PRAC FINAL REPORT

19 June 2007

FRONT COVER:

PRAC Project Number: 105

Granted to: Professor Grant Wach Department of Earth Sciences, Dalhousie University, Life Sciences Centre, Room 3060 1355 Oxford Street, Halifax, NS, B3H 4J1 Tel: 1 (902) 494 8019 Fax: 1 (902) 494 8669 Email: Grant.Wach@dal.ca

Project Title: Micropaleontological (Foraminifera and Noannoplankton) analysis of the

Tertiary sediments of the Scotian Shelf: Stratigraphy and sediment transport.

Projects Start Date and Duration: January 2003 to June 2007

The Period of Time Covered: 3 years 6 months

Date of Submission: 19th June 2007

Submitted To PRAC Representative: Rod Doane Director, Research and Development Petroleum Research Atlantic Canada Tel: ((02) 494-1896 Fax: (902) 494-2489 Email : rod.doane@pr-ac.ca Web: www.pr-ac-ca

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SUMMARY: The Scotian Basin which extends for 1200 km and covers an area of about 300,000 Km3

from shelf to 4000 m water depth was the site of continuous sedimentation since the

opening of the Atlantic Ocean in Middle Triassic until now. During the rifting stage red

beds and evaporates were deposited, followed by clastic sedimentations intercalated by

periods of carbonate deposition during drifting phase (Kidston et al. 2002). A thick pile

of sediments deposited during Mesozoic and Cenozoic periods dominated by fluvio-

deltaic sediments (Fig.1). The Tertiary Banquereau Formation consist of fluvial-deltaic to

deepwater sediments which are stratigraphically poorly constrained (Hogg, et al., 2001).

These Tertiary deposits have a potential as a hydrocarbon play but few details are known

about this system. The dominance of clastic beds in this sedimentary sequence

complicate the task of accurately defining the exact position of boundaries between the

members and formations which necessitates additional tools and methods. One such tool

is micropaleontological studies which is the subject of the current project. Discovery of

the Sable Island gas field and other showings in the late 1990s in the offshore Nova

Scotia and Newfoundland encouraged such studies on the rock cuttings obtained during

drilling of tens of boreholes in the region. Cutting and core samples from Shubenacadie

H-100, Sauk A-57, Cohasset A-52 boreholes and Jeanne d’Arc Basin (Corehole CH-16)

were studied as part of this project (Fig.2). In the absence of core samples in the drilled

boreholes, cuttings can be used to obtain important results concerning the age,

depositional environments and water depth as well as sediment transport pathways in a

thick offshore sequences like that of Scotian margin. Planktonic foraminifera and

nannofossils are the most useful fossils in this respect.

SCIENTIFIC OBJECTIVES:

The objectives of the project are to study microfossils in the cutting samples obtained

from the offshore boreholes of Tertiary Banquereau and older Cretaceous formations. In

a thick pile of sedimentary succession like offshore Nova Scotia where more or less

monotonous alternations of clastic sediments form the bulk stratigraphy, the task of

delineating the boundaries between different formations and members in a precise way

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and determining their paleoenvironments on lithological basis only is not easy. For this

reason micropaleontological studies can play an excellent tool in this respect. The main

aims of this project are:

Studying planktonic foraminiferal assemblages in boreholes samples.

Studying nannofossils in boreholes samples.

Studying benthic foraminifera in borehole samples.

Studying dinoflagellates and palynomorphs to develop a detailed event

biostratigraphic framework and climatic changes for the Cenozoic section of

Offshore Eastern Canada. Also to study the taxonomy, paleoenvironment and

determine the prevalence and age of the offshore currents.

Determining depositional environment and age of the studied sediments and

determining the presence or absence of unconformities between them. The

planktonic and benthic foraminifera are good paleoenvironment indicators and

also help in identifying some other events like hurricanes; while the nannofossils

are good age controllers.

Develop age-control for a sequence stratigraphic framework and determining

sediment transport pathways and depocenters.

SUMMARY OF PROJECT PROGRESS:

The following borehole cutting samples were studied:

1. SHUBENACADIE H-100: The location, stratigraphy and litholg of this borehole

are shown in Figs.2 and 4. Shubenacadie H-100 was drilled to a depth of 4200m

starting from a water depth of 1476.5 m. The boundary between Miocene and

Eocene is recorded at a depth of 3050 m. Fifty two cutting samples and slides

containing picked specimens provided by BIO were studied and about 170

benthic foraminifer’s taxa or taxa groups were identified.

