This work presents the chemostratigraphy analysis based on total organic carbon (TOC) and the evolution of the carbon and
oxygen stable isotopes in the whole rock samples around the Pliensbachian/Toarcian boundary in the Peniche section (uppermost
part of Lemede Formation and lowermost part of Cabo Carvoeiro Formation). These are partial results which form part of a
group of studies, being processed, that include isotope analyses of 87Sr/86Sr, 18O, 13C and major, minor and trace elements in
whole rock and belemnites

Duarte, L. V.

Rodrigues, R.

Veiga de Oliveira, L. C.

English

New University of Lisbon's Repository

Ciências da Terra (UNL), 16 
63
Chemostratigraphy (TOC, ?13C, ?18O) around the
Pliensbachian/Toarcian boundary in the reference section
of Peniche (Lusitanian Basin, Portugal) 
L. C. Veiga de Oliveira 1, L. V. Duarte 2 & R. Rodrigues3
1 Petrobras/Cenpes, Cidade Universitária, Ilha do Fundão, 21941-915, Rio de Janeiro, Brazil; lcveiga@petrobras.com.br 
2 Dep. Ciências da Terra, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3000-272 Coimbra, Portugal;  
lduarte@ci.uc.pt 
3 Dep. de Estratigrafia e Paleontologia, Faculdade de Geologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil;
rene@uerj.br 
Resumo
Palavras-chave: Estratigrafia química, COT, Isótopos estáveis, Pliensbaquiano, Toarciano, Bacia Lusitânica, Portugal
São apresentados os resultados das análises quimioestratigráficas baseadas em carbono orgânico total (COT) e isótopos 
estáveis de oxigénio e carbono, em amostras de rocha total recolhidas ao longo do limite Pliensbaquiano–Toarciano do perfil de 
Peniche (parte superior da Formação de Lemede e parte inferior da Formação de Cabo Carvoeiro). Estes resultados fazem parte 
de um conjunto de estudos, em andamento, que incluem análises de 87Sr/86Sr, ?18O, ?13C e elementos maiores, menores e traços, 
tanto em rocha total como em belemnites.  
Résumé
Mots-clés: Chimiostratigraphie, COT, Isotopes stables, Pliensbachien, Toarcien, Bassin Lusitanien, Portugal
Sont présentés les résultats d’analyses chimiostratigraphiques basées en carbone organique total (COT) et isotopes stables 
d’oxygène et de carbone, dans des échantillons de roche totale recueillis tout le long de la limite Pliensbachien–Toarcien de la
coupe de Peniche (depuis la partie supérieure de la Formation de Lemede jusqu’à la partie inférieure de la Formation de Cabo 
Carvoeiro). Ces résultats font partie intégrante d’un ensemble d’études, en cours, qui  englobent des analyses de 87Sr/86Sr ???18O, 
?13C et d’éléments majeurs, mineurs  et trace, tant en roche totale qu’en des belemnites.  
Abstract 
Key-words: Chemostratigraphy, TOC, Stable isotopes, Pliensbachian, Toarcian, Lusitanian Basin, Portugal
This work presents the chemostratigraphy analysis based on total organic carbon (TOC) and the evolution of the carbon and 
oxygen stable isotopes in the whole rock samples around the Pliensbachian/Toarcian boundary in the Peniche section (uppermost 
part of Lemede Formation and lowermost part of Cabo Carvoeiro Formation). These are partial results which form part of a 
group of studies, being processed, that include isotope analyses of 87Sr/86Sr, ?18O, ?13C and major, minor and trace elements in 
whole rock and belemnites.  
                    Ciências da Terra (UNL)                             Lisboa              Nº 16                                                 2007 pp. 63-66, 2 fig.
