Results in Geochemistry最新文献

{"title":"Petrogenesis of the Katangan mafic rocks, Zambia: Insights from lithogeochemistry, large igneous province classification, and petrological modeling","authors":"R.R.B. Bacha ,&nbsp;J.E. Mungall ,&nbsp;R.E. Ernst","doi":"10.1016/j.ringeo.2023.100027","DOIUrl":"https://doi.org/10.1016/j.ringeo.2023.100027","url":null,"abstract":"<div><p>The Neoproterozoic Katangan mafic rocks are composed of gabbro and basalt sills, dykes, and flows. They are characterized as a large igneous province distributed throughout the 450 km long and 600 km wide arcuate Central African Copperbelt (CACB), and are in southeastern Democratic Republic of Congo and northwestern Zambia. Understanding the petrogenesis of these mafic intrusive rocks is vital to assist future studies, as examples regarding their relation to the vast Cu and Co deposits in the Central African Copperbelt or consequences of Rodinia's break up. Lithogeochemical data suggest that these rocks were formed due to an extensional regime developed during the rifting stage of the CACB, which resulted in the upwelling of the asthenospheric mantle. Consequently, petrological modeling demonstrated how these rocks derived from primitive magmas and evolved chemically through fractional crystallization, assimilation, and magma mixing, generating a range of compositions with close chemical affinity. Based on this analysis, we have subdivided them into two main groups with distinct sources each further subdivided into two subgroups. A voluminous group with ocean island basalt (OIB) affinities is widespread throughout the basin and can be modeled as the product of crustal assimilation by a picritic magma, concomitant with fractional crystallization. Magma types of this group have interacted with upper crust to develop a characteristic high Th/Ti trace element character. A less common magma represents the product of interactions between a tholeiite with enriched mid-ocean ridge (E-MORB) affinity with metasomatized subduction zone-modified lithospheric mantle (SZLM) to generate an array of moderately to extremely potassic magmas, which we classify as shoshonitic to ultrapotassic.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"12 ","pages":"Article 100027"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49724331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integration of fractal modeling and correspondence analysis reconnaissance for geochemically high-potential promising areas, NE Iran","authors":"Seyed Aliakbar Hosseini ,&nbsp;Nasser Keshavarz Faraj Khah ,&nbsp;Pooria Kianoush ,&nbsp;Peyman Afzal ,&nbsp;Arash Ebrahimabadi ,&nbsp;Reza Shirinabadi","doi":"10.1016/j.ringeo.2023.100026","DOIUrl":"https://doi.org/10.1016/j.ringeo.2023.100026","url":null,"abstract":"<div><p>Most geochemical and geostatistical analysis in mining exploration requires removing regional trends in order to obtain local anomalies. In this paper, stream sediment samples, which collected from Khusf area (NE Iran), was studied based on Concentration-Area (C-A) fractal model as well as correspondence analysis methods to find high-potential areas elements. Correspondence analysis with 170 samples through 20 elements concentration values in each sample was performed. According to correspondence analysis, among one or several elements in the study area, local anomalies were separated which the highest concentration relates to the variables Pb, As, and Cd elements. After the correspondence analysis, the best variogram for the Khusf area was studied. Elemental concentration maps was then produced through estimating the values using kriging method. Therefore, using the fractal method, between three statistical sets of elements, it was concluded that the third set showed the anomaly for Pb, As, and Cd elements with local anomaly values respectively determined as 55, 7.2, and 0.88 ppm. Although Cd element is not genetically related to same source of Pb and As, utilizing integrated approach, Cd anomalies has also been detected in the area as a promising element zone. Finally, it is suggested that this region has the possibility of Basic Metals occurrence and suggests further geophysical operations on a local identification scale.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"11 ","pages":"Article 100026"},"PeriodicalIF":0.