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The mineralogy, bulk geochemical composition, chemistry and U–Pb ages of detrital zircons in sediments from the La Pesca (LP) and Tesoro Altamira (TA) beaches, NW Gulf of Mexico are analyzed. The aim of this study is to infer the weathering history and provenance of sediments, and to identify the potential source terranes that are contributing sediments to the LP and TA beach areas. The beach sediments are rich in quartz and aluminosilicates. The Chemical Index of Weathering (CIW') and trace elements such as Th, Sr, U, and Ba reveal high weathering intensity for the LP and TA beach sediments. Major-element based diagrams and trace elemental ratios based on Co, Cr, Sc, La, and Th contents in sediments indicate felsic provenance, which is further supported by a negative europium anomaly and rare earth element (REE) patterns. The Th/U ratios (>0.3) together with positive cerium and negative europium anomalies of zircons in the LP and TA beaches indicate igneous origin. The comparison of zircon U–Pb ages of this study with ages reported from the adjacent terranes revealed that the Proterozoic (Paleoproterozoic: 1607.07–1943.45 Ma and Mesoproterozoic: 1021.19–1586.52 Ma) zircons are derived from the Oaxaquia, Mesa Central, Sierra Madre Oriental Provinces of Mexico and Mazatzal–Yavapai Province of the USA. On the other hand, Mesozoic (Jurassic 146.49–199.43 Ma and Cretaceous 68.46–136.82 Ma) and Cenozoic (Eocene 33.97–51.46 Ma and Oligocene 23.39–33.86 Ma) zircons are contributed by the Mexican volcanic rocks, Mesa Central and Sierra Madre Oriental Provinces in Mexico, and Mogollon-Datil Volcanic field and Colorado Plateau in USA. The rivers and their tributaries draining from the source areas are considered as a carrier and agent of distributing sediments along the northwestern Gulf of Mexico coastal areas, which are subsequently mixed by littoral currents. Simplified diagram showing river drainage basins, source terranes and seasonal surface current transport directions in the northwestern Gulf of Mexico. [Display omitted] • Mineralogy, bulk sediment geochemical composition, and U–Pb ages of detrital zircons are investigated from two beaches. • Chemical Index of Weathering (CIW') and trace element ratios indicate high intensity of weathering in source region. • Felsic provenance is characterized based on bulk sediment geochemical and detrital zircon age data. • Detrital zircons are brought by the rivers draining from the source terranes and are later mixed by the littoral currents. [ABSTRACT FROM AUTHOR]

The Compostela area is located in the western Trans‐Mexican Volcanic Belt, which consists of volcanic rocks that produced during the Pliocene to Recent volcanism. In this paper, we present petrography, whole‐rock major‐ and trace‐element concentrations, Ar–Ar ages, and Sr–Nd isotopic data of volcanic rocks from the Compostela area in the south of the city of Tepic, Nayarit, Mexico. These volcanic rocks are of intermediate composition and belong to the transitional series: basaltic trachyandesites [52.72–53.94 wt% SiO2; 0.69–2.53 wt% MgO] and subalkaline series: low‐Si [55.11–60.94 wt% SiO2; 0.79–2.74 wt% MgO] and high‐Si [61.60–62.71 wt% SiO2; 0.36–0.80 wt% MgO] andesites. The 40Ar/39Ar dating of two basaltic trachyandesites yields plateau ages of 1.05 ± 0.15 Ma and 1.07 ± 0.17 Ma and the andesites yielded a plateau age of 2.42 ± 0.36 Ma. These results indicate that the studied rocks were formed during the Pleistocene in two discrete episodes. The basaltic trachyandesites show enriched light rare earth elements patterns relative to high rare earth elements [(La/Yb)N = 5.81–8.07] with negligible Eu anomalies. The andesites display enriched large‐ion lithophile elements (Ba, K) with anomalies of Nb (Th/Ce) and Ti in the three groups identified in the subalkaline series. The basaltic trachyandesites appear in a tight cluster of initial 87Sr/86Sr ratios (0.703519–0.703882) as compared to the basaltic andesite 87Sr/86Sr (0.704073) and positive ɛNd(t) values of +5.6 to +3.4, respectively, indicating that the basaltic trachyandesites were derived from intermediate magmas from a shallow mantle source. Geochemical modelling reveals that both basaltic trachyandesite and andesite rocks were derived by a process of crystal fractionation accompanied by assimilation of crustal rocks at the lower or middle level. Geochemical ratios and multidimensional discrimination diagrams, combined with the cross‐section of the subduction zone indicates that basaltic trachyandesites were generated from a rift and/or Ocean Island Basalt‐type source, whereas andesites were generated from a slab‐derived source in a subduction environment. [ABSTRACT FROM AUTHOR]

The Salina Cruz and Puerto Ángel beach areas in the Gulf of Tehuantepec, Mexican Pacific coast represent an important economic sector of the region. In this study, the mineralogy and geochemistry of bulk sediments, and geochronology of 400 detrital zircons recovered from the beach sediments were analysed to investigate their origin. The sediments are abundant in quartz, feldspar, ilmenite, cordierite, aragonite and anorthite. The chemical index of weathering revealed a moderate to intense weathering in the source area. The chondrite normalized REE patterns of bulk sediments are similar to the found in the Upper Continental Crust, suggesting the derivation of sediments from felsic igneous rocks. The REE patterns of zircons and the trace elemental ratios reveal a continental crust origin. Zircon U–Pb ages in the Salina Cruz beach were represented by Proterozoic (~545.1–1314.1 Ma; n = 170) and Cenozoic (~0.01–66 Ma; n = 20). The Puerto Ángel beach was abundant in Proterozoic zircon grains (~600.9–1171.4 Ma; n = 109) and followed by Mesozoic grains (~73.78–246.9 Ma; n = 40). The comparison of zircon U–Pb ages of this study with probable source rocks reveals that the Oaxaquia Terrane and Chiapas Massif Complex were the major contributors of Proterozoic zircons to the coastal areas. Similarly, the results indicate that the Cenozoic zircons were contributed by the Chiapas Massif Complex, coastal batholith and Cuicateco Terrane. The Mesozoic zircons are very few, derived from the nearby Xolapa Complex and the Chuacús Terrane. [ABSTRACT FROM AUTHOR]

The Mesa Virgen Calerilla (MVC) is located in the state of Zacatecas, Mexico. The most intense volcanism, which occurred during the Eocene, formed extensive ignimbrite deposits exposed in some parts as lava spills of rhyolitic (felsic) composition. This felsic volcanism may represent much of the MVC. This study describes whole‐rock geochemistry and mineralogy data from felsic volcanic rocks in the MVC to address their petrogenesis and tectonic setting. The MVC covers a compositional spectrum ranging from trachyte, dacite, to high‐silica rhyolite. The petrography and mineral assemblages indicate that the felsic rocks are composed of K‐feldspar (sanidine), quartz, plagioclase, and biotite. The felsic volcanic rocks have a composition of 64.08–78.17 wt% (SiO2)adj, 0.14–0.69 wt% (TiO2)adj, and 0.11–0.62 wt% (MgO)adj with 12–54 Mg number [Mg# = 100 × (Mg2+/[Mg2+ + Fe2+])]. These felsic volcanic rocks showed enrichment in light rare earth elements (LREE; [La/Sm]N = 3.80–7.19), and are depleted in heavy rare earth elements [HREE; (Tb/Yb)N ratios 0.35–1.84], along with negative Ba, Nb, Sr, P, Eu, and Ti anomalies. The geochemical characteristics and petrogenetic modelling indicate that felsic volcanic rocks are derived from partial melting process of an upper‐middle continental crust. The tectono‐magmatic model and multidimensional tectonic discrimination diagram indicate that an extensional‐related setting prevails for the MVC. [ABSTRACT FROM AUTHOR]

