# Palynology and geochemistry of the Frasnian global transgression in the Parnaíba Basin, Brazil

P Steemans, E Pereira, A Le Hérissé, Y Grahn, M Streel, M Brito, S

Bergamaschi, R Rodrigues

► To cite this version:

P Steemans, E Pereira, A Le Hérissé, Y Grahn, M Streel, et al. Palynology and geochemistry of the Frasnian global transgression in the Parnaíba Basin, Brazil. Review of Palaeobotany and Palynology, 2021, 284, pp.104345. 10.1016/j.revpalbo.2020.104345. hal-05251255

HAL Id: hal-05251255

https://hal.univ-brest.fr/hal-05251255v1

Submitted on 12 Sep 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Palynology and geochemistry of the Frasnian global transgression in the Parnaiba Basin, Brazil

Steemans P. <fnref n="1" />,*, Pereira E. <fnref n="2" />, Le Herisse A. <fnref n="3" />, Grahn Y. <fnref n="4" />, Streel M. <fnref n="1" />, Brito M. <fnref n="2" />, Bergamaschi S. <fnref n="2" />, Rodrigues R. <fnref n="2" />

## Abstract :

An integrated palynological and geochemical approach has been initiated to date and to precise the geochemical events of the Pimenteiras Formation, in the Late Devonian from the Parnaiba Basin, Brazil. Based on good biostratigraphic markers and presence of index species among miospores, acritarchs and chitinozoa, the investigated sequences are referred to the Middle to early Late Frasnian. Among Miospores, Chelinospora concinna and Verrucosisporites Witt-eras are likely to be from the BPi Interval Zone defined in the Amazon Basin. Chitinozoans of the Early to early Late Frasnian Angochitina (Lagenochitina) avelinoi zone of the Parnaiba Basin are present, and acritarch assemblages are also consistent with a Middle to early Late Frasnian age, by comparison to assemblages previously described in other Brazilian basins. Some important accompanying species of palynomorphs are illustrated. In the studied outcrops, black shale intervals are referred to top of the Radioactive Sale B and Radioactive Shale C according to Rodrigues (1995) definitions. Top of Radioactive Shale B shows good concentration of terrestrial organic matter, but low potential source of gas. By comparison Radioactive Shale C of the upper part of the Pimenteiras Formation, with important concentration of marine organic matter have low to high potential as source of gas and condensate. This study shows that a progressive flooding took place during the Devonian period in the Parnaiba Basin with maximum marine transgression in the Frasnian. These global events of interest for hydrocarbon exploration, are regarded as markers for Gondwanan regional chronostratigraphic correlations. (C) 2020 Published by Elsevier B.V.

## Highlights

* Miospores, acritarchs and chitinozoans are relatively abundant and well preserved. * Palynomorphs provide a concordant age corresponding to the mid-Frasnian. * Miospores are correlated with the

<footnote n="1">¹ EDDy/Palaeopalynology, Allée du six Août 14, Bât B-18, University of Liège, B-4000 Liège, Belgium</footnote>

<footnote n="2">² Department of Stratigraphy and Paleontology, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, Bloco A, Sala 4030, Maracanã, Rio de Janeiro 20559-900, Brazil</footnote>

<footnote n="3">³ University of Brest, UMR 6538 CNRS «Domaines océaniques», IUEM, CS 93837, rue Dumont D'Urville, 29280 Plouzané, France</footnote>

<footnote n="4">⁴ Calle Azucena 10, 29680 Estepona, Spain</footnote>

<footnote>* Corresponding author : P. Steemans, email address : p.steemans@ulg.ac.be</footnote>
conodont biostratigraphic scale from the Boulonnais. ► Palynomorphs are characteristic of the Gondwana and more precisely from Brazil. ► Effective generation of hydrocarbon is dependent of the igneous effect.

**Keywords** : Miospores, Acritarchs, Chitinozoan, Geochemistry, Frasnian, Brazil
# 1. Introduction

The Brazilian Palaeozoic basins contain thick Devonian shaley sections. These sections often display interlaminated mudstones/siltstones/very fine sandstones deposited in offshore conditions. The chronology of Palaeozoic sea-level changes suggested by Haq and Schutter (2008) demonstrated that a new long-term sea-level rise began in the Middle Devonian and reached its peak in the early Late Devonian (Frasnian). In the Parnaíba Basin, black-shale intervals with relatively high Total Organic Carbon (TOC) values (> 4.0%) are frequently detected in the Devonian section. These geochemical signatures are likely related to the Late Devonian worldwide transgression described in the literature (Lüning et al., 2004; Souza et al. 2013, Bond and Wignall, 2008; Trindade and Carvalho, 2018). Therefore, the present work intends to describe the TOC content excursions recorded in the Devonian section of the Parnaíba Basin and date these excursions by means of palynology, to fit the intervals to the global sea-level curve.
The complementary geochemical data used in this work detailed has made possible for a better understanding of the control of the anoxic / dysoxic conditions of the organic matter preservation, which would typically have taken place within the flooding surfaces associated with the transgression events. In the Devonian section of the Parnaíba Basin, these surfaces— which show the highest TOC content and the highest Hydrogen Index (HI)—represent the most important hydrocarbon generation intervals.

Rodrigues (1995) identified three potentially generating shale intervals within the Pimenteiras Formation, calling them Radioactive Shales A, B and C. According to Rodrigues (1995), the Radioactive Shale A is positioned approximately at the Eifelian / Givetian boundary; has a maximum thickness of 20 m and exhibits TOC contents ranging from 1.0 to 3.0% and contains type III organic matter. The Radioactive Shale B, Middle Givetian in age, has a maximum thickness of 20 m, TOC contents ranging from 1.0 to 3.5% and type II and III organic matter. According to Rodrigues (1995), the Radioactive Shale C, deposited during the Frasnian, is correlatable to the main source rock intervals in the Solimões (Jandiatuba Formation) and Amazonas (Barreirinhos Formation) basins. It is the main interval of radioactive shale layer in the basin, reaching a thickness of 40 m. It has TOC contents ranging from between 1.0 and 5.0% and type II organic matter.

The gas accumulations related to these intervals in the Parnaíba Basin normally display a dry composition. Dry composition is normally indicating a generation at high maturation stage. However, in Parnaíba Basin, this condition is not reached by burial, suggesting an atypical process of generation related to the heat effect of dolerite intrusions (Rodrigues, 1995; Rodrigues et al., 1995, 2012; Zambrano et al., 2017; Miranda et al., 2018; Cioccari and Mizusaki, 2019).
The palynological samples has revealed a rich assemblage of acritarchs, chitinozoans and miospores. Despite their relative abundance, they all agree with regard to dating the geochemichal events of an equivalent Frasnian age. New observations in Brazil and new data from the Boulonnais Area, Northern France (Streel et al., in press) have made it possible to correlate the Brazilian outcrops with the European conodont zones and therefore with the stratotypes of the Frasnian.

Finally, for the first time, a high precision palynological study has dated the most important source rock intervals of the Parnaíba Basin, the geochemical aspects of which have been described in detail. These integrated results are particularly important and will greatly contribute to more precise future basin modelling studies.

## 2. Geological background

### 2.1. Overview

The Parnaíba Basin is currently distributed over an approximately circular area, with about 600,000 km² of which is located in north-eastern Brazil (Fig. 2), where it covers part of the states of Piauí, Maranhão, Tocantins, Pará, Ceará and Bahia (Pereira et al., 2012). Due to its great stratigraphic similarity with other basins (Gabon, Ghana, Northeast Brazil), some researchers (Milani and Thomaz Filho, 2000; Almeida and Carneiro, 2004; Pereira et al., 2012) suggest that the depositional basin scenario could have occupied an area two to three times greater than the basin's current area during the Palaeozoic era. The thickness of the sedimentary column is about 3,500 m in the depocenter, while the average thickness of the basin is about 2,000 m.

### 2.2. Stratigraphic framework
Kegel (1953) was the first to suggest the Late Devonian age for sediments in the Parnaíba Basin. These sediments make up the upper part of the Pimenteiras, Cabeças, and lowermost Longá formations (Góes and Feijó, 1994; Grahn et al., 2006). The Pimenteiras Fm (than Member) was established by Small (1914) for a 20 m thick shale sequence near the town of Pimenteiras, in the State of Piauí. Plummer (1948) divided the Pimenteiras Formation into an upper sandy member and a lower shaly member. Andrade and Daemon (1974) assigned a Late Eifelian to Late Famennian age span to the Pimenteiras Formation, whereas Loboziak et al. (2000) do not consider the fully developed part of the top of the unit to be younger than Early or Middle Famennian. The upper part of the formation is partly developed into finely laminated and radioactive dark shale which are best developed in the subsurface of the basin and only exposed in outcrops on its western margin (Loboziak et al., 2000). The maximum thickness of the formation is over 500 m in the central part of the basin. A gap corresponding to the Late Givetian and earliest Frasnian is present all over the basin, and the upper part of the Pimenteiras Formation is entirely of Late Devonian age (Rodrigues et al., 1995; Grahn et al., 2006). This younger interval of the formation is hitherto unknown in the eastern outcrop belt of the Parnaíba Basin (Melo, 1988). Similar ages for the upper levels of the Pimenteiras Formation were also obtained recently by Andrade et al. (2009) on the western edge of the basin.

The overlying Cabeças Formation was established by Plummer (1948). Beurlen (1965) included its lowermost part in the Pimenteiras Formation, and Aguiar (1971) placed the upper part in the overlying Longá Formation. The Cabeças Formation is here treated in its original sense (Melo and Loboziak, 2003; Grahn et al., 2006) as defined in its type area near Dom Expedito Lopes (formerly the town of Cabeças), State of Piauí. Daemon (1974) and Andrade and Daemon (1974) found evidence placing the formation in the western part of the Parnaíba Basin in the Late Famennian age. Throughout the basin an erosional hiatus separates the latest
Famennian glaciogenic strata of the upper Cabeças from variably older sediments belonging to the Pimenteiras and lower Cabeças formations, and towards the western margin the former also overlap directly onto metamorphics of the Precambrian basement (Loboziak et al., 2000). The lithology in the lower Cabeças lacks diamictites and differs from the Pimenteiras Formation in that it has a higher content of sandstone beds. In its upper part the Cabeças Formation features a regressive progradation and fast intergradation of alluvial fan, fan delta and fan delta front systems and glacial lobes at the top (Caputo and Crowell, 1985). The maximum thickness (on the eastern flank of the basin) is about 300 m. While no in-situ fossils older than the Famennian have been established in the Cabça Fm, shelly faunas from the Middle Devonian occur in outcrops traditionally attributed to the lowest part of the formation along the eastern margin of the basin (Melo, 1988). These fossiliferous sandstones correspond to Kegel's (1953) "Passagem Member", now dated as late early or middle Givetian by Breuer and Grahn (2011), and consist of alternating hempestites, and sigmoidal lobes that are genetically related to the Pimenteiras Formation. The Longá Formation was introduced by Albuquerque and Dequech (1950) for a section in the valley of the Longá River, and along the road between Campo Maior and Castelo in the State of Piauí. Kegel (1953) and Lange and Petri (1967) considered it Frasnian in age. Kegel (1953) reported a shelly fauna, including rare Malvinokaffric elements (Melo, 1988), and possible tentaculitids in basal Longá Formation outcrops at the Barreiras Farm, on the eastern flank of the basin. Malvinokaffric faunas became extinct during the early Givetian (Bosetti et al., 2011), and tentaculitids are unknown later than the Frasnian. However, closer inspection of the latter (Melo in Grahn and Melo, 2005) revealed that the alleged "tentaculitids" are in fact serpulitid worm tubes characterized by annular structures. The lower (latest Famennian) part of the Longá Formation (lateral facies to the uppermost Cabeças Fm.) features rhythmites including micaceous, sideritic and well laminated greenish-grey shale with bioturbated interbedded
siltstone. The formation above (Tournaisian) contains argillaceous, cross-laminated sandstones with conglomeratic horizons, and silty shales and siltstones in the upper part. The total thickness of the formation is about 150 m (Caputo, 1984). Reworked palynomorphs were found in the lower Longá Formation, in the central and western parts of the basin. This corresponds to chitinozoans occurrences likely to have been reworked and which were reported by Cruz (in Lima and Leite, 1978) from the Valença do Piauí region, on the eastern flank of the Parnaíba Basin.

**3. Material and methods**

The samples that support the geochemical and palynological analysis of this study were collected from outcrops located on the western boundary of the Parnaíba Basin.

The samples were collected from outcrops along the roads in Tocantins State (Fig. 1). Three outcrops (sites 10, 11, 12) were described in detail at the edge of the road and were stratigraphically positioned (Fig. 2), producing a composite stratigraphic section of around 70 meters. Fourteen samples were collected from these sections in the Pimenteiras Formation. In an additional 20 metre thick section (Site 35) of the Pimenteiras Formation thirty-one samples were collected (Fig. 3). Twelve other samples were collected in site 37 (Fig. 4). They are distributed as follows in the sites: Site 10: samples 5-8; Site 11: samples 9-12; Site 12: samples 13-18; Site 35: samples 48-78; Site 37: samples 80-91. All the samples were processed for geochemical (Tbl. 1) and palynological analysis.

Before sending the samples for TOC and Rock-Eval pyrolysis analyses, they were macerated and powdered at 80 mesh (0.177 mm), and then acidified with hydrochloric acid, for removal of carbonates.

The TOC of the samples was obtained via Leco SC-632 equipment and reported as a relative weight percentage of the original sample. The Rock-Eval pyrolysis analyses were
made in a Vinci Technologies pyrolyzer, in accordance with the procedures of Espitalié et
al. (1977). The S1 (free liquid hydrocarbons present in the rock, in mg HC/g rock); S2
(hydrocarbon generating potential of the organic matter present in the rock, in mg HC/g rock);
S3 (CO2 generated by the organic matter present in the rock, in mg CO2/g rock) and Tmax
(maximum hydrocarbon generation temperature in °C, measured at the maximum height of
the S2 peak) were then read. The hydrogen indices [HI = (S2/TOC)×100, in mg HC/g TOC]
were also calculated.

The geochemical analyses were carried out in the Laboratory of Chemical Stratigraphy and Organic Geochemistry of the Faculty of Geology of the Rio de Janeiro State University.

All samples were also processed for palynological studies. This processing was
performed by Palynological Laboratory Services, U.K. The samples were first scraped and
washed before being crushed to <1mm fragments. A weight of 35g was then used for
processing.

Samples were treated with 20% hydrochloric acid (HCl) until any reactions had ceased. The samples were then left in the HCl for approximately one hour, to ensure that carbonate digestion was complete. They were then topped up with water and allowed to settle for at least one hour, after which time they were decanted. This stage was repeated to bring the samples to a neutral pH.

Samples were then treated with 40% hydrofluoric acid (HF) and warmed on a hotplate at 50°C for two hours. Next, they were removed from the hotplate and left in the HF for approximately 12 hours to complete the silicate digestion, during which time they were stirred occasionally.

Samples were then topped up with water and sieved over a 10-micron sieve cloth; the
collected fraction was brought to a neutral pH and placed in a Pyrex glass beaker. The
samples were then simmered on a hotplate at 100°C for approximately 1 hour, before being
topped up and re-sieved over the 10-micron sieve. The residue was collected and brought to a
neutral pH.

The residues were then re-sieved to separate and provide a 10-53µ and a >53µ
fraction. The >53µ was then placed in a glass vial, as this would not require any oxidation. A
representative sample of the 10-53µ residue was placed in a glass vial to provide a kerogen
(pre oxidation) slide.

Most of the samples required a short period of cold concentrated nitric acid, ranging in
time from 5 minutes to 10 minutes. One or two of the samples required a very short sonication
of about 10 seconds, to reduce the amount of organic amorphous residue present.

Both the 10-53µ and >53µ fractions were mounted in Norland Optical adhesive No61.
The slides are housed at the University of Liège, Department of Geology, EDDy
Lab/Palynology.

The different palynomorphs observed during this study have been photographed and are illustrated on plates I to XV. They have been grouped by biological affinities: acirtarchs (Pl. I-II), chitinozoans (Pl. III-IV) and miospores (Pl. V-XV). A list of all species with their author(s) is provided in the appendix.

In accordance with the recommendations of the Subcommission on Devonian stratigraphy, Newletter N° 22 (2007, p.2), in this paper we used the subdivision of the Early Frasnian into Early and Middle Frasnian, to replace of Early and late Early Frasnian.

**4. Results and discussion**

**4.1. Geochemistry data**

According to Rodrigues' (1995) definitions, the geochemical characteristics (Tbl. 1) of
the lithological and sedimentological aspects of the outcrops studied (Fig. 2-4), allow for the
recognition of the top of Radioactive Shale B in sites 10 and 37. The Radioactive Shale C—of
the lower part of the upper Pimenteiras Formation—is recognised in site 12 and in the totality of the section recorded in site 35, as well as in the shales of the upper part of the Pimenteiras Formation in site 11. Theses radioactive shales were originally described by Rodrigues (1995) using geochemistry data and log profiles from wells located in the center of the Parnaíba Basin.

The top of Radioactive Shale B, recorded in site 10, and the lower part of site 37, is characterised by a TOC of around 1%, which implies a good concentration of organic matter. In most of the samples, the S2 values of between 0.69 and 3.00 mg HC / g rock, and the hydrogen index of between 70 and 200 mg HC / g COT, indicate a low source potential for gas.