Ciências da Terra (UNL), 16
64
Introduction
The Lusitanian Basin (Portugal) is located on the 
western margin of the Iberian Plate, and belongs to a 
group of Atlantic Ocean marginal basins which began 
their formation during the rift phase at the Late Triassic. 
It has a NE-SW orientation and is almost 300 km in 
length and 150 km wide, including the offshore, with a 
maximum thickness of 5 km. These sediments belong to 
Upper Triassic–Upper Cretaceous, with Tertiary cover 
and is mainly Jurassic sediments.  
The Lower Jurassic is particularly well represented 
in the Lusitanian Basin with various important 
geological outcrops. The Peniche region is one of the 
most important sections, due to the excellent exhibition 
of a continuous series of carbonates, with more than 450 
m, deposited between Sinemurian to Toarcian.  
The present study included the carbon and oxygen 
stable isotopes and total organic carbon (TOC) analysis 
in the whole rock samples around the Pliensbachian/ 
/Toarcian boundary in the Peniche section (uppermost 
part of Lemede Formation and lowermost part               
of Cabo Carvoeiro Formation). These are part of a 
multidisciplinary study that includes a group of 
chemostratigraphy analysis (TOC, “Rock-Eval” 
pyrolysis, biomarkers, carbon an oxygen isotopes, 
minor and major elements, on the whole rock, and 
carbon, oxygen and strontium isotopes on the belemnite 
fossil) and calcareous nannofossil biostratigraphy in the 
Pliensbachian–Lower Toarcian section of Peniche 
(OLIVEIRA & al., 2005a,b). 
Methodology 
The analyses used 71 samples collected along 25 
meters of the section (Figs. 1 and 2). All samples were 
pulverized in a porcelain dish to obtain particles smaller 
than 80 mesh. Of these, 68 samples were submitted to 
the total organic carbon analyses (TOC) and in 38 
samples the values of stable isotope carbon (?13C) and 
oxygen (?18O) were obtained from the whole rock 
carbonate fraction. The analyses were performed at the 
Petrobras Research Center (Cenpes, Brazil) laboratories. 
The determinations of the TOC values were made in the 
LECO-SC444 and oxygen and carbon isotopic values 
were obtained using a Kiel Carbonate Device III 
coupled to a MAT 252 Thermo Finnigan mass 
spectrometer.  
The results of TOC were expressed as a percentage 
(%) and on every tenth analyzed sample a duplicated 
analysis was made. The equipment was calibrated daily 
with standards, before initiating the analyses. This 
process uses approximately 10 mg of sample, which 
was placed in a vacuum chamber and heated to 70 0C
and reacted with phosphoric acid for 6 minutes. The 
water and carbon dioxide generated were captured at -
1700C with liquid nitrogen. Then this mixture was 
brought to -1100C when the subsequently released pure 
CO2 was again collected at -1700C with liquid nitrogen.   
All oxygen and carbon isotopic results are reported 
in parts per mil (0/00) relative to PDB and calibrated by 
routine preparation and analysis by the carbonate 
standard NBS-19 (?13C=1.950/00, ?18O= -2.200/00). Day 
to day precision (+ 1 ?) based on NBS-19 analyses was 
+ 0.05 for ?13C and + 0.08 for ?18O.
Results and discussion
Isotopic analysis: In the marl-limestone succession 
that encompasses the Pliensbachian/Toarcian boundary 
in Peniche, the ?13C and ?18O values decrease, 
gradually, from the middle part, up to the uppermost 