2. COHASSET A-52: The location, stratigraphy and litholg of this borehole are

shown in Figs.2 and 3. Twenty meters of core intervals 2069-2219 m were

studied in Cohasset A-52 borehole drilled to a total depth of 2835 m. The forams

collected from shale and mudstones were exclusively benthic and 95-100% of

them are agglutinated with rare calcareous ones. In addition to foraminifera,

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thecamoebians and mollusk shells were identified. Six samples from core-8

(interval 2218.51-2215.9 m), twelve samples from core-7 (interval 2167.98-

2160.12 m), twelve samples from core-3 (interval 2124.72-2117.65 m), and

twelve samples from core-1 (interval 2077.33-2069.90 m). The following

conclusions can be drawn:

1. Foraminiferal analysis of early Cretaceous rocks indicated intervals

belonging to paralic environments,

2. There is high potential of the agglutinated foraminifera and thecamoebians

associations for interpreting paleoenvironment because of the

considerable similarity between them and corresponding modern ones,

3. The “marsh type” foraminiferal associations is comparable with those

recorded from the Cretaceous sediments of Utah and southern Alberta; this

is the first one fully documented in the Atlantic Margin and

4. Integrated foraminiferal and sedimentological analysis helped in

recognizing paleo-hurricane deposits preserved in marsh sediments.

Distribution of foraminiferal associations from Miocene to Upper Cretaceous showed

that the Miocene succession contain mostly planktonic and calcareous benthic

foraminifera. The identified benthics are Bulimina, Glandulina, Melonis,

Plectofrondicularia, Pyrgo, Quinqueleculina, Sigmilopsis, Uvigerina and

Cyclammina; indicative of middle-lower bathyl environment. Agglutinated benthic

foraminifera found in the Eocene-Late Cretaceous sediments are indicative of typical

lower bathyl environment. Most of the agglutinated benthic foraminifera recorded in

the Early Eocene-Upper Cretaceous sediments are large sized opportunistic ones such

as Ammodiscus, Bathysiphon, Trochamminoides, Paratrochamminoides,

Glomospirella, Reophax and Subreophax; they reflect hemipelagic turbiditic

sequences.

3. SAUK A-57: The location, stratigraphy and litholg of this borehole are shown in

Figs. 2 and 5. Thirty eight samples from Sauk A-57 and fifty one samples from

Shubenacadie H-100 boreholes were studied for their nannofossils (Coccoliths)

content. They showed low degree of diversity and abundance in the Pliocene and

younger sediments in Sauk A-57 borehole which is indicated by moderate

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deposition and/or preservation that can be attributed to high input of clastic

sediments and near-shore depositional environment of deposition. Meanwhile

Miocene and older sections showed higher abundance and diversity which is

especially distinctive in the Eocene as a sign of increasing open marine influence.

Deeper Paleocene sediments are also poor in nannofossils. Similar results are

observed in Shubenacadie H-100 borehole where the Pliocene and younger strata

showed poor preservation and low diversity of nannofossils which become more

diverse and abundant in Miocene and older sediments; while they were apparently

not preserved in Oligocene section. Rich nannofossils content in Miocene and

older sediments in these boreholes are promising for establishing good and

reliable biostratigraphic subdivisions of the Tertiary/Cretaceous offshore

sediments.

4. GRAND BANKS: JEANNE D’ARC BASIN (Corehole 16): It was drilled in

66.8 m of water to a depth of 448 m; the rocks consist of fine grained sandstones,

siltstones and claystones which generally exhibit a fining upward sequence

through the Banquereau Formation (Fig.2 and 6). The study included both

dinoflagellates and palynomorphs. The aim of the study is to develop a detailed

event biostratigraphic framework and climatic changes for the Cenozoic of

offshore Eastern Canada, taxonomy, paleoenvironment and to determine the

prevalence and age of the offshore currents. The Scotian Margin has several

modern and Cenozoic erosional events that have removed crucial intervals of the

rock record, e.g. Oligocene unconformity. The Grand Banks wells are one of the

most complete records of Cenozoic sedimentation along the offshore of eastern

Canada. This provides a strong stratigraphic tie to the offshore basins of Nova

Scotia.