The data of the hydrogen index shows that, in thermally immature samples (values of Tmax ≤ 435 °C), the organic matter ranges from type IV to type III. This suggests the predominance of degraded terrestrial organic matter according to Jones (1987). This interpretation concurs with the works of Rodrigues (1995) and Rodrigues et al. (1995), who concluded that the shales below Radioactive Shale C are characterised by a greater influence of higher plants in terms of organic matter composition.

The radioactive Shale C was recorded in sites 12 and 35 and the middle section of site 37. This interval is characterised by TOC contents of 1.0 to 6.95%, implying a moderate to high concentration of organic matter. The S2 values of between 1.17 and 11.28 mg HC / g rock, and the hydrogen index of between 100 and 336 mg HC / g COT, indicate a low to high potential source of gas and condensate.

Considering that the samples are thermally immature (values of Tmax < 430 °C), the hydrogen index data suggests that the organic matter of this interval is heterogeneous, showing a mixture of type IV to type II. However, the literature (Rodrigues, 1995; Rodrigues et al., 1995) shows that the organic matter of Radioactive Shale C is predominantly composed of marine algae. As marine organic matter predominates, it is possible to infer that the lower
values of the hydrogen content are casually related to the higher proportion of oxidised
organic matter. As the radioactive shales C contains the highest proportion of marine organic
matter and the highest total organic carbon contents (sites 12 and 35)—when compared to the
Radioactive Shale B and to the upper shales of the Pimenteiras Formation—it can be
concluded that they may represent deposits related to the maximum marine flood surface
(Rodrigues, 1995) and may therefore represent deeper and more distal areas of terrestrial
organic matter influx.

The shales of the upper part of the Pimenteiras Formation are recorded in site 11,
where they come into contact with the Cabeças Formation. The total organic carbon contents
range from 1 to 2%, representing a high concentration of organic matter. The S2 values of
between 2 and 5 mg HC / g rock, and the hydrogen content of between 150 and 230 mg HC /
g COT, characterise a moderate potential source of gas.

Since the samples analysed are less thermally developed (values of Tmax < 430 °C), the
values of the hydrogen index—at around 150 mg HC / g COT—characterise a predominance
of type III organic matter. This aligns with the findings of Rodrigues (1995) and Rodrigues et
al. (1995), which describe a greater proportion of higher plants in the composition of the
organic matter of the shales above the Radioactive Shale C.

The geochemistry results indicate that the Radioactive Shale B of the Pimenteiras
Formation—recorded in the outcropping—exhibit a good concentration of terrestrial organic
matter, with a low potential source of gas. The Radioactive Shale C of the Pimenteiras
Formation, described in sites 12 and 35, has a good to excellent concentration of marine
organic matter and is a low to high potential source of gas and condensate. Lastly, the shales
of the upper part of the Pimenteiras Formation, recorded in site 11, show a moderate
concentration of terrestrial organic matter with a moderate potential source of gas. However,
the pyrolysis analysis shows that the organic matter contained in the Pimenteiras Formation is thermally immature in all outcrops studied in the southwestern area of the Parnaíba Basin.

## 4.2. Acritarchs and other microalgae (fig. 5)

Müller's (1962) palynozonal scheme, based on the combination of major palynomorph groups (acritarchs, miospores and chitinozoans) for the Silurian-Mississippian interval of the Parnaíba Basin in northeastern Brazil, represents the first attempt at dating the pre-Tertiary sedimentary sequence. Müller's pioneering work was followed by other palynological investigations and the proposition of regional zonation by Etna (1967b, 1971); Andrade and Daemon (1974); Daemon (1974, 1976); and Quadros (1982, 1988). Since that time, these studies have remained largely unrevised. However, the opportunity offered by a long collaboration with Petrobras in recent years, based mostly on the study of subsurface materials, has enabled us to systematically analyse acritarch assemblages from the Amazon, Parnaíba and Solimões basins, to define biostratigraphic subdivisions based on these marine and possibly freshwater planktonic microfloras, and to evaluate their stratigraphic value for the Palaeozoic succession in comparison with chitinozoans and miospores. This work is, for the most part confidential. With the experience acquired is used here to discuss the biostratigraphic dating of the outcrops analysed, complementing the data and chitinozoans and miospores.

Acritarchs and other microalgae are well represented in the samples studied, even though miospores are dominant in some samples. A total of 70 species have been identified (see list in the appendix). Among those definitively identified, are some characteristic species of the Late Devonian. The data obtained enables the subdivision of that interval into two assemblages: the oldest from the Middle to earliest Late Frasnian age; the youngest from the early Late Frasnian age. The palynological results with acritarchs are correlated and largely
calibrated by available miospores and chitinozoans zonations (Melo and Loboziak, 2003; Grahn et al., 2006) in use in the same regions. As previously mentioned, we take account of the recent subdivision of the Early Frasnian, into Early and Middle Frasnian. This has affected the dating of the local Bpi miospore Zone of Melo and Loboziak (2003), with the upper part now being referred to as the Middle Frasnian instead of late Early Frasnian. This data makes it possible to correlate the assemblages, including acritarchs and prasinophytes, with Late Devonian assemblages documented from the Amazonas Basin (Le Hérissé, 2001), and other regional studies providing information of the stratigraphical distribution of some species (Brito and Quadros, 1984; Oliveira and Burjack, 1996; Oliveira and Burjack, 1997; Quadros, 1997). We also refer to the unpublished thesis by Oliveira (1997) and unpublished personal data. The difficulty lay in working with different outcrops, since we have observed variations in the suites of acritarchs and other microalgae on a site by site basis —suggesting some variations in their biostratigraphy, as previously suggested from the study of miospores. However, the first occurrence of some species, and the associations of species within the different sites, has allowed us to suggest quite an effective resolution in the biostratigraphic analysis.

### 4.2.1 First assemblage

A first assemblage of the Middle to earliest Late Frasnian age is suggested, in the material studied. This is due to the association of the following species—*Crucidia camirense* (Pl. 1, fig. 7), *Duvernaysphaera cruciformis* nov. sp. (Pl. 1, figs 14-16), *Leiofusa bisubulata* (Pl. 2, fig. 6), *Mediocorpore conspicuus* (Pl. 2, fig. 1), *Petrovina connata* (Pl. 1, fig. 5), *Pseudolunulidia micropunctata* (Pl. 1, fig. 8) and *Puteoscortum limai* (Pl. 2, fig. 5)—in sites 10 and 12, and to the occurrence of *Leiofusa bisubulata*, *Mediocorpore conspicuus*, *Pseudolunulidia micropunctata* and *Puteoscortum limai* in the lower two-thirds of site 35.
Comparisons and correlations were made with coeval assemblages known to exist within subsurface successions in the Parnaíba and Amazon basins (Le Hérissé unpublished data).

*Leiofusa bisubulata* which we used in association with other species represented here to characterise the Middle Frasnian is an index species of interest in the eponymous zone. This zone existed prior to the Late Frasnian and overlaps with it and is marked by a consistent occurrence of *Maranhites* spp. with internal dots. The first specimens of this group appear sporadically in the upper part of the *Leiofusa bisubulata* zone.

The *Leiofusa bisubulata* Interval Zone encompasses the main part of the radioactive shale interval of the Parnaíba Basin (Frasnian anoxic event or Rodrigues, 2001; Rodrigues et al., 1995), with equivalents in the lower Frasnian of the Amazonas Basin (Barreireinha Formation). However, even though good components of the radioactive shales, such as the large Tasmanites and leiospheres are well represented in some samples, such as in site 12 but also higher, we never have an over-representation of these elements compared to the Amazonas basin. This fact along with some of the other biostratigraphical results detailed below, might suggest that we are above the interval with a maximum of radioactive shales.

The occurrence of *Crucidia camirense* and *Petrovina connata* at the base of site 10 suggests that these samples are not of earliest Frasnian age. This is because the oldest records of the two species are in the upper part of the *Leiofusa bisubulata* biozone in other sections of the Parnaíba Basin (based on unpublished data), and this is also reflected in the reference core RSP-1 of the Paraná Basin, where *Petrovina connata* was defined (Burjack and Oliveira, 1996).

Important additional species in the first interval, which were distinguished in this study include: *Advenasphaeridium australis* (Pl. 2, fig. 4), *A. acerosum*, ?*Chomotriletes* sp. (a new form, Pl. 2, figs 7-9), *Diaphorochroa gracile* (Pl. 2, fig. 11), *Duvernaysphaera cruciforme* nov. sp. (Pl. 1, figs 14-16) associated with *D. angelae/tessella* (Pl. 1, figs 17) and
well represented, *D. radiata* (Pl. 2, fig. 2), *D. tenucingulata*, *Estiastra spinireticulata* (Pl. 2, fig. 16), *Exochoderma arca*, *Geron elegans*, *Hemiruptia legaultii*, *Leiofusa fastidiona*, common *Maranhites* (without dots) with *Maranhites brasiliensis* (Pl. 1, fig. 1), *M. lobulatus*, *M. magnus*, *M. primus*, *M. stockmansii* (Pl. 1, fig. 3), some *Navifusa bacilla* (Pl. 1, fig. 9) with the crescentic variants and the long and fine *N. bacilla* var. *procera*, *Naevisphaeridium sprucegrovenense* (Pl. 2, fig. 12), *Polyedryxium fragosulum*, *P. pharaone*, *Pterospermopsis pernambucensis*, *Tinacula simplex* (Pl. 2, fig. 19), *Umbellasphaeridium deflandrei* (Pl. 1, fig. 11), *U. saharicum*, *Unellium ampullium* (Pl. 2, fig. 10), *U. piriforme* and some triapsidate *Veryhachium*.

### 4.2.1.1. Correlation with previous regional zonation

In the Parnaíba Basin, the *Leiofusa bisi bata* zone encompasses the combined upper part of the *Samarisporites triangulatus* (Lrg), which is not represented here, the *Verrucosisporites bulliferus*-*Geminospora piliformis* (Bpi) and the lower part of the *Rugospora bricei*-*Diducites mucronatus* (BMu) miospore zones of Melo and Loboziak (2003). It corresponds to the *L. avetunoi* chitinozoan zone (Grahn et al., 2006). The higher part of the local Bpi miospore zone is now reassigned to the Middle Frasnian. The Early to early Late Frasnian strata of the Parnaíba Basin correspond to Müller's (1962) palynozone Q, at least—as well as to the transition between interval V and VI, sensu Daemon and Contreiras (1971), Andrade and Daemon (1974) and Daemon (1974, 1976).

### 4.2.1.2. International correlations

*Umbellasphaeridium saharicum*, also recently registered by Andrade et al. (2020) in the upper levels of the Pimenteiras Formation in the southwestern border of the Parnaíba Basin, while never abundant, is of interest in the zone—as a complement to the eponymous
species and other key taxa—because of its stratigraphic value as an Upper Devonian index in the Brazilian Palaeozoic basins (see also Melo, 2005). It is consistent with the Frasnian through Strunian (Zones L5-L7) range of the species in the Algerian Sahara (Jardiné, 1972; Jardiné et al., 1974). In Ghana, in some successions which are somewhat equivalent to the succession in the Parnaíba and Maranhão Basin, the species is recorded in the Frasnian (Bär and Riegel, 1974). It is also an important species present in the Frasnian assemblage SA3 of Argentina (Noetinger and Di Pasquo, 2011). The first record of the species was certainly by Regali (1964), in the Tucano-Jatobá Basin of northeastern Brazil. The said occurrence, first dated as Middle (?) Devonian by Regali (1964), was later reinterpreted as Frasnian by Brito (1976) and as Strunian by Quadros (1980) and Dino et al. (2011). Another historical record is in the Mac-Mahon Basin, in the upper Famennian-Strunian, as “acritarche à entonnoirs” N°441-33 by Lanzoni and Magloire (1969). The accurate stratigraphic distribution of *Umbellasphaeridium saharicum* in the U.S.A. is more complex, since the material is associated with reworked elements in the Late Devonian (Wood, 1979).

There is a good correlation with the Late Devonian of Argentina, particularly the Los Monos Formation assemblages described in the Tarija Basin. Many of the species recorded by Ottone (1986) occur in the Leiofusa bisubulata biozone, such as: *Leiofusa bisubulata* (as *Leiofusa* sp. Pl.7, figs. 1, 8 in Ottone) (Pl. 2, 6), *Maranhites mosesii* (Pl. 1, 4) and *Pseudolunulidia* spp. The re-description of *Crucidia camirense* (Pl. 1, fig. 7) in Argentina is also noteworthy, after the species was first illustrated in Bolivia by Boneta (1975). With the presence of *Crucidia camirense* in Argentina, among other elements in Argentina, we consider the age of these Argentinian assemblages as most likely early Late Frasnian, rather than Late Givetian to Early Frasnian as suggested by Ottone (1996).

As discussed earlier, direct comparisons are also possible with the Paraná Basin and the reference RSP-1 borehole, previously studied by Burjack et al. (1987), Loboziak et al.
(1988), and Oliveira (1997). Many of the species found in the *Leiofusa bisubulata* biozone were described for the first time in the RSP-1 core-drill (Oliveira and Burjack, 1996; Oliveira and Burjack, 1997), yet many species are still *nomen nudum*. The equivalent of the Dc-Lb Zone is the interval between 60.50 m and 200 m. Species in common include

*Advenasphaeridium acerosum* (nomen nudum), *A. australis* (nomen nudum) (Pl. 2, fig. 4),

*Crucidia camirense* (Pl. 1, 7), *Diaphorochroa gracile* (nomen nudum) (Pl. 2, fig. 11),

*Naevisphaeridium hercyniana*, *Leiofusa bisubulata*, *Petrovina connata* (Pl. 1, fig. 5), the netromorphs *Navifusa bacilla crescentis* (Pl. 1, fig. 9) and *Pseudoluculidia micropunctata* (Pl. 1, fig. 8).

### 4.2.2. Second assemblage

The stratigraphically higher assemblage, defined in the last three samples of site 35 the last four samples of site 11 and up to sample 86 in site 37. It contains significant species that are unrepresented in the lower assemblage, including *Horologinella quadrispina* (Pl. 1, figs 12-13), *Maranhites mosesii*, *Pseudomaranhites densus*, *Pterospermopsis crassimarginata* (Pl. 1, fig. 6), *Veryhachium capitata* nov. sp. (Pl. 2, fig. 17), *Veryhachium insanum* nov sp. (Pl. 2, fig. 18) and *V. pannucens*.

In the Amazon Basin, the succession of *Veryhachium insanum*, *Bipolarisvelata accreta* and the introduction of *Horologinella quadrispina* is observed in the reference core Caima PH-2 (Le Hérissé, 2001; Le Hérissé, Longhim, Melo, in prep.), at the boundary between Middle and Late Frasnian. It corresponds also to an interval marked by the appearance of *Maranhites mosesii*.

The order of appearance of some of these species is also the same in the upper part of the RSP-1 core in the Paraná Basin (see Oliveira, 1997, Fig. 18). But the material does not include the introduction of *Horologinella quadrispina* (Pl. 1, figs 12-13).
*Pterospermopsis crassimarginata* is also a common component of the zone, but it can be mentioned as a precocious appearance of this species in the Paraná Basin, where it has been defined for the first time.

*Puteoscortum williereae* is the index species of Zone Pw (Vanguestaine et al., 1983) and is characteristic of the lower Famennian in Belgium. Our data points to an earlier introduction of the species in the Frasnian of Brazilian successions, whereas its regional exit is in the Middle Famennian.

In terms of correlation with previous regional zonation, the higher assemblage recognised here will be equivalent to the lower part of the *Tugospora bricei-Diducites mucronatus* (BMu) zone of the Late Frasnian age, according to Melo and Loboziak (2003) and Grahn and Melo (2006).

### 4.3. Chitinozoans

Devonian chitinozoans from the Parnaíba Basin were first discussed by Müller (1962). His Silurian through Lower Carboniferous Biozones were divided into seven zones, ranging from N (upper Visean) to T (upper Silurian), based on chitinozoans, spores and acritarchs. The Pimenteiras Formation corresponds to his Zone Q (upper Zone R–P by Brito, 1967, 1971 and Q–P by Quadros, 1982). These zones were, until recently, regarded as a reference palynomorph biozonation for the Parnaíba Basin (e.g. Brito, 1967, 1971; Daemon, 1974, 1976; Quadros, 1982, Molyneux et al., 1996). Daemon refined the Silurian–early Carboniferous sequence into 12 biozones based on miospores. In his scheme, the upper zones 5 and 6 correspond to the Pimenteiras Formation. Sommer and Van Boekel (1964) described Middle Devonian chitinozoans from outcrops of the lower Pimenteiras Formation on the western margin of the Parnaíba Basin. Concurrently, Daemon (1964) formulated a generalised chitinozoan biostratigraphy for the basin using Müller's zonal scheme as a framework. Lange
(1967) briefly mentioned chitinozoans from the Parnaíba Basin, and Cruz and Quadros (1985) described a new chitinozoan species from the latest Frasnian – early Famennian. More recently, chitinozoans have been discussed and correlated with miospores in papers by Grahn et al. (2001, 2005, 2006, 2008) and Breuer and Grahn (2011). The Pimenteiras Formation consists of a lower Middle Devonian section, separated by a hiatus from the upper Late Devonian section.

