L-1. The removal data for GO and FLG were fitted using the Freundlich equation （R2 = 0.55, 0.94, respectively）. The data presented in this study for carbonaceous NM removal from wastewater provides quantitative informa- tion for environmental exposure modeling and life cycle assessment.