TECHNOLOGY TRANSFER:

The obtained results were presented in the following conferences and meetings. Details

are given in Publications Section at the end of the report.

Presentations in the Atlantic Geoscience Society (AGS) 31st Colloquium &

Annual General Meeting, Saint John, Feb.4-6, 2005

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Presentations in GAC-MAC-CSPG-CSSS HALIFAX 2005 conference, 16-20

May 2005, held in Halifax, NS, Canada

Presentations in the AAPG 2005 Annual Meeting, Calgary, Canada.

Presentations in the AAPG 2006 Annual Convention, April 9-12, 2006; George R.

Brown Convention Center, Houston, USA.

PUBLICATIONS:

Papers accepted for publication:

Fiorini, F., Scott, D. and Wach, G. (In Press in Micropaleontology).

Characterization of paralic paleoenvironments and identification of hurricane

deposits based on benthic foraminiferal analysis of early Cretaceous sediments of

Scotian Margin.

Skilliter, D.M., Williams, G.L., Fensome, R.A., Guerstein, G.R., MacRae, R.A.

and Wach, G. ( ). Preliminary results of a biostartigraphic study of Cenozoic

strata of the Grand banks, Newfoundland. Poster presentation

Abstracts:

Arbour, V., Jones, S., Gard, G., Crux, J., Scott, D., Younger, C. and Wach, G.

(2005). Nannofossil biostratigraphy as a tool for stratigraphic precision in the

Tertiary and Mesozoic Offshore Nova Scotia: Preliminary findings. GAC-MAC-

CSPG-CSSS meeting, HALIFAX 15-18 May, 2005. Program with Abstracts.

Fiorini, F., Fensome, R.A., Scott, D.B., Thomas, F.C. and Wach, G.D. (2005).

Benthic foraminiferal association in Cenozoic and Late Cretaceous deposits from

Shubenacadie H-100 well (Scotian Slope). Atlantic Geosciences Society 31st

Colloquium & Annual General Meeting, February 4-6, 2005, Saint John, New

Brunswick, Canada. Program with Abstracts, p.19.

Fiorini, F., Fensome, R.A., Scott, D.B., Thomas, F.C. and Wach, G.D. (2005).

Cretaceous to Miocene benthic foraminifera from the Scotian Shelf and Slope

wells Cohasset A-52 and Shubenacadie H-100, GAC-MAC-CSPG-CSSS

meeting, HALIFAX 15-18 May, 2005. Program with Abstracts.

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Fensome, R.A., Williams, G.L., Crux, J., McRae, R.A., Thomas, F.C., Grad, G.

and Fiorini, F. (2005). Biostratigraphic age control of Late Cretaceous-Cenozoic

strata on the Scotian Margin: an eventual story. AAPG Meeting, Calgary, Canada.

Mason, S., Arbour, V., Scott, D., Wach, G. and Younger, C. (2006). Nannofossils

biostratigraphy of Sauk A-57 and Shubenacadie H-100 offshore Nova Scotia.

AAPG 2006 Annual Convention, April 9-12, 2006; Houston, USA

Technical Reports:

1. Shubenacadie H-100 Borehole: Flavia Fiorini (2005). Report on benthic

foraminifera from Shubenacadie H-100 well (Scotian Slope).10p.

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REFERENCES: Hogg, J.R., D.A. Dolph, D. Mackidd and K. Michel, 2001. Petroleum systems of the

deepwater Scotian salt provinvce, offshore Nova Scotia, Canada. Proceedings of the GCSSEPM Foundation 21st Annual Research Conference, Petroleum Systems of Deep-water Basins, December 2-5, 2001, Houston Texas, 23-34.

Kidston, A.G. Brown, D.E. Altheim, B. and Smith, B.M. 2002. CNSOPB Hydrocarbon potential of Nova Scotia’s deep water slope: Deep water report, Oct. 2002, version 1.0, Halifax, Nova Scotia, Canada.

Wielens, J.B.W, 2003. Overpressures on the Scotian Shelf. Geological Survey of Canada Open File 1557. 142p.

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Fig. 1: Generalized stratigraphic section of Nova Scotian Margin.