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49737978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enrichment characteristics of potential risk elements in the black soil region of Northeast China","authors":"Huimin Dai ,&nbsp;Ze Yang ,&nbsp;Yihe Zhang ,&nbsp;Qiuyan Li ,&nbsp;Kai Liu ,&nbsp;Nana Fang","doi":"10.1016/j.ringeo.2022.100021","DOIUrl":"https://doi.org/10.1016/j.ringeo.2022.100021","url":null,"abstract":"<div><p>Heavy metals in topsoil mainly originate from the natural geological background and human activities, and once the soil is contaminated with heavy metals, it is difficult to restore it to its original natural state. Therefore, it is important to assess the level of influence of heavy metals in soil to provide information for agricultural production. To clarify the intensity of anthropogenic impact on the soil environment in the black soils region (BSR), we used the geochemical data of 0–20cm topsoil (anthropogenic impact depth) and 150–180cm subsoil(natural background) to analyze the topsoil heavy metal enrichment coefficient for cadmium, mercury, lead, arsenic, zinc, nickel, copper, chromium, and their spatial distribution characteristics in BSR . The analysis showed that the heavy metal enrichment coefficients of lead, arsenic, zinc, nickel, copper and chromium are basically less than 2.0 in BSR, and there are only localized points with enrichment coefficients of greater than 2.0. Cadmium and mercury are more obviously enriched in the black soils area, and the enrichment areas are mainly distributed south of Harbin. The mercury enrichment area is distributed in a north–eastward strip along Shenyang, Changchun, and Harbin, and the cadmium enrichment areas are mainly distributed south of Changchun, with a continuous distribution to Tieling City. the enrichment of heavy metals in the topsoil is closely related to the population density by comparing spatial distribution patterns of the geological background, topography and land use, and the obvious enrichment areas for heavy metals are located in and around cities, especially in industrial cities and their surrounding areas. The enrichment depth of 40 cm is further evidence that the heavy metals in topsoil mainly originate from human activities.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"10 ","pages":"Article 100021"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49737444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precise zircon U-Pb dating of the Mesoproterozoic Gawler large igneous province, South Australia","authors":"Elizabeth A. Jagodzinski ,&nbsp;Anthony J. Reid ,&nbsp;James L. Crowley ,&nbsp;Claire E. Wade ,&nbsp;Stacey Curtis","doi":"10.1016/j.ringeo.2022.100020","DOIUrl":"https://doi.org/10.1016/j.ringeo.2022.100020","url":null,"abstract":"<div><p>The Mesoproterozoic Gawler Range Volcanics and Benagerie Volcanic Suite of the Gawler Craton and Curnamona Province, South Australia, together with associated intrusive magmatism, define an intracontinental, subaerial large igneous province (LIP) preserving an estimated 110 000 km³ of volcanic rock, which hosts one of the world's largest orebodies, the Fe oxide-Cu-Au-U deposit at Olympic Dam, and numerous other related Cu-Au deposits. New high-precision Chemical Abrasion Isotope Dilution Thermal Ionization Mass Spectrometry (CA-TIMS) U-Pb dates on volcanic zircons allow for regional correlations between stratigraphic units of the GRV and BVS, and an understanding of how magmatic styles, temperatures, composition and mantle source input evolve over the duration of the LIP. The new dates indicate that the entire volcanic province erupted over a geologically short time interval of less than 10 million years, from c. 1595 to 1586 Ma, culminating in a widespread, voluminous flood rhyolite province that erupted in less than 1.5 million years, and most likely in 260,000 years or less. This follows a pattern of volcanism that is similar in duration and volume to mafic and bimodal continental LIPs, of which the mafic-dominated Phanerozoic continental flood basalt provinces are the more common end member.