Gneiss–migmatitic rocks and granites between the Cubatão and Itariri shear zones characterize the Mongaguá Complex-Coastal Terrane. Three major units are defined: (1) the Itariri Suite (IS) composed of monzogranites, granodiorites, tonalites, and locally gneiss–migmatitic rocks; (2) the Areado pluton composed of monzogranite and locally tonalite; and (3) the Ribeirão do Óleo Pluton mainly composed of monzogranites, which is the subject of this article. Combined field observations, petrography, Sr–Nd–Hf isotopes, U–Pb zircon data, and preliminary geochemical studies are presented for the Ribeirão do Óleo Pluton (ROP), intrusive in granite-gneisses of the IS. It is a plutonic association of weakly peraluminous, medium-to-high-K biotite monzogranites that surround microgranular intermediate enclaves, which are products of magma mingling. Different from the most examples of magma mingling described in the literature, the ROP mingling did not result from the intrusion of hot mafic magma into colder host felsic magma. Conversely, the emplacement of the monzogranite started most likely during the medium-to-final stage of crystallization of the quartz microdiorite. A detailed study of LA-ICP-MS U–Pb zircon ages, including zircon morphology and internal structure, was useful to determine more precisely the emplacement sequence and the relation between the units of the ROP. Intermediate and acid facies have Paleoproterozoic and Neoproterozoic inheritances, moreover a mixture of xenocrysts, antecrysts, and autocrysts, indicative of a complex evolution of the ROP. Several magma crystallization pulses are recorded at 655–624 Ma, 627–601 Ma, and 613–586 Ma. The negative εHf(t) ranging from − 17.26 to − 12.51 in monzogranites, εNd(t) values of − 10.66 to − 7.83 at t = 600 Ma in both facies, 87Sr/86Sr of ca. 0.708 for the monzogranite and 0.706 for the quartz microdiorite indicate a strong crustal contribution in the genesis of intermediate and acid magmas of this pluton. [ABSTRACT FROM AUTHOR]

The Mantiqueira Province (MP) is the major tectonic unit of southern Brazil, resulting from the closure of the Adamastor Ocean during Gondwana assembly. The Ribeira Belt (RB), the largest domain of the MP, has developed in several episodes of convergence during the Brasiliano-Pananafricano Orogeny and is subdivided into several terranes. One of them is the Embu Terrane (ET) that hosts metasedimentary successions and granitic bodies of different tectonic contexts. A combined study of petrography, geochemistry, LA–ICP–MS zircon U—Pb dating, and Hf isotope geology was carried out on the Juquiá (JG) and Sete Barras (SBG) granites of the southeastern ET, hosted by metasupracrustal rocks. The JG yielded U—Pb zircon ages of 799 ± 5 Ma and 755 ± 3 Ma, while the SBG U—Pb zircon and monazite ages of 602 ± 2 Ma and 598 ± 2 Ma respectively. Both granites have Neoarchean/Paleoproterozoic Hf(T DM) model ages and strongly negative εHf (t) values in zircon. Whole rock isotopic data support an evolved crustal signature, pointing to sources of long-lived crustal residence. The JG is a ferroan calc-alkalic peraluminous two-mica granite, while the SBG is a ferroan alkali-calcic peraluminous two-mica granite. The acquired data disclose two distinct magmatic episodes in ET: the Tonian Juquiá magmatism took place during the final stages of the Rodinia break-up or initial stages of expansion of one of the hypothetical oceans in the region and the Ediacaran Sete Barras magmatism might have been formed at the local transtensional area during final West Gondwana amalgamation. The data presented here and the wide-ranging geochronological data assemblage from the RB allowed a new paleogeographic reconstruction of the West Gondwana assembly. Unlabelled Image • Tectonic setting of the Embu Terrane granites (Ribeira Belt), southern Brazil. • New paleogeographic reconstruction of the Gondwana assembly in Precambrian times. • Emplacement of the Juquiá granite (799 Ma) in final stage of the Rodinia break-up. • Emplacement of the Sete Barras granite (602 Ma) in a regional compressive phase. [ABSTRACT FROM AUTHOR]

Highlights • There are sanukitoids and anatectic granites in the Bundelkhand Craton. • U-Pb zircon dating of a sanukitoid yielded a crystallization age of 2577 ± 16 Ma. • Sanukitoids are derived from a crustal source. • Sanukitoids and anatectic granites formed in a subduction-collision environment. Abstract In this paper, we present in situ zircon U–Pb ages as well as whole-rock elemental and Sm-Nd isotopic compositions for late Archean sanukitoids of the Bundelkhand Craton, India. The LA–ICP–MS zircon U–Pb dating results of the sanukitoids (s.l.) indicate that these rocks were emplaced at 2577 ± 16 Ma, with inherited zircon at an age of 2644 ± 25 Ma, and are coeval with high-K anatectic granites (2544–2583 Ma). The sanukitoids (s.l.) are characterized by high-alumina (15–16 wt.%), Mg# (27–50) and TiO 2 (0.31–0.87 wt.%). They have a strongly enriched signature in terms of incompatible trace elements (LREEs and LILE) pointing to a subduction-related or crustal source. The high-K anatectic granites are characterized by Al 2 O 3 (12–15 wt.%), Mg# (13–39) and TiO 2 (0.06–0.8 wt.%); they have enriched and variable concentrations of LILEs and REEs; and negative Eu anomalies (Eu/Eu* = 0.15–0.93). The whole-rock ε Nd (t) values (−3.64 to −1.66) indicate a crustal component. These isotopic and geochemical characteristics indicate that the sanukitoid plutons originated from the mixing of metasomatized mantle melts with anatectic melts and were followed by homogenization at shallow levels of emplacement, whereas the high-K anatectic granites indicate reworking of the pre-existing TTG crust during the cratonic stabilization ca. 2.5 Ga. This interpretation suggests a temporal evolution from TTG-domination through sanukitoids (s.l.) to anatectic leucogranites by an internal reworking of the continental crust, involving subduction-collision environments in the late Archean era. Such magmatic events and tectonics during the late-Archean in the Bundelkhand Craton resemble other Archean cratons, such as the Dharwar, North China, Karelian, Superior Province, Pilbara, Kaapvaal and Amazonian. [ABSTRACT FROM AUTHOR]

Abstract The Paleoarchean geodynamical evolution of the Bundelkhand Craton is discussed based on the geochemistry (major, trace and rare earth elements) and Sm Nd isotope systematic of mafic-ultramafic rocks from volcano-sedimentary succession of the Babina and Mauranipur greenstone belts. The petrography and mineral assemblages of these mafic-ultramafic rocks imply that they were gone through greenschist to amphibolite facies metamorphism. Geochemical analyses indicate that mafic rocks from the Babina are characterized by SiO 2 = 43.9–51.2 wt%, MgO = 5.4–11.0 wt%, TiO 2 = 0.3–1.14 wt% and Mg# = 44–77, whereas the Mauranipur are characterized by higher silica (51.8–55.6 wt%), MgO = 6.9–9.5 wt% and Mg# = 59–70. The ultramafic rocks from the Babina and Mauranipur contain SiO 2 = 46.9–50.3 wt%, MgO = 20.2–21.1 wt%, TiO 2 = 0.33–0.46 wt% and Mg# = 77–82. Six samples of mafic-ultramafic rocks from the Babina greenstone belt yield 147Sm 143Nd whole rock isochron age of ca. 3.4 Ga. Sm Nd isotopic studies of mafic rocks from the Babina and Mauranipur reveal that they were derived from a depleted mantle source. Bivariate diagrams such as Cr vs. Ni and V suggest that these magmas might have evolved through fractionation of clinopyroxene and olivine. The mafic rocks from the Babina displayed almost a flat REE and HFSE profile [(La/Yb) PM = 0.87–1.40] with negative Nb (Nb/Nb* = 0.13–0.77) and positive Pb anomalies that could be attributed to metasomatic agents derived from subducting crustal rocks. The Mauranipur mafic rocks show slightly enriched REE [(La/Yb) PM = 1.1–1.7; (La/Sm) PM = 1.1–2.0] with negative Nb anomalies (Nb/Nb* = 0.13–0.77), which are most likely the effects of crustal contamination. The ultramafic rocks from both areas and ultramafic cumulate rock from the Mauranipur display a progressive enrichment from Th, La to Yb, with negative Nb anomalies (Nb/Nb* = 0.40–0.73) with lack of Zr anomalies (Zr/Zr* = 0.10–0.30) that could be attributed to their derivation from shallower mantle. These data collectively suggest that the mafic-ultramafic rocks have been interpreted to be derived from oceanic crust in a subduction-related setting with depleted mantle composition. Highlights • Mafic-ultramafic nature, ultramafic rocks show cumulate texture. • The Babina greenstone belt yield Sm Nd whole rock isochron age of ca. 3.4 Ga • Mafic-ultramafic magmas derived from a depleted mantle sources. • These rocks are derived from oceanic crust in a subduction-related setting. [ABSTRACT FROM AUTHOR]