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Fig.2: Map of Nova Scotia and Newfoundland showing the locations of the studied offshore boreholes.

Shubenacadie H-100

Sauk A-57

Cohasset-A-52

CH-16

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Fig. 3:Stratigraphic cross-section of Cohasset A-52 borehole (taken from Wielens, 2003)

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Fig. 4:Stratigraphic cross-section of Shubenacadie H-100 borehole (taken from Wielens, 2003)

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Fig. 5:Stratigraphic cross-section of Sauk A-57 borehole (taken from Wielens, 2003)

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Fig. 6: Stratigraphic section of CH-16 borehole, Grand banks showing Cenozoic

Section.

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Report on benthic foraminifera from Shubenacadie H-100 well (Scotian Slope)

by

Flavia Fiorini

Department of Earth Sciences, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada, (e-mail: flavia.fiorini@dal.ca)

June 2005

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ABSTRACT

A Late Cretaceous-Cenozoic section from Shubenacadie H-100 well located on the Scotian Slope has been investigated.

The benthic foraminiferal content of 52 cutting samples (corresponding to 10 m interval) previously collected for stratigraphic analysis within the interval 2140-4200 m, has been studied in order to provide information about distribution and taxonomy, as well as to evaluate the paleoenvironments.

INTRODUCTION

Shubenacadie H-100 was drilled in 1476.5 m water depth to a depth of 4200 m (Figure 1). The Miocene-Eocene unconformity is recorded at 3050 m.

The 52 cutting samples have been provided by Bedford Institute of Oceanography. Slides containing picked specimens from the fossiliferous samples are stored in the Department of Earth Sciences (Dalhousie University).

About 170 benthic foraminifera taxa or taxa groups have been identified: their distribution is plotted in Tab.1.

Micropaleontological identification relies mainly upon original descriptions and also upon several works, especially by AGIP (1982), Ascoli (1976), Bolli et al. (1994), Gradstein et al. (1989), Holbourn and Kuhnt (2000), Jenkins and Murray (1981), Kinsey (2000), Koutsoukos (2000), Kuhnt (1990), Nagy et al. (2000), Thomas (1988), van Morkhoven, et al. (1986), Williams et al. (1990).

Paleoenvironmental significance of foraminiferal associations is estabilished by comparison assemblages with the one recorded from other authors (Bolli et al., 1994: Holbourn and Kuhnt, 2000: Jenkins and Murray, 1981; Koutsoukos, 2000; Kuhnt, 1990; van Morkhoven, et al., 1986; Williams et al., 1990) in sediments from the same age.

RESULTS AND DISCUSSION

The results of the micropaleontological analysis and the paleoenvironmetal interpretation are presented below starting from the top of the well and summarized in Figure 2. The distribution of the recorded species for each sample is plotted in Table 1.

Interval from sample 2140-2150m to 2340-2350m Age: Pliocene/Late Miocene Examined samples: 2140-2150m, 2180-2190m, 2220-2230m, 2260-2270m, 2300-2310m, 2340-2350m Description: Samples belonging to this interval are rich of foraminifers: the majority of them are planktonic.

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The benthic association consists mainly of calcareous foraminifers. The majority of benthic foraminifers belong to genera Pyrgo, Glandulina, Uvigerina, Bulimina, Melonis, Plectrofrondicularia, Quinqueloculina and Sigmoilopsis. Interpretation: Most of the investigated samples belonging to this interval are characterized by well preserved benthic foraminifers. Most occurring taxa are well known from deepwater Miocene (Neogene) deposits elsewhere. Interval from sample 2380-2390m to 2660-2670m Age: Miocene Examined samples: 2380-2390m, 2420-2430m, 2460-2470m, (2500-2510m, 2540-2550m, 2580-2590m, 2620-2630m- mudstone), (2660-2670m - sandstone/mudstone) Description: This interval results poor of fossils and almost barren in the lower part. Planktic foraminifers are more numerous than benthic that are mostly calcareous. Interpretation: Bathyal environment. From sample 2700-2710m to 2860-2870m Age: Miocene Examined samples: (2700-2710m, 2740-2750m, 2780-2790m, 2815-2825m, 2860-2870m mudstone) Description: This interval results poor of fossils and barren in the lower part. Planktic foraminifera are most numerous than benthic. In the upper part of the interval (sample 2700-2710m) the benthic foraminifera association is mostly represented by coarse agglutinated taxa. Cyclammina cancellata occurs in this interval together with Haplophragmoides spp. and coarse agglutinated. Interpretation: Bathyial environment - clastic sedimentation. Sample 2900-2910m Examined sample: 2900-2910 (mudstone) Description: The sample is mostly characterized by planktic foraminifera. The benthic foraminiferal association is characterized by calcareous and agglutinated foraminfera. Calcareous benthic foraminifera belonging to the genera Planulina, Uvigerina, Globocassidulina, Fissurina and Bulimina occur together with coarse the arenaceous foraminifera Haplophragmoides spp. and Reticulophragmoides spp..