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"10 ","pages":"Article 100020"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49724246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age and origin of the Cortlandt intrusive complex, New York State: A detailed look at the Stony Point and Rosetown plutons","authors":"D.G. Bailey ,&nbsp;M.V. Lupulescu ,&nbsp;J.R. Chiarenzelli ,&nbsp;R.M. Conrey ,&nbsp;J.W. Wuebber ,&nbsp;M.H. Anders","doi":"10.1016/j.ringeo.2023.100024","DOIUrl":"https://doi.org/10.1016/j.ringeo.2023.100024","url":null,"abstract":"<div><p>The Cortlandt Complex is a classic alkaline intrusive complex exposed along the Hudson River in southeastern New York. Early work by James Dana in the 1880s set the stage for over 100 additional studies over the next century. Studies in the past few decades have focused on constraining the genetic relationships between phases of the intrusive complex and the timing of emplacement relative to peak metamorphism and deformation during the Taconic orogeny.</p><p>LA-MC-ICP-MS U/Pb zircon emplacement ages were obtained on five samples from the Cortlandt Complex. The five samples yielded dates ranging from 443 to 454 Ma, with an overall weighted mean emplacement age of 447.1 +/- 4.5 Ma. Three of the five samples contained inherited zircons, nearly all of Mesoproterozoic age. A sample of the adjacent Annsville Phyllite contained a diverse population of detrital zircons. The most common ages are between 1.25 and 1.85 Ga, although zircons of Neoarchean age are also present.</p><p>The westernmost and relatively small Rosetown and Stony Point plutons are lithologically and compositionally diverse. Major and trace element trends indicate a complex petrogenesis, which is supported by variable initial isotope ratios. The geochemical data indicate that the mafic magmas were derived primarily from an asthenospheric mantle source, while the inherited zircons and more radiogenic isotope ratios of the silicic units imply a significant crustal component was involved in their formation.</p><p>The timing and composition of intrusions in the Cortlandt Complex indicate that they are not the result of subduction related to the Taconic Orogeny. We suggest that the mafic units are the result of post-collisional, slab-failure induced asthenospheric upwelling, while the silicic units are primarily partial melts of Grenville-age, garnet amphibolites in the lower crust.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"10 ","pages":"Article 100024"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49724243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New U-Pb baddeleyite ID-TIMS ages from the intrusive high-Ti-Sr rocks of the Southern Paraná LIP, Brazil: Implications for correlations with environmental disturbances during the Early Cretaceous","authors":"Brenda C. Rocha ,&nbsp;Sean P. Gaynor ,&nbsp;Valdecir A. Janasi ,&nbsp;Joshua H.F.L. Davies ,&nbsp;Luana M. Florisbal ,&nbsp;Breno L. Waichel ,&nbsp;Urs Schaltegger","doi":"10.1016/j.ringeo.2023.100023","DOIUrl":"https://doi.org/10.1016/j.ringeo.2023.100023","url":null,"abstract":"<div><p>Large volumes of mafic igneous rocks are commonly emplaced during Large Igneous Province (LIP) eruptions, and these mafic rocks are often contemporaneous with periods of environmental disturbances, such as global ocean anoxia, and as a result, mass extinctions. The Paraná-Etendeka LIP is no exception, and has been previously correlated with, and interpreted to be the cause of the Valanginian oceanic anoxic event (OAE), a small global environmental disturbance. Here, we present new U-Pb ID-TIMS baddeleyite ages from high-Ti-Sr mafic intrusive rocks from the Paraná LIP, in Brazil. While these data are potentially complicated by the presence of Pb-loss and inheritance, it is possible to interpret geologically meaningful ages from them. The first high-precision age is reported for the type-locality of the Florianópolis Dyke Swarm, in North Santa Catarina Island, which yields an age of 132.53 ± 0.40/0.40/0.42 Ma. We also report an age of 132.07 ± 0.27/0.30/0.33 Ma for a dolerite sill, which intrudes organic-rich sedimentary rocks of the Paraná Basin. The emplacement of high-Ti-Sr magmas at <em>ca.</em> 132 Ma suggests that there was up to 2 Myr of intrusive magmatism in the southern part of the Paraná LIP. Further investigation on the mafic intrusive magmatism from the Paraná LIP through robust high-precision geochronology is required to elucidate the proposed linkage more clearly with environmental changes during the Early Cretaceous.