part of Spinatum Zone, with smaller values in the 
lowermost part of the Polymorphum Zone, with an 
absolute variation of around -2.00/00 (fig. 1). 
Am
m
on
ite
s
zo
ne
s
S
am
pl
es
St
ag
es
Li
th
os
tra
tig
ra
ph
y
sp
ina
tu
m
po
lym
or
ph
um
lev
iso
ni
To
ar
ci
an
Pl
ie
ns
ba
ch
ia
n
Calcilutite
Calcarenite
Marl
Calcareous Marl
Fig. 1 – Carbon and oxygen isotope values around the 
Pliensbachian/Toarcian boundary in Peniche.
In the Lower Toarcian studied section (Polymorphum 
Zone and lowermost part of Levisoni Zone) the ?13C and 
?18O values show an inverse behavior compared to the Upper 
Pliensbachian section (middle to uppermost part of Spinatum
Zone). In the Lower Toarcian the ?13C data shows a positive 
trend (a spread of +2.0‰) with a maximum value in the 
middle-upper portion of the Polymorphum Zone and a 
minimum in the lowermost part of the Levisoni Zone. This 
event, recently confirmed by S. HESSELBO & al. (2007), was 
verified previously in the Coimbra area (DUARTE & al., (2004a) 
and in other distal sectors of the Lusitanian Basin (DUARTE
& al., 2007). Similar variations were observed by B. 
VAN DE SCHOOTBRUDGGE & al. (2005) and I. ROSALES
& al. (2004), in the Llanbedr Mochras Farm Borehole 
(Wales) and in the Basque-Cantabrian Basin, respectively. 
In spite of our study just using whole rock samples, and 
the studies of B. VAN DE SCHOOTBRUDGGE & al. (2005) 
and I. ROSALES & al. (2004) used belemnites, the 
absolute variation was similar, around -2.0‰. 
Ciências da Terra (UNL), 16 
65
A
m
m
on
ite
s
zo
ne
s
Sa
m
pl
es
St
ag
es
Li
th
os
tra
tig
ra
ph
y
sp
ina
tu
m
po
lym
or
ph
um
lev
iso
ni
To
ar
ci
an
Pl
ie
ns
ba
ch
ia
n
Calcilutite
Calcarenite
Marl
Calcareous Marl
Fig. 2 – TOC and insoluble residue values around the 
Pliensbachian-Toarcian boundary in Peniche. 
The ?18O values, in spite of the positive excursion 
immediately observed after the Pliensbachian/Toarcian 
boundary, show a general tendency to decrease within 
the Polymorphum Zone, with the smallest values 
observed in the lower portion of the Levisoni Zone, 
followed by a sudden reversion to higher isotopic 
values. Similar isotopic behavior was verified by I. 
ROSALES & al. (2004) for the Basque–Cantabrian Basin, 
suggesting a good correlation between Peniche and 
North Spain sections. In the Peniche section, the lowest 
isotopic values found in the lowermost part of the
Levisoni Zone, would correspond to the smallest values 
registered in the lowermost part of the Serpentinus                 
(= Levisoni) Zone, in the Spanish section.   
TOC analysis: In general, the TOC values are low, 
around 0.2% in the Spinatum Zone, further upwards 
they increase to 0.5% in the Polymorphum Zone, whilst 
they decrease again to 0.2% in the lowermost Levisoni 
Zone (fig. 2). 
The low TOC values registered in the 
Polymorphum-lowermost part of Levisoni Zone interval 
of Peniche don't coincide with the high values observed 
in the same interval of North-European area (JENKYNS
& al., 2002). In fact, the Lower Toarcian series of the 
Lusitanian Basin are characterized by the absence of 
black shales as a result of local sedimentary conditions 
(DUARTE, 1997; DUARTE & al. 2004ab, 2005). 
Acknowledgements 
We thank to Petrobras/Cenpes/Pdexp/Geoq staff for 
carbonate C-isotope, Total Organic Carbon and Insoluble 
Residue analyses, especially to Luiz Antonio F. Trindade, 