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Interpretation: The majority of benthic foraminifera recorded within this sample are characteristic of deepwater environment. Interval from sample 2940-2950m to 3020-3030m Age: Miocene Examined samples: 2940-2950m, 2980-2990m, 3020-3030m mudstone Description: As the above described sample, also this interval is dominated by planktic foraminifers. The benthic foraminiferal association is strongly dominated by agglutinated taxa as Recurvoides spp., Karreriella spp., Cyclammina spp, Bathisiphon spp. and coarse agglutinated. Interpretation: The majority of benthic foraminifera recorded within this interval are characteristic of deepwater environments. Clastic sedimentation is suggested by the abundance of coarse agglutinated benthic foraminifera. Interval from sample 3060-3070m to 3180-3190m Age: Eocene Examined samples: (3060-3070m, 3100-3110m, 3140-3150m, 3180-3190m, 3185-3190m Description: The foraminiferal assemblage from this interval consists exclusively of agglutinated benthic taxa mostly with organic cement: Ammodiscus, Bathisiphon, Cyclammina, Karreriella, Haplopragmoides, Horomosina, Paratrochamminoides, Recurvoides, Reophax, Reticulophragmoides, Subreophax, Trochamminoides are the most common benthic forainifera genera within this interval. Planctic foraminifers, calcareous benthic, and agglutinated foraminifers with calcitic cement are absent. Interpretation: The taxa recorded in this interval are agglutinated benthic foraminifera from deepwater environment probably below the CCD: plankton calcareous benthos and aggliutinated benthos with calcitic cement do not occur. The majority of the benthic taxa recorded within this interval are opportunistic taxa and are described by several authors as flysch-type fauna. Interval from sample 3220-3230m to 3300-3310 Age: Eocene Examined samples (3220-3230m mudstone), (3260-3270m mudstone), (3300-3310m chalk) Description:

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This interval contains rare benthic and planktonic foraminifers. The benthic association is similar to the one recorded between 3060 and 3190 m. The lowermost part of the interval is barren. Interpretation: The foraminiferal association suggests a bathyal environment with clastic sedimentation. Sample 3340-3350m Examined sample: 3340-3350m (chalk) Description: The majority of foraminifers recorded within this sample are planktonic. Benthic foraminifers are rare and both calcareous and agglutinated. Interpretation: The rare occurrence of benthic foraminifera suggests a bathyal environment above the CCD. Interval from sample 3380-3390m to 3420-3430m Age: Paleocene Examined samples: 3380-3390m (Chalk) and 3420-3430m Description: The foraminiferal fauna is mostly characterized of planktonic foraminifers. Benthic foraminifers are mostly agglutinated with either calcitic or organic cement. The most common benthic taxa recorded within the interval are: coarse agglutinated, Ammodiscus cretaceous, Bathisiphon spp., Dorothia trochoides, Gaudryina Reophax, Rizhammina spp., Spiroplectammina spectabilis, Textularia cf. T. plummerae, Trochamminoides cf. T. subcoronatus. Interpretation: Bathyal environment. Sample 3460-3470m Age: Paleocene-Maastrichtian Description: This samples contains very few planktic and benthic foraminifera. Benthic foraminiferal associations is characterized by agglutinated specimens (mainly of small size) of Ammodiscus spp., Bathisiphon cf. B. discretus, Glomospira charoides, Glomospirella spp., Rezhakina epigona, Saccammina spp., Trochamminoides subcoronatus. Interpretation: Benthic foraminifers are mainly small and characteristic of "flysch-type" benthic foraminiferal associations (opportunistic species typical of hemipelagic layer of turbiditic sequences)