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"10 ","pages":"Article 100023"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49737452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal, geochemical and isotopic constraints on plume-driven felsic and mafic components in a Mesoproterozoic flood rhyolite province","authors":"Claire E. Wade ,&nbsp;Justin L. Payne ,&nbsp;Karin M. Barovich ,&nbsp;Anthony J. Reid ,&nbsp;Elizabeth A. Jagodzinski ,&nbsp;Stacey Curtis ,&nbsp;Jesse Hill","doi":"10.1016/j.ringeo.2022.100019","DOIUrl":"10.1016/j.ringeo.2022.100019","url":null,"abstract":"<div><p>Formation of the Gawler felsic large igneous province (LIP) involved a mantle plume and mafic underplating underneath a metasomatised subcontinental lithospheric mantle (SCLM). Minor extrusive basalt to andesite rocks show the evolution of mantle composition during the initial stages of LIP formation (ca. 15931590 Ma). The earliest basaltic magmatism has low Nb/Yb ratios, low (La/Yb)N, and high ε_Nd(i), representing a relatively depleted region from within the metasomatised SCLM. The more depleted composition and higher volume of this magmatism is consistent with early plume-head driven melts. Subsequent basaltic magmatism shows increasing enrichment in the source, evidenced by increasing Nb/Yb and Th/Nb ratios and decreasing ε_Nd(i). The final stage of basaltic magmatism is marked by an isotopically juvenile SCLM source characterised by lower Th/Nb ratios, possibly representing a rejuvenation phase.</p><p>Dacite to rhyolite rocks record the behaviour of crustal melting above a mantle plume. Older dacite to rhyolite units extruded 1593.611588.47 Ma represent compositionally heterogeneous rocks that correlate temporally with the basaltic to andesitic units. The Nd isotopic record suggests an increasing SCLM component from the early to late stages of felsic magmatism, occurring synchronously with increasing enrichment in basaltic magmas. Younger dacite to rhyolite units (1586.661586.39 Ma) have no associated mafic component, are geochemically and isotopically homogeneous and represent large volumes of felsic lava extruded in 300 Kyr. The final stage of felsic magmatism (1586.39 Ma) is marked by crystal-rich dacite, decreasing ε_Nd(i) and lower Ti-in-zircon temperatures which are interpreted to represent the waning phase of the mantle plume and increasing crustal melting.</p><p>This study provides a rare example of temporally constrained geochemical and isotopic compositions in mafic and felsic volcanism in a LIP. Our detailed petrogenetic work best demonstrates the generation of the Gawler LIP occurred in an intracontinental, plume setting analogous to a mafic LIP model.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"9 ","pages":"Article 100019"},"PeriodicalIF":0.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666277922000053/pdfft?md5=9dc4ef08847e6a525b7184fb05c1dd70&pid=1-s2.0-S2666277922000053-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77461526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Southeast Asian dust flux reconstructed using accurately dated stalagmite thorium concentrations","authors":"T. Verniers ,&nbsp;H. Couper ,&nbsp;F.A. Lechleitner ,&nbsp;J.U.L. Baldini","doi":"10.1016/j.ringeo.2022.100017","DOIUrl":"10.1016/j.ringeo.2022.100017","url":null,"abstract":"<div><p>Mineral dust flux is an important component of the global climate system, but chronological uncertainties complicate interpretations of the timing and magnitude of paleo-dust fluxes. This study establishes a correlation between modern satellite-derived atmospheric dust concentration data and stalagmite thorium concentrations (from published records of stalagmites growing over the last 500 years), and subsequently applies this relationship to reconstruct Asian dust flux during the late Pleistocene using published records. Thorium is an element often associated with mineral dust, and because most stalagmite records are dated using uranium-thorium disequilibrium techniques, a spatiotemporally large, yet untapped, database of thorium concentrations exists. Specifically, 194 thorium records from South-East (SE) Asian stalagmites were compiled to produce a composite SE Asian dust flux record for the past 100,000 years. The new dust flux record is consistent with the perspective that dust flux