The chitinozoans encountered in the present study constitute a characteristic Frasnian assemblage, although not earliest or latest Frasnian. They are typical for the early to early Late Frasnian *Angochitina (Lagenochitina) avelinoi* (Pl. 3, figs 1-2) regional interval range zone of the Parnaíba Basin, which corresponds to the lower *Hoegisphaera glabra* global interval range zone (Paris et al., 2000). *Angochitina mourai* (Pl. 3, figs 3, 4) and *Angochitina avelinoi* (Lange, 1952) are recorded in the Late Devonian of the major intracratonic basins of Brazil. The latter species has a more restricted range in the Paraná (early Late Frasnian) and Amazonas Basins (early Frasnian). In the Parnaíba Basin, there is a variety of *Angochitina mourai* with a long neck, common in the early Late Frasnian. *Lagenochitina* sp. A in Grahn and Melo (2005) (Pl. 4, figs 5-6), along with similar specimens, are recorded from the early Frasnian but are also common in the early Late Frasnian. *Fungochitina pilosa* (Collinson and Scott, 1958) (Pl. 4, figs 1-2) is something of a vast basket, and specimens like *Fungochitina pilosa* have been recorded from the late early Eifelian to the Frasnian. *Lagenochitina sommeri* (Lange, 1952) (Pl. 4, figs 3-4) was first described from the early Frasnian in the Amazonas Basin, but also occurs in the early Late Frasnian of the Parnaíba Basin. Both *Angochitina* sp. C and *Fungochitina microspinosa* (Grahn and Melo, 2005) (Pl. 3, figs 9-10) are common Frasnian species in the Parnaíba Basin. Although an early Frasnian age cannot be excluded, the chitinozoans present are altogether more similar to an early late Frasnian age.
## 4.4. Miospores

### 4.4.1 Results

Several studies on miospores are available for the Frasnian of the Parnaíba Basin. Most have been carried out by Loboziak and his co-authors (e.g., Burjak et al., 1987; Dino et al., 1996; Grahn et al., 2006, 2008; Loboziak et al., 2000; Loboziak et al., 1994; Loboziak et al., 1992b). Few papers describing the whole Frasnian assemblage of outcrops or cores from the western Gondwana are available.

The miospores observed here are well preserved, and yellow to pale brown in colour. The assemblages are rich and diverse. The most prolific samples in miospores are the N° AM7, AM8, AM9, AM89 and AM95. Samples AM50, AM53, AM55, AM60, AM65, AM70, AM80, AM85 and AM88 contain rare miospores. In all the samples, miospores are more abundant than marine palynomorphs, especially in the upper part of the section where acritarchs are rarer. This decrease in the quantity of acritarch input has also been noted in the upper part of the Pimenteiras Formation of the Well 2-PM-1-MA (Loboziak et al., 1992b), probably corresponding to a regression.

Weak variations in the composition of the assemblages have been observed throughout the sequence, except for very minor differences. Moreover, as the different sections are being separated by outcrop gaps, their lateral geometrical relationship is somewhat difficult to achieve.

The richest levels in miospores contain more or less the same assemblage in which the most helpful species for biostratigraphy are known from the classical Boulonnais area from Northern France (Streel et al., 1987, Loboziak and Streel, 1988). Among them, the following species have been observed: *Samarisporites triangulatus* (pl. 15, figs 1-3), *Chelinospora concinna* (Pl. 7, figs 6-9), *Verrucosisporites bulliferus* (Pl. 15, figs 4-6), *Lophozonotriletes media* (Pl. 13, figs 9-10), etc. These suggest the Frasnian age. The oldest sample from the site
10 (AM7) already contains, among others, *Verrucosisporites bulliferus* (Pl. 15, figs 4-6) and *Lophozonotriletes media* (Pl. 13, figs 9-10)

In the Boulonnais area of northern France (Streel et al, 2000), miospores occur in the same sections as conodonts. The chronostratigraphic limits of the Frasnian stage, fixed on conodonts in the Montagne Noire area, can thus be transferred to the Boulonnais area. In this area, *Chelinospora concinna* and *Samarisporites triangulatus*—which characterise the TCo Zone— first occur in the upper Givetian but are still present in the Early and Middle Frasnian.

*Verrucosisporites bulliferus* first occurs in the early Frasnian and *Lophozonotriletes media* in the Middle Frasnian (BJ and BM Zones), but both are still present in the upper Frasnian and the Famennian. *Rugospora bricei*, *Grandispora gracilis* and *Diducites plicabilis* (BA Zone or Regional “IV” Zone) first occur successively in the upper Frasnian but are still present in the Famennian (Streel, 2009).

A Middle to Late Frasnian (but not latest) age is therefore suggested for all the studied samples.

## 4.4.2. Discussion

### 4.4.2.1. Correlations with Brazilian biostratigraphic scale (Fig. 6)

Miospores from the Givetian to the Tournaisian have been studied by Loboziak et al. (2000) in the Tocantins Valley of the Parnaíba Basin located some 120 km away from the sections studied here. The biozones from the Boulonnais area (Streel et al. 1987), ranging from TCo to BM-"IV"(or BA Zone), were used in this paper as well as in Loboziak and Melo (2002). New biozone names (BPi - BMu-TP) were introduced later by Melo and Loboziak (2003) in the Amazon Basin. Among the Tocantins Valley samples from the Pimenteiras Formation, 12 are shown to belong to the Frasnian. A total of 32 taxa have been identified in these 12 samples including 9 taxa which are restricted to the Frasnian. From our samples there
are only 15 taxa in common with these 32 taxa recorded in the Tocantins Valley. 7 of the 32 taxa are also known in the Cabeças Formation belonging to the Latest Famennian where they are “ascribed to reworking on the basis of differential preservation or color” (Loboziak et al., 2000, p. 308). However, it is possible to correlate the two areas, thanks to the species *Lophozonotriletes media*, *Grandispora tabulata* (Pl. 13, figs 1-2), *Verrucosisporites bulliferus* and *Samarisporites* sp. C (synonym of S. sp. E in Melo and Loboziak, 2003) (Pl. 14, figs 10-12).

In the samples studied herein, *Verrucosisporites bulliferus* is one of the eponymous species of the BPi Interval Zone—along with *Geminospora piliformis*—according to the biozonation established in Brazil by Melo and Loboziak (2003). This biozone is marked by the FOB of *Verrucosisporites bulliferus*. The analysed samples should thus belong to the BPi Interval Zone in Brazil, despite the absence of observation of *Geminospora piliformis*—a species that is poorly scattered and collected. However, Melo and Loboziak (2003) note that in the Paraná Basin's Ponta Grossa Formation, *Geminospora piliformis* appears with *Lophozonotriletes media* in the upper part of the zone, allowing the zone to be subdivided into two parts, and demonstrates a correlation of this higher interval with the BM Oppel zone of Western Europe. The BPi Zone has also been observed in the Amazon Basin, and probably also in the Solimões Basin within the Jandiatuba and Uerê Formations.

*Rugospora bricei* is a species appearing in Biozone BA (ex “IV” Refional Zone) in Western Europe (Streel et al., 1987). This species is also known in Brazil and appears close to the base of the BMu Biozone (Melo and Loboziak, 2003). The species has been identified in the Parnaíba, Amazon, and Paraná Basins (Burjack et al., 1987; Grahn et al., 2006; Melo and Loboziak, 2003). Two specimens like *Rugospora bricei* have been observed in site 10, samples 7 and 8. However, the nature of the convolute proximal muri is different to those of the original species; they are too coarse. Thus, the two specimens are here considered as
*Rugospora cf. Rugospora bricei* (Pl. 14, figs 7-8). *Rugospora bricei* is also close to *Rugospora radiata*. The main differences are in the size and arrangement of the rugulae in *Rugospora flexuosa* are much coarser (Higgs et al., 2013). These last two species are known in the Famennian.

Among other important species for the biostratigraphy, *Camarozonotriletes concavus* (Pl. 7, figs 4-5) first appears in the Eifelian and is supposed to have disappeared close to the BJ-BM boundary (Loboziak and Melo, 2002). *Grandispora tabulata* first appears just below *V. bulliferus* and is known up to the Famennian (Loboziak et al. 1988). *Auroraspora macra* (Pl. 7, figs 1-3), which has been known since sample 7, first appears at the boundary between Biozones BM and BA (ex “IV” Regional Zone) (Loboziak et al., 1988) and is known up to the Tournaisian (Zwan, 1980).

Most of the spores are geographically cosmopolitan, except for some species that are restricted to the Gondwana like *Geminospora piliformis*, *Grandispora gabesensis*, *Grandispora libyensis* (Pl 10, figs 6-7) and *Grandispora tabulata*.

### 4.4.2.2. Correlation with the European biostratigraphic scales (Fig. 6)

Givetian to Lower Famennian deposits, containing miospores, are widespread on the territory of the Pripyat Depression in SE Belarus and the Timan–Pechora Province in Russia. The biostratigraphy of these deposits is based also on conodonts in the Timan-Pechora (see in Streel et al., submitted).

Correlations during the Late Givetian to Middle Frasnian between Boulonnais and Eastern Europe are shown to be obvious from *varcus* to *punctata* conodont Zones. They are less obvious from the Middle Frasnian to the Early Famennian (Obukhovskaya, 2000; Streel et al., 2000; Telnova, 2008; Telnova et al., 2019)
*Geminospora lemurata* (Pl. 9, figs 5-6) is well known and distributed worldwide, appearing just above the Eifelian / Givetian boundary. This species characterises the Lem Interval Biozone (Streel et al., 1987). *Samarisporites triangulatus* first appears in the late Givetian and is the eponymous species of the TA and TCo Biozones (Streel et al., 1987) in Europe. The species may reach the Tournaisian in both Brazil and Tunisia (Loboziak et al., 1992a; Loboziak et al., 1988; Melo and Loboziak, 2003). *Chelinospora concinna*, the second eponymous species of the TCo Biozone, appears below the Givetian / Frasnian boundary. *Verrucosisporites bulliferus* appears above the base of the Frasnian and characterises Biozones BJ and BM (Streel et al., 1987), which are both included in the lower part of the Frasnian. Finally, *Lophozonotriletes media* is characteristic of the BM Biozone (Streel et al., 1987), around the Middle Frasnian.

The synthesis of miospore based on Givetian to Famennian biostratigraphy in the Boulonnais (Loboziak and Streel 1988) did not provide detailed analysis of the data accumulated by Loboziak et al. (1983) in the Upper Frasnian. Restudy of this data and new samples collected in boreholes from neighboring Flanders (Belgium) allow for better characterization of the transition from Middle to Lowermost Famennian and a comparison with contemporary Eastern Europe miospores based zonations. (Streel et al., 2020 submitted). The correlation at the BM/BA transition dated Upper Frasnian by the *henana* conodont Zone in Eastern Europe points to the inaccuracy of the Ferques succession and Hydrequent Formations with regard to tracing the base of the Upper Frasnian in the Boulonnais. A first look at the many recorded ranges of taxa immediately suggests, in the first instance, a sampling gap between these formations. Obviously, it also suggests a deep change in the vegetation cover occurring at that level corresponding more or less to the Lower Kellwasser Event (LKW) starting in the lower *henana* conodont Zone (Becker et al. 2016).
If the Melo and Loboziak's (2003) correlation of the Brazilian BPi Zone with the West European BJ and BM Zones makes sense, alignment of the base of the Brazilian BMu Zone with the base of the West European BA (ex "IV") Zone is not secure. Nevertheless the FOB in the Pimenteiras Formation of *Auroraspora macra*, *Samarisporites* sp C in Loboziak, Streel and Vanguestaine 1983 (synonym of S. sp. E in Melo and Loboziak 2003) and possible *Rugospora bricei* occurring within the lowermost part of BA Zone (ex IV a-b or BA pre-gracilis subzone in Streel 2009) confirm the presence of an early part of the Upper Frasnian.

**5. Geochemistry and maximum flooding surface**

Some authors (Myers, 2004; Sutton et al., 2004; Lüning et al., 2004; Rodrigues, 2005; and references therein) have described the relationship between TOC content and the stratigraphy of sequences. Organic matter preservation in the sedimentary record depends on many factors. Myers (2004) pointed out that the most important factors are the physiogeography of the basin, climate, terrestrial organic productivity, marine aquatic organic productivity, oceanic circulation, sedimentation rate and water depth. With the exception of climate and oceanic circulation, the other factors described by Myers (2004) are influenced by relative sea level change.

Under lowstand conditions, the high sediment influx product, the dilution of the organic marine matter content and the organic terrestrial matter are highly oxidised. In this context, the amount of organic matter preserved in the sediments is low and the consequent TOC values are inexpressive.

In the transgressive system tract, the rapid increase in relative sea level caused the shoreline to retreat landward. It resulted in a progressive extension of the shallow marine shelf deposition, and in a reduction of the clastic sediment supply. According to Lüning et al. (2004), the transgression has likely led to sediment starvation because the detritus became
trapped in river mouths, thus preventing the dilution of the organic matter on the shelf. These conditions led to the progressive expansion of the deep distal area of the basin until it reached the maximum flooding surface (MFS). In this basin, therefore, there was an extension of the anoxic conditions, which permitted an increase in the preservation of organic matter.

The retreat of sediments at the shoreline decreased the dilution of organic matter in the depositional setting. In contrast with the lowstand conditions, the TOC values increased, reaching a maximum at MFS.

As also observed in the section studied in this work, Creaney and Passey (1993) noted that many marine source rocks are characterised by an initial abrupt upward increase in organic content, which, in contrast with background values, and a subsequent gradual decrease in organic content (Myers, 2004). The authors attributed this pattern to the control of the organic carbon contents by the clastic sedimentation rate, under anoxic bottom water conditions. The rapid increment of TOC results from the retreat of the sediments in the source, during the transgression. The subsequent gradual decrease in TOC reflects the increase in the clastic sediment supply and the dilution of organic carbon during highstand progradation. In this context, the MFS is positioned at the turning point of the TOC curve.

Most authors consider it to be partly contained in the lower highstand, and partly in the upper transgressive systems tracts (Sutton et al., 2004; Posamentier and Allen, 1999).

This succession is well defined in the section studied, where the TOC ranges from low to moderate in site 10 (Figure 03). In the subsequent interval (site 12), associated with Radioactive Shale C, the TOC shows an abrupt increase, defining the improved conditions for organic matter preservation. These conditions mark the maximum flooding surface. This interval is also observed at the base of site 35. In the interval above (site 11), the TOC decreases towards the Cabeças Formation, which indicates the start of the regression system and the consequent increased inflow of sediment toward the basin.
**6. Conclusions**

The palynological results—based on acritarchs, chitinozoans and miospores—are relatively well concordant, and correlatable with Devonian palynozones in use in northern Brazilian basins.

The occurrence of several species of acritarchs—such as *Leiofusa bisubulata*, *Mediocorpore conspicuus* and *Pseudolunulidia micropunctata*—in sites 10 and 12, and in the lower 2/3 of site 35, have made it possible to distinguish a first assemblage of Middle to earliest Late Frasnian age.

In the last three samples of site 35 and the last four samples of site 11, and from site 37 up to sample 86, we observe the occurrence of *Horologiuella quadrispina*, *Maranhites mosesii*, *Pseudomaranhites densus*, *Pterospermoidei*, *crassimarginata*, *Veryhachium capitata* nov. sp., *Veryhachium insanum* nov. sp. and *V. pannuceum*. This points to a late Frasnian age, quite equivalent to that of the miospore Biozone *Rugospora bricei-Diducites mucronatus* (BMu).

The chitinozoans that were identified in the different slides belong to a common assemblage characteristic of the Frasnian and, more precisely, neither the earliest nor the latest Frasnian. They belong to the early-early Late Frasnian *Angochitina (Lagenochitina) avelinoi* regional interval range zone of the Parnaíba Basin. This is equivalent to the lower *Hoegisphaera glabra* global interval range zone, which is the second and youngest global chitinozoan biozone of the Frasnian. The miospores do not show variations in the different samples and have been studied as a whole and unique assemblage. Species like *Verrucosisporites bulliferus* and *Lophozonotriletes media* clearly demonstrate a mid-Frasnian age. The analysed samples would belong to the BPi Interval Zone and possibly an early part of the BMu Zone in Brazil.
The present work has characterised the global marine flooding surfaces (FS) recorded in the Devonian section of the Brazilian Palaeozoic basins as seen in the Parnaíba Basin, using the geochemistry parameter Total Organic Carbon content (TOC) and Pyrolysis data.

Two intervals of interest were recorded, according to their TOC content, in the Devonian section we studied. These were Radioactive Shale B and Radioactive Shale C, recorded in the Pimenteiras Formations (latest Eifelian to late early Givetian in the lower part and Frasnian, but not earliest, to Famennian in the upper part), which are richest in organic matter concentration. The proxies studied in this work show a regional distribution in the basins—probably associated with a coeval anoxic / dysoxic depositional condition over a large area of the basin.

The Late Devonian sections presented in this study demonstrated that progressive flooding took place during Devonian era in the Parnaíba Basin—which, in the Frasnian, shows the maximum marine transgression. These global events are regarded as markers for regional chronostratigraphic correlations in Gondwana.

This global event is also an object of interest for hydrocarbon exploration, as it relates to the identification of source rock intervals. However, the conditions for oil and gas generation for this basin are closely related to the specific evolutionary model, for which the atypical model is the most effective.

# APPENDIX

List of species encountered in the material and/or cited in the text

## Acritarchs

*Advenasphaeridium acerosum* Burjack and Oliveira *apud* Oliveira, 1997, *nomen nudum*

*Advenasphaeridium australis* Burjack and Oliveira 1997, *nomen nudum*

*Arkonites bilixus* Legault 1973
*Bimerga bensonii* Wood, 1995

*Bipolarisvelata accreta* Burjack and Oliveira *apud* Oliveira, 1997, *nomen nudum*

*Chomotriletes* sp.