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Sample 3495-3505m Age: Paleocene-Maastrichtian Description: This sample contains very few planktonic foraminifers. Benthic foraminifers are agglutinated belonging to genera: Ammodiscus, Paratrochamminoides, Recurvoides, Reophax, Saccammina, Trochamminoides. The size of these foraminifers is bigger than the ones in sample 3460-3470. Interpretation: Flysch-type benthic foraminiferal association. Sample 3535-3545m Age: Maastrichtian Description: Planktic foraminifera are more abundant than benthic. The benthic foraminifera occurring in this sample belong to the gerera Ammodiscus, Bolivina, Globobulimina, Globulina, Lagenammina, Reophax, Rizhammina, Saccammina, Spiroplectammina, Trochammina and Trochamminoides. Interpretation: Bathyal environment. Interval from sample 3620-3630m to 3660-3670m Age: Maastrichtian Description: This interval is characterized by high abundances of planktonic foraminifera. The benthic foraminifera are rare and either calcareous or agglutinated and belong to the genera Gavelinella, Globorotalites, Gyroidinoides, Pyramindina, Stensioeina, Horomosina, Reophax and Subreophax Interpretation: Bathyal environment. Interval from sample 3700-3710m to 3780-3790m This interval is characterized by the occurrence of benthic and planktic foraminifers. The benthic association consists of agglutinated foraminifers. Interpretation: Bathyal environment. Interval from sample 3820-3830m to 3980-3990m

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Examined samples: 3820-3830m (shale), 3860-3870m (shale and mudstone), 3900-3910m (shale and mudstone), 3940-3950m (shale), 3980-3990m (shale and mudstone) Description: Samples belonging to this interval are poor foraminifera. Interpretation: The majority of benthic foraminifers recorded within the interval are characteristic of flysch-type bathyal environment. Interval from sample 4020-4030m to 4190-4200m Examined samples: 4020-4030m (shale), 4060-4070m (shale), 4100-4110m, 4140-4150m (shale), 4170-4180m (shale), 4190-4200m (shale) Description: Very rare benthic foraminifers are recorded within the interval. Planktic foraminifera are abundant from 4020m to 4070m and less frequent in the lowermost part of the interval. Interpretation: Bathyal environment. CONCLUSIONS

The study of their distribution from Miocene to Upper Cretaceous and the different foraminiferal associations led to the following results:

1. The upper part of the succession (Miocene), contain mainly planktonic and

calcareous benthic foraminifera. The occurring benthic species within this interval, belonging to genera Bulimina, Glandulina, Melonis, Plectrofrondicularia, Pyrgo, Quinqueloculina, Sigmilopsis, Uvigerina and Cyclammina, are indicative of a middle-lower bathyal environment.

2. The Eocene - Late Cretaceous deposits are characterized by foraminiferal

associations typical of lower bathyal environment. Agglutinated benthic foraminifera (indicating clastic sedimentation in lower bathyal environment) are recorded within this interval.

3. The majority of agglutinated benthic foraminifers recorded in the Early Eocene-

Upper Cretaceous deposits are big-size, robust and coarse-grained opportunistic taxa (Ammodiscus, Bathysiphon, Trochamminoides, Paratrochamminoides, Glomospirella, Reophax and Subreophax), characteristic of hemipelagic layer of turbiditic sequences.

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REFERENCES LIST

1. AGIP, 1982. Foraminiferi Padani (Terziario e Quaternario). Milan, pls. I-LII.

2. Ascoli, P., 1976. Foraminiferal and ostracods biostratigraphy of the Mesozoic-Cenozoic, Scotian shelf, Atlantic Canada. Maritime Sediments Spec. Publ. 1, part B, 653-771.

3. Bolli, H.M., Beckmann, J-P., Saunders, J.B., 1994. Benthic foraminiferal

biostratigraphy if the south Caribbean region. Cambridge university Press, 408 p.

4. Gradstein, F.M., Kaminski, Ma., 1989. Taxonomy and biostratigraphy of new and emended species of cenozoic deep-water agglutinated foraminifera from the Labrador and North Seas. Micropaleontology, 35, 72-96.

