New sedimentological and palynological data from surface Miocene strata in the central Amazonas Basin area

ABSTRACT The scarcity of stratigraphic data has hindered the demarcation of the outcropping area of Miocene deposits of the Amazon Basin, represented informally by the Novo Remanso Formation. Moreover, this unit is characterized by a sparse and irregular geographic distribution due to its sedimentological features and rare fossil content. Miocene deposits cropping out in central Amazonas Basin area were described in sedimentological terms and analyzed palynologically. All analyses were undertaken in samples collected at the Uatumã River banks (Itapiranga and São Sebastião do Uatumã cities). Lithostratigraphic data shows that Novo Remanso Formation consists of sandstones, with subordinate conglomerates and pelites, characteristic of a meandering fluvial paleosystem, with fluvial channel, point bar, floodplain and crevasse splay facies. The palynoflora retrieved from five samples consists exclusively of continental-origin palynomorphs dominated by angiosperms species. Trilete spores are well represented, while gymnosperms pollen grains are minor components. The presence of Psilastephanoporites tesseroporus, Syncolporites poricostatus, Jandufouria seamrogiformis and Polypodiaceoisporites potoniei ensure these deposits fits into the Grimsdalea magnaclavata palynozone (Regali et al. 1974a, b), and the Grimsdalea magnaclavata/Crassoretitriletes vanraadshooveni palynozones of Jaramillo et al. (2011) considered Middle Miocene age. This age is confirmed by the zonation of Jaramillo et al. (2011), based on the LADs of Bombacacidites baumfalki (11.57Ma) and Crototricolpites annemariae (12.91Ma); and the FAD of Psilastephanoporites tesseroporus (14.00Ma). With these new data presented herein, it is possible to assume that the Miocene strata represented by the Novo Remanso Formation covers a larger area in the basin than previously considered, and that it may be extended for about 300 km until the Manacapuru village, indicating a Miocene subsidence phase.

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A taxonomic review of the species of CharaxScopoli, 1777 (Teleostei: Characidae: Characinae) with description of a new species from the rio Negro bearing superficial neuromasts on body scales, Amazon basin, Brazil

Neotropical Ichthyology ◽

10.1590/1982-0224-20130175 ◽

2014 ◽

Vol 12 (2) ◽

pp. 193-228 ◽

Cited By ~ 6

Author(s):

Naércio A. Menezes ◽

Carlos Alberto S. de Lucena

Keyword(s):

New Species ◽

Geographic Distribution ◽

Amazon Basin ◽

Junior Synonym ◽

Museum Collections ◽

Taxonomic Review ◽

Rio Negro ◽

Three New Species ◽

A New Species ◽

Pelvic Fin

The species of Charaxwere reviewed by Lucena (1987) who a little later (1989) added three new species to the genus. Examination of recently collected specimens from museum collections documented the more extensive geographic distribution for most species and revealed the existence of a new species in which superficial neuromasts were discovered and are herein described. These skin structures were also detected in C. metae Eigenmann, 1922. Anal- and pelvic-fin hooks previously observed only on the anal-fin of one species of the genus are described herein in some other species. Charax unimaculatus Lucena is considered a junior synonym of C. michaeli Lucena. All the species are redescribed and the new species described.

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Pollen morphology of Ukrainian species of the genus Pedicularis L. (Orobanchaceae Vent.)

Biodiversity Research and Conservation ◽

10.2478/v10119-011-0021-y ◽

2012 ◽

Vol 24 (1) ◽

pp. 5-13 ◽

Cited By ~ 1

Author(s):

Olena M. Peregrym ◽

Zoya M. Tsymbalyuk ◽

Sergei L. Mosyakin

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Pollen Morphology ◽

Pollen Grains ◽

Taxonomic Revision ◽

Palynological Data ◽

First Time ◽

Scanning Electron

Abstract Pollen grains of 10 species of Pedicularis occurring in Ukraine were investigated using light and scanning electron microscopy. Palynological data on 6 species are reported for the first time. General pollen morphology of the genus Pedicularis is presented. Three types of apertures (2-syncolpate, 3-colpate, and 3-syncolpate) and seven subtypes of sculpture (3-syncolpate pilate, 3-syncolpate microscabrate-tubeculate, 2-syncolpate microscabrate, 2-syncolpate microscabrate-tubeculate, 2-syncolpate microscabrate-tubeculate-perforate, 2-syncolpate microfoveolate, and 2-syncolpate microscabrate-perforate) are indentified. The subgenus Pedicularis is heterogeneous in its types of apertures and sculpture of the surface, which indicates the need of further taxonomic revision of the group.