*Crucidia camirense* (Lobo Boneta) Ottone, 1996

*Diaphorochroa gracile* Burjack and Oliveira *apud* Oliveira, 1997, *nomen nudum*

*Disparifusa urariaensis* Le Hérissé, 2013, *nomen nudum*

*Duvernaysphaera angelae* (=D. tessella) Deunff, 1964

*Duvernaysphaera capitana* (Wicander) Le Hérissé nov.comb

*Duvernaysphaera cruciformis* Le Hérissé, 2001, *nomen nuan*.

*Duvernaysphaera heliocentrica* Burjack and Oliveira *apud* Oliveira, 1997

*Duvernaysphaera radiata* Brito, 1967a

*Duvernaysphaera stellata* Deunff, 1964b

*Duvernaysphaera tenuicingulata* Staplin, 1951

*Eisenackidium triplodermum* (Cramer) Eisenack et al., 1973.

*Estiastra spinireticulata* Oliveira and Burjack, 1997

*Exochoderma arca* Wicander and Wood, 1981

*Exochoderma irregulare* Wicander, 1974

*Geron elegans* Oliveira and Burjack, 1997

*Gorgonisphaeridium winslowiae* Staplin et al., 1965

*Hemiruptia legaultii* Ottone, 1996

*Horologinella horologia* (Staplin) Jardiné, Combaz, Peniguel and Vachey, 1972

*Horologinella quadrispina* Jardiné, Combaz, Magloire, Peniguel and Vachey, 1972

*Leiofusa bisubulata* Brito and Quadros, 1984

*Leiofusa fastidiona* (Cramer and Díez) nov. comb.

*Maranhites brasiliensis* Brito, 1965 emend Burjack and Oliveira 1989
*Maranhites britoi* Stockmans and Willière, 1969 R5+R6+R7+R8

*Maranhites lobulatus* Burjack and Oliveira 1989

*Maranhites magnus* Burjack and Oliveira 1989

*Maranhites mosesii* (Sommer, 1956) Brito, 1967

*Maranhites stockmansii* (Martin) Martin, 1984

*Mediocorpore conspicuus* Burjack and Oliveira *apud* Oliveira, 1997, *nomen nudum*

*Multiplicisphaeridium ramusculosum* (Deflandre) Lister, 1970

*Naevisphaeridium desiderata* (Burjack and Oliveira *apud* Oliveira, 1997) *nomen nudum* nov. comb

*Naevisphaeridium sprucegrovense* (Staplin, 1961) nov. comb.

*Navifusa bacilla* (Deunff) Playford, 1977

*Navifusa bacilla* (Deunff) Playford, 1977 *form. percentis*

*Navifusa bacilla* var. *procera* (Deunff, 1966) nov.comb.

*Palacanthus ledanoisii* Deunff, 1957, end Playford, 1977

*Petrovina connata* Oliveira and Burjack, 1996

*Polyedryxium embudum* Cramer, 1964

*Polyedryxium fragosulum* Playford, 1977

*Polyedryxium pharaone* Deunff, 1961

*Polyedryxium* sp. or *Muraticavea munifica* Wicander and Wood, 1981

*Pseudolunulidia micropunctata* Brito and Quadros, 1984

*Pseudomaranhites densus* Quadros, 1996

*Pterospermopsis crassimarginata* Burjack and Oliveira *apud* Oliveira, 2007, *nomen nudum*

*Pterospermopsis pernambucensis* (Brito) Eisenack et al., 1973

*Puteoscortum limai* Burjack and Oliveira *apud* Oliveira, 1997

*Puteoscortum williereae* Martin, 1981
*Pyloferites* sp.

*Stellinium comptum* Wicander and Loeblich, 1977

*Stellinium divisum* Le Hérissé, 2013, *nomen nudum*

*Stellinium micropolygonale* (Stockmans and Willière) Playford 1977

*Stellinium oppidum* Deunff, 1980

*Tasmanites* spp.

*Tinacula simplex* Quadros, 1999

*Tunisphaeridium tentaculaferum* (Martin) Cramer, 1971

*Tyligmasoma* sp. A of Playford in Playford and Dring, 1981

*Umbellasphaeridium deflandrei* (Moreau-Benoit) Jardiné et al., 1972

*Umbellasphaeridium saharicum* Jardiné, Combaz, Maguire, Peniguel and Vachey, 1972

*Unellium ampullium* Wicander, 1974

*Unellium lunatum* (Stockmans and Willière 1966) Eisenack et al., 1979

*Unellium piriforme* Rauscher, 1969

*Veryhachium arctatum* Deunff, 1980

*Veryhachium capitata* Le Hérissé, 2001, *nomen nudum*

*Veryhachium insanum* Le Hérissé, 2001, *nomen nudum*

*Veryhachium pannuceum* Wicander and Loeblich Jr., 1977

*Veryhachium roscidum* Wicander, 1974

*Veryhachium trispinosum* (Eisenack) Deunff, 1966

*Veryhachium trispinosum/roscidum* complex

*Winwaloeusia distracta* (Deunff) Deunff, 1977

## Chitinozoans

*Angochitina avelinoi* (Lange, 1952)

*Angochitina mourai* (Lange, 1952)
*Angochitina* sp. C ? Grahn and Melo, 2005

*Lagenochitina* sp. A Grahn and Melo, 2005

*Fungochitina microspinosa* Grahn and Melo, 2005

*Fungochitina pilosa* Collinson and Scott, 1958

*Lagenochitina sommeri* (Lange, 1952)

## Miospores

*Auroraspora macra* Sullivan, 1968

*Camarozonotriletes concavus* Loboziak and Streel, 1988

*Chelinospora concinna* Allen, 1965

*Cyrtospora tumida* Breuer and Steemans 2013

*Diducites plicabilis* Van Veen 1981

*Geminospora lemurata* Balme emend. Playford, 1963

*Geminospora piliformis* Loboziak et al., 1968

*Grandispora gabesensis* Loboziak and Streel, 1989

*Grandispora gracilis* (Kedo) Streel in Becker et al. 1974

*Grandispora libyensis* Moreau Benoit, 1980

*Grandispora tabulata* Loboziak and Streel, 1988

*Lophozonotriletes medi* (Laugourdeau-Lantz, 1967)

*Rugospora bricei* Loboziak and Streel, 1988

*Rugospora flexuosa* (Jushko) Streel in Becker et al., 1974

*Rugospora radiata* (Kedo) Byvscheva, 1985

*Samarisporites* sp. C in Loboziak et al., 1983

*Samarisporites triangulatus* Allen, 1965

*Verruciretusispora magnifica* (McGregor) Owens, 1971

*Verrucosisporites bulliferus* Richardson and McGregor, 1986
Acknowledgments

We would like to thank the two anonymous reviewers who have made valuable improvements
to the realisation of this manuscript. We thank M. Jones for the processing of the samples and
Enda Breen for the reviewing of the English. PS is FSR-FNRS Senior Research Associate.

EP, MB, SB, and RR are grateful to CNPq, FAPERJ, Finep and FUSP for the research
fellowship (MB) and for financial support in the scope of the Project "Rede GASBRAS".

Conflict of interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

P. Steemans

References

Aguiar, G.A. 1971. Revisão geológica da bacia paleozóica do Maranhão. An. XXV Cong. Brasil. Geol. Soc. Brasil., São Paulo, Brazil, 3, 113-122.

Almeida, F.F.M., Carneiro, C.D.R. 2004. Inundações marinhas fanerozóicas no Brasil e recursos minerais associados. In: Mantsesso-Neto, V., Bartorelli, A., Carneiro, C.D.R., Brito-Neves, B.B. (eds). Geologia do continente sul-americano: evolução da obra de Fernando Flávio Marques de Almeida. Beca, São Paulo, Brazil, 3, 43-58.

Andrade, C.L.N., Cardoso, T.R.M., Santos, R.R., Dino, R., Machado A.J., 2020. Organic facies and palynology from the middle to late Devonian of the Pimenteiras Formation, Parnaíba Basin, Brazil. J. S. Am. Earth. Sci., 99, https://doi.org/10.1016/j.jsames.2019.102481

Andrade, S.M., Daemon, R.F., 1974. Litoestratigrafia e bioestratigrafia do flanco sudoeste da Bahia do Parnaíba (Devoniano e Carbonífero). An. 28º Congr. Brasil. Geol., Porto Alegre, 2, 129-137.
Bär, P., Riegel, W., 1974. Les Microflores des séries paléozoïques du Ghana (Afrique occidentale) et leurs relations paléofloristiques. Sc. Géol. Bull., 27 (1-2), 39-58.

Becker, R.T. 2007. International union of Geological Sciences, commission on stratigraphy.
Subcommission on Devonian Stratigraphy, Newsletter, 22, 111p.

Becker, R.T., Königshof, P., Brett, C.E., 2016. Devonian climate, sea level and evolutionary
events: an introduction, in: Becker, R.T., Königshof, P., Brett, C.E. (Eds.), Devonian climate,
sea level and evolutionary events. Geological Society, London, Special Publications, 423, 1-
10.

Beurlen, K., 1965. Observações no Devoniano do Estado do Pará. Anais Acad. Brasil. Ciên., Rio de Janeiro, 37, 61-75.

Bond, D.P.G., Wignall, P.B., 2008. The role of sea-level change and marine anoxia in the
Frasnian–Famennian (Late Devonian) mass extinction. Palaeogeogr. Palaeoclimatol.
Palaeoecol., 263(3-4), 107-118.

Bosetti, E.P., Grahn, Y., Horodyski, R. E., Mendlowicz Mauller, P., Breuer, P., Zabini, C., 2011. An earliest Givetian “Lilliput Effect” in the Paraná Basin, and the collapse of the Malvinokaffric shelly fauna. Palaeontol. Z., 85, 49-65.

Breuer, P., Grahn, Y., 2011. Middle Devonian spore stratigraphy in the eastern outcrop belt of the Parnaíba Basin, northeastern Brazil. Rev. Esp. Micropal., 43, 19-38.

Breuer, P., Steemans, P., 2013. Devonian spore assemblages from northwestern Gondwana:
Taxonomy and biostratigraphy. Spec. Pap. Paleontol., 89, 1-163.

Brito, I.M., 1967. Silurian and Devonian Acritarcha from Maranhão Basin, Brazil. Micropal., 13 (4), 473-482.

Brito, I.M., 1971. Contribuição ao conhecimento dos microfósseis silurianos e devonianos da Bacia do Maranhão. V – Acritarcha Herkomorphitae e Prismatomorphitae. An. Acad. Brasil. Ci., 43 (Suplemento), 201-208.
Brito, I.M., 1976. Contribuição ao conhecimento dos microfósseis Devonianos de Pernambuco. III. Aguns Acritarcha comuns aos do Devoniano do Saara. An. Acad. Brasil. Ci., 48 (4), 747-756.

Brito, I.M., Quadros, L.P., 1984. Novas ocorrências de Acritarchae no Devoniano da Bacia do Parnaiba. Bol. IG-USP, 15, 15-19.

Burjack, M.I.A., Oliveira, S. F. 1989. Contribuição ao conhecimento morfológico e sistemático do Género *Maranhites* Brito. In Paleobotânica e Palinologia na América do Sul - 1987, Bol. IG-USP, 7, 45-67.

Burjack, M.I.A., Loboziak, S., Streel, M., 1987. Quelques données nouvelles sur les miospores dévoniennes du bassin du Paraná (Brésil), Soc. Geol., 40, 381-391.

Caputo, M.V., 1984. Stratigraphy, tectonics, palaeomatology, and paleogeography of northern basins of Brazil. - Unpub. Ph.D Thesis, Univ. of California, Santa Barbara, 586 p.

Caputo, M.V., Crowell, J.C., 1985. Migration of glacial centers across Gondwana during Paleozoic Era. Geol. Soc. America Bull. 96, 1020-1036.

Cioccari, G.M. and Mizusaki, A.M.F., 2019. Sistemas petrolíferos atípicos nas Bacias Paleozoicas Brasileiras – Uma revisão. Geociências, 38, 367-390.

Collinson, C., Scott, A.J., 1958. Chitinozoan faunule of the Devonian Cedar Valley Formation. Illinois State Geological Survey. Circular 247, 1-34.

Creaney, S., Passey, Q.R., 1993. Recurring patterns of total organic carbon and source rock quality within a sequence stratigraphic framework. AAPG Bull., 77, 386-401.

Cruz, N.M.C., Quadros, L.P., 1985. *Sommerochitina langei*, um novo fóssil-guia do Devoniano Superior da Bacia do Parnaíba. In: Campos, D.A.; Ferreira, C.S.; Brito, I.M., Viana, C.F. (eds.). Coletânea de trabalhos paleontológicos; trabalhos apresentados no VIII Congresso Brasileiro de Paleontologia—1983. Brasília, DNPM, 289-293.
Daemon, R.F., 1964. Estratigrafia preliminar dos Chitinozoa da Bacia do Maranhão.

Salvador, PETROBRAS/RPBA (Unpubl. report.), 1-18.

Daemon, R.F., 1974. Palinomorfos-guias do Devoniano Superior e Carbonífero Inferior das bacias do Amazonas e Parnaíba. An. Acad. Bras. de Ciênc., 46, 549-587.

Daemon, R. F., 1976. Correlação bioestratigráfica entre os sedimentos do Siluriano, Devoniano e Carbonífero Inferior das bacias do Amazonas, Parnaíba e Paraná. Anais 29º Congres. Brasil. Geol. Soc. Bras. Geol., Ouro Preto., 2, 189-194.

Daemon, R.F., Contreiras, C.J.A., 1971. Zoneamento palinológico da Bacia do Amazonas. Anais do XXV Congr. Brasil. Geol. Soc. Bras. Geol., São Paulo, Brazil, 3, 79-88.

Dino, R., Melo, H.G., Grahn, Y., 1996. Devonian palynoliths from the western border of the Parnaíba Basin, Tocantins valley region, northern Brazil, Program and Abstract. 9th Internat. Palynol. Cong. Houston, 34.

Espitalie, J., Laporte, J.L., Madec, M., Marquis, F., Leplat, P., Paulet, J., Boutefeu, A., 1977.

Méthode rapide de caractérisation des roches mères, de leur potentiel pétrolier et de leur degré d'evolution, Rev. Inst. Fr. Pet., 32 23-32.

Góes, A.M.O, Feijó, F.J., 1994. Bacia do Parnaíba. Bol. Geociên.Petrobras, 8, 58-60.

Grahn, Y., Melo, J.H.G., 2005 Middle and Late Devonian Chitinozoa and biostratigraphy of the Parnaíba and Jatoba Basins, northeastern Brazil. Palaeontogr. Abt. B, 272, 1-68.

Grahn, Y., Loboziak, S., Melo, J.H.G., 2001. Integrated miospore-chitinozoan biozonation of the Parnaíba Basin and its correlation with Petrobras (Müller 1962) Silurian–Lower Carboniferous palynozones. In: Melo J.H.G., Terra G.J.S. (eds.) Correlação de sequências paleozoicas sul-americanas. Ciência-Técnica-Petróleo. Seção: Exploração de Petróleo, 20, 81-89.
Grahn, Y., Melo, J.H.G., Loboziak, S., 2006. Integrated middle and late Devonian miospore and chitinozoan zonation of the Parnaíba Basin, Brazil: An Update. *Rev. Brasil. Paleont.* 9, 283-294.

Haq, B. U., Schutter, S.R., 2008. A Chronology of Palaeozoic Sea-Level Changes. *Science*, 322(5898), 64-68.

Higgs, K., Prestianni, C., Streel, M., Thorez, J., 2013. High resolution miospore stratigraphy of the Upper Famennian of eastern Belgium, and correlation with the conodont zonation. *Geol. Belg.*, 16(1-2), 84-94.

Jardiné, S., 1972. Microplancton (Acritarches) et limites stratigraphiques du Silurien terminal au Dévonien supérieur. C.R. Septième Congr. Int. Stratig. Géol. Carbon., Krefeld. (Aug. 1971), 1, 313-323.

Jardiné, S., Combaz, A., Magloire, L., Peniguel, C., Vachey, G., 1974. Distribution stratigraphique des Acritarches dans le paléozoïque du Sahara algérien. *Rev. Palaeobot. Palynol*, 18, 99-129.

Jones, R.W., 1987. Organic Facies In. Prooks, J., Welte, D. (Eds.), Advances in Petroleum Geochemistry. Acad. Press., London, UK., 2, 1-90.

Kegel, W. 1953. Contribuição para o estudo do Devoniano da bacia do Parnaíba. Bol. Div. Geol. e Min. DNPM., 1:1, 1-48

Lange, F.W., 1952. Quitinozoários de Folholho Barreirinha, Devoniano de Paraná. Dusenia, 3, 373-386.

Lange, F.W. 1967. Biostratigraphic subdivision and correlation of the Devonian in the Paraná Basin. Bol. Parana. Geociên., 21/22, 63-98.

Lange, F.W., Petri, S. 1967. The Devonian of the Paraná Basin. Bol. Paranaense Geociên., 21/22, 5-55.
Lanzoni, E., Magloire, L., 1969. Associations palynologiques et leurs applications stratigraphiques dans le Dévonien supérieur et Carbonifère inférieur du Grand Erg occidental (Sahara algérien). Rev. Inst. fr. Pétr. Ann. Comb. Liq., XXIV (4), 441-469.

Le Hérissé, A., 2001. Evolution of Devonian phytoplanktonic assemblages in the upper Ererê Formation and Curuá Group (Barreirinha and lower Curiri formations), Tapajós River area, Amazon Basin, northern Brazil. In: Melo J.H.G., Terra G.J.S. (eds.). Correlação de sequências paleozoicas sul-americanas. Ciência-Técnica-Petróleo. Seção: Exploração de Petróleo, 20, 117-124.