5. Holbourn A., Kuhnt, W., 2000. Endemiic and cosmopolitan Upper cretaceous

agglutinated foraminiferaof the western African margin, equatorial and central Africa. In: Hart, M.B., Kaminski, M.A., Smart, C.W. (eds). Proceedings of the Fifth International Workshop on Agglutinated Benthic Foramminifera. Grzybowski Foundation Special Publication, 7, 127-148.

6. Jenkins, D.G., Murray, J.W., 1981. Stratigraphical Atlas of fossil Foraminifera.

British Micropalaeontological Society Series, 310 p.

7. Kinsey, S., 2000. Paleogene benthic foraminiferal biostratigraphy of the Halten Terrace area, Norway. In: Hart, M.B., Kaminski, M.A., Smart, C.W. (eds). Proceedings of the Fifth International Workshop on Agglutinated Benthic Foramminifera. Grzybowski Foundation Special Publication, 7, 221-241.

8. Koutsoukos, E.A.M., 2000. " Flysh-type" foraminiferal assemblages in the

cretaceous of northeastern Brazil. In: Hart, M.B., Kaminski, M.A., Smart, C.W. (eds). Proceedings of the Fifth International Workshop on Agglutinated Benthic Foramminifera. Grzybowski Foundation Special Publication, 7,243-260.

9. Kuhnt, W., 1990. Agglutinated foraminifera of western Mediterranean Upper

cretaceous pelagic limestones (Umbrian Appennines, Italy and Betic Cordillera, Southern Spain). Micropaleontology, 36, 397-330.

10. Maclean, B.C. and Wade, J.A., 1993. East coast basin atlas series: seismic

markers and stratigraphic picks in Scotian Basin wells.Atlantic Geoscience Centre, Geological Survey of Canada, 276 p.

11. Nagy, J., Kaminsky, M.A., Kuhnt, W., Bremer, M.A., 2000. Agglutinated

Foraminifera from Neritic to Bathyal Facies in the Paleogene of Spitsbergen and the Barents Sea. In: Hart, M.B., Kaminski, M.A., Smart, C.W. (eds). Proceedings

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of the Fifth International Workshop on Agglutinated Benthic Foramminifera. Grzybowski Foundation Special Publication, 7, 331-361.

12. Thomas, F.C., 1988. Taxonomy and stratigraphy of selected Cenozoic benthic

foraminifera, Canadian Atlantic margin. Micropaleontology, 34, 67-82.

13. van Morkhoven, F.P.C.M., Berggren, W.A., Edwards, A.S., 1986. Cenozoic cosmopolitan deep-water benthic Foraminifera. Elf Aquitaine, 421 p.

14. Williams, G.L., Ascoli, P., Barss, M.S., Bujak, J.P., Davies, E.H., Fensome, R.A.,

Willimson, M.A., 1990. Biostratigraphy and related studies. In: Keen, M.G., Williams, G.L., Geology of the Continentqa Margin of Eastern Canada, Geological Survey of Canada, Geology of Canada, 2, 87-137.

FIGURE AND TABLE CAPTION Figure 1: Location map of Shubenacadie H-100 well. Figure 2: Summary of stratigraphic information (from other authors personal communication and Maclean and Wade, 1993) and paleoenvironmental interpretations based on foraminiferal analysis. Tab 1: Distribution of benthic foraminifera within Shubenacadie H-100 well. X indicates the occurrence, |X the last occurrence within the well.

APPENDIX 1

The data on benthic foraminifera from Shubenacadie H-100 have been recently presented during conferences:

Fiorini F., Fensome R.A., Scott D.B., Thomas F.C. & Wach G.D., 2005. Benthic foraminiferal associations in Cenozoic and Late Cretaceous deposits from Shubenacadie H-100 well (Scotian Slope). Atlantic Geoscience Society 31st Colloquium & Annual General Meeting, February 2005, Saint John, New Brunswick, Canada.

Fiorini F., Fensome R.A., Scott D.B., Thomas F.C. & Wach G.D., 2005. Cretaceous to

Miocene benthic foraminifera from the Scotian Shelf and Slope wells Cohasset A-52 and Shubenacadie H-100. Geological Association of Canada, Mineralogical Association of Canada, Canadian Society of Petroleum Geologists and Canadian Society of Soil Sciences Meeting, Halifax 15-18 May, 2005.