Jorge T. Silva, Eduardo S. A. Conde, Leandro Maurieli, 
Maurílio L. Martins, Ligia J. L. Aquino and M. Fátima B. de 
Almeida. Thanks   are also due to Edison J. Milani and Oscar 
Strohschoen Junior. 
References 
DUARTE, L. V. (1997) – Facies analysis and sequential evolution of the Toarcian-Lower Aalenian series in the Lusitanian Basin 
(Portugal). Comun. Inst. Geol. Mineiro, Lisboa, t. 83, pp. 65-94. 
DUARTE, L. V., OLIVEIRA, L. C. V. & RODRIGUES, R. (2007) – Carbon isotopes as a sequence stratigraphic tool: examples from 
the Lower and Middle Toarcian marly limestones of Portugal. Bol. Geol. Min., Madrid, nº 118 (1), pp. 3-18.  
DUARTE, L. V., PERILLI, N., DINO, R., RODRIGUES, R. & PAREDES. R. (2004a) – Lower to Middle Toarcian from the Coimbra 
region (Lusitanian Basin, Portugal): Sequence Stratigraphy, Calcareous Nannofossils and stable-isotope evolution. Riv. Ital. 
Paleont. Stratigrafia., Milano, nº 110, pp. 115-127. 
DUARTE, L. V., RODRIGUES, R., OLIVEIRA, L. C. V. & SILVA, F. (2005) – Avaliação preliminar das variações do carbono orgânico 
total nos sedimentos margosos do Jurássico inferior da Bacia Lusitânica (Portugal). XIV Sem. Geoquímica & VIII Congr. 
Geoquímica Países Língua Portuguesa, Aveiro, pp. 39-43.  
DUARTE, L. V. (Coord.), WRIGHT, V. P., FERNANDÉZ-LOPÉZ, S., ELMI, S., KRAUTTER, M., AZERÊDO, A. C., HENRIQUES, M. H.,
RODRIGUES, R. & PERILLI, N. (2004b) – Early Jurassic carbonate evolution in the Lusitanian Basin: facies, sequence 
stratigraphy and cyclicity. In: DUARTE, L. V. & HENRIQUES, M. H. (Eds.), Carboniferous and Jurassic Carbonate Platforms 
of Iberia. 23rd IAS Meet. Sedimentology, Coimbra, Field Trip Guide Book, vol. I, pp. 45-71. 
Ciências da Terra (UNL), 16
66
HESSELBO, S. P., JENKYNS, H. C., DUARTE, L. V. & OLIVEIRA, L. C. V. (2007) – Carbon-isotope record of the Early Jurassic 
(Toarcian) Oceanic Anoxic Event from fossil wood and marine carbonate (Lusitanian Basin, Portugal). Earth Plan. Sc. 
Letters, Amsterdam, nº 253, pp. 455-470, 5 fig. 
JENKYNS, H. C., JONES, C. E., GRÖCKE, D. R., HESSELBO, S. P. & PARKINSON, D. N. (2002) – Chemostratigraphy of the Jurassic 
System: applications, limitations and implications for palaeoceanography. J. Geol. Soc. London, vol. 159, pp. 351-378. 
OLIVEIRA, L. C. V., DUARTE, L. V., PERILLI, N., RODRIGUES, R. & LEMOS, V. B. (2005) – Estratigrafia química (COT, ?13C, ?18O)
e nanofósseis calcários na passagem Pliensbaquiano-Toarciano no perfil de Peniche (Portugal). Resultados preliminares. 
Pesq. Geociências, Porto Alegre, nº 32 (2), pp. 3-16. 
OLIVEIRA, L. C. V., DUARTE, L. V. & RODRIGUES, R. (2005) – Estratigrafia química (COT, ?13C e ?18O) na passagem 
Pliensbaquiano-Toarciano no perfil de Peniche (Portugal). Resultados Preliminares. XIV Sem. Geoquímica & VIII Congr. 
Geoquímica Países Língua Portuguesa, Aveiro, pp. 185-188.  
ROSALES, I., QUESADA, S. & ROBLES, S. (2004) – Paleotemperature variations of Early Jurassic seawater recorded in geochemical 
trends of belemnites from the Basque–Cantabrian basin, northern Spain. Palaeogeogr., Palaeoclim., Palaeoecol., 
Amsterdam, nº 203, pp. 253-275. 
VAN DE SCHOOTBRUGGE, B., BAILEY, T. R., ROSENTHAL, Y., KATZ, M. E., WRIGHT, J. D., FEIST-BURKHARDT, S., MILLER, K. G. &
FALKOWSKI, P. G. (2005) – Early Jurassic Climate change and the radiation of organic-walled phytoplankton in the Thetys 
Ocean. Paleobiology, London, vol. 31, pp. 73-97. 