Lima, E.C., Leite, J.F. 1978. Projeto Estudo Global dos Recursos Minerais da Bacia Sedimentar do Parnaíba; integraçãomgeológico-metalogenética, relatório final da etapa III. Internal report, CPRM-Companhia de Pesquisa de Recursos Minerais, Recife, PE, Brazil, Vol. 1-2.

Loboziak, S., Caputo, M.V., Melo, J.H.G., 2000. Middle Devonian-Tournaisian miospore biostratigraphy in the southwestern outcrop belt of the Parnaíba Basin, North-Central Brazil. Rev. Micropal., 43, 301-318.

Loboziak, S., Streel, M., Burjack, M.A.I., 1988. Miospores du Dévonien moyen et supérieur du bassin du Parana, Brésil: Systématique et stratigraphie. / Middle-Upper Devonian miospores from the Parana Basin: Systematics and Stratigraphy. Sc. Géol., Bull. Mém., 41(3-4), 351-377.

Loboziak, S., Steemans, P., Streel, M., Vachard, D., 1992a. Biostratigraphie par miospores du Dévonien inférieur à supérieur du sondage MG-1 (Bassin d'Hammadah, Tunisie).

Comparaison avec les données des faunes. Rev. Palaeobot. Palynol., 74, 193-205.

Loboziak, S., Streel, M., Caputo, M.V., Melo, J.H.G., 1992b. Middle Devonian to Lower Carboniferous miospores stratigraphy in the central Parnaíba Basin (Brazil). Ann. Soc. Géol. Belg., 115, 215-226.
Loboziak, S., Melo, H.G., Quadros, L.P., Daemon, R.F., 1994. Devonian-Dinantian miospore biostratigraphy of the Solimões and Parnaíba Basins (with some considerations on the Devonian of the Paraná Basin). Petrobras/Cenpes, Rio de Janeiro, Technical Report 2.

Loboziak, S., Melo, J.H.G., 2002. Devonian miospore successions of Western Gondwana: Update and correlation with Southern Euramerican miospore zones. Rev. Palaeobot. Palynol., 121, 133-148.

Lüning, S., Wendt, J., Belka, Z., Kaufmann, B. 2004. Temporal-spatial reconstruction of the early Frasnian (Late Devonian) anoxia in NW Africa: New field data from the Ahnet Basin (Algeria). Sedim. Geol., 163, 237-264.

Melo, J.H.G. 1988. The Malvinokaffric realm in the Devonian of Brazil. - In: McMillan, N.J., Embry, A. F., Glass, D.J. (eds.). Devonian of the World. Canadian Soc. Petrol. Geol. Mem., 1 (14), 669-703

Melo, J.H.G., 2005. Selected Devonian palynological biohorizons in Brazilian Palaeozoic basins: State-of-the-art. In: Gondwana VII, Mendoza, Academia Nacional de Ciencias; Cordoba, Argentina, Abstracts, 240

Melo, J.H.G., Loboziak, S., 2003. Devonian-Early Carboniferous miospore biostratigraphy of the Amazon Basin, northern Brazil. Rev. Palaeobot. Palynol., 124, 131-202.

Milani, E.J., Thomaz Filho, A., 2000. Sedimentary basins of South America. In: Cordani, U.G.; Milani, E.J., Thomas Filho, A., Campos, D.A. (Eds). Tectonic evolution of South America. Rio de Janeiro: International Geological Congress, 31, pp. 389-450.

Miranda, F.S., Vettorazzi, A.L., Cunha, P.R.C., Aragão, F.B., Michelon, D., Caldeira, J.L., Porsche, E., Martins, C., Ribeiro, R.B., Vilela, A.F., Corrêa, J.R., Silveira, L.S., Andreola, K., 2018. A Typical igneous-sedimentary petroleum system of the Parnaíba Basin, Brazil: Seismic, well logs and cores. In Daly, M.C., Fuck, R.A., Julià, J., Macdonald, D.I.M., Watts,
A.B. (Eds.). Cratonic Basin Formation: A Case Study of the Parnaíba Basin of Brazil. Geol. Soc., Lond., Sp. Pub, 472, 341-360.

Molyneux, S.G., Le Hérissé, A., Wicander, R., 1996. Palaeozoic phytoplankton. In: Jansonius, J., McGregor, D.C. (eds.). Palynology: Principles and applications. Salt Lake City, AASP Found, 2, 493-529.

Müller, H., 1962. Report on palynological results of samples examined from wells in Maranhão. Salvador, PETROBRAS/RPBA (Unpubl. report.), 44 p.

Myers, K.J., 2004. Organic-rich facies and hydrocarbon source rocks. In: Emery, D., Myers, K.J. (Eds.). Sequence Stratigraphy, Blackwell Science, Oxford 238-257.

Noetinger, S., Di Pasquo, M.M., 2011. Devonian palynological assemblages from the San Antonio x-1 Borehole, Tarija Basin, northwestern Argentina. Geol. Acta, 9 (2), 199-216.

Obukhovskaya, T., 2000. Miospores of the Givetian Frasnian boundary deposits in Belarus. Acta Palaeobo., 40(1), 17-23

Oliveira, S.F., 1997. Palinologia da seqüência devoniana da Bacia do Paraná no Brasil, Paraguai e Uruguai: Implicações bioclimatigráficas, paleoambientais e paleogeográficas. Ph.D. Thesis, Universidade de São Paulo, Brazil.

Oliveira, S.F., Burjack, M.I.A., 1996. *Petrovina connata* gen. n., sp. n. provavelmente relacionado à *Chlorophyta*, da Formação Ponta Grossa (Neodevoniano), Bacia do Paraná, MT, Brasil. Revista Universidade de Guarulhos. Sér. Geociên., 1 (3), 46-50.

Oliveira, S. F., Burjack, M.I.A., 1997. Nova espécie de paleomicroplâncton de parede orgânica (acritarco) da Formação Ponta Grossa (Frasniano) Bacia do Paraná, MT, Brasil, Revista Universidade de Guarulhos, Sér. Geociên., 2 (67), 86-91.

Ottone, E.G., 1996. Devonian palynomorphs from the Los Monos Formation, Tarija Basin, Argentina. Palynology, 20, 105-155.
Paris, F., Winchester-Seeto, T., Boumendjel, K., Grahn, Y., 2000. Toward a global biozonation of Devonian chitinozoans. Cour. Forschung. Senck., 220, 39-55.

Pereira, E., Carneiro, C.R., Bergamaschi, S., Almeida, F.F.M., 2012. Evolução das Sinéclises Paleozoicas: Províncias Solimões, Amazonas, Parnaíba e Paraná. In: Hasui, Y., Carneiro, C.D.R., Almeida, F.F.M., Bartorelli, A. (Eds.), Geologia do Brasil. Beca, Sao Paulo, Brazil, pp. 374-394.

Plummer, F.B. 1948. Estados do Maranhão e Piauí. Unoub. Internal report, Conselho Nac.Petról. Rio de Janeiro, Brasil, Relatório de 1946, 87-134.

Posamentier, H.W., Allen, G.P., 1999. Siliciclastic sequence stratigraphy – Concepts and applications. SEPM Concepts in Sedimentology and Paleontology, 7, 210.

Quadros, L.P., 1980. Ocorrência de palinomorfos em sementos paleozóicos da Bacia de Jatobá (Pernambuco). Rev. Brasil. Geociên., 10, 181-2.

Quadros, L.P., 1982. Distribuição bioestratigráfica dos Chitinozoa e Acritarchae na Bacia do Parnaíba. Ciência Técnica-Petróleo. Seção: Expl. Petról., 12, 1-76.

Quadros, L.P., 1996. Pseudomaraphites novo gênero de acritarco do Devoniano superior da Bacia do Amazonas. Anais XXIX Congresso Brasileiro de Geologia, Soc. Bras. Geol. Salvador de Bahia, 1996, Paléontologia, 2, 281-284.

Quadros, L.P., 1999. Nervos acritarcos do Devoniano Superior da Bacia do Amazonas. Acta Geol. Leopol., 23 (49), 15-27.

Rodrigues, R., 1995. A Geoquímica orgânica da bacia do Parnaíba. Ph.D. Thesis, Porto Alegre, Rio Grande do Sul, Brasil. Universidade Federal do Rio Grande do Sul.

Rodrigues, R., 2001. Caracterização geoquímica do evento anóxico/disóxico do Frasniano nas bacias do Amazonas e Parnaíba. In: J.H.G. Melo and G.J.S. Terra (eds.). Correlação de sequências paleozoicas sul-americanas. Ciênca-Técnica-Petróleo. Seção: Expl. Petról., 20, 109-116.
Rodrigues, R., 2005. Chemostratigraphy. In: Koutsoukos, E. (Ed). Applied Stratigraphy. Springer, New York, 165-178.

Rodrigues, R., Loboziak, S., Melo, J.H.G., Alves, D.B., 1995. Geochemical characterization and miospore biochonostratigraphy of the Frasnian anoxic event in the Parnaíba Basin, Northeast Brazil. Bull. Centres Rech. Explo. - Prod. Elf Aquitaine, 19 (2), 319-327.

Rodrigues, R., Pereira, E., Bergamaschi, S., 2012. Rochas Geradoras Devonianas e Permianas nas Bacias Paleozóicas Brasileiras, In: Anais da Rio Oil & Gas Expo and Conference 2012, Instituto Brasileiro de Petróleo, Gás e Biocombustíveis - IBP, Rio de Janeiro, Brasil.

Sommer, F.W., Van Boekel, N.M., 1964. Quitinozoários do Devoniano de Goiás. An. Acad. Brasil. Ciên., 36, 423-431.

Small, H.L. 1914. Geologia e supprimento d'agua subteranea no Piauhy e parte do Ceará. Inspec. de Obras Contra as Seccas. Serie I.D. Geol. 32, 1-186.

Souza, M.S.P., Mauller, P.M., Cardoso, J.R., Rodrigues, R., Pereira, E., 2013. Caracterização Geoquímica e Bioestratigráfica das Superfícies de Inundação Marinha da Seção Meso-Neodevoniana, na Região de Dom Aquino (MT), Noroeste da Bacia do Paraná, Brasil. Anuário do Instituto de Geociências (UFRJ. Impresso), 36(1), 15-25.

Streel, M., 2009. Upper Devonian miospore and conodont zone correlation in western Europe. In: Königshof, P. (Ed.), Devonian change: Case studies in palaeogeography and palaeoecology. Geol. Soc., Lond., Sp. Pub., 314, 163-176.

Streel, M., Higgs, K.T., Loboziak, S., Riegel, W., Steemans, P., 1987. Spore stratigraphy and correlation with faunas and floras in the type marine Devonian of the Ardenno-Rhenish regions. Rev. Palaeobot. Palynol., 50, 211-229.

Streel, M., Caputo, M.V., Loboziak, S., Melo, J.H.G., 2000a. Late Frasnian-Famennian climates based on palynomorph analyses and the question of the Late Devonian glaciations. Earth-Sc. Rev., 52(1), 121-173
Streel, M., Loboziak, S., Steemans, P., Bultynck, P., 2000b. Devonian miospore stratigraphy and correlation with the global stratotype sections and points. In: Bultynck, P. (Ed.), Subcommission on Devonian Stratigraphy. Cour. Forsch.-Inst. Senckenberg, 220, 9-23.

Streel, M., Boulvain, F., Dusar, M., Loboziak, S., Steemans, P., submitted. Updating Frasnian miospore zonation from the Boulonnais (Northern France) and comparison with new data from the Upper Palaeozoic cover on the Brabant Massif (Western Belgium). Geologica Belgica.

Sutton, S.J., Ethridge, F.G., Almon, W.R., Dawson, W.C., Edwards, K.K., 2004. Textural and sequence-stratigraphy controls on sealing capacity of Lower and Upper Cretaceous shales, Denver basin, Colorado. AAPG Bull., 88, 1185-1206

Telnova, O.P., 2008. Palynological characterization of Givetian-Frasnian deposits in the reference Borehole section 1-Balneologicheskva (Southern Timan). Stratigraphy and Geological Correlation, 16(2), 143-161.

Telnova, O., Soboleva, M., Sobolev, D., 2019. Upper Devonian *Cristatisporites deliquescens* Palynozone and its Correlation (Timan-North Urals Region). Filodiritto Editore -Proceedings, 253-261.

Trindade, V.S.F., Carvalho, M.A., 2018. Paleoenvironment reconstruction of Parnaíba Basin (north, Brazil) using indicator species analysis (IndVal) of Devonian microphytoplankton. Mar. Micropaleont., 140, 69-80.

Vanguestaine, M., Declairfayt, T., Rouhart, A., Smeesters, A., 1983. Zonation par acritarches du Frasnien supérieur-Famennien inférieur dans les bassins de Dinant, Namur, Herve et Campine (Dévonien supérieur de Belgique). Ann. Soc. Géol. Belg., 106, 121-171.

Zambrano, E.R.N.; Oliveira, O.M.C.; Severiano Ribeiro, H.J.P., 2017. Caracterização geoquímica com indícios paleoambientais de folhelhos da Formação Pimenteiras, estado do Tocantins, Bacia do Parnaíba, Brasil. Rev. Inst. Geoc. USP, 17, 67-78.
Zwan, C.J. van der, 1980. Aspects of late devonian and early carboniferous palynology of southern Ireland. II. The Auroraspora macra morphon. Rev. Palalaebot. Palynol., 30, 133-155.

Fig. 1: Location map of the studied sites.

Fig. 2: Sedimentological compound section of sites 10, 12 and 11, and the correspondent TOC contents of the Pimenteiras Formation in the sites.

Fig. 3: Sedimentological section of site 35, and the correspondent TOC contents of the Pimenteiras Formation in the site.

Fig. 4: Sedimentological section of site 37, and the correspondent TOC contents of the Pimenteiras Formation in the site.

Fig. 5: Miospore biostratigraphic scale from the Old Red Sandstone Continent (A), correlated with Brazil (B). Most probable age of the analysed samples (C). Extension of the most diagnostic species of Acritarchs and other microalgal remains recognised in the material studied, age and correlation of the interval represented.

Fig. 6: Miospore biostratigraphic scale from the Old Red Sandstone Continent (A), correlated with Brazil (B). Based on the biostratigraphic range observed in the Boulonais sections, France (Streel et al., in preparation) of some important species. Most probable age of the analysed samples (C)