New major and trace element, and Sr, Nd and Pb isotope data for samples from the Volcán Tacaná, along with the published data from the Tacaná Volcanic Complex (TVC) and Chiapanecan Volcanic Belt (CVB), were used to better constrain the petrogenesis of the Pliocene to Holocene volcanism in southwestern Mexico. The TVC volcanic rocks sampled in this study were andesite, whereas the literature samples included, besides andesites, one subalkali basalt and a few dacites. The CVB housing the prominent El Chichón volcano, on the other hand, showed more alkalic magmatic products (trachyandesite and basaltic trachyandesite) but also included a few basalts and dacites. The enclaves and lithic fragments sampled from both TVC and CVB showed wide SiO 2 compositions similar to the volcanic products. The CVB rocks are more enriched in REE, LILE, and HFSE than the TVC. The combined data of volcanic rocks were evaluated through conventional multi-element diagrams as well as subduction- or crust-sensitive parameters. Although the TVC constitutes the northern end of the Central American Volcanic Arc (CAVA), some chemical differences were documented between them such as the TVC rocks have higher LILE, REE, HFSE, and combined ratio parameters. More importantly, the CVB seems to be significantly different from both TVC and CAVA as well as from other continental arcs such as higher LILE, REE, HFSE, and distinct isotopic signature, which may indicate that the origin of the CVB volcanism represents a direct action of the abundant strike-slip faults and extensional system prevalent in this area. Finally, the relationship of basic and evolved rocks from the CVB, especially on isotope-isotope diagrams, also suggests that the lower crust may have contributed to evolved magmas during the ascent of basic magmas through the crust. [ABSTRACT FROM AUTHOR]

The Neoarchean Rio das Velhas and Pitangui greenstone belts are situated in the southern São Francisco Craton, Minas Gerais, Brazil. These greenstone belts were formed between ca. 2.79–2.73 Ga, and consist mostly of mafic to ultramafic volcanics and clastic sediments, with minor chemical sediments and felsic volcanics that were metamorphosed under greenschist facies. Komatiites are found only in the Rio das Velhas greenstone belt, which is composed of high-MgO volcanic rocks that have been identified as komatiites and high-Mg basalts, based on their distinctive geochemical characteristics. The Rio das Velhas komatiites are composed of tremolite + actinolite + serpentine + albite with a relict spinifex-texture. The Rio das Velhas komatiites have a high magnesium content ((MgO) adj ≥ 28 wt.%), an Al-undepleted Munro-type [(Al 2 O 3 /TiO 2 ) adj and (CaO/Al 2 O 3 ) adj ] ratio ranging from 27 to 47 and 0.48 to 0.89, relatively low abundances of incompatible elements, a depletion of light rare earth elements (LREE), a pattern of non-fractionated heavy rare- earth elements (HREE), and a low (Gd/Yb) PM ratio (≤ 1.0). Negative Ce anomalies suggest that alteration occurred during greenschist facies metamorphism for the komatiites and high-Mg basalts. The low [(Gd/Yb) PM < 1.0] and [(CaO/Al 2 O 3 ) adj < 0.9)], high [(Al 2 O 3 /TiO 2 ) adj > 18] and high HREE, Y, and Zr content suggest that the Rio das Velhas komatiites were derived from the shallow upper mantle without garnet involvement in the residue. The chemical compositions [(Al 2 O 3 /TiO 2 ) adj , (FeO) adj , (MgO) adj , (CaO/Al 2 O 3 ) adj , Na, Th, Ta, Ni, Cr, Zr, Y, Hf, and REE] indicate that the formation of the komatiites, high-Mg basalts and basalts occurred at different depths and temperatures in a heterogeneous mantle. The komatiites and high-Mg basalts melted at liquidus temperatures of ~ 1450–1550 °C. The Pitangui basalts are enriched in the highly incompatible LILE (large-ion lithophile elements) relative to the moderately incompatible HFS (high field strength) elements. The Zr/Th ratio ranging from 76 to 213 and the relationship between the Nb/Th and Th/Yb ratios indicate that there is no crustal contamination in the Pitangui greenstone basalts. New multi-dimensional discrimination diagrams and conventional normalized multi-element diagrams indicate an island arc (IA) setting for the komatiites and high-Mg basalts from the Rio das Velhas and a mid ocean-ridge (MOR) to IA setting for the basalts from the Pitangui greenstone belts. [ABSTRACT FROM AUTHOR]

New multi-dimensional discrimination diagrams have been used to identify plate tectonic setting of Precambrian terrains. For this work, nine sets of new discriminant-function based multi-dimensional discrimination diagrams were applied for thirteen case studies of Precambrian basic, intermediate and acid magmas from Africa to highlight the application of these diagrams and probability calculations. The applications of these diagrams indicated the following results: For northern Africa: to Wadi Ghadir ophiolite, Egypt indicated an arc setting for Neoproterozoic (746 ± 19 Ma). For South Africa: Zandspruit greenstone and Bulai pluton showed a collision and a transitional continental arc to collision setting at about Mesoarchaean and Neoarchaean (3114 ± 2.3 Ma and 2610-2577 Ma); Mesoproterozoic (1109 ± 0.6 Ma and 1100 Ma) ages for Espungabera and Umkondo sills were consistent with an island arc setting. For eastern Africa, Iramba–Sekenke greenstone belt and Suguti area, Tanzania showed an arc setting for Neoarchaean (2742 ± 27 Ma and 2755 ± 1 Ma). Chila, Bulbul-Kenticha domain, and Werri area indicated a continental arc setting at about Neoproterozoic (800-789 Ma); For western Africa, Sangmelima region and Ebolowa area, southern Cameroon indicated a collision and continental arc setting, respectively for Neoarchaean (∼2800–2900 Ma and 2687-2666 Ma); Finally, Paleoproterozoic (2232-2169 Ma) for Birimian supergroup, southern Ghana a continental arc setting; and Paleoproterozoic (2123-2108 Ma) for Katiola-Marabadiassa, Côte d'Ivoire a transitional continental arc to collision setting. Although there were some inconsistencies in the inferences, most cases showed consistent results of tectonic settings. These inconsistencies may be related to mixed ages, magma mixing, crustal contamination, degree of mantle melting, and mantle versus crustal origin. [ABSTRACT FROM AUTHOR]

