SEQÜÊNCIAS DEPOSICIONAIS DA FORMAÇÃO TACIBA (GRUPO ITARARÉ, NEOCARBONÍFERO A EOPERMIANO) NA REGIÃO DE MAFRA (SC), BACIA DO PARANÁ
SEQÜÊNCIAS DEPOSICIONAIS DA FORMAÇÃO TACIBA (GRUPO ITARARÉ, NEOCARBONÍFERO A EOPERMIANO) NA REGIÃO DE MAFRA (SC), BACIA DO PARANÁ
复制标题
SEQÜÊÊNCIAS DEPOSICIONAIS DA FORMAÇË TACIBA (GRUPO ITARARÉ, NEOCARBONÍFERO A EOPERMIANO) NA REGIÍ DE MAFRA (SC), BACIA DO PARANÁ
DOI：
10.5327/rbg.v36i2.1225
复制
发表时间：
2006
影响因子：
1.4
通讯作者：
J. C. Castro
中科院分区：
文献类型：
--
作者：
L. C. Weinschütz;J. C. Castro
Taciba组构成了Itarare群的第三个主要的向上变细旋回，包括三个成员：Rio Segredo砂岩、Chapeu do Sol杂岩和Rio do Sul韵律岩、粉砂岩和页岩。在巴拉那盆地东缘的马夫拉地区，不存在Rio Segredo砂岩，Chapeu do Sol杂岩突然覆盖在Lontras页岩（下伏坎波穆劳地层的顶部单元）上。通过对四口取心威尔斯井和附近补充露头的研究，确定了塔茨巴组的两个沉积层序。在Vila Ruthes井（VR-1）和露头剖面中，较低的塔西巴-I序列（TC-I）由65 m厚的杂砂岩层段组成，其中夹有大量泥质砂岩（泥浆）、粉砂岩和薄韵律岩;这些岩性显示滑塌、扭曲层、砂岩岩脉，以及带有滴石的大型原地浊积岩块。在其上部，杂混岩分层，并含有丰富的落石;它在PP-10井（向西）横向通过，进入一个粗化的、向上连续的泥页岩、粉砂岩和滑塌的薄韵律岩。在没有低位体系域（Rio Segredo段）的情况下，上述所有岩相都可以归入海进体系域和高位体系域。在层序TC-II的底部出现了一个不同相和厚度的砂岩层段，可能是一个低位体系域。在RB-3井中，有52米的沟道浊积岩（A3砂岩）覆盖在薄层韵律岩上，并带有冰湖或海洋环境的坠石;在与SL-2井互补的露头剖面中，有40米的河流-三角洲成因的S形砂岩（A2砂岩）。PP-10井开采了4.5m的河流-河口砂岩（A4砂岩），在Vila Ruthes露头剖面（与VR-1井互补），A1砂岩由冰消系统组成，含坠石的泥页岩被三角洲前缘砂岩覆盖。与RB-3井互补的露头剖面由冰消层段组成，层厚10 m，上覆薄层砾岩和砂岩、生物扰动含油气砂岩和页岩，代表海侵体系域。最后，PP-10井对层序TC-II的上部进行了取样：两个向上变粗的阶纹页岩、粉砂岩和韵律岩序列，具有滑塌构造和少量坠岩，形成了层序的高位体系域。
The Taciba Formation constitutes the third major finingupward cycle of Itarare Group, and encompasses three members: Rio Segredo sandstone, Chapeu do Sol diamictite, and Rio do Sul rhythmite, siltstone and shale). In Mafra area, eastern margin of Parana Basin, the Rio Segredo sandstone do not occur, and the Chapeu do Sol diamictite abruptly overlies the Lontras Shale (top unit of the underlying Campo Mourao Formation). The study of four cored wells and complementary nearby outcrops, allowed to identify two depositional sequences for Taciba Formation. In the Vila Ruthes well (VR-1) and outcrop section, the lower, Taciba-I sequence (TC-I) consists of a 65m-thick interval of diamictite with intercalations of massive argillaceous sandstone ( slurry ), siltitstone and thin rhythmite; these lithologies display slumping, contorted beds, sandstone dykes, and also a large, in situ turbidite block with dropstone. In its upper part the diamictite is stratified and contains abundant dropstones ; it passes laterally in well PP-10 (westwards) to a coarsening-upwards succession of varvic shale, siltstone and slumped thin rhythmite. In the absence of a lowstand tract (Rio Segredo Member), all the above lithofacies can be assigned to transgressive and highstand systems tract. A sandstone interval displaying different facies and thicknesses occur at the base of sequence TC-II, possibly as a lowstand systems tract. In RB-3 well there are 52m of channelized turbidites (A3 Sandstone) overlying thin-bedded rhythmites with dropstones of a glaciolacustrine or marine setting; in the outcrop section which complements the SL-2 well, it occurs 40m of sigmoidal sandstones of fluvio-deltaic origin (A2 Sandstone). The PP-10 well recovered 4.5m of fluvial-estuarine sandstone (A4 Sandstone), and in Vila Ruthes outcrop section (complementary of well VR-1) the A1 Sandstone is composed of a deglaciation system with dropstone-bearing varvites overlain by delta front sandstone. The outcrop section which complements RB-3 well is composed of a deglaciation interval with 10m-thick stratified diamictite, overlain by thin stratified conglomerate and sandstone, bioturbated fossiliferous sandstone and shale, representing the transgressive systems tract. Finally the PP-10 well sampled the upper part of sequence TC-II: two coarsening-upward successions of varved shale, siltstone and rhythmite, with slump structures and few dropstones , forming the highstand systems tract of the sequence.