Chemostratigraphy (TOC, 13C, 18O) around the Pliensbachian/Toarcian boundary in the reference section of Peniche (Lusitanian Basin, Portugal)

Repositório da Universidade Nova de Lisboa

Ciências da Terra (UNL), 16 63Chemostratigraphy (TOC, 13C, 18O) around thePliensbachian/Toarcian boundary in the reference sectionof Peniche (Lusitanian Basin, Portugal) L. C. Veiga de Oliveira 1, L. V. Duarte 2 & R. Rodrigues31 Petrobras/Cenpes, Cidade Universitária, Ilha do Fundão, 21941-915, Rio de Janeiro, Brazil; lcveiga@petrobras.com.br 2 Dep. Ciências da Terra, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3000-272 Coimbra, Portugal;  lduarte@ci.uc.pt 3 Dep. de Estratigrafia e Paleontologia, Faculdade de Geologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil;rene@uerj.br ResumoPalavras-chave: Estratigrafia química, COT, Isótopos estáveis, Pliensbaquiano, Toarciano, Bacia Lusitânica, PortugalSão apresentados os resultados das análises quimioestratigráficas baseadas em carbono orgânico total (COT) e isótopos estáveis de oxigénio e carbono, em amostras de rocha total recolhidas ao longo do limite Pliensbaquiano–Toarciano do perfil de Peniche (parte superior da Formação de Lemede e parte inferior da Formação de Cabo Carvoeiro). Estes resultados fazem parte de um conjunto de estudos, em andamento, que incluem análises de 87Sr/86Sr, 18O, 13C e elementos maiores, menores e traços, tanto em rocha total como em belemnites.  RésuméMots-clés: Chimiostratigraphie, COT, Isotopes stables, Pliensbachien, Toarcien, Bassin Lusitanien, PortugalSont présentés les résultats d’analyses chimiostratigraphiques basées en carbone organique total (COT) et isotopes stables d’oxygène et de carbone, dans des échantillons de roche totale recueillis tout le long de la limite Pliensbachien–Toarcien de lacoupe de Peniche (depuis la partie supérieure de la Formation de Lemede jusqu’à la partie inférieure de la Formation de Cabo Carvoeiro). Ces résultats font partie intégrante d’un ensemble d’études, en cours, qui  englobent des analyses de 87Sr/86Sr 18O, 13C et d’éléments majeurs, mineurs  et trace, tant en roche totale qu’en des belemnites.  Abstract Key-words: Chemostratigraphy, TOC, Stable isotopes, Pliensbachian, Toarcian, Lusitanian Basin, PortugalThis work presents the chemostratigraphy analysis based on total organic carbon (TOC) and the evolution of the carbon and oxygen stable isotopes in the whole rock samples around the Pliensbachian/Toarcian boundary in the Peniche section (uppermost part of Lemede Formation and lowermost part of Cabo Carvoeiro Formation). These are partial results which form part of a group of studies, being processed, that include isotope analyses of 87Sr/86Sr, 18O, 13C and major, minor and trace elements in whole rock and belemnites.                      Ciências da Terra (UNL)                             Lisboa              Nº 16                                                 2007 pp. 63-66, 2 fig.Ciências da Terra (UNL), 1664IntroductionThe Lusitanian Basin (Portugal) is located on the western margin of the Iberian Plate, and belongs to a group of Atlantic Ocean marginal basins which began their formation during the rift phase at the Late Triassic. It has a NE-SW orientation and is almost 300 km in length and 150 km wide, including the offshore, with a maximum thickness of 5 km. These sediments belong to Upper Triassic–Upper Cretaceous, with Tertiary cover and is mainly Jurassic sediments.  The Lower Jurassic is particularly well represented in the Lusitanian Basin with various important geological outcrops. The Peniche region is one of the most important sections, due to the excellent exhibition of a continuous series of carbonates, with more than 450 m, deposited between Sinemurian to Toarcian.  