The central Bundelkhand greenstone complex in Bundelkhand craton, northern India is one of the well exposed Archaean supracrustal amphibolite, banded iron formation (BIF) and felsic volcanic rocks (FV) and associated with grey and pink porphyritic granite, tonalite–trondhjemite–granodiorite (TTG). Here we present high precision zircon U–Pb geochronological data for the pinkish porphyritic granites and TTG. The zircons from the grey-pinkish porphyritic granite show three different concordia ages of 2531 ± 21 Ma, 2516 ± 38 Ma, and 2514 ± 13 Ma, which are interpreted as the best estimate of the magmatic crystallization age for the studied granites. We also report the concordia age of 2669 ± 7.4 Ma for a trondhjemite gneiss sample, which is so far the youngest U–Pb geochronological data for a TTG rock suite in the Bundelkhand craton. This TTG formation at 2669 Ma is also more similar to Precambrian basement TTG gneisses of the Aravalli Craton of north western India and suggests that crust formation in the Bundelkhand Craton occurred in a similar time-frame to that recorded from the Aravalli craton of the North-western India. [ABSTRACT FROM AUTHOR]

Multidimensional discrimination diagrams (2006–2011) for basic and ultrabasic igneous rocks were applied to Precambrian rock suites from the Amazonian and São Francisco cratons, and the Tocantins Province, Brazil, to infer their possible tectonic settings. The chosen study cases in the Amazonian craton include the ca. 3.0 Ga metabasalts of the Identidade greenstone belt, 1.87–1.80 Ga Parauapebas anorogenic basalt-rhyolite dikes, 1.86–1.82 Ga Rio Branco anorogenic gabbro-basalt association, ca. 1.76–1.74 Ga Aripuanã and Teles Pires intracratonic basalt-felsic volcanic associations, and 1.76–1.74 Ga Jamari and 1.60–1.53 Ga Serra da Providência arc-related gabbroic rocks. In the São Francisco craton, we selected 1.48 Ga arc-related amphibolites of the Rio Capim greenstone belt, continental mafic dikes of Uauá (2.6 Ga), Curaçá and Chapada Diamantina (1.5 Ga), and Espinhaço (ca. 1.0 Ga). In the Tocantins Province, ca. 3.0 Ga komatiites associated with oceanic basalts of the Crixás and Guarinos greenstone belts were studied. The application of the diagrams generally provided consistent results with the authors’ proposed tectonic settings based on field relationships and geochemical data. The exceptions are some within-plate (continental) mafic dikes and basalts for which our diagrams do not work well. For comparison, we also used two ternary and two bivariate traditional discrimination diagrams for the data from the Amazonian craton, whose results were poorer than the newer multidimensional diagrams. [ABSTRACT FROM AUTHOR]

Fifty-five new multi-dimensional diagrams, mostly based on log-ratio transformations, were used to decipher tectonic settings for 17 cases of Precambrian belts in Canada, the USA, Poland, Finland, Jordan, Democratic Republic of Congo and Zambia, China, and India. The results of different sets of diagrams for basic-ultrabasic, intermediate, and acid magmas were generally internally consistent. Possible reasons for some inconsistencies may be related to the use of a sample group of mixed ages because of their uncertainties, extreme element mobility caused by metamorphism especially of high-grade type, analytical data quality, different petrogenetic processes for basic to acid magmas such as mantleversuscrustal origin, and some deficiencies that still exist in the multi-dimensional diagrams. To partly overcome the last problem, one new multi-dimensional diagram is proposed and used to discriminate mid-ocean ridge and oceanic plateau settings. [ABSTRACT FROM AUTHOR]

Fifteen multi-dimensional diagrams for basic and ultrabasic rocks, based on log-ratio transformations, were used to infer tectonic setting for eight case studies of Borborema Province, NE Brazil. The applications of these diagrams indicated the following results: (1) a mid-ocean ridge setting for Forquilha eclogites (Central Ceará domain) during the Mesoproterozoic; (2) an oceanic plateau setting for Algodões amphibolites (Central Ceará domain) during the Paleoproterozoic; (3) an island arc setting for Brejo Seco amphibolites (Riacho do Pontal belt) during the Proterozoic; (4) an island arc to mid-ocean ridge setting for greenschists of the Monte Orebe Complex (Riacho do Pontal belt) during the Neoproterozoic; (5) within-plate (continental) setting for Vaza Barris domain mafic rocks (Sergipano belt) during the Neoproterozoic; (6) a less precise arc to continental rift for the Gentileza unit metadiorite/gabbro (Sergipano belt) during the Neoproterozoic; (7) an island arc setting for the Novo Gosto unit metabasalts (Sergipano belt) during Neoproterozoic; (8) continental rift setting for Rio Grande do Norte basic rocks during Miocene. [ABSTRACT FROM AUTHOR]

Fly ash (FA), a residue of coal combustion, has been accepted as a hazardous solid waste all over the world. Even though several approaches for its utilization in agriculture and material industry have been proposed, the amount of the stocked FA is increasing because production exceeds the amount that can be utilized. We propose the use of aromatic grasses for better in situ remediation of FA landfill hazards and to get several tangible and intangible benefits. [ABSTRACT FROM AUTHOR]

Although for ultrabasic and basic magmas a plethora of tectonomagmatic diagrams have been used, with the exception of one bivariate diagram for refined tectonic setting of orogenic andesites, none is available for highly abundant intermediate magma. We present 3 sets of discrimination diagrams obtained from the correct statistical methodology of loge-ratio transformation and linear discriminant analysis. All major element loge-ratio variables in 3664 samples, only immobile major and trace element loge-ratio variables in 1858 samples, and immobile trace element loge-ratio variables in 1512 samples were used. These diagrams with probability-based tectonic field boundaries and high success rates (about 69%-96%, 63%-100%, and 64%-100%, respectively, for diagrams based on all major elements, immobile major and trace elements, and immobile trace elements) were first tested for fresh and highly altered rocks. The expected tectonic setting was indicated from our diagrams. The probability-based decisions and total percent probability estimates can fully replace the actual plotting of samples in the diagrams. The probability calculations were then used for tectonic discrimination of 7 case studies of Archean to Proterozoic rocks. An island arc setting was indicated for the Wawa greenstone belt (Canada), implying the existence of plate tectonic processes during the Late Archean, for western Tasmania (Australia) during the Cambrian, and for Chichijima Island (Bonin Islands, Japan) during the Eocene. Similarly, an arc setting (indecisive island or continental type) was obtained for south-central Sweden during the Paleoproterozoic and for Adola (southern Ethiopia) during the Neoproterozoic. A within-plate setting was inferred for the Neoproterozoic Malani igneous complex, Rajasthan, India. A collision setting was indicated for the Alps (France-Italy-Switzerland) during the Late Carboniferous. Modeling of likely as well as extreme processes indicates that these diagrams are robust against postemplacement compositional changes caused by analytical errors, element mobility, Fe-oxidation, alteration, and petrogenetic processes. [ABSTRACT FROM AUTHOR]