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Crevasse splays within a lignite seam at the Tomisławice opencast mine near Konin, central Poland: architecture, sedimentology and depositional model

Geologos ◽

10.2478/logos-2020-0002 ◽

2020 ◽

Vol 26 (1) ◽

pp. 25-37 ◽

Cited By ~ 1

Author(s):

Lilianna Chomiak

Keyword(s):

Middle Miocene ◽

Structural Features ◽

Fine Grained ◽

Opencast Mine ◽

Main River ◽

Main River Channel ◽

Lignite Mine ◽

Flooding Event ◽

Crevasse Splay ◽

Sandy Sediments

AbstractThe present article focuses predominantly on sandy deposits that occur within the Middle Miocene lignite seam at the Tomisławice opencast mine, owned by the Konin Lignite Mine. As a result of mining activity, these siliciclastics were available for direct observation in 2015–2016. They are situated between two lignite benches over a distance of ~500 m in the lower part and ~200 m in the higher part of the exploitation levels. The maximum thickness of these sandy sediments, of a lenticular structure in a S–N cross section, is up to 1.8 m. With the exception of a thin lignite intercalation, these siliciclastics comprise mainly by fine-grained and well-sorted sands, and only their basal and top layers are enriched with silt particles and organic matter. Based on a detailed analysis of the sediments studied (i.e., their architecture and textural-structural features), I present a discussion of their genesis and then propose a model of their formation. These siliciclastics most likely formed during at least two flood events in the overbank area of a Middle Miocene meandering or anastomosing river. Following breaching of the natural river levee, the sandy particles (derived mainly from the main river channel and levees) were deposited on the mire (backswamp) surface in the form of crevasse splays. After each flooding event, vegetation developed on the top of these siliciclastics; hence, two crevasse-splay bodies (here referred to as the older and younger) came into existence. As a result, the first Mid-Polish lignite seam at the Tomisławice opencast mine is currently divided in two by relatively thick siliciclastics, which prevents a significant portion of this seam from being used for industrial purposes.

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Taxonomic placement of Millettia occidentalis (Leguminosae, Papilionoideae), a rare liana from the Amazon Basin

Phytotaxa ◽

10.11646/phytotaxa.261.1.3 ◽

2016 ◽

Vol 261 (1) ◽

pp. 75

Author(s):

RODRIGO A. CAMARGO ◽

ANA MARIA G.A. TOZZI

Keyword(s):

Geographic Distribution ◽

Amazon Basin ◽

New Combination ◽

Preliminary Evaluation ◽

Distribution Map ◽

Terra Firme ◽

Conservation Assessment

A new combination is proposed for Millettia occidentalis, a rare liana endemic to a small locality of the Amazon Basin, in Brazil. Morphology and geographic distribution supports its transfer to Deguelia and a specimen at IAN is designated as lectotype. Validation in Deguelia is needed for use in impending floristic treatments, as well as to promote conservation and new field efforts. It occurs in “terra firme” forests (non-flooded), on high lands and appears to be very rare range-wide, based on documented occurrences. Description, illustration, distribution map, some ecological notes and a preliminary evaluation of its conservation assessment are provided.

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The effect of fluvial environments on sediment bleaching and Holocene luminescence ages — A case study from the German Alpine Foreland

Geochronometria ◽

10.2478/s13386-013-0120-y ◽

2013 ◽

Vol 40 (4) ◽

pp. 283-293 ◽

Cited By ~ 7

Author(s):

Patrick Schielein ◽

Johanna Lomax

Keyword(s):

Statistical Modelling ◽

Moderate Degree ◽

Point Bar ◽

Fine Grained ◽

Sedimentary Environments ◽

Fine Grain ◽

Floodplain Deposits ◽

Crevasse Splay ◽

Channel Deposits ◽

Floodplain Sediments

Abstract This study investigates the potential of luminescence to date deposits from different fluvial sedimentary environments; namely point bar deposits, sandy and silty channel fills and floodplain sediments. Samples were taken from Holocene (<5 ka) terraces of the Lech and Danube rivers, for which independent age constraint is available through 14C ages, archaeological data and historical maps. OSL-ages were obtained using small aliquots of coarse grain quartz for the majority of samples. Two further samples were dated by the IRSL-signals of polymineral fine grain extracts, as no sufficient number of coarse grains could be extracted from these sediments. In order to detect and ac-count for incomplete bleaching, we used the decision process suggested by Bailey and Arnold [Statistical modelling of single grain quartz De distributions and an assessment of procedures for estimating burial dose. Quaternary Science Reviews 25, 2475–2502, 2006]. Although their model was designed for single grains of quartz, our study shows that it is also applicable to multiple grains of quartz, pro-vided that a low number of luminescent grains is present on one aliquot. Luminescence ages of point bar deposits and a sandy channel fill correspond most closely to the independent age control. In the floodplain, sand-striped floodplain channel deposits were incompletely bleached to a moderate degree, yielding ages with acceptable overestimations, while fine-grained floodplain deposits were worst bleached. One crevasse splay deposit was so severely incompletely bleached that none of the age models was able to yield accurate ages.