The present study included the carbon and oxygen stable isotopes and total organic carbon (TOC) analysis in the whole rock samples around the Pliensbachian/ /Toarcian boundary in the Peniche section (uppermost part of Lemede Formation and lowermost part               of Cabo Carvoeiro Formation). These are part of a multidisciplinary study that includes a group of chemostratigraphy analysis (TOC, “Rock-Eval” pyrolysis, biomarkers, carbon an oxygen isotopes, minor and major elements, on the whole rock, and carbon, oxygen and strontium isotopes on the belemnite fossil) and calcareous nannofossil biostratigraphy in the Pliensbachian–Lower Toarcian section of Peniche (OLIVEIRA & al., 2005a,b). Methodology The analyses used 71 samples collected along 25 meters of the section (Figs. 1 and 2). All samples were pulverized in a porcelain dish to obtain particles smaller than 80 mesh. Of these, 68 samples were submitted to the total organic carbon analyses (TOC) and in 38 samples the values of stable isotope carbon ( 13C) and oxygen ( 18O) were obtained from the whole rock carbonate fraction. The analyses were performed at the Petrobras Research Center (Cenpes, Brazil) laboratories. The determinations of the TOC values were made in the LECO-SC444 and oxygen and carbon isotopic values were obtained using a Kiel Carbonate Device III coupled to a MAT 252 Thermo Finnigan mass spectrometer.  The results of TOC were expressed as a percentage (%) and on every tenth analyzed sample a duplicated analysis was made. The equipment was calibrated daily with standards, before initiating the analyses. This process uses approximately 10 mg of sample, which was placed in a vacuum chamber and heated to 70 0Cand reacted with phosphoric acid for 6 minutes. The water and carbon dioxide generated were captured at -1700C with liquid nitrogen. Then this mixture was brought to -1100C when the subsequently released pure CO2 was again collected at -1700C with liquid nitrogen.   All oxygen and carbon isotopic results are reported in parts per mil (0/00) relative to PDB and calibrated by routine preparation and analysis by the carbonate standard NBS-19 ( 13C=1.950/00, 18O= -2.200/00). Day to day precision (+ 1 ) based on NBS-19 analyses was + 0.05 for 13C and + 0.08 for 18O.Results and discussionIsotopic analysis: In the marl-limestone succession that encompasses the Pliensbachian/Toarcian boundary in Peniche, the 13C and 18O values decrease, gradually, from the middle part, up to the uppermost part of Spinatum Zone, with smaller values in the lowermost part of the Polymorphum Zone, with an absolute variation of around -2.00/00 (fig. 1). AmmoniteszonesSamplesStagesLithostratigraphyspinatumpolymorphumlevisoniToarcianPliensbachianCalcilutiteCalcareniteMarlCalcareous MarlFig. 1 – Carbon and oxygen isotope values around the Pliensbachian/Toarcian boundary in Peniche.In the Lower Toarcian studied section (Polymorphum Zone and lowermost part of Levisoni Zone) the 13C and 18O values show an inverse behavior compared to the Upper Pliensbachian section (middle to uppermost part of SpinatumZone). In the Lower Toarcian the 13C data shows a positive trend (a spread of +2.0‰) with a maximum value in the middle-upper portion of the Polymorphum Zone and a minimum in the lowermost part of the Levisoni Zone. This event, recently confirmed by S. HESSELBO & al. (2007), was verified previously in the Coimbra area (DUARTE & al., (2004a) and in other distal sectors of the Lusitanian Basin (DUARTE& al., 2007). Similar variations were observed by B. VAN DE SCHOOTBRUDGGE & al. (2005) and I. ROSALES& al. (2004), in the Llanbedr Mochras Farm Borehole (Wales) and in the Basque-Cantabrian Basin, respectively. In spite of our study just using whole rock samples, and the studies of B. VAN DE SCHOOTBRUDGGE & al. (2005) and I. ROSALES & al. (2004) used belemnites, the absolute variation was similar, around -2.0‰. Ciências da Terra (UNL), 16 65AmmoniteszonesSamplesStagesLithostratigraphyspinatumpolymorphumlevisoniToarcianPliensbachianCalcilutiteCalcareniteMarlCalcareous MarlFig. 2 – TOC and insoluble residue values around the Pliensbachian-Toarcian boundary in Peniche. The 18O values, in spite of the positive excursion immediately observed after the Pliensbachian/Toarcian boundary, show a general tendency to decrease within the Polymorphum Zone, with the smallest values observed in the lower portion of the Levisoni Zone, followed by a sudden reversion to higher isotopic values. Similar isotopic behavior was verified by I. ROSALES & al. (2004) for the Basque–Cantabrian Basin, suggesting a good correlation between Peniche and North Spain sections. In the Peniche section, the lowest isotopic values found in the lowermost part of theLevisoni Zone, would correspond to the smallest values registered in the lowermost part of the Serpentinus                 (= Levisoni) Zone, in the Spanish section.   