In present work, we applied two sets of new multi-dimensional geochemical diagrams (Verma et al., 2013) obtained from linear discriminant analysis (LDA) of natural logarithm-transformed ratios of major elements and immobile major and trace elements in acid magmas to decipher plate tectonic settings and corresponding probability estimates for Paleoproterozoic rocks from Amazonian craton, São Francisco craton, São Luís craton, and Borborema province of Brazil. The robustness of LDA minimizes the effects of petrogenetic processes and maximizes the separation among the different tectonic groups. The probability based boundaries further provide a better objective statistical method in comparison to the commonly used subjective method of determining the boundaries by eye judgment. The use of readjusted major element data to 100% on an anhydrous basis from SINCLAS computer program, also helps to minimize the effects of post-emplacement compositional changes and analytical errors on these tectonic discrimination diagrams. Fifteen case studies of acid suites highlighted the application of these diagrams and probability calculations. The first case study on Jamon and Musa granites, Carajás area (Central Amazonian Province, Amazonian craton) shows a collision setting (previously thought anorogenic). A collision setting was clearly inferred for Bom Jardim granite, Xingú area (Central Amazonian Province, Amazonian craton) The third case study on Older São Jorge, Younger São Jorge and Maloquinha granites Tapajós area (Ventuari-Tapajós Province, Amazonian craton) indicated a within-plate setting (previously transitional between volcanic arc and within-plate). We also recognized a within-plate setting for the next three case studies on Aripuanã and Teles Pires granites (SW Amazonian craton), and Pitinga area granites (Mapuera Suite, NW Amazonian craton), which were all previously suggested to have been emplaced in post-collision to within-plate settings. The seventh case studies on Cassiterita-Tabuões, Ritápolis, São Tiago-Rezende Costa (south of São Francisco craton, Minas Gerais) showed a collision setting, which agrees fairly reasonably with a syn-collision tectonic setting indicated in the literature. A within-plate setting is suggested for the Serrinha magmatic suite, Mineiro belt (south of São Francisco craton, Minas Gerais), contrasting markedly with the arc setting suggested in the literature. The ninth case study on Rio Itapicuru granites and Rio Capim dacites (north of São Francisco craton, Serrinha block, Bahia) showed a continental arc setting. The tenth case study indicated within-plate setting for Rio dos Remédios volcanic rocks (São Francisco craton, Bahia), which is compatible with these rocks being the initial, rift-related igneous activity associated with the Chapada Diamantina cratonic cover. The eleventh, twelfth and thirteenth case studies on Bom Jesus-Areal granites, Rio Diamante-Rosilha dacite–rhyolite and Timbozal-Cantão granites (São Luís craton) showed continental arc, within-plate and collision settings, respectively. Finally, the last two case studies, fourteenth and fifteenth showed a collision setting for Caicó Complex and continental arc setting for Algodões (Borborema province). [ABSTRACT FROM AUTHOR]

Abstract: Kalmegh (Andrographis paniculata Wall. ex Nees) is a medicinal herb of tropical south east Asia and native to India and Sri Lanka. It has been used herb for liver ailment in all prevailing systems of medicine viz. Ayurvedic, Unani, Homeopathic and modern throughout most of the south East Asian countries viz. China, India, Sri Lanka, Indonesia, Thailand, Burma, and Vietnam, etc. Commercially cultivation of Kalmegh is done through seeds. Optimal germination potential, temperature and first as well as final count day are three primary parameters for developing the seed quality standards. Germination of Kalmegh variety ‘CIM-Megha’ was carried out at six constant temperatures at an interval of every ‘5°C’ from ‘15 to 40°C’ temperatures coupled with 16h light and 8h dark photo period. The temperature of ‘25°C’ was found optimally suitable with ‘94.6’ and ‘23.6’ percentage of germination and germination energy, respectively, while the temperature at ‘40°C’ was deleterious with no germination. Significant decrease in percentage of germination and germination energy was observed at ‘15°C’, ‘20°C’, ‘30°C’ and ‘35°C’ of temperature in comparison to ‘25°C’. The study further revealed that days 5-6 and days 7-9 after seed sowing were the ideal for first and final count, respectively for seed germination of Kalmegh. [Copyright &y& Elsevier]

Abstract: Palmarosa (Cymbopogon martinii) is a major essential oil bearing crop commercially cultivated in India. However, the potentiality of its commercial cultivation is restricted due to the supply of poor quality seed material, i.e. poor seed germination percent/vigour and lack of knowledge about the seed rate for nursery raising/direct sowing and viability period under storage conditions. Seed germination tests of varieties PRC-1, Trishna, Tripta, Vaishnavi were carried out in Petri plates under two temperature regimes: uncontrolled, i.e. room temperature (average minimum 27°C–average maximum 39°C) and controlled and constant (15°C, 20°C, 25°C with 16h light and 8h dark photoperiod). Maximum germination percentage and germination energy percent were recorded in ‘Trishna’ (34.25 and 8.56), followed by ‘PRC-1’ (34.25 and 8.56), ‘Tripta’ (15.75 and 3.94) and ‘Vaishnavi’ (10.25 and 2.56) on final count day at controlled and constant temperature. The corresponding data were recorded (26.00 and 6.50), followed by (25.50 and 6.37), (9.50 and 2.37) and (10.00 and 2.50) under uncontrolled temperature. Differential behavior of the said varieties under different temperature regimes was attributable to their genetic make-up. Results showed that day 2 and days 3–4 was the best for first count, day 5 and days 6–7 for final count and day 5 and days 6–7 for germination period at uncontrolled and controlled and constant temperature, respectively. [ABSTRACT FROM AUTHOR]

• First report of two discrete episodes of Neoarchean TTG magmatism in the BC. • 3.34 Ga TTG pluton in the eastern part of the BC. • Six major periods of felsic magmatism during 3.55–2.50 Ga. • Sanukitoid and anatectic granite show peak continental growth during ~2.58–2.50 Ga. • Geochemistry, Hf and Nd isotopes suggest Eoarchean to Neoarchean crustal reworking. In this contribution we present field relations, U-Pb zircon geochronology, in-situ Lu-Hf isotopes, bulk-rock Sm-Nd isotopes and geochemistry of the tonalite-trondhjemite-granodiorite (TTG) gneiss, sanukitoid and anatectic granites from the Central Bundelkhand granite-greenstone terrane (CBGGT). The present study provides a comprehensive insight into the crust-mantle evolution, reworking, and cratonization of the Bundelkhand Craton (BC) during the Archean Eon. We report two discrete episodes of Neoarchean TTG magmatism at ~ 2.71 and ~ 2.68 Ga from the BC for the first time. Additionally, we identify a TTG gneiss that is significantly older (~3.34 Ga) than thus far assumed in the eastern part of the area. Furthermore, zircon U-Pb ages of the sanukitoids and the anatectic granites suggest synchronous emplacement at 2.58–2.50 Ga. Zircon of Paleoarchean TTG, Neoarchean TTG, sanukitoid, and anatectic granites show εHf (t) values in the following ranges: +1.7 to −0.9, +4.1 to −10.7, −3.6 to −6.2, and −5.9 to −7.8, respectively, which are indicative of significant crustal reworking. Neoarchean TTG gneiss shows εNd (t) and εHf (t) value of + 4.5 and + 10.0 to −6.8, respectively, indicating a juvenile crustal source and probably formed by the partial melting of deep-seated mafic crust in the garnet stability field. Neoarchean TTGs formed in arc creation/collision to the Paleoarchean nucleus of the BC. The amalgamation of diverse micro-blocks occurred by the arc-continent collision and probable breakoff of the descending slab between crustal blocks of the BC during Neoarchean. This event generated anatectic granites by intense partial melting of the existing crust, which resulted as closing of subduction and marked as final stabilization and cratonization of the BC. This event also shows evidence that the BC did not amalgamate until ~2.50 Ga. [ABSTRACT FROM AUTHOR]