is a function of westerly wind strength across Asia and regional aridity. Dansgaard-Oeschger (D-O) event expression within the median stalagmite ²³²Th record is variable, with several D-O events evident within stalagmite δ¹⁸O records not evident within the new dust record. This may reflect East Asian Summer Monsoon (EASM) moisture source region Sea Surface Temperature (SST) variability (affecting stalagmite δ¹⁸O) but stable westerly wind regime (resulting in invariant ²³²Th concentrations) or the fact that these events were too brief to trigger biome shifts. This study presents encouraging first results suggesting that stalagmite thorium concentrations partially reflect dust flux over cave sites. Although here we use a compilation of records, and the spread of data within each time slice is high, future studies at well-understood cave sites where thorium input to the cave is predominantly via dry deposition may require only single stalagmites to produce adequate absolutely dated dust reconstructions.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"7 ","pages":"Article 100017"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S266627792200003X/pdfft?md5=e57955b88cef348091a70e455f669595&pid=1-s2.0-S266627792200003X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83501494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"U-Th isotope data for dust sampled along a west to east transect in eastern Australia and some bedrock from the Flinders Ranges","authors":"S. Turner ,&nbsp;A. Dosseto ,&nbsp;P.O. Suresh ,&nbsp;M. Turner ,&nbsp;H. Handley ,&nbsp;P. Hesse","doi":"10.1016/j.ringeo.2022.100016","DOIUrl":"10.1016/j.ringeo.2022.100016","url":null,"abstract":"<div><p>In this communication we present Uranium-Thorium (U-Th) isotope data for surficial dusts sampled along a west to east transect in eastern Australia and some selected bedrock samples from the Flinders Ranges near the western end of the transect. The dusts have lost ²³⁸U and ²³⁴U within the last 350 kyr implying a combination of chemical (bulk U loss) and physical (recoil loss of ²³⁴U) weathering. Near-surface bedrock is not always in U-Th isotope secular equilibrium as commonly assumed in studies of weathering, erosion and soil production.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"6 ","pages":"Article 100016"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666277922000028/pdfft?md5=ae11266c7bf706eda9c0bf5d5b602b52&pid=1-s2.0-S2666277922000028-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81535302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chronology and geochemistry of the Caribbean Large Igneous Province in Jamaica","authors":"Simon F. Mitchell ,&nbsp;Andrew C. Kerr ,&nbsp;Alan R. Hastie","doi":"10.1016/j.ringeo.2022.100015","DOIUrl":"10.1016/j.ringeo.2022.100015","url":null,"abstract":"<div><p>Jamaica has a complex geological history with rocks belonging to the Cretaceous Caribbean Large Igneous Province (CLIP) in the east and Cretaceous oceanic island arc rocks in the centre and west. We present a new geochemical dataset for the CLIP and correlate this dataset and previous datasets using radiolarians and planktic foraminifers to the geological timescale. The palaeontological dating indicates that two phases of plateau activity – ‘main’ phase in the late Turonian-mid Coniacian (c. 92-87 Ma) and an ‘extended’ phase in the Coniacian to mid Campanian (c. 88-75 Ma). These phases are also seen in the Beata Ridge and on the Lower Nicaragua Rise. The geochemistry indicates that both phases are typical large igneous province plateau basalts. The ‘main’ phase has slightly more depleted light rare earth elements than the extended phase, indicating mantle source heterogeneity, and a (Sm/Yb)_n &gt;1 indicates a deeper average depth of melting for the ‘main’ phase. The association of the basalts with sediments containing specific microfossil assemblages clearly demonstrates the existence of these two magmatic phases in Jamaica.</p></div>","PeriodicalId":101085,"journal":{"name":"Results in Geochemistry","volume":"6 ","pages":"Article 100015"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666277922000016/pdfft?md5=57a2efbf2172f49b0679c82cb235ad1b&pid=1-s2.0-S2666277922000016-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73042639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}