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Interpretasi Lingkungan Pengendapan Formasi Batuan Menggunakan Analisis Elektrofasies di Lokasi Tapak Puspiptek Serpong

EKSPLORIUM ◽

10.17146/eksplorium.2017.38.1.3538 ◽

2017 ◽

Vol 38 (1) ◽

pp. 29

Author(s):

Heri Syaeful ◽

Adi Gunawan Muhammad

Keyword(s):

Depositional Environment ◽

Gamma Ray ◽

River System ◽

Shape Variation ◽

Point Bar ◽

Meandering River ◽

The North ◽

Rock Formations ◽

Subsurface Material ◽

Crevasse Splay

ABSTRAKKegiatan karakterisasi material bawah permukaan penyusun pondasi tapak merupakan bagian dari studi tapak instalasi nuklir. Karakterisasi dilakukan dengan berbagai metode, diantaranya pemahaman tentang sistem pengendapan formasi batuan. Sebagai bagian dari metode interpretasi lingkungan pengendapan, analisis pemodelan fasies berdasarkan elektrofasies memberikan informasi yang cepat mengenai sistem pengendapan suatu formasi batuan. Metodologi yang digunakan adalah dengan interpretrasi log sinar gamma (log GR) menggunakan korelasi relatif antara variasi bentuk log dan fasies sedimentasi. Berdasarkan analisis diketahui Formasi Bojongmanik terbentuk pada lingkungan marine-lagoonal dengan pengaruh gelombang sangat rendah. Log GR yang menunjukan bentuk funnel, bergerigi dan simetris, mengindikasikan fasies shoreface, lagoon, dan tidal point bar. Arah sedimentasi, cekungan, dan suplai pada pengendapan sedimen Formasi Bojongmanik diinterpretasikan relatif ke utara. Formasi Serpong diendapkan pada sistem sungai bermeander dan tersusun atas endapan point bar, crevasse splay dan floodplain. Hasil analisis ini diharapkan dapat menjadi panduan dalam analisis lanjutan terkait karakterisasi material pondasi. ABSTRACTThe activity of subsurface material composing site foundation characterization is part of nuclear installation siting study. Characterization conducted by several methods, such as understanding the depositional environment of rock formations. As a segment of depositional environment interpretation method, facies model analysis based on electrofacies provides quicker information on depositional system of rock formation. Methodology applied is gamma ray log (log GR) interpretation using relative correlation between log shape variation and sedimentation facies. Based on the analysis, Bojongmanik Formation was deposited on marine-lagoonal environment with very low wave influence. Log GR that shows shape of funnel, serrated, and symmetry, indicate shoreface, lagoon, and tidal point bar facies. The direction of sedimentation, basin, and supply of Bojongmanik Formation interpreted relatively to the north. Serpong Formation deposited on meandering river system, and composed of point bar deposit, crevasse splay, and floodplain deposit. The result of analysis is expected to be guidance in further analysis related to the characterization of foundation materials.

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First record of Selaginella conduplicata Spring (Selaginellaceae) in the Brazilian Atlantic Forest, Northeastern Brazil

Check List ◽

10.15560/16.5.1283 ◽

2020 ◽

Vol 16 (5) ◽

pp. 1283-1287

Author(s):

Luiz Armando de Araújo Góes-Neto ◽

Alexandre Salino

Keyword(s):

Atlantic Forest ◽

Geographic Distribution ◽

Amazon Basin ◽

Conservation Status ◽

First Record ◽

Northeastern Brazil ◽

Brazilian Atlantic Forest ◽

Diagnostic Characters ◽

Brazilian Northeast ◽

Present Description

This is the first voucher-based record of Selaginella conduplicata Spring in the Brazilian Atlantic Forest and the Brazilian Northeast. This species was considered restricted to the Amazon Basin, and here we report its occurrence beyond the Amazonian limits, expanding its distribution. Illustrations of the diagnostic characters of the species, information of geographic distribution and conservation status are presented. Besides, we present description as well as taxonomic and nomenclatural comments.

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Multidisciplinary palaeoenvironmental characterisation of the late Permian Matinde Formation, Mozambique

10.5194/egusphere-egu21-1128 ◽

2021 ◽

Author(s):

Gilda Lopes ◽

Zélia Pereira ◽

Paulo Fernandes ◽

Márcia Mendes ◽

João Marques ◽

...