Palaeo‐Mesoarchean Banded Iron formations (BIFs) of central Bundelkhand greenstone belts occur from Babina (in the west) to Mahoba (in the east) via Mauranipur along with the E–W trending of the Bundelkhand Tectonic Zone (BTZ). In the present study, we report petrological, geochemical, and mineralogical data of BIFs from the Babina, Mauranipur, and Mahoba greenstone belts of central Bundelkhand Greenstone Complex to address their source characteristics and deposition environment. The lithological association of BIFs in the Babina and Mauranipur greenstone belts consists of pillowed basic–ultrabasic volcanics and metasediments, whereas in the Mahoba greenstone belt, BIFs and quartzite occur within basic volcanics. These lithological associations collectively suggest that the entire succession was deposited in a marine environment. Based on geological setting, they are classified as Algoma‐type. The main mineral assemblages of the Babina and Mauranipur BIFs are composed of magnetite, quartz, ±garnet, hornblende, chlorite, and apatite, whereas the Mahoba BIFs along with magnetite and quartz, poised of two distinct mineral assemblages; the first one is Opx–Cpx–Grt and the other one is Grt–Hbl. The preliminary P–T study of these BIFs implies that they had gone through amphibolite‐ to granulite‐facies metamorphism. The geochemical characteristics show that BIFs from the Babina and Mauranipur greenstone belts are dominated by higher quartz and magnetite (total content = 90.63–99.95 wt.%), whereas the Mahoba greenstone belt is characterized by lesser quartz and magnetite components (total content = 86.68–94.58 wt.%). The PAAS (Post Archean Average of Australian Sediments)‐normalized REE patterns display significant positive Eu anomaly (Eu/Eu* up to 2.50) with well‐represented negative Ce anomalies (Ce/Ce* = 0.27–1.20). The REE and trace element ratios of BIFs from the Babina and Mauranipur greenstone belts suggest that they were formed by high‐T hydrothermal fluid activity without or very less continental input. Moreover, the Mahoba greenstone belt BIFs are formed by low‐T hydrothermal fluid activity with substantial continental input. Their chemical variation suggests the shallowing of the proto‐basin from the Babina in the west to Mahoba in the east. Tectonic discrimination plots imply the BIFs of the Babina, Mauranipur, and Mahoba greenstone belts of the central Bundelkhand Greenstone Complex are formed in a back‐arc tectonic setting. [ABSTRACT FROM AUTHOR]

The Pinos Volcanic Complex (PVC) is located in the San Luis Potosi Volcanic Field (SLPV) and southern region of the Mesa Central that includes Oligocene rhyolites and trachydacites. These felsic volcanic rocks are characterized by porphyritic textures with a main mineralogical arrangement of phenocrystals of quartz, potassium feldspar (sanidine), plagioclase and biotite embedded in a vitreous matrix with microcrystals of quartz. They display peraluminous, high-silica, alkaline (not peralkaline) composition, with flat heavy rare earth element concentrations and negative Eu anomalies values. They are enriched in large-ion lithophile elements (LILEs; Rb, Ba, K, Th, Ce) relative to highfield-strength elements (HFSE; Nb, Zr, P, Ti). Trace element ratios trend highlights variable degree of partial melting rather than the role of fractional crystallization. The petrogenetic modelling of trace elements reveal that the felsic volcanic rocks are consistent with their formation via partial melting of the middle/upper continental crust. Multi-dimensional tectonic discriminant diagrams and magmatic model indicate an extensional tectonic environment for the genesis of the felsic volcanic rocks. • The PVC is represented by mainly felsic volcanic rocks. • Partial melting of the middle-upper continental crust generated the felsic volcanic rocks. • Magmatic events occurred in the PVC during middle Oligocene in an extensional regime. [ABSTRACT FROM AUTHOR]

The southern part of the Mesa Central (MC) province, Mexico, is formed of several Cenozoic volcanic complexes. The Sierra de San Miguelito Complex (SSMC) is in the south-eastern part of the MC. The SSMC consists of: (1) mafic volcanic rocks of porphyritic texture and trachybasalt/basalt compositions; (2) intermediate volcanic rocks of porphyritic texture and basaltic-trachyandesite, basaltic andesite and andesite compositions; and (3) silicic volcanic rocks of porphyritic texture and rhyolite composition. New 40Ar/39Ar dating results, in combination with major- and trace-element data, and Sr-Nd-Pb isotope data, are used to investigate the petrogenesis and geodynamic evolution of SSMC. The 40Ar/39Ar radiometric age data constrains the magmatic events in the SSMC to between 34 and 21 Ma. Chondrite-normalized rare-earth element patterns are distinct for each volcanic succession; mafic and intermediate lavas have relatively flat light rare earth element (LREE) and large ion lithophile element (LILE) patterns, whereas the silicic volcanic rocks show enrichment in LREE and high field strength elements (HFSE). Within each volcanic phase, the total rare-earth element concentrations increase from mafic to silicic, and the size of the negative Eu anomalies progressively increase (Eu/Eu* from 0.02 to 1.04). The initial 87Sr/86Sr ratios are widely distributed (from 0.70344 to 0.71973) whereas the initial 143Nd/144Nd ratios are somewhat low and show a narrower range (0.51245 to 0.51287), indicating the mafic magmas derived from a slightly heterogeneous source. Geochemical modelling of the mafic volcanic rocks reveals two sources of magma: (1) a parental magmas generated from melting underlying lithospheric mantle; and (2) a second lithospheric melt contaminated by lower crust. Intermediate magmas evolved from assimilation and fractional crystallization (AFC) processes of both lithospheric melts, at shallower levels. The silicic volcanic rocks in the area, however, were probably derived from partial melting of sedimentary rocks within the upper–middle continental crust. New multidimensional tectonic discrimination diagrams, combined with the magmatic model, indicates that volcanic activities in the region were generated in an extensional environment. • The SSMC is represented by minor mafic and mainly intermediate and silicic rocks. • 40Ar/39Ar data show magmatic events occurred between 34 and 21 Ma in an extensional regime. • Partial melting of the lithospheric mantle generated the mafic volcanic rocks. • Intermediate rocks evolved through AFC processes of the lithospheric melts. [ABSTRACT FROM AUTHOR]

Geochemical data from Early Cretaceous volcanic rocks (ultra-basic, basic, intermediate) from the Fresnillo area (Chilitos Formation), Zacatecas, are presented in this study. These rocks are characterized by variable SiO 2 = 38.1–61.7 wt %, Al 2 O 3 = 17.5–27.2 wt %, and MgO = 0.21–6.4 wt % with the Mg# = 20.6–78.9. They are influenced by variable degrees of hydrothermal alteration, being the propylitic more dominant than argillic alteration. The geochemistry displays strong enrichment in light rare earth elements (LREEs) and large ion lithophile elements (LILEs). Moreover, a depletion in high field strength elements (HFSEs; e.g., Nb, Ta, Ti) and nearly flat heavy rare earth element (HREE) patterns are observed. Negligible or absence negative Eu anomalies indicate that fractional crystallization of plagioclase played an insignificant role during the magma evolution. The geochemical features suggest that volcanic rocks are derived from partial melting of an enriched mantle source that has experienced assimilation (low degree) and fractional crystallization. The low La/Nb (0.68–2.23) and Nb/Y (0.19–0.69) ratios, relatively high Zr/Y (3.68–10.56) and Th/Ta (1.03–3.65) ratios, and progressively enriched normalized patterns clue an island arc and most likely a back-arc basin environment for the Chilitos Formation in the Fresnillo area. New multidimensional discrimination diagrams indicate a mid-ocean ridge to island arc setting. A new tectono-magmatic model combined with previous geological observations indicate that the Chilitos Formation was formed in a back-arc tectonic setting and was part of the Guerrero terrane during the Late Jurassic to Early Cretaceous time. • The Chilitos Formation exposed during Early Cretaceous magmatism. • They are partially influenced by hydrothermal alteration. • Mafic magma is derived from partial melting of an enriched mantle source. • A back-arc setting was inferred for the Fresnillo area (Chilitos Formation). [ABSTRACT FROM AUTHOR]