<table><caption>Tbl. 1: Pyrolysis and Total Organic Carbon content (TOC) data from Sites 10, 11, 12 and 35 using Rock-Eval Pyrolysis method.</caption><thead><tr><th rowspan="2">Profundida<br>de</th><th rowspan="2">Bar<br>quin<br>ha</th><th rowspan="2">Barq.<br>+Amo<br>st.</th><th rowspan="2">De<br>sca<br>r.</th><th rowspan="2">P<br>es<br>o</th><th rowspan="2">R<br>.l</th><th colspan="2">C<br>O</th><th rowspan="2">Mas<br>sa<br>(mg)</th><th rowspan="2">S1<br>(mg<br>/g)</th><th rowspan="2">S2<br>(mg<br>/g)</th><th rowspan="2">S3<br>(mg<br>/g)</th><th rowspan="2">Tm<br>ax(°<br>C)</th><th colspan="2">C<br>O</th><th rowspan="2">I<br>H</th><th rowspan="2">I<br>O</th></tr><tr><th>T<br>%</th><th>S<br>%</th><th>T<br>%</th><th>S<br>%</th></tr></thead><tbody><tr><td rowspan="5">AMT 01</td><td rowspan="5">37.0<br>49</td><td rowspan="5">37.30<br>2</td><td rowspan="5">37.<br>29<br>7</td><td>0.<br>2<br>5<br>3</td><td>9<br>5<br>8</td><td>0.<br>1<br>40</td><td>1.<br>7</td><td rowspan="5">AM-<br>1</td><td rowspan="5">63.0<br>2</td><td rowspan="5">0.0<br>5</td><td rowspan="5">4.7<br>5</td><td rowspan="5">0.2</td><td rowspan="5">42<br>5</td><td rowspan="5">1.<br>40</td><td>3<br>3<br>9</td><td>1<br>4</td></tr></tbody></table>
<table><tbody><tr><td>AMT 01 A</td><td>38.2<br>37</td><td>38.48<br>5</td><td>38.<br>48<br>1</td><td>0.<br>2<br>4<br>8</td><td>9<br>8</td><td>1.<br>29</td><td>0<br>1<br>0</td><td>1-<br>TOA</td><td>54.6<br>9</td><td>0.0<br>7</td><td>4.4<br>6</td><td>0.1<br>6</td><td>43<br>1</td><td>1.<br>29</td><td>3<br>4<br>6</td><td>1<br>2</td></tr><tr><td>AMT 02</td><td>37.9<br>07</td><td>38.16<br>1</td><td>38.<br>15<br>8</td><td>0.<br>2<br>5<br>4</td><td>9<br>9</td><td>1.<br>47</td><td>0<br>0<br>5</td><td>2-TO</td><td>58.9<br>9</td><td>0.0<br>7</td><td>5.1<br>1</td><td>0.4</td><td>42<br>6</td><td>1.<br>47</td><td>3<br>4<br>8</td><td>2<br>7</td></tr><tr><td>AMT 03</td><td>36.9<br>53</td><td>37.20<br>6</td><td>37.<br>20<br>2</td><td>0.<br>2<br>5<br>3</td><td>9<br>8</td><td>1.<br>22</td><td>0<br>0<br>5</td><td>3-TO</td><td>56.6<br>8</td><td>0.0<br>7</td><td>3.7<br>9</td><td>0.2<br>4</td><td>42<br>6</td><td>1.<br>22</td><td>3<br>1<br>2<br>0</td><td>1<br>0</td></tr><tr><td>AMT 04</td><td>38.0<br>79</td><td>38.33<br>1</td><td>38.<br>32<br>9</td><td>0.<br>2<br>5<br>2</td><td>9<br>9</td><td>1.<br>24</td><td>0<br>0<br>5</td><td>4 TO</td><td>51.7</td><td>0.0<br>5</td><td>4.4<br>1</td><td>0.1<br>4</td><td>42<br>8</td><td>1.<br>24</td><td>3<br>5<br>6</td><td>1<br>1</td></tr><tr><td>AMT 05</td><td>38.4<br>21</td><td>38.67<br>0</td><td>38.<br>65<br>6</td><td>0.<br>2<br>4<br>9</td><td>9<br>4</td><td>1.<br>16</td><td>0.<br>1<br>1</td><td>5 TO</td><td>73.5</td><td>0.0<br>5</td><td>1.6<br>5</td><td>0.1<br>5</td><td>43<br>0</td><td>1.<br>16</td><td>1<br>4<br>2</td><td>1<br>3</td></tr><tr><td>AMT 05 A</td><td>37.1<br>16</td><td>37.37<br>0</td><td>37.<br>36<br>1</td><td>0.<br>2<br>5<br>4</td><td>9<br>6</td><td>1.<br>10</td><td>0.<br>0<br>7</td><td>5A<br>TO</td><td>56.7<br>4</td><td>0.0<br>2</td><td>0.9<br>1</td><td>0.2<br>9</td><td>43<br>0</td><td>1.<br>1</td><td>8<br>3</td><td>2<br>6</td></tr><tr><td>AMT 06</td><td>37.7<br>36</td><td>37.98<br>4</td><td>37.<br>97<br>3</td><td>0.<br>2<br>4<br>8</td><td>9<br>6</td><td>0.<br>77</td><td>0.<br>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>AMT 07</td><td>37.2<br>97</td><td>37.54<br>7</td><td>37.<br>52<br>6</td><td>0.<br>2<br>5<br>0</td><td>9<br>2</td><td>0.<br>55</td><td>0.<br>0<br>5</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>AMT 07 REP</td><td>37.3<br>28</td><td>37.57<br>8</td><td>37.<br>56<br>2</td><td>0.<br>2<br>5<br>0</td><td>9<br>4</td><td>0.<br>54</td><td>0.<br>0<br>7</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>AMT 08</td><td>37.7<br>06</td><td>37.95<br>7</td><td>37.<br>55<br>1</td><td>0.<br>2<br>5<br>1</td><td>9<br>5</td><td>0.<br>98</td><td>0.<br>1<br>0</td><td>8TO</td><td>56.2<br>8</td><td>0.0<br>3</td><td>0.6<br>9</td><td>0.2<br>2</td><td>42<br>9</td><td>0.<br>98</td><td>7<br>0</td><td>2<br>2</td></tr><tr><td>AMT 09</td><td>38.0<br>05</td><td>38.25<br>6</td><td>38.<br>24<br>7</td><td>0.<br>2<br>5<br>1</td><td>9<br>6</td><td>2.<br>21</td><td>2.<br>0<br>2</td><td>9 TO</td><td>67.1</td><td>0.0<br>5</td><td>0.1<br>7</td><td>0.2<br>2</td><td>42<br>2</td><td>2.<br>21</td><td>1<br>4<br>9</td><td>8</td></tr><tr><td>AMT 10</td><td>38.5<br>67</td><td>38.81<br>7</td><td>38.<br>81<br>0</td><td>0.<br>2<br>5<br>0</td><td>9<br>7</td><td>2.<br>01</td><td>0.<br>4<br>6</td><td>10<br>TO</td><td>48.2<br>4</td><td>0.0<br>6</td><td>4.6<br>4</td><td>0.4<br>1</td><td>42<br>7</td><td>2.<br>01</td><td>2<br>3<br>1</td><td>2<br>0</td></tr><tr><td>AMT 11</td><td>37.7<br>53</td><td>38.00<br>2</td><td>37.<br>99<br>3</td><td>0.<br>2<br>4<br>9</td><td>9<br>6</td><td>1.<br>34</td><td>0.<br>2<br>0</td><td>11<br>TO</td><td>49.5</td><td>0.0<br>6</td><td>2.2<br>1</td><td>0.3<br>6</td><td>42<br>3</td><td>1.<br>34</td><td>1<br>6<br>5</td><td>2<br>7</td></tr><tr><td>AMT 12</td><td>37.4<br>25</td><td>37.67<br>9</td><td>37.<br>67<br>3</td><td>0.<br>2<br>5<br>4</td><td>9<br>8</td><td>1.<br>31</td><td>0.<br>1<br>0</td><td>12<br>TO</td><td>61.1</td><td>0.0<br>8</td><td>2.0<br>9</td><td>0.5<br>4</td><td>42<br>5</td><td>1.<br>31</td><td>1<br>6<br>0</td><td>4<br>1</td></tr></tbody></table>
<table><tbody><tr><td rowspan="2">AMT 13</td><td>38.8</td><td>39.14</td><td>39.13</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>96</td><td>9</td><td>7</td><td>5</td><td>9</td><td>6.</td><td>1</td><td>13</td><td>48.4</td><td>0.1</td><td>9.5</td><td>0.9</td><td>41</td><td>6.</td><td>4</td><td>1</td><td>4</td><td>4</td><td>4</td><td>4</td></tr><tr><td rowspan="2">AMT 14</td><td>37.8</td><td>38.05</td><td>38.05</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td></tr><tr><td>09</td><td>9</td><td>4</td><td>5</td><td>9</td><td>3.</td><td>4</td><td>14</td><td>0.1</td><td>7.9</td><td>0.7</td><td>42</td><td>3.</td><td>3</td><td>2</td><td>2</td><td>2</td><td>2</td><td>2</td><td>2</td></tr><tr><td rowspan="2">AMT 15</td><td>37.2</td><td>37.48</td><td>37.48</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>31</td><td>2</td><td>6</td><td>5</td><td>9</td><td>3.</td><td>4</td><td>15</td><td>3.1</td><td>1.2</td><td>41</td><td>3.</td><td>0</td><td>3</td><td>3</td><td>9</td><td>9</td><td>9</td><td>9</td><td>9</td></tr><tr><td rowspan="2">AMT 16</td><td>37.3</td><td>37.64</td><td>37.64</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>94</td><td>4</td><td>7</td><td>5</td><td>9</td><td>2.</td><td>4</td><td>16</td><td>0.0</td><td>3.5</td><td>0.7</td><td>42</td><td>2.</td><td>4</td><td>2</td><td>2</td><td>8</td><td>8</td><td>8</td><td>8</td></tr><tr><td rowspan="2">AMT 17</td><td>38.9</td><td>39.20</td><td>39.20</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td></tr><tr><td>48</td><td>1</td><td>5</td><td>5</td><td>9</td><td>3.</td><td>2</td><td>17</td><td>0.1</td><td>7.7</td><td>1.0</td><td>42</td><td>3.</td><td>4</td><td>3</td><td>3</td><td>3</td><td>3</td><td>3</td><td>3</td></tr><tr><td rowspan="2">AMT 18</td><td>36.9</td><td>37.22</td><td>37.22</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td></tr><tr><td>71</td><td>0</td><td>6</td><td>4</td><td>9</td><td>2.</td><td>2</td><td>18</td><td>0.0</td><td>7.3</td><td>0.4</td><td>42</td><td>2.</td><td>7</td><td>1</td><td>1</td><td>6</td><td>6</td><td>6</td><td>6</td></tr><tr><td rowspan="2">AMT 19</td><td>38.0</td><td>38.34</td><td>38.34</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td></tr><tr><td>99</td><td>9</td><td>0</td><td>5</td><td>4</td><td>1.</td><td>0</td><td>19</td><td>0.0</td><td>0.4</td><td>2.4</td><td>43</td><td></td><td>4</td><td>4</td><td>4</td><td>7</td><td>7</td><td>7</td><td>7</td></tr><tr><td rowspan="2">AMT 20</td><td>37.4</td><td>37.71</td><td>37.71</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>65</td><td>4</td><td>4</td><td>4</td><td>4</td><td>0.</td><td>1</td><td>0.1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td></tr><tr><td rowspan="2">AMT 21</td><td>38.1</td><td>38.38</td><td>38.38</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>30</td><td>1</td><td>0</td><td>5</td><td>5</td><td>1.</td><td>0</td><td>21T</td><td>0.0</td><td>0.9</td><td>1.0</td><td>43</td><td>1.</td><td>5</td><td>6</td><td>6</td><td>2</td><td>2</td><td>2</td><td>2</td></tr><tr><td rowspan="2">AMT 22</td><td>37.9</td><td>38.18</td><td>38.18</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>32</td><td>2</td><td>0</td><td>5</td><td>4</td><td>0.</td><td>1</td><td>0.1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td></tr><tr><td rowspan="2">AMT 23</td><td>38.6</td><td>38.85</td><td>38.85</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>06</td><td>6</td><td>7</td><td>5</td><td>9</td><td>1.</td><td>0</td><td>23</td><td>0.0</td><td>2.3</td><td>0.3</td><td>42</td><td>1.</td><td>9</td><td>2</td><td>2</td><td>6</td><td>7</td><td>7</td><td>7</td></tr><tr><td rowspan="2">AMT 24</td><td>37.9</td><td>38.23</td><td>38.23</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td></tr><tr><td>81</td><td>2</td><td>9</td><td>5</td><td>9</td><td>2.</td><td>1</td><td>24</td><td>0.0</td><td>4.3</td><td>0.7</td><td>42</td><td>2.</td><td>1</td><td>3</td><td>3</td><td>4</td><td>7</td><td>7</td><td>7</td></tr><tr><td rowspan="2">AMT 25</td><td>37.9</td><td>38.24</td><td>38.24</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td></tr><tr><td>94</td><td>6</td><td>3</td><td>5</td><td>9</td><td>0.</td><td>0</td><td>0.0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td rowspan="2">AMT 25 REP</td><td>39.1</td><td>39.42</td><td>39.42</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>73</td><td>3</td><td>8</td><td>5</td><td>9</td><td>0.</td><td>0</td><td>0.0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr></tbody></table>
<table><tbody><tr><td rowspan="2">AMT 26</td><td>37.9</td><td>38.21</td><td>38.21</td><td>21</td><td>5</td><td>9</td><td>1.</td><td>2</td><td>26</td><td rowspan="2">51.3</td><td rowspan="2">0.0</td><td rowspan="2">4.0</td><td rowspan="2">0.2</td><td rowspan="2">42</td><td rowspan="2">1.</td><td rowspan="2">0</td><td rowspan="2">1</td></tr><tr><td>61</td><td>4</td><td>2</td><td>3</td><td>9</td><td>97</td><td>6</td><td>TO</td><td>6</td><td>6</td><td>7</td><td>7</td><td>97</td><td>6</td><td>4</td></tr><tr><td rowspan="2">AMT 27</td><td>37.3</td><td>37.60</td><td>37.60</td><td>60</td><td>4</td><td>9</td><td>2.</td><td>3</td><td>27</td><td rowspan="2">51.6</td><td rowspan="2">0.0</td><td rowspan="2">4.1</td><td rowspan="2">0.6</td><td rowspan="2">42</td><td rowspan="2">2.</td><td rowspan="2">7</td><td rowspan="2">2</td></tr><tr><td>56</td><td>5</td><td>1</td><td>9</td><td>8</td><td>35</td><td>7</td><td>TO</td><td>8</td><td>4</td><td>2</td><td>4</td><td>35</td><td>6</td><td>6</td></tr><tr><td rowspan="2">AMT 28</td><td>37.1</td><td>37.35</td><td>37.35</td><td>33</td><td>5</td><td>9</td><td>1.</td><td>2</td><td>28</td><td rowspan="2">50.2</td><td rowspan="2">0.0</td><td rowspan="2">0.9</td><td rowspan="2">1.0</td><td rowspan="2">41</td><td rowspan="2">1.</td><td rowspan="2">5</td><td rowspan="2">6</td></tr><tr><td>05</td><td>7</td><td>2</td><td>2</td><td>0</td><td>59</td><td>8</td><td>TO</td><td>5</td><td>0.9</td><td>3</td><td>9</td><td>59</td><td>7</td><td>5</td></tr><tr><td rowspan="2">AMT 29</td><td>38.7</td><td>38.99</td><td>38.99</td><td>98</td><td>5</td><td>9</td><td>0.</td><td>0</td><td></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td></tr><tr><td>41</td><td>3</td><td>4</td><td>2</td><td>6</td><td>89</td><td>8</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 30</td><td>36.5</td><td>36.82</td><td>36.82</td><td>81</td><td>4</td><td>9</td><td>0.</td><td>1</td><td>30</td><td rowspan="2">65</td><td rowspan="2">0.0</td><td rowspan="2">0.5</td><td rowspan="2">0.3</td><td rowspan="2">42</td><td rowspan="2">0.</td><td rowspan="2">6</td><td rowspan="2">3</td></tr><tr><td>72</td><td>1</td><td>2</td><td>9</td><td>6</td><td>90</td><td>1</td><td>TO</td><td>5</td><td>3</td><td>8</td><td>9</td><td>1</td><td>7</td><td>1</td></tr><tr><td rowspan="2">AMT 31</td><td>38.3</td><td>38.62</td><td>38.62</td><td>61</td><td>4</td><td>9</td><td>0.</td><td>1</td><td>31</td><td rowspan="2">47.0</td><td rowspan="2">0.0</td><td rowspan="2">0.4</td><td rowspan="2">0.4</td><td rowspan="2">42</td><td rowspan="2">0.</td><td rowspan="2">4</td><td rowspan="2">4</td></tr><tr><td>80</td><td>8</td><td>5</td><td>8</td><td>5</td><td>97</td><td>4</td><td>TO</td><td>3</td><td>4</td><td>2</td><td>97</td><td>5</td><td>1</td></tr><tr><td rowspan="2">AMT 32</td><td>38.4</td><td>38.73</td><td>38.73</td><td>72</td><td>5</td><td>9</td><td>1.</td><td>2</td><td>32</td><td rowspan="2">51.7</td><td rowspan="2">0.0</td><td rowspan="2">2.4</td><td rowspan="2">0.5</td><td rowspan="2">42</td><td rowspan="2">1.</td><td rowspan="2">6</td><td rowspan="2">3</td></tr><tr><td>80</td><td>1</td><td>7</td><td>1</td><td>8</td><td>48</td><td>2</td><td>TO</td><td>6</td><td>8</td><td>6</td><td>5</td><td>48</td><td>8</td><td>8</td></tr><tr><td rowspan="2">AMT 33</td><td>38.2</td><td>38.48</td><td>38.48</td><td>48</td><td>4</td><td>9</td><td>1.</td><td>3</td><td>33</td><td rowspan="2">53.6</td><td rowspan="2">0.0</td><td rowspan="2">1.6</td><td rowspan="2">0.2</td><td rowspan="2">42</td><td rowspan="2">1.</td><td rowspan="2">1</td><td rowspan="2">1</td></tr><tr><td>40</td><td>7</td><td>2</td><td>7</td><td>8</td><td>34</td><td>1</td><td>TO</td><td>5</td><td>3</td><td>1</td><td>34</td><td>9</td><td>7</td></tr><tr><td rowspan="2">AMT 34</td><td>37.5</td><td>37.81</td><td>37.81</td><td>80</td><td>5</td><td>9</td><td>1.</td><td>1</td><td>34</td><td rowspan="2">54.2</td><td rowspan="2">0.0</td><td rowspan="2">1.6</td><td rowspan="2">0.2</td><td rowspan="2">42</td><td rowspan="2">1.</td><td rowspan="2">4</td><td rowspan="2">2</td></tr><tr><td>65</td><td>6</td><td>9</td><td>1</td><td>7</td><td>14</td><td>3</td><td>TO</td><td>4</td><td>6</td><td>8</td><td>2</td><td>14</td><td>6</td><td>5</td></tr><tr><td rowspan="2">AMT 35</td><td>37.7</td><td>37.95</td><td>37.95</td><td>52</td><td>5</td><td>9</td><td>0.</td><td>0</td><td></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td></tr><tr><td>02</td><td>2</td><td>3</td><td>0</td><td>1</td><td>28</td><td>7</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 36</td><td>39.1</td><td>39.44</td><td>39.44</td><td>43</td><td>5</td><td>9</td><td>0.</td><td>0</td><td></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td></tr><tr><td>98</td><td>9</td><td>1</td><td>1</td><td>3</td><td>19</td><td>8</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 37</td><td>38.8</td><td>39.11</td><td>39.11</td><td>07</td><td>5</td><td>8</td><td>0.</td><td>1</td><td></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td></tr><tr><td>57</td><td>0</td><td>0</td><td>3</td><td>4</td><td>39</td><td>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 37 ARG BRC</td><td>37.7</td><td>38.03</td><td>38.03</td><td>01</td><td>5</td><td>9</td><td>1.</td><td>1</td><td>37 ARG</td><td rowspan="2">67.7</td><td rowspan="2">0.0</td><td rowspan="2">0.8</td><td rowspan="2">0.2</td><td rowspan="2">42</td><td rowspan="2">1.</td><td rowspan="2">8</td><td rowspan="2">2</td></tr><tr><td>83</td><td>5</td><td>2</td><td>2</td><td>1</td><td>00</td><td>8</td><td>BRC</td><td>7</td><td>2</td><td>2</td><td>6</td><td>00</td><td>2</td><td>2</td></tr><tr><td rowspan="2">AMT 38</td><td>38.4</td><td>38.66</td><td>38.66</td><td>63</td><td>4</td><td>8</td><td>0.</td><td>1</td><td></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td></tr><tr><td>17</td><td>5</td><td>8</td><td>8</td><td>9</td><td>32</td><td>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table>
<table><tbody><tr><td rowspan="2">AMT 39</td><td>38.0</td><td>38.30</td><td>38.29</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>55</td><td>6</td><td>2</td><td>5</td><td>9</td><td>3.</td><td>1</td><td>39</td><td>53.9</td><td>0.1</td><td>4.6</td><td>1.6</td><td>42</td><td>3.</td><td>3</td><td>4</td><td>7</td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 40</td><td>38.5</td><td>38.82</td><td>38.82</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>79</td><td>9</td><td>1</td><td>5</td><td>9</td><td>2.</td><td>1</td><td>40</td><td>61.6</td><td>0.0</td><td>3.2</td><td>1.4</td><td>41</td><td>2.</td><td>1</td><td>5</td><td>3</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 41</td><td>38.9</td><td>39.24</td><td>39.24</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>95</td><td>2</td><td>4</td><td>4</td><td>9</td><td>3.</td><td>1</td><td>41</td><td>56.1</td><td>0.1</td><td>5.0</td><td>2.3</td><td>42</td><td>3.</td><td>6</td><td>7</td><td>5</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 42</td><td>37.9</td><td>38.15</td><td>38.15</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td></tr><tr><td>07</td><td>6</td><td>0</td><td>4</td><td>9</td><td>3.</td><td>0</td><td>42</td><td>59.4</td><td>0.1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 42 REP</td><td>37.2</td><td>37.54</td><td>37.54</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>96</td><td>5</td><td>5</td><td>4</td><td>9</td><td>3.</td><td>0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 43</td><td>38.7</td><td>38.97</td><td>38.97</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>20</td><td>2</td><td>0</td><td>5</td><td>9</td><td>0.</td><td>0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 44</td><td>37.6</td><td>37.85</td><td>37.85</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>06</td><td>7</td><td>8</td><td>5</td><td>8</td><td>0.</td><td>0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 45</td><td>37.7</td><td>38.00</td><td>38.00</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>52</td><td>2</td><td>5</td><td>5</td><td>9</td><td>0.</td><td>0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 46</td><td>38.0</td><td>38.24</td><td>38.24</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>01</td><td>9</td><td>9</td><td>4</td><td>9</td><td>0.</td><td>0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 47</td><td>38.9</td><td>39.25</td><td>39.25</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>87</td><td>7</td><td>5</td><td>5</td><td>9</td><td>0.</td><td>0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 48</td><td>37.1</td><td>37.41</td><td>37.41</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>61</td><td>1</td><td>5</td><td>5</td><td>9</td><td>4.</td><td>2</td><td>48</td><td>82.4</td><td>0.1</td><td>4.9</td><td>1.6</td><td>42</td><td>4.</td><td>1</td><td>3</td><td>9</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 49</td><td>37.8</td><td>38.05</td><td>38.05</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>03</td><td>3</td><td>5</td><td>5</td><td>9</td><td>1.</td><td>3</td><td>49</td><td>83.3</td><td>0.0</td><td>2.8</td><td>43</td><td>1.</td><td>4</td><td>1</td><td>0</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 50</td><td>38.8</td><td>39.14</td><td>39.14</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>94</td><td>0</td><td>0</td><td>4</td><td>9</td><td>6.</td><td>0</td><td>50</td><td>45.5</td><td>0.2</td><td>11.</td><td>1.9</td><td>42</td><td>6.</td><td>6</td><td>2</td><td>8</td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 51</td><td>38.8</td><td>39.09</td><td>39.09</td><td>0.2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td></tr><tr><td>47</td><td>7</td><td>7</td><td>5</td><td>9</td><td>2.</td><td>0</td><td>51</td><td>46.8</td><td>0.0</td><td>4.4</td><td>0.1</td><td>42</td><td>2.</td><td>8</td><td>4</td><td>5</td><td></td><td></td><td></td><td></td></tr></tbody></table>
<table><tr><td></td><td></td><td></td><td></td><td>0.</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td></td><td></td><td></td><td></td><td>2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 95</td><td>38.6</td><td>38.94</td><td>38.94</td><td>38.94</td><td>5</td><td>9</td><td>1.</td><td>0</td><td>95</td><td>0.0</td><td>2.5</td><td>0.8</td><td>42</td><td>1.</td><td>7</td><td>5</td><td>1</td></tr><tr><td>91</td><td>3</td><td>0</td><td>0</td><td>2</td><td>9</td><td>44</td><td>9</td><td>TO</td><td>60.5</td><td>6</td><td>8</td><td>5</td><td>7</td><td>44</td><td>9</td><td>9</td></tr><tr><td></td><td></td><td></td><td></td><td>0.</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="2">AMT 51</td><td>38.3</td><td>38.44</td><td>38.44</td><td>38.44</td><td>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>19</td><td>4</td><td>4</td><td>8</td><td>2</td><td>9</td><td>2.</td><td>1.</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td></td><td></td><td></td><td></td><td>5</td><td>5</td><td>21</td><td>6</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr></table>