Keyword(s):

Pollen Grains ◽

Depositional Environments ◽

Phase Correlation ◽

Late Permian ◽

Palynological Data ◽

Coal Beds ◽

Palynological Assemblages ◽

Southern Central ◽

Flooding Events

The Muar&#225;dzi Sub-basin is part of the Moatize-Minjova Basin (MMB), an important Karoo aged coalfield in Tete Province, Mozambique. It is a WNW-ESE trending, elongated sedimentary basin located in the eastern part of the MMB, whilst during the late Permian was situated in the southern-central part of Gondwana. In this study, we undertook a multidisciplinary approach involving the lithological, palynofacies, and palynological analysis of samples collected from 3 coal exploration boreholes (DW11, DW21, and DW141) collected from this sub-basin. A total of 99 core samples were collected and studied, allowing for the characterisation of depositional environments and existing palaeofloras for this sub-basin.The palynological data indicates that all the successions have a Lopingian age, and a vast lowland fluvial setting existed in an area controlled by tectonic movements associated with a continental rifting phase. Correlation between the three sections enabled the recognition of an initial meandering fluvial system affected by repeated flooding events that changed to a braided river. The palynofacies corroborate the interpreted fluvial model and the palynological record obtained.The existence of a humid and warm climate during the Lopingian led to the development of vast floodplains and diversified wetland types, typical of lowland settings recorded in the analysed samples. The palynofacies analysis also indicate that the thick coal beds&#8217; development is associated with deposition in anoxic to dysoxic environments. Furthermore, the Glossopteris Province vegetation, responsible for the coal development in the Muar&#225;dzi Sub-basin, is documented in the palynological assemblages, allowing for the characterization of a flora dominated by glossopterids (Protohaploxypinus and Striatopodocarpites) and gymnosperm pollen (Alisporites). The palaeofloral analysis based on palynological data also shows that associated ferns (e.g., Osmundidacites senectus, Thymospora pseudothiessenii), sphenophytes (e.g., Calamospora) and lycophytes (e.g., Lundbladispora, Kraeuselisporites) were common in this area. Additionally, upland vegetation indicators in the palynological assemblages, as monosaccate pollen grains, are rare, indicating that upland regions were distant from the studied sections.&#160;AcknowledgementsThis research was fully supported by the project PALEOCLIMOZ (PTDC/CTA-GEO/30082/2017), funded by Funda&#231;&#227;o para a Ci&#234;ncia e Tecnologia, Portugal. The authors would also like to acknowledge the financial support of the Portuguese Foundation of Science and Technology (FCT) to CIMA through UIDP/00350/2020.&#160;

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Seismically induced soft-sediment deformation in crevasse-splay microdelta deposits (Middle Miocene, central Poland) – reply

Geological Quarterly ◽

10.7306/gq.1477 ◽

2019 ◽

Vol 63 (2) ◽

Author(s):

Lilianna CHOMIAK ◽

Piotr MACIASZEK ◽

Robert WACHOCKI ◽

Marek WIDERA ◽

Tomasz ZIELIŃSKI

Keyword(s):

Middle Miocene ◽

Soft Sediment ◽

Central Poland ◽

Sediment Deformation ◽

Soft Sediment Deformation ◽

Crevasse Splay

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Facies architecture of fluviatile deposits of the Jurassic-Cretaceous Bertangga Formation, Peninsular Malaysia

Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen ◽

10.1127/njgpa/2020/0943 ◽

2020 ◽

Vol 298 (2) ◽

pp. 177-195

Author(s):

Hassan Baioumy ◽

Chong Jing Ting ◽

Sherif Farouk ◽

Khaled Al-Kahtany

Keyword(s):

Depositional Environment ◽

Facies Analysis ◽

Flow Direction ◽

Volcanic Rocks ◽

Peninsular Malaysia ◽

Carbonaceous Shale ◽

Point Bar ◽

Facies Associations ◽

Crevasse Splay ◽

Floodplain Sediments

Bertangga Formation is a part of the Jurassic-Cretaceous non-marine sequences in Thailand and Malaysia. However, its facies analysis and depositional model have not been investigated in detail. Eleven lithofacies have been described in the Bertangga Formation and combined five facies associations including channel, point bar, floodplain, crevasse splay and swamp facies associations. Channel deposits are stacked bodies of fining upward sequences with prevalent erosional bases, formed by vertical aggradation and avulsion of channels. Point bar sands comprise cross bedded sandstone bodies formed in upper flow regime and possible lateral accretion surfaces. Crevasse splay deposits form sheets of fine-to-medium-grained sandstone. Floodplain sediments are composed of motteled grey mudstone. Swamp depositional environment is characterized by an association of coal, carbonaceous shale and siltstone. Facies analysis allows reconstruction of the depositional environment of the Bertangga Formation as a meandering fluvial system. Facies association also shows the increasingly distal and fine-grained trend from west to east of the studied area, which suggests possible eastward paleo-flow direction of the river. The existence of kaolinite in all samples indicates weathering of felsic rocks under acidic conditions. In the same time, the presence of smectite in the eastern part of the study area may suggest a contribution of mafic and/or volcanic rocks to the source of sediments in this area.

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