Paleogene−Neogene volcanic complexes are commonly found in the southern part of the Mesa Central province (MC), Mexico. The Sierra de San Miguelito Complex (SSMC) is located in the southeastern part of the MC and consists of two main phases of Oligocene and Miocene units as follows: (1) basaltic group of porphyritic texture of basalt/trachybasalt compositions; and (2) rhyolite-ignimbrite group of porphyritic texture of trachydacite/trachyte compositions. Chondrite-normalized rare-earth element patterns for the basaltic group display enrichment in light rare earth elements (LREE) and large ion lithophile elements (LILE), whereas the rhyolite-ignimbrite group shows enrichment in LREE and high field strength elements (HFSE). The Eu anomalies within the SSMC become progressively more negative from the basaltic group to the rhyolite-ignimbrite group (Eu/Eu* = 1.13 to 0.02) suggest upper crust (crustal contamination) participates during magma generation. Trace element modelling reveals that the basaltic group evolved through a mixing process between mafic and felsic end−members. In contrast, chondrite-normalized and multi-element models reveal that the rhyolite-ignimbrite group evolved by partial melting of the upper continental crust. New multi-dimensional discrimination diagrams along with the Nb–Ta anomalies reveal that the SSMC volcanic rocks were generated in an extensional environment. • The Sierra de San Miguelito Complex (SSMC) exposed during Oligocene–Miocene. • Basaltic group rocks are derived from mantle through crustal evolution. • Rhyolite–Ignimbrite group rocks evolved by partial melting of continental crust. • The SSMC volcanic rocks were generated in an extensional environment. [ABSTRACT FROM AUTHOR]

Key message: Thchit42 constitutive expression for fungal resistance showed synchronisation with leaf augmentation and transcriptome analysis revealed the Longifolia and Zinc finger RICESLEEPER gene is responsible for plant growth and development. Pelargonium graveolens essential oil possesses significant attributes, known for perfumery and aromatherapy. However, optimal yield and propagation are predominantly hindered by biotic stress. All biotechnological approaches have yet to prove effective in addressing fungal resistance. The current study developed transgenic geranium bridging molecular mechanism of fungal resistance and plant growth by introducing cassette 35S::Thchit42. Furthermore, 120 independently putative transformed explants were regenerated on kanamycin fortified medium. Primarily transgenic lines were demonstrated peak pathogenicity and antifungal activity against formidable Colletotrichum gloeosporioides and Fusarium oxysporum. Additionally, phenotypic analysis revealed ~ 2fold increase in leaf size and ~ 2.1fold enhanced oil content. To elucidate the molecular mechanisms for genotypic cause, de novo transcriptional profiles were analyzed to indicate that the auxin-regulated longifolia gene is accountable for augmentation in leaf size, and zinc finger (ZF) RICESLEEPER attributes growth upregulation. Collectively, data provides valuable insights into unravelling the mechanism of Thchit42-mediated crosstalk between morphological and chemical alteration in transgenic plants. This knowledge might create novel opportunities to cultivate fungal-resistant geranium throughout all seasons to fulfil demand. [ABSTRACT FROM AUTHOR]

The primary objective of this article is to introduce a physicochemical model along with a computational algorithm that is valuable for quantifying the occurrence of silica scaling and fouling within geothermal production wells. This model utilizes two-phase flow parameters, temperature and pressure profiles, as well as brine composition to forecast the timing of production pipe constriction caused by amorphous silica deposition over time. The model is applicable to systems with temperatures ranging from 270°C to 305°C, vapor pressures ranging from 55 to 93 bars, and enthalpies ranging from 1189 kJ/kg to 1400 kJ/kg. The predictive model was calibrated using data gathered from six distinct wells within the Los Humeros geothermal field in Mexico, and subsequently, it was applied to forecast outcomes in two additional wells. When the conditions of temperature, pressure, and enthalpy remain relatively constant throughout the production process, the model developed in this study accurately predicts the times at which a certain percentage of pipe sealing occurs in wells with high volumetric fractions of liquid (el>0.5) and temperatures between 270°C and 305°C. The prediction error is less than 3%. [ABSTRACT FROM AUTHOR]

The article focuses on the use of aromatic plants in phytoremediation as a sustainable method for the remediation of sites polluted with heavy metals. It states that soil remediation of heavy metals using conventional technologies requires a significant capital cost. It comments on the benefits of using aromatic plants as suitable phytoremediation candidates and the risks related to non-aromatic edible crops. It talks about the use of aromatic plants in essential oils and food processing.

The article talks about geochemistry as an aiding tool to understand tectonic setting of igneous rocks associations, but continental mafic dykes and flood basalts are targets that even geochemical discrimination diagrams fail to correctly classify. It talks of this paradox explained through crustal contamination, degree of mantle melting and mantle source characteristics. It also makes a mention of plotting geochemical data for key continental mafic dyke swarms in multi-dimensional diagrams.

Andrographis paniculata is a source of diterpenoids and 2′-oxygenated flavonoids, which are of utility in pharmaceutical industry and ayurvedic formulations. With the aim of producing quality herb, an experiment was conducted with different combinations of bio-inoculants and vermicompost (VC) in controlled condition. It was observed that the highest Leaf:Stem (L:S) ratio, fresh herb yield and andrographolide yield (0.82, 300 g pot −1 and 29.8 g kg −1 dry herb, respectively) was recorded when the soil was incorporated with VC along with Azotobacter chrococcum (T 3 ). Further there was a significant improvement in all soil fertility parameters. However, when all the bio-inoculants ( A. chrococcum + Bacillus megaterium + Pseudomonas monteilii + Glomus intraradices ) were mixed with VC, there was a significant improvement in soil dehydrogenase, alkaline, and acidic phosphatase activity. A positive correlation coefficient ( p < 0.01) could be derived amongst plant growth, yield and soil properties ( r = 0.45–0.85). The study suggests that application of the bio-inoculants and organic fertilizers can enhance productivity while maintaining the desired quality of the herb. [ABSTRACT FROM AUTHOR]

Abstract: The story of Jatropha curcas (Jatropha) was started in 2003 when the Planning Commission of India decided 20% blending of Jatropha oil (biodiesel) in petroleum diesel by 2010 and 30% by the year 2030. After that China, Japan, Belgium, Brazil, Tanzania, Mexico, Thailand, Malaysia, Philippines, and East and South Africa have set their own plans to blend Jatropha oil in petroleum diesel. It is not unexpected that almost every paper about Jatropha starts its introduction with the energy, environment and economic benefits and wishful thinking of reducing global warming. Unfortunately, Jatropha could not succeed so far in energy sector as expected, for which it was the most popularized energy crop. Many of the actual investments and policy decisions on Jatropha have convincingly been made without any scientific and technological backup. It has become clear that the positive claims on Jatropha are numerous which have popularized it as a potential source in biodiesel production but many of them still remain as theoretical assumptions and have not been verified yet practically. This letter reports briefly the status of past hopes to ground reality on the basis of what a few scientific studies on Jatropha. [Copyright &y& Elsevier]

Abstract: For the discrimination of four tectonic settings of island arc, continental arc, within-plate (continental rift and ocean island together), and collision, we present three sets of new diagrams obtained from linear discriminant analysis of natural logarithm transformed ratios of major elements, immobile major and trace elements, and immobile trace elements in acid magmas. The use of discordant outlier-free samples prior to linear discriminant analysis had improved the success rates by about 3% on the average. Success rates of these new diagrams were acceptably high (about 69% to 97% for the first set, about 69% to 99% for the second set, and about 60% to 96% for the third set). Testing of these diagrams for acid rock samples (not used for constructing them) from known tectonic settings confirmed their overall good performance. Application of these new diagrams to Precambrian case studies provided the following generally consistent results: a continental arc setting for the Caribou greenstone belt (Canada) at about 3000Ma, São Francisco craton (Brazil) at about 3085–2983Ma, Penakacherla greenstone terrane (Dharwar craton, India) at about 2700Ma, and Adola (Ethiopia) at about 885–765Ma; a transitional continental arc to collision setting for the Rio Maria terrane (Brazil) at about 2870Ma and Eastern felsic volcanic terrain (India) at about 2700Ma; a collision setting for the Kolar suture zone (India) at about 2610Ma and Korpo area (Finland) at about 1852Ma; and a within-plate (likely a continental rift) setting for Malani igneous suite (India) at about 745–700Ma. These applications suggest utility of the new discrimination diagrams for all four tectonic settings. In fact, all three sets of diagrams were shown to be robust against post-emplacement compositional changes caused by analytical errors, element mobility related to low or high temperature alteration, or Fe-oxidation caused by weathering. [Copyright &y& Elsevier]

