| 1. Identity statement | ||||
| Reference Type | Conference Paper (Conference Proceedings) | |||
| Site | mtc-m21c.sid.inpe.br | |||
| Holder Code | isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S | |||
| Identifier | 8JMKD3MGP3W34R/3R3TD4P | |||
| Repository | sid.inpe.br/mtc-m21c/2018/05.07.16.56 | |||
| Metadata Repository | sid.inpe.br/mtc-m21c/2018/05.07.16.56.30 | |||
| Metadata Last Update | 2020:12.07.21.11.37 (UTC) administrator | |||
| Secondary Key | INPE--PRE/ | |||
| Citation Key | TatumiRoss:2018:AgMoAp | |||
| Title | Age models applied to Amazon fluvial sediments  | |||
| Year | 2018 | |||
| Access Date | 2024, May 18 | |||
| Secondary Type | PRE CN | |||
| 2. Context | ||||
| Author | 1 Tatumi, Sonia Hatsue 2 Rossetti, Dilce de Fátima | |||
| Resume Identifier | 1 2 8JMKD3MGP5W/3C9JGTQ | |||
| Group | 1 2 DIDSR-CGOBT-INPE-MCTIC-GOV-BR | |||
| Affiliation | 1 Universidade Federal de São Paulo (UNIFESP) 2 Instituto Nacional de Pesquisas Espaciais (INPE) | |||
| Author e-Mail Address | 1 2 dilce.rossetti@inpe.br | |||
| Conference Name | Encontro Nacional de Física da Matéria Condensada (ENFMC) | |||
| Conference Location | Foz do Iguaçu, PR | |||
| Date | 06-11 maio | |||
| History (UTC) | 2018-05-07 16:56:52 :: simone -> administrator :: 2018 2020-12-07 21:11:37 :: administrator -> simone :: 2018 | |||
| 3. Content and structure | ||||
| Is the master or a copy? | is the master | |||
| Content Stage | completed | |||
| Transferable | 1 | |||
| Content Type | External Contribution | |||
| Abstract | Sediment samples were collected from the State of Amazonas to be dated by the method of Optically Stimulated Luminescence (OSL). OSL shine down curves of quartz grains were measured with blue excitation and detecting the emission in the UV region. When quartz is exposed to sunlight, its OSL intensity is bleached. During subsequent burial, ionizing radiation strikes the grain surfaces and the energy is eventually transfer to the crystal releasing charge carriers, which can be trapped in defects and impurities locate in the crystalline lattice forming metastable states. The concentration of these states increases with burial time. If the grain is optically excited, the charges are released and can recombine to emit light (OSL). OSL intensity is proportional to burial time and provide the sample age. In this case, the ionizing radiation flux is generated by natural radioactive isotopes from the U-235/U-238, Th-232 and K-40 series present in the sediment, as well as, the cosmic radiation incident in the depositional site. In this work, 10 samples were collected at various depths using aluminum tubes. Parcels of each sample were separated for OSL and gamma spectroscopy analyses. OSL measurements were performed according to the single aliquot regeneration (SAR) protocol. The age model was applied to determine the equivalent doses (De) of quartz grains. Gamma-ray spectra were carried out to determine the radioactive content of the samples. Values of the radioactive isotopes concentrations were used to calculate annual dose rates (DA) of the sediments. The ages (I) of the samples were determined by the equation I = De DA . The results showed age dispersions between 13 to 29%. Ages of samples with dispersion less than 20% were calculated using the central age model (CAM) and the finite mixture age model (FMM). Samples with dispersion greater than 20% had their ages determined by the minimum age model (MAM) and FMM. The ages results obtained ranged from 5,600 to 142,700 years, which is consistent with sediment deposition during the latest Mid-Late Pleistocene to mid-Holocene. We conclude that the methodology and the models adopted were satisfactory for age determination. These results are valuable to approach issues concerning paleoenvironmental and paleoclimatic reconstructions before the establishment of the modern drainage systems. | |||
| Area | SRE | |||
| Arrangement | urlib.net > BDMCI > Fonds > Produção anterior à 2021 > DIDSR > Age models applied... | |||
| doc Directory Content | there are no files | |||
| source Directory Content | there are no files | |||
| agreement Directory Content |
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| 4. Conditions of access and use | ||||
| Language | en | |||
| User Group | simone | |||
| Reader Group | administrator simone | |||
| Visibility | shown | |||
| Update Permission | not transferred | |||
| 5. Allied materials | ||||
| Next Higher Units | 8JMKD3MGPCW/3ER446E | |||
| Host Collection | urlib.net/www/2017/11.22.19.04 | |||
| 6. Notes | ||||
| Empty Fields | archivingpolicy archivist booktitle callnumber copyholder copyright creatorhistory descriptionlevel dissemination doi e-mailaddress edition editor format isbn issn keywords label lineage mark mirrorrepository nextedition notes numberoffiles numberofvolumes orcid organization pages parameterlist parentrepositories previousedition previouslowerunit progress project publisher publisheraddress readpermission rightsholder schedulinginformation secondarydate secondarymark serieseditor session shorttitle size sponsor subject targetfile tertiarymark tertiarytype type url versiontype volume | |||
| 7. Description control | ||||
| e-Mail (login) | simone | |||
| update | ||||