<table><thead><tr><th>Sit<br>e</th><th>Sample<br>s</th><th>S1 (mg HC/g<br>rock)</th><th>S2 (mg HC/g<br>rock)</th><th>S3 (mg CO2/g<br>rock)</th><th>Tmax(°<br>C)</th><th>TOC<br>(%)</th><th>HI (mg HC/g<br>TOC)</th></tr></thead><tbody><tr><td rowspan="4">11</td><td>12</td><td>0.08</td><td>2.09</td><td>0.54</td><td>425</td><td>1.31</td><td>160</td></tr><tr><td>11</td><td>0.06</td><td>2.21</td><td>0.36</td><td>423</td><td>1.34</td><td>165</td></tr><tr><td>10</td><td>0.06</td><td>4.64</td><td>0.41</td><td>427</td><td>2.01</td><td>231</td></tr><tr><td>9</td><td>0.05</td><td>3.30</td><td>0.17</td><td>422</td><td>2.21</td><td>149</td></tr><tr><td rowspan="6">12</td><td>18</td><td>0.07</td><td>7.31</td><td>0.44</td><td>428</td><td>2.68</td><td>273</td></tr><tr><td>17</td><td>0.11</td><td>7.78</td><td>1.00</td><td>427</td><td>3.19</td><td>244</td></tr><tr><td>16</td><td>0.07</td><td>3.54</td><td>0.71</td><td>424</td><td>2.51</td><td>141</td></tr><tr><td>15</td><td>0.10</td><td>3.14</td><td>1.22</td><td>418</td><td>3.09</td><td>102</td></tr><tr><td>14</td><td>0.11</td><td>7.99</td><td>0.73</td><td>427</td><td>3.38</td><td>236</td></tr><tr><td>13</td><td>0.17</td><td>9.55</td><td>0.92</td><td>417</td><td>6.57</td><td>145</td></tr><tr><td rowspan="4">10</td><td>8</td><td>0.03</td><td>0.69</td><td>0.22</td><td>429</td><td>0.98</td><td>70</td></tr><tr><td>7</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>6</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>5</td><td>0.04</td><td>1.55</td><td>0.15</td><td>430</td><td>1.16</td><td>142</td></tr><tr><td rowspan="6">35</td><td>48</td><td>0.13</td><td>4.99</td><td>1.64</td><td>420</td><td>4.24</td><td>118</td></tr><tr><td>49</td><td>0.03</td><td>2.86</td><td>0.20</td><td>430</td><td>1.94</td><td>147</td></tr><tr><td>50</td><td>0.26</td><td>11.28</td><td>1.95</td><td>420</td><td>6.95</td><td>162</td></tr><tr><td>51</td><td>0.05</td><td>4.47</td><td>0.11</td><td>427</td><td>2.43</td><td>184</td></tr><tr><td>52</td><td>0.06</td><td>1.86</td><td>0.94</td><td>424</td><td>1.53</td><td>122</td></tr><tr><td>54</td><td>0.04</td><td>2.82</td><td>0.38</td><td>432</td><td>1.00</td><td>282</td></tr><tr><td rowspan="6">62</td><td>55</td><td>0.05</td><td>9.26</td><td>0.76</td><td>429</td><td>3.05</td><td>304</td></tr><tr><td>58</td><td>0.06</td><td>7.36</td><td>0.30</td><td>429</td><td>2.37</td><td>311</td></tr><tr><td>59</td><td>0.08</td><td>9.87</td><td>0.82</td><td>431</td><td>2.75</td><td>359</td></tr><tr><td>60</td><td>0.04</td><td>6.15</td><td>0.49</td><td>426</td><td>2.30</td><td>267</td></tr><tr><td>61</td><td>0.06</td><td>7.90</td><td>0.31</td><td>427</td><td>2.76</td><td>286</td></tr><tr><td>62</td><td>0.07</td><td>10.18</td><td>0.25</td><td>428</td><td>3.03</td><td>336</td></tr><tr><td>63</td><td>0.07</td><td>8.60</td><td>0.47</td><td>429</td><td>2.70</td><td>319</td></tr><tr><td>64</td><td>0.06</td><td>6.18</td><td>0.97</td><td>427</td><td>2.38</td><td>260</td></tr><tr><td>65</td><td>0.05</td><td>7.20</td><td>0.52</td><td>426</td><td>2.31</td><td>312</td></tr></tbody></table>
<table><tr><td>66</td><td>0.07</td><td>7.61</td><td>0.79</td><td>431</td><td>2.32</td><td>328</td></tr><tr><td>67</td><td>0.09</td><td>8.94</td><td>0.24</td><td>427</td><td>3.05</td><td>293</td></tr><tr><td>68</td><td>0.12</td><td>9.27</td><td>0.90</td><td>427</td><td>3.49</td><td>266</td></tr><tr><td>69</td><td>0.06</td><td>2.69</td><td>0.75</td><td>421</td><td>1.72</td><td>156</td></tr><tr><td>70</td><td>0.03</td><td>1.52</td><td>0.39</td><td>429</td><td>0.99</td><td>154</td></tr><tr><td>71</td><td>0.04</td><td>1.83</td><td>0.18</td><td>427</td><td>1.24</td><td>148</td></tr><tr><td>73</td><td>0.03</td><td>1.17</td><td>0.28</td><td>427</td><td>1.01</td><td>116</td></tr><tr><td>74</td><td>0.03</td><td>0.87</td><td>0.24</td><td>420</td><td>1.22</td><td>71</td></tr><tr><td>75</td><td>0.13</td><td>8.99</td><td>1.73</td><td>424</td><td>2.80</td><td>321</td></tr><tr><td>76</td><td>0.03</td><td>5.06</td><td>0.31</td><td>433</td><td>4.20</td><td>120</td></tr><tr><td>77</td><td>0.04</td><td>3.93</td><td>0.45</td><td>432</td><td>3.82</td><td>103</td></tr><tr><td>78</td><td>0.03</td><td>3.72</td><td>0.21</td><td>432</td><td>3.73</td><td>100</td></tr></table>

<table><tr><td>82</td><td>0.08</td><td>4.31</td><td>0.24</td><td>424</td><td>1.27</td><td>339</td></tr><tr><td>83</td><td>0.06</td><td>2.07</td><td>0.31</td><td>421</td><td>1.00</td><td>207</td></tr><tr><td>84</td><td>0.08</td><td>2.12</td><td>0.23</td><td>422</td><td>1.04</td><td>204</td></tr><tr><td>85</td><td>0.07</td><td>3.02</td><td>0.5</td><td>422</td><td>2.69</td><td>112</td></tr><tr><td>86</td><td>0.05</td><td>2.99</td><td>0.27</td><td>421</td><td>2.46</td><td>122</td></tr><tr><td><b>37</b></td><td>87</td><td>0.22</td><td>5.89</td><td>1.15</td><td>428</td><td>2.50</td><td>236</td></tr><tr><td>88</td><td>0.06</td><td>3.27</td><td>0.65</td><td>425</td><td>2.84</td><td>115</td></tr><tr><td>89</td><td>0.04</td><td>1.16</td><td>0.56</td><td>426</td><td>2.05</td><td>57</td></tr><tr><td>90</td><td>0.04</td><td>1.63</td><td>0.7</td><td>425</td><td>1.83</td><td>89</td></tr><tr><td>91</td><td>0.08</td><td>4.24</td><td>1.41</td><td>423</td><td>1.69</td><td>251</td></tr></table>

samples

<table><thead><tr><th></th><th></th><th>TOC (%)</th></tr></thead><tbody><tr><td>1</td><td></td><td>1.31</td></tr><tr><td>2</td><td></td><td>1.34</td></tr><tr><td>3</td><td></td><td>2.01</td></tr><tr><td>4</td><td></td><td>2.21</td></tr><tr><td>5</td><td></td><td>2.68</td></tr><tr><td>6</td><td></td><td>3.19</td></tr><tr><td>7</td><td></td><td>2.51</td></tr><tr><td>8</td><td></td><td>3.09</td></tr><tr><td>9</td><td></td><td>3.38</td></tr><tr><td>10</td><td></td><td>6.57</td></tr><tr><td>11</td><td></td><td>0.98</td></tr><tr><td>12</td><td></td><td>1.16</td></tr></tbody></table>
Plate I

Acritarchs: Specimens are located according the sample number and the England finders coordinates. The diameter size is provided in µm.

1. *Maranhites brasiliensis* Brito, 1965 emend Burjack and Oliveira 1989. Site 11, AM 12, 18K 224, D24/2, total diameter 125 µm

2. *Maranhites lobulatus* Burjack and Oliveira 1989, Site 11, AM 12, 18K 224, Q26, total diameter 145 µm

3. *Maranhites stockmansii* (Martin) Martin, 1984, Site 11, AM 12, 18K 224, Q26, total diameter 145 µm

4. *Maranhites mosesii* (= *M. insulatus* Burjack and Oliveira, 1989) (Sommer, 1956) Brito, 1967. Site 11, AM 12, 18K 224, E35/4, total diameter 120 µm

5. *Petrovina connata* Oliveira and Burjack, 1959. Site 10, AM 7, 18K 220, K13/4, total diameter 145 µm, cells 45 µm.

6. *Pterospermopsis crassimarginata* Burjack and Oliveira *apud* Oliveira, 2007, *nomen nudum*. Site 11, AM 12, 18K 224 D10/2, total diameter 45-50 µm

7. *Crucidia camirense* (Lobo Boneta) Ottone, 1996, Site 10, AM 7, 18K 220, F16/3, total length of the processes 20-35 µm.

8. *Pseudolunulidia micropunctata* Brito and Quadros, 1984. Site 35, AM 68, 18L30, 77131, J44/2, central body width 41 µm.

9. *Navifusa bacilla* (Deunff) Playford, 1977 forma *crescentis*. Site 10, AM 7, 18K220, T42/4, width of central body 25 µm.

10. *Disparifusa urariaensis* Le Hérissé, 2013, *nomen nudum*, Site 11, AM 12, 18K224, N15/2, length 52 µm, width 22 µm.

11. *Umbellasphaeridium deflandrei* (Moreau-Benoit) Jardiné et al., 1972. Site 11, AM 10, 18K 223, L31/2, total diameter 38 µm
12, 13. *Horologinella quadrispina* Jardiné, et al., 1972. 12. Site 11, AM 9, 18K 222, H17/4, central body 45x50 µm, process length 6-10 µm. 13. Site 35, AM 78, 18L33, 77146, G29, central body 42x24 µm, process length 14.5 µm

14-16. *Duvernaysphaera cruciformis* Le Hérissé, 2001, *nomen nudum* sp. nov.sp. 14. Paratype, site 35, AM 58, 18L27, 77116, S36, central body 30 µm, flange 5,6 µm; 15. Paratype, site 35, AM 58, 18L27, 77116, P32, central body 36 µm, flange 3 µm; 16. Holotype, site 35, AM 76, 18L32, 77141, Q28, central body 36 µm, flange 6,7 µm

17. *Duvernaysphaera angelae* (=D. tessella) Deunff, 1964. Site 11, AM 12, 18K224, Q38/3, Total diameter 45 µm.

## Plate II

Acritarchs: Specimens are located according to the sample number and the England finders coordinates. The diameter size is provided in µm.

1. *Mediocorpore conspicuus* Burjack and Oliveira *apud* Oliveira, 1997, *nomen nudum*. Site 11, AM 12, 18K 224, E16/2, total length 1-à µm, width, 40 µm, length of the central body 85 µm.

2. *Duvernaysphaera radialis* Frito, 1967a. Site 11, AM 12, 18K 224, M43/3, total diameter 140 µm.

3. *Puteoscortum williereae* Martin, 1981. Site 35, AM 78, 77148, C40/3, CC 42 µm, LP 21 µm

4. *Advenasphaeridium australis* Burjack and Oliveira 1997, *nomen nudum*. Site 11, AM 11, 18K 223, H43/2, central body 39 µm, Lp 33 µm

5. *Puteoscortum williereae* Martin, 1981. Site 37, AM 89, 77163, S41, CC 33 µm, Lp 22 µm
6. *Leiofusa bisubulata* Brito and Quadros, 1984. Site 35, AM 68, 77133, Q 29/4, central body 35x156 µm, Lp 56 µm.

7-9. ?Chomotriletes sp. A. 7. Site 11, AM 9, 18K 222, J13/4, total diameter 56 µm. 8. Site 37, AM 85, 77151, P15, total diameter 31 µm; 9. Site 37, AM 85, 77151, N32 Total diameter 50 µm.