TOC analysis: In general, the TOC values are low, around 0.2% in the Spinatum Zone, further upwards they increase to 0.5% in the Polymorphum Zone, whilst they decrease again to 0.2% in the lowermost Levisoni Zone (fig. 2). The low TOC values registered in the Polymorphum-lowermost part of Levisoni Zone interval of Peniche don't coincide with the high values observed in the same interval of North-European area (JENKYNS& al., 2002). In fact, the Lower Toarcian series of the Lusitanian Basin are characterized by the absence of black shales as a result of local sedimentary conditions (DUARTE, 1997; DUARTE & al. 2004ab, 2005). Acknowledgements We thank to Petrobras/Cenpes/Pdexp/Geoq staff for carbonate C-isotope, Total Organic Carbon and Insoluble Residue analyses, especially to Luiz Antonio F. Trindade, Jorge T. Silva, Eduardo S. A. Conde, Leandro Maurieli, Maurílio L. Martins, Ligia J. L. Aquino and M. Fátima B. de Almeida. Thanks   are also due to Edison J. Milani and Oscar Strohschoen Junior. References DUARTE, L. V. (1997) – Facies analysis and sequential evolution of the Toarcian-Lower Aalenian series in the Lusitanian Basin (Portugal). Comun. Inst. Geol. Mineiro, Lisboa, t. 83, pp. 65-94. DUARTE, L. V., OLIVEIRA, L. C. V. & RODRIGUES, R. (2007) – Carbon isotopes as a sequence stratigraphic tool: examples from the Lower and Middle Toarcian marly limestones of Portugal. Bol. Geol. Min., Madrid, nº 118 (1), pp. 3-18.  DUARTE, L. V., PERILLI, N., DINO, R., RODRIGUES, R. & PAREDES. R. (2004a) – Lower to Middle Toarcian from the Coimbra region (Lusitanian Basin, Portugal): Sequence Stratigraphy, Calcareous Nannofossils and stable-isotope evolution. Riv. Ital. Paleont. Stratigrafia., Milano, nº 110, pp. 115-127. DUARTE, L. V., RODRIGUES, R., OLIVEIRA, L. C. V. & SILVA, F. (2005) – Avaliação preliminar das variações do carbono orgânico total nos sedimentos margosos do Jurássico inferior da Bacia Lusitânica (Portugal). XIV Sem. Geoquímica & VIII Congr. Geoquímica Países Língua Portuguesa, Aveiro, pp. 39-43.  DUARTE, L. V. (Coord.), WRIGHT, V. P., FERNANDÉZ-LOPÉZ, S., ELMI, S., KRAUTTER, M., AZERÊDO, A. C., HENRIQUES, M. H.,RODRIGUES, R. & PERILLI, N. (2004b) – Early Jurassic carbonate evolution in the Lusitanian Basin: facies, sequence stratigraphy and cyclicity. In: DUARTE, L. V. & HENRIQUES, M. H. (Eds.), Carboniferous and Jurassic Carbonate Platforms of Iberia. 23rd IAS Meet. Sedimentology, Coimbra, Field Trip Guide Book, vol. I, pp. 45-71. Ciências da Terra (UNL), 1666HESSELBO, S. P., JENKYNS, H. C., DUARTE, L. V. & OLIVEIRA, L. C. V. (2007) – Carbon-isotope record of the Early Jurassic (Toarcian) Oceanic Anoxic Event from fossil wood and marine carbonate (Lusitanian Basin, Portugal). Earth Plan. Sc. Letters, Amsterdam, nº 253, pp. 455-470, 5 fig. JENKYNS, H. C., JONES, C. E., GRÖCKE, D. R., HESSELBO, S. P. & PARKINSON, D. N. (2002) – Chemostratigraphy of the Jurassic System: applications, limitations and implications for palaeoceanography. J. Geol. Soc. London, vol. 159, pp. 351-378. OLIVEIRA, L. C. V., DUARTE, L. V., PERILLI, N., RODRIGUES, R. & LEMOS, V. B. (2005) – Estratigrafia química (COT, 13C, 18O)e nanofósseis calcários na passagem Pliensbaquiano-Toarciano no perfil de Peniche (Portugal). Resultados preliminares. Pesq. Geociências, Porto Alegre, nº 32 (2), pp. 3-16. OLIVEIRA, L. C. V., DUARTE, L. V. & RODRIGUES, R. (2005) – Estratigrafia química (COT, 13C e 18O) na passagem Pliensbaquiano-Toarciano no perfil de Peniche (Portugal). Resultados Preliminares. XIV Sem. Geoquímica & VIII Congr. Geoquímica Países Língua Portuguesa, Aveiro, pp. 185-188.  ROSALES, I., QUESADA, S. & ROBLES, S. (2004) – Paleotemperature variations of Early Jurassic seawater recorded in geochemical trends of belemnites from the Basque–Cantabrian basin, northern Spain. Palaeogeogr., Palaeoclim., Palaeoecol., Amsterdam, nº 203, pp. 253-275. VAN DE SCHOOTBRUGGE, B., BAILEY, T. R., ROSENTHAL, Y., KATZ, M. E., WRIGHT, J. D., FEIST-BURKHARDT, S., MILLER, K. G. &FALKOWSKI, P. G. (2005) – Early Jurassic Climate change and the radiation of organic-walled phytoplankton in the Thetys Ocean. Paleobiology, London, vol. 31, pp. 73-97. 

https://run.unl.pt/bitstream/10362/4793/1/CT_16_07_L_Oliveira_et_al.pdf

Chemostratigraphy (TOC, 13C, 18O) around the Pliensbachian/Toarcian boundary in the reference section of Peniche (Lusitanian Basin, Portugal)

Abstract

Similar works

Full text

Available Versions

New University of Lisbon's Repository

Repositório da Universidade Nova de Lisboa