{"title":"The Santa Vitória Alloformation: an update on a Pleistocene fossil-rich unit in Southern Brazil","authors":"R. P. Lopes, S. Dillenburg, J. Savian, J. Pereira","doi":"10.1590/2317-4889202120200065","DOIUrl":null,"url":null,"abstract":"The Santa Vitória Formation is a lithostratigraphic unit known for its fossil assemblage of Pleistocene mammals, established in 1973 from sediments exposed along the banks of Chuí Creek, in the southern coastal plain of the state of Rio Grande do Sul (CPRS), Brazil. The original description was presented in a Masters’ dissertation and never formally described in a peer-reviewed publication. Moreover, surveys and fossil collecting efforts developed in the last decade have led to a better understanding of its origin and nature. An updated description of this unit is presented here, which outcrops in areas occupied by barrier-lagoon depositional systems originated by eustatic oscillations. The formation encompasses Middle-Upper Pleistocene fluvial and eolian depositional systems and paleosols formed chiefly of fine to medium quartz sand, with subordinate clay, concentrations of iron and manganese oxides, and caliche nodules of pedogenic origin. It conformably overlies upper shoreface-foreshore marine deposits, and is overlain by loess deposited during the last glacial period. Here is proposed to re-define it as Santa Vitória Alloformation, considering that the use of an allostratigraphic framework to characterize this unit has the practical purpose of group-ing depositional systems genetically unrelated to the barrier-lagoon systems.","PeriodicalId":9221,"journal":{"name":"Brazilian Journal of Geology","volume":"17 1","pages":""},"PeriodicalIF":1.3000,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"7","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Brazilian Journal of Geology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1590/2317-4889202120200065","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 7
Abstract
The Santa Vitória Formation is a lithostratigraphic unit known for its fossil assemblage of Pleistocene mammals, established in 1973 from sediments exposed along the banks of Chuí Creek, in the southern coastal plain of the state of Rio Grande do Sul (CPRS), Brazil. The original description was presented in a Masters’ dissertation and never formally described in a peer-reviewed publication. Moreover, surveys and fossil collecting efforts developed in the last decade have led to a better understanding of its origin and nature. An updated description of this unit is presented here, which outcrops in areas occupied by barrier-lagoon depositional systems originated by eustatic oscillations. The formation encompasses Middle-Upper Pleistocene fluvial and eolian depositional systems and paleosols formed chiefly of fine to medium quartz sand, with subordinate clay, concentrations of iron and manganese oxides, and caliche nodules of pedogenic origin. It conformably overlies upper shoreface-foreshore marine deposits, and is overlain by loess deposited during the last glacial period. Here is proposed to re-define it as Santa Vitória Alloformation, considering that the use of an allostratigraphic framework to characterize this unit has the practical purpose of group-ing depositional systems genetically unrelated to the barrier-lagoon systems.
Santa Vitória组是一个岩石地层单元,以其更新世哺乳动物的化石组合而闻名,于1973年在巴西南里约热内卢Grande do Sul (CPRS)南部沿海平原Chuí Creek沿岸暴露的沉积物中建立。最初的描述是在一篇硕士论文中提出的,从未在同行评审的出版物中正式描述过。此外,在过去十年中开展的调查和化石收集工作使人们对其起源和性质有了更好的了解。本文对该单元进行了更新的描述,其露头位于由起伏振荡形成的屏障-泻湖沉积体系所占据的地区。该地层包括中上更新世河流和风成沉积体系,古土壤主要由细至中石英砂组成,次之为粘土,含铁和锰氧化物,以及成土成因的钙质结核。它整合地覆盖在上滨—前滨海相沉积物上,并被末次冰期沉积的黄土覆盖。本文建议将其重新定义为Santa Vitória异地层格架,考虑到使用异地层格架来表征该单元具有将与屏障-泻湖体系在遗传上无关的沉积体系分组的实际目的。
期刊介绍:
The Brazilian Journal of Geology (BJG) is a quarterly journal published by the Brazilian Geological Society with an electronic open access version that provides an in-ternacional medium for the publication of original scientific work of broad interest concerned with all aspects of the earth sciences in Brazil, South America, and Antarctica, in-cluding oceanic regions adjacent to these regions. The BJG publishes papers with a regional appeal and more than local significance in the fields of mineralogy, petrology, geochemistry, paleontology, sedimentology, stratigraphy, structural geology, tectonics, neotectonics, geophysics applied to geology, volcanology, metallogeny and mineral deposits, marine geology, glaciology, paleoclimatology, geochronology, biostratigraphy, engineering geology, hydrogeology, geological hazards and remote sensing, providing a niche for interdisciplinary work on regional geology and Earth history.
The BJG publishes articles (including review articles), rapid communications, articles with accelerated review processes, editorials, and discussions (brief, objective and concise comments on recent papers published in BJG with replies by authors).
Manuscripts must be written in English. Companion papers will not be accepted.