10. *Unellium ampullium* Wicander, 1974. Site 11, AM 12, 18K 224, V28/2, central body 18 µm, process length 20 µm.

11. *Diaphorochroa gracile* Burjack and Oliveira *apud* Oliveira, 1927, *nomen nudum*. Site 35, AM 65, 77126, M43, CC 40 µm, LP 18 µm

12. *Naevisphaeridium sprucegrovenense* (Staplin, 1961) *nov. comb*. Site 35, AM 65, 77126, 039/4, CC 28 µm, LP 12 µm

13. *Naevisphaeridium desiderata* (Burjack and Oliveira *apud* Oliveira, 1997) *nomen nudum* *nov comb*. Site 37, AM 85, 77151, H36/1. Central body 31 µm, Lp 11 µm

14. *Puteoscortum limai* Burjack and Oliveira *apud* Oliveira, 1997. Site 11, AM 11, 18K 223, P25/4, central body 48 µm, Lp 22 µm

15. *Stellinium micropolygonale* (Stockmans and Willière) Playford 1977. Site 10, AM 7, 18K220, F14/4, central body 33 Lp 48 µm

16. *Estiastra spinireticu*ta Oliveira and Burjack, 1997. Site 35, AM 78, 77146, U33/4, CC 33 µm, LP 10 µm

17. *Veryhachium capitata* Le Hérissé, 2001 *nomen nudum*. Site 35, AM 75, 77136, J42/3, CC 22 µm, LP 9 µm.

18. *Veryhachium insanum* Le Hérissé, 2001, *nomen nudum*. Site 35, AM 78, 77146, U33/4, CC 24.5 µm, LP 9 µm

19. *Tinacula simplex* Quadros, 1999 Site 35, AM 58, 18L27, 77118, R39, length 89 µm, maximum width 54 µm
**20. Bipolarisvelata accreta** Burjack and Oliveira *apud* Oliveira, 1997, *nomen nudum*. Site 11, AM 12, 18K 224, E26, central body 55x35 µm, polar filamentous projections 50-65 µm long.

## Plate III

Chitinozoans: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.

1, 2. *Angocitina avelinoi* (Lange 1952). Site 11, AM11 15, O22/0; AM11 15, R30/3.

3, 4. *Angochitina mourai* (Lange 1952). Site 35, Am49 40, C32/0; Am58 50, M23/0.

5, 6. *Angochitina mourai* long neck variant *sensu* Grahn and Melo 2005. Site 37, Am85 85, H14/4; AM 58 50 U23/4.

7, 8. *Angochitina* sp.C? Grahn and Melo 2005. Site 37, Am89 95, X14/4; AM89 95, M17/3.

9, 10. *Fungochitina microspinosa* Grahn and Melo 2005. Site 37, AM89 95, M17/2; AM65 60, W24/0.

## Plate IV

Chitinozoans: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.

1, 2. *Fungochitina pilosus* (Collinson and Scott 1958). Site 35, AM65 60, C29/0; AM82 55, K17/2.

3, 4. *Lagenochitina sommeri* (Lange 1952). Site 11, AM9 11, J25/3; AM89 95, U29/0.

5, 6. *Lagenochitina* sp.A Grahn and Melo 2005. Site 37 AM89 95, O24/0; AM11 15, K27/1.

## Plate V

Miospores: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.
**1-3.** *Acinosporites acanthomammillatus* Richardson, 1965. 1 : Site 10 Am7 2, K19/2 ; 2 : Site 10 Am7 2, M21/0 ; Site 11 Am9 10, D17/3.

**4-6.** *Acinosporites eumammillatus* Loboziak et al., 1988. 4 : Site 10 Am7 2, Q17/3 ; 5 : Site 10 Am7 2, D17/1/3 ; Site 10 Am7 2, K23/0.

**7-9.** *Acinosporites lindlarensis* Riegel, 1968. 7 : Site 35 Am89 96 O15/3 ; 8 : Site 35 Am89 96 A, Q20/2 ; Site 35 Am89 96 B Q20/2.

**10.** *Ancyrospora langii* (Taugourdeau-Lantz) Allen, 1965. Site 35 Am65 60, G23/1.

**11.** *Ancyrospora simplex* Guennel, 1963. Site 35 Am76 75, W28/2.

## Plate VI

Miospores: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.

**1-3.** *Ancyrospora* sp. 1. 1 : Site 35 Am 6. 60, V18/2 ; 2 : Site 35 Am75 70, F34/1 ; 3 : Site 35 Am75 70, F34/1.

**4-5.** *Aneurospora gregstii* Aneurospora greggsii (McGregor) Streel, 1974. 4 : Site 10 Am8 6, N15/2 ; 5 : Site 11 Am9 10, T1 1/2.

**6-7.** *Apiculiretusispora* sp. 6. Site 10 Am7 2, K18/1 ; 7 : Site 10 Am7 2, N16/1-3.

**8.** *Archaeozonotriletes* sp. Am 68 65, U23/1.

**9-11.** *Archaeozonotriletes variabilis* Naumova, 1953. 9 : Site 11 Am7 2, E17/0 ; 10 : Site 11 Am9 10, V19/4 ; 11 : site 11 Am9 10, G22/0.

**12.** *Auroraspora* sp. Site 11 Am8 6, T18/0.

## Plate VII

Miospores: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.
**1-3.** *Auroraspora macra* Sullivan, 1968. 1 : Site 10 Am7 2, V17/2 ; 2 : Site 10 Am7 2, R19/3-4 ; 3 : Site 10 Am7 2, C23/2.

**4-5.** *Camarozonotriletes concavus* Loboziak et Streel, 1988. 4 : Site 10 Am7 2, O24/4 ; 5 : Site 35 Am89 95, M19/0.

**6, 9.** *Chelinospora concinna* Allen, 1965. Two different foci on the same specimen ; Site 10 Am7 2, V19/3B.

**7-9.** *Chelinospora paravermiculata* Loboziak et al., 1988. 8 : site 11 Am9 10, N18/0 ; 9 : site 35 Am 89 96, V20/0.

**10.** *Chelinospora* sp. Site 10 Am8 6, D16/3.

**11-12.** *Corystisporites corystus* Richardson, 1965. 11 : site 35 Am68 65, T26/2 ; 12 : site 35 Am85 85, 732-895.

**Plate VIII**

Miospores: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.

**1.** *Cymbosporites catillus* Allen, 1965. Site 10, Am8 6, K27/3.

**2.** *Cymbosporites cyathus* Allen, 1965. Site 10, Am8 6, U19/3.

**3-6.** *Cymbosporites magnus* (McGregor) McGregor and Camfield 1982. 3 : Site 10 Am7 2, R16/0 ; 4 : Site 10, Am 7 2, T16/3 ; 5 : Site 10, Am8 6, W23/0 ; 6 : Site 11, Am9 10, J16/3.

**7.** *Cyrtospora* sp. Site 10, Am 7 K18/1-3.

**8-9.** *Cyrtospora tumida* Breuer and Steemans 2013. Site 10, Am8 6, M22/1; Site 10 Am8 6, M26/0.

**10.** *Diatomozononotriletes franfklinii* McGregor and Camfield 1982. Site 10 Am 7 2, O17/2.

**11-12.** *Dibolisporites* sp. 1. 11 : Site 10 Am7 2, R22/3 ; 12 : Site 11, Am9 10, H17/0.
## Plate IX

Miospores: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.

1. *Dibolisporites* sp. 1. Am78 80, W32-0.

2. *Emphanisporites rotatus* McGregor emend. McGregor, 1973. Site 10, Am7 2, N21/3.

3-4. *Geminospora convoluta* Breuer and Steemans, 2013. 3: Site 10 Am7 2, M23/4; 4 : site 37, Am89 95, F24/4.

5-6. *Geminospora lemurata* Balme emend. Playford, 1983. 5 : Site 10, Am7 2, X16/2 ; 6 : Site 10, Am 7 2, B17/0.

7-8. *Geminospora macromanifesta* (Naumova) Arkhangeleska 1953. 7 : Site 35, Am76 75, N28/3 ; 8 : Site 37 Am 88 90, O28/0.

## Plate X

Miospores: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.

1-3. *Geminospora punctata* Owens, 1971. 1 : Site 10, Am8 6, K16/0 ; 2 : Site 10, Am8 6, Q20/3 ; 3 : Site 10, Am7 2, F16/3.

4-5. *Grandispora gabensis* Loboziak and Streel, 1989. 4 : Site 37, Am89 95, X22/1-3 ; 5 : Site 37 Am89 95, Q19/0.

6-7. *Grandispora libyensis* Moreau-Benoit, 1980. 6 : Site 35, Am58 50, M26/0 ; 7: Site 35, Am62 55, U24/0.

## Plate XI

Miospores: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.
**1-2.** *Grandispora naumovae* (Kedo) McGregor, 1973. 1: Site 37 Am85 85, Q29/0; 2: Site 12, Am17 35, V20/0.

**3-4.** *Grandispora permulta* (Daemon) Loboziak et al. 1999. 3: Site 10, Am8 6, M19/0; 4: Site 37, Am89 96, V17/0.

**5-6.** cf. *Grandispora* sp. 1. 5: Site 35 Am68 65, T18/0; 6: Site 37, Am89 95, L27/4.

## Pl. XII

Miospores: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.

**1-2.** *Grandispora* sp. 2. 1: Site 37, Am89 95, N14/0; 2: Site 35, Am65 60, Q15/3.

**3.** *Grandispora* sp.3. Site 35, Am76 75; P20/0.

**4-5.** *Grandispora* sp. 4. 4: Site 35, Am 76 75, P20/0; Site 35, Am75 70, L35/3.

**6.** *Grandispora* sp. A in Loboziak et al., 1981. Site 3, Am88 90, V20-3.

## Pl. XIII

Miospores: Specimens are located according the sample number and the England finders coordinates. The scale bar is annotated in µm.

**1-2.** *Grandispora tabuta* Loboziak and Streel, 1988. 1: Site 37, Am89 96, X17/2; 2: Site 10, Am7 2, B21/3.

**3.** *Incertae sedis*. Site 35, Am78 80; P19/0.

**4.** *Grandispora velata* (Richardson) McGregor, 1973. Site 35, Am85 85, X31/3.

**5.** *Hystricosporites* sp. Site 35, Am58 50, V25/0.

**6.** *Knoxisporites dedaleus* (Naumova) Streel, 1977. Site 10, Am7 2, G16/4.

**7-8.** *Lophozonotriletes dentatus* Hughes and Playford, 1961. 7: Site 10 Am7 2, S22/3; 8: Site 10, Am8 6, T16/1.
**9-10.** *Lophozonotriletes media* Taugourdeau-Lantz, 1967. 9; Site 10 Am7 2, L16/0 ; 10 :
H16/2.

11. *Lopozonotriletes* sp. Site 10, Am 8 6 ; Q15/4.

Pl. XIV

Miospores: Specimens are located according the sample number and the England finders
coordinates. The scale bar is annotated in µm.

1-4 n. g. n. sp. 1: site 35, Am19 4, V20/0 ; 2 : Site 11, Am9 10 V20/0 ; 3 : Site 11, Am9 10,
X22/3 ; 4 : Site 11, Am9 10 , P16/0.

5. *Raistirickia* sp. A in Richardson 1965: Site 11, Am9 10, Q18/2.

6. *Retusotriletes* sp. Site 10, Am7 2, J21/2.

7-8. *Rugospora cf. Rugospora bricei* in Loboziak and Streel, 1988: Site 10, Am7 2, B19/0 ;
8 : Site 10, Am7 2, O18/36.

9. *Samarisporites* sp., Site 10, Am7 2, F19/3.

10-12. *Samarisporites* sp. C in Loboziak et al. 1983. 10 : Site 10, Am7 2, T16/3 ; 11 : Site 10, Am 7 2, 12, V24/1 ; Site 11, A9 10, O17/2.

Pl. XV

Miospores: Specimens are located according the sample number and the England finders
coordinates. The scale bar is annotated in µm.

1-3. *Samarisporites triangulatus* Allen, 1965. 1 : Site 10, Am8 6, X21/2 ; 2 : Site 11, Site 11, Am9 10, Q22/1 ; 3 : Site 10, Am7 2 ; G21/0.

4-6. *Verrucosisporites bulliferus* Richardson et Mc Gregor, 1986.4 : Site 10, Am7 2, V16/4 ;
5 : Site 37, Am89 96 ; V17/1 ; 6 : Site 7, Am 8 6, G27/4.
**7-9. Verrucosisporites premnus-scurrus** Morphon Breuer and Steemans, 2013. 7: Site 10, Am7 2, B17/1-3; 8: Site 11, Am9 10, N18/3; Site 10, Am7 2, S18/3.

Highlights

* Miospores, acritarchs and chitinozoans are relatively abundant and well preserved

* Palynomorphs provide a concordant age corresponding to the mid-Frasnian

* Miospores are correlated with the conodont biostratigraphic scale from the Boulonnais

* Palynomorphs are characteristic of the Gondwana and more precisely from Brazil

* Effective generation of hydrocarbon is dependent of the igneous effect
<figure><img src="image_2.png" /><figcaption>Figure 1</figcaption></figure>

<figure><img src="image_3.png" /><figcaption>Figure 2</figcaption></figure>
<figure><img src="image_4.png" /><figcaption>Figure 3</figcaption></figure>
<figure><img src="image_5.png" /><figcaption>Figure 4</figcaption></figure>
<figure><img src="image_6.png" /><figcaption>Figure 5</figcaption></figure>
<figure><img src="image_7.png" /><figcaption>Figure 6</figcaption></figure>

<figure><img src="image_8.png" /></figure>
<figure><img src="image_9.png" /><figcaption>Plate I.</figcaption></figure>
<figure><img src="image_10.png" /></figure>

<figure><img src="image_11.png" /></figure>

<figure><img src="image_12.png" /></figure>

<figure><img src="image_13.png" /></figure>

<figure><img src="image_14.png" /></figure>

<figure><img src="image_15.png" /></figure>

<figure><img src="image_16.png" /></figure>

<figure><img src="image_17.png" /></figure>

<figure><img src="image_18.png" /></figure>

<figure><img src="image_19.png" /></figure>

<figure><img src="image_20.png" /></figure>

<figure><img src="image_21.png" /></figure>

<figure><img src="image_22.png" /></figure>

<figure><img src="image_23.png" /></figure>

<figure><img src="image_24.png" /></figure>

<figure><img src="image_25.png" /></figure>

<figure><img src="image_26.png" /></figure>

<figure><img src="image_27.png" /></figure>

<figure><img src="image_28.png" /></figure>

<figure><img src="image_29.png" /></figure>
<figure><img src="image_30.png" /></figure>
<figure><img src="image_31.png" /></figure>

11

<figure><img src="image_32.png" /></figure>

12

<figure><img src="image_33.png" /></figure>

13

<figure><img src="image_34.png" /></figure>

14

<figure><img src="image_35.png" /></figure>

15

<figure><img src="image_36.png" /></figure>

16
<figure><img src="image_37.png" /></figure>

<figure><img src="image_38.png" /></figure>

<figure><img src="image_39.png" /></figure>

<figure><img src="image_40.png" /></figure>

<figure><img src="image_41.png" /></figure>

<figure><img src="image_42.png" /></figure>

<figure><img src="image_43.png" /></figure>

<figure><img src="image_44.png" /></figure>

<figure><img src="image_45.png" /></figure>

<figure><img src="image_46.png" /></figure>

<figure><img src="image_47.png" /></figure>
<figure><img src="image_48.png" /></figure>

<figure><img src="image_49.png" /></figure>

<figure><img src="image_50.png" /></figure>

<figure><img src="image_51.png" /></figure>

<figure><img src="image_52.png" /></figure>

<figure><img src="image_53.png" /></figure>

<figure><img src="image_54.png" /></figure>

<figure><img src="image_55.png" /></figure>

<figure><img src="image_56.png" /></figure>

<figure><img src="image_57.png" /></figure>

<figure><img src="image_58.png" /></figure>

<figure><img src="image_59.png" /></figure>
<figure><img src="image_60.png" /><figcaption>Plate VII.</figcaption></figure>
<figure><img src="image_61.png" /><figcaption>Plate VIII.</figcaption></figure>
<figure><img src="image_62.png" /></figure>

<figure><img src="image_63.png" /></figure>

<figure><img src="image_64.png" /></figure>

<figure><img src="image_65.png" /></figure>

<figure><img src="image_66.png" /></figure>

<figure><img src="image_67.png" /></figure>

<figure><img src="image_68.png" /></figure>

<figure><img src="image_69.png" /></figure>
<figure><img src="image_70.png" /></figure>

<figure><img src="image_71.png" /></figure>

<figure><img src="image_72.png" /></figure>

<figure><img src="image_73.png" /></figure>

<figure><img src="image_74.png" /></figure>

<figure><img src="image_75.png" /></figure>

<figure><img src="image_76.png" /></figure>
<figure><img src="image_77.png" /></figure>
<figure><img src="image_78.png" /></figure>

<figure><img src="image_79.png" /></figure>

<figure><img src="image_80.png" /></figure>

<figure><img src="image_81.png" /></figure>

<figure><img src="image_82.png" /></figure>

<figure><img src="image_83.png" /></figure>
<figure><img src="image_84.png" /></figure>
<figure><img src="image_85.png" /><figcaption>Plate XIV.</figcaption></figure>
<figure><img src="image_86.png" /><figcaption>Plate XV.</figcaption></figure>