期刊
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
卷 355, 期 -, 页码 98-114出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.jvolgeores.2017.05.008
关键词
Parana-Etendeka Igneous Province; Stratigraphy of LIP; Basalt; Volcanology; Lava emplacement
资金
- CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico -Brazil)
- BG-Brazil/Shell
- University of Aberdeen
- Federal University of Rio Grande do Sul
- CNPq [479784/2012-4]
- FAPERGS [100713]
- FAPESP [2012/06082-6]
- Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [12/06082-6] Funding Source: FAPESP
The volcanic rocks of the Lower Cretaceous Parana-Etendeka Igneous Province, in Brazil, are grouped in the Serra Geral Group. The province can be chemically divided into low-TiO2, and high-TiO2. In southern Brazil, the low-TiO2 lava pile reaches a thickness of similar to 1 km and is formed of heterogeneous lava packages here divided into four lava formations. Torres Formation (TF) is characterized by chemically more primitive basaltic (>5 wt% MgO) compound pahoehoe flow fields; these lavas stratigraphically overly aeolian sandstones of Botucatu Formation and represent the onset of the volcanic activity. Vale do Sol Formation (VSF) groups vertically stacked sheet-like rubbly pahoehoe basaltic andesites (SiO2 > 51 wt%; MgO < 5 wt%). These lavas covered the former basalts in the Torres Syncline axis and pinch out towards southwest and represent the most voluminous mafic lava flows. Dacites and rhyolites of Palmas Formation (PF) overlay VSF flows in the central and eastern outcrop area and rest directly upon TF lavas in the west. The acidic units were emplaced as lava domes and widespread tabular lava flows. Esmeralda Formation (EF) is the upper stratigraphic unit and it is formed by a basaltic pahoehoe flow field emplaced during the waning phase of volcanic activity of the low-TiO2 lava sequence. Sedimentary inter beds are preserved throughout the whole lava pile and were deposited during quiescence periods of volcanic activity, and represent important stratigraphic markers (e.g. TF-VSF contact). The newly proposed stratigraphy provides promptly recognized stratigraphic units in a regional framework of fundamental importance for future correlations and provide vital information in the understanding of how the Parana-Etendeka Igneous Province evolved through time. (C) 2017 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据