The Goochland Terrane is an enigmatic crustal block in the Appalachian Piedmont Province of central Virginia, USA. Sparse exposures of terminal Mesoproterozoic and late Neoproterozoic igneous rocks in the central Goochland Terrane offer the opportunity to investigate both the continental affinity of the terrane during the Proterozoic Eon and the timing and mechanisms of crustal growth. We apply multiple geochemical tools to these rocks: tectonic discrimination using whole-rock major and trace element abundances; whole-rock Sm-Nd isotopes; O, U-Pb, and Lu-Hf isotope analyses of spots in zircon; and measurement of O isotopes in multi-grain quartz separates. Eruption of the Sabot Amphibolite protolith is difficult to date, but we tentatively assign an age of 552 ± 11 Ma. Goochland Terrane continental crust first separated from the mantle prior to ca. 1050–1010 Ma intrusion of the Montpelier Anorthosite and the State Farm Gneiss protolith. The granitic magma that became the State Farm Gneiss protolith could have been derived entirely from partial melting of this initial Goochland Terrane crust. In contrast, the magmas that became the Montpelier Anorthosite, Neoproterozoic granitoid, and the Sabot Amphibolite were mixtures of mantle melt and preexisting Goochland Terrane crust. This production of juvenile continental crust occurred during continental extension and, eventually, rifting. The timing and compositions of terminal Mesoproterozoic magmatism in the Goochland Terrane closely match those in the nearby Blue Ridge Province. Although the compositions of the Neoproterozoic magmas in the two regions are similar, intrusion and possibly eruption occurred about 10 M.y. later in the Goochland Terrane. [ABSTRACT FROM AUTHOR]

A new multidimensional scheme consistent with the International Union of Geological Sciences (IUGS) is proposed for the classification of igneous rocks in terms of four magma types: ultrabasic, basic, intermediate, and acid. Our procedure is based on an extensive database of major element composition of a total of 33,868 relatively fresh rock samples having a multinormal distribution (initial database with 37,215 samples). Multinormally distributed database in terms of log-ratios of samples was ascertained by a new computer program DOMuDaF, in which the discordancy test was applied at the 99.9% confidence level. Isometric log-ratio (ilr) transformation was used to provide overall percent correct classification of 88.7%, 75.8%, 88.0%, and 80.9% for ultrabasic, basic, intermediate, and acid rocks, respectively. Given the known mathematical and uncertainty propagation properties, this transformation could be adopted for routine applications. The incorrect classification was mainly for the “neighbour” magma types, e.g., basic for ultrabasic and vice versa. Some of these misclassifications do not have any effect on multidimensional tectonic discrimination. For an efficient application of this multidimensional scheme, a new computer program MagClaMSys_ilr (MagClaMSys— Mag ma Cla ssification M ajor-element based Sys tem) was written, which is available for on-line processing on http://tlaloc.ier.unam.mx/index.html . This classification scheme was tested from newly compiled data for relatively fresh Neogene igneous rocks and was found to be consistent with the conventional IUGS procedure. The new scheme was successfully applied to inter-laboratory data for three geochemical reference materials (basalts JB-1 and JB-1a, and andesite JA-3) from Japan and showed that the inferred magma types are consistent with the rock name (basic for basalts JB-1 and JB-1a and intermediate for andesite JA-3). The scheme was also successfully applied to five case studies of older Archaean to Mesozoic igneous rocks. Similar or more reliable results were obtained from existing tectonomagmatic discrimination diagrams when used in conjunction with the new computer program as compared to the IUGS scheme. The application to three case studies of igneous provenance of sedimentary rocks was demonstrated as a novel approach. Finally, we show that the new scheme is more robust for post-emplacement compositional changes than the conventional IUGS procedure. [ABSTRACT FROM AUTHOR]

Natural catalysts are important for the low-cost and large-scale production of carbon nanostructures. In this study, we used a natural material obtained from thin bands of sedimentary rocks known as Banded Iron Formation (BIF). BIF powders (pristine and ball-milled) were used as catalysts for the large-scale production of nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) via an aerosol-assisted catalytic chemical vapor deposition (AACCVD) experiment. The morphology and composition profiles of the BIF powders and N-MWCNT samples were analyzed by scanning and transmission electron microscopies, X-ray diffraction, X-ray photoelectron (XPS) and Raman spectroscopies, and thermogravimetric analysis. XRD characterizations revealed that the BIF powders were mainly composed of quartz and hematite. This result was also confirmed by Raman spectroscopy. The production efficiency of 340% wt./wt. of the N-MWCNTs was obtained by 1 h ball-milled BIF powders. The specific surface area of the N-MWCNTs reached 37.87 m2/g. The type of nitrogen doping, oxygen functional groups, silicon, and carbon species (sp2 and sp3) hosted at the surface of the N-MWCNTs were quantified by XPS. The electrochemical response of electrodes composed of the N-MWCNTs were studied via cyclic voltammetry, electrochemical impedance, and coulombic efficiency determination to assess the possible applications of our synthesized materials as energy storage or sensor systems. The magnetic properties and effects of acid and thermal treatments on the morphology of the N-MWCNTs are also presented. • Facile route to produce high yield of nitrogen-doped carbon nanotubes using natural catalyst. • SiO 2 –Fe 3 O 2 new natural material as catalyst interacting with nitrogen molecules for enhanced yield of nanocarbons. • Competitive surface area in pristine nitrogen-doped carbon nanotube. • Produced N-MWCNTs could be used as electrodes in energy storage and sensor systems. [ABSTRACT FROM AUTHOR]

In X-ray fluorescence (XRF) spectrometry, matrix-effect corrections for two types of linear regressions (ordinary and uncertainty-based weighted) have been performed for the first time and compared for the determination of major elements in rocks and minerals. The analytical data from different laboratories for 62 international geochemical reference materials (GRMs) were first processed to obtain better estimates of the mean values, along with lower uncertainties (narrower confidence limits of the mean), which were used in the XRF calibrations. The blank intensities were subtracted from the response for each GRM and the respective uncertainties were estimated. The uncertainty-based weighted least-squares linear regression (UWLR) model, being statistically more appropriate than the ordinary least-squares linear regression (OLR) model, provided more reliable regression equations than the OLR. All calculations and matrix-effect corrections were achieved through a newly developed online computer program. Similarly, matrix-effect corrections involving 11 α and 26 α (alphas) are presented and compared. The best UWLR method involving 26 α was successfully applied to the 62 GRMs and 4 similarly complex rock matrices as the calibrators. Both evaluations confirmed the usefulness of the UWLR model. This UWLR model was also compared with the OLR 26 α model for 62 GRMs treated as unknowns and shown to perform better. Thus, the UWLR model, along with the proposed matrix-effect correction method of 26 α, can be recommended as the most appropriate procedure for the calibration of XRF instruments, instead of the commonly used OLR models. This is the first time when 26 α are advantageously in a better estimate of influence coefficients used for major element determinations in rock and mineral samples. Because the UWLR calibration is based on a large number of GRMs of many rock and mineral types, it should be useful for all kinds of geological materials. Unlabelled Image • Matrix-effect correction equations developed and used for the UWLR model. • A large number (62) of calibrators used for the XRF calibration. • A large number (26) of alpha-corrections used in geochemistry. • Total 99% uncertainties in complex matrices, a novel approach in geochemistry. [ABSTRACT FROM AUTHOR]