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Fensome R.A., Williams G.L., Crux J., MacRae R.A., Thomas F.C., Gard G. & Fiorini F., 2005. Biostratigraphic age control of Late Cretaceous-Cenozoic strata on the Scotian Margin: an eventful story. AAPG 2005 Annual Meeting, Calgary, Canada.

Figure 1.

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25

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COREHOLE 23

Figure 1. Location of Grand Banks Corehole

CRETACEOUS TO PLEISTOCENE BENTHIC FORAMINIFERA FROM GRAND BANKS COREHOLE 23

F. Fiorini1*, R.A. Fensome2, A. MacRae3, D.B. Scott1, F.C. Thomas2, and G.D. Wach1

1 Department of Earth Sciences, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada, (e-mail: flavia.fiorini@dal.ca)

2 Natural Resources Canada, Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, Dartmouth, Nova Scotia B2Y 4A2, Canada

Figure 5. Photographs of cores from Grand Banks Corehole 23 and position of the studied samples. Cores 13, 12 and 11 consist of dark grey clay. Core 10 consists of very dark clay. Core 9 consists of white silty clay, calcareous and glauconitic. Core 8 is a light green silt. Core 7 is sandy. Core 5 consists of silt and clay. Core 4 is a silty clay. Core 3 is sandy. Core 2 consists of silt and clay.

AKNOWLEDGEMENTS This project is founded by PRAC (Petroleum Research Atlantic Canada). Thanks are due to the CNOPB for permitting us to sample Grand Banks coreholes. Thanks to Chloe Younger for the samples processing. REFERENCES NEDERBRAGT, A., 1989. Maastrichtian Heterohelicidae (Planktonic Foraminifera) from the North West Atlantic. Journal of Micropalaeontology, 8(2): 183-206. FAIRCHILD, W.W., 1966. Paleontology of the Grand Banks coreholes. Imperial Oil Report IPRCER-5MG-66. Exploration Research and Service Department Calgary, Alberta, 137 p. WILLIAMS, G.L. and BRIDEAUX, W.W., 1975. Palynological analysis of Upper Mesozoic and Cenozoic rocks of the Grand Banks, Atlantic Continental Margin Geological Survey of Canada Bulletin 236

Figure 4. Benthic foraminifera distribution and frequencies within the Campanian / Maastrichtian interval of Corehole 23. The frequencies of the benthic foraminifera taxa add up to 100%. Fifty-seven taxa at the generic or specific level have been identified. Only frequencies of the most abundant taxa or taxa group are plotted in this chart. Praebulimina spp. group comprises P. carseyae P. laevis (Fig. 6a). and P. reussi. Pseudovigerina spp. group consists mainly of P. cristata. Gavelinella spp. group is characterized by: G. beccaiiformis, G. monterelensis, G. spissicostata, G. cf. G. pertusa and Gavelinella sp.1. Agglutinated foraminifera group consists mainly of: Gaudryina spp., Tritaxia trilatera and Tritaxia sp.1.

AG

SAMPL

DEPTH

BENTHIC FORAMINIFERA (%)

BARREN

NO FORAMINIFERA RECORDED

CORED INTER

FAIRCHILD (196

WILLIAMS & BRIDEAUX (1975)

NEDERBRAGT

Figure 2. Grand Banks Corehole 23: Biostratigraphy (based on planktonic foraminifera analysis and palynology); location of the cores within the corehole (no core recovery from core 6); position of the 21 samples studied for the benthic foraminifera analysis; occurrence and percentages of benthic foraminifera.

Figure 6. Benthic foraminifera specimens from Upper Campanian / Lower Maastrictian interval of Corehole 23. a - Praebulimina laevis. Sample 281.43 m. b - Bolivina sp.1. Sample 310.24 m. c - Ramulina sp. Sample 282.30 m. d - Euvigerina sp. Sample 310.24 m .

a

b c d

Grand Banks Corehole 23 is one of 25 coreholes drilled in 1965 on the Grand Banks off Newfoundland by PanAmerican Petroleum Corporation (Fig. 1). The microfossil content of these sediments has previously been studied to determine a zonation of the strata. No paleoenvironmental interpretation or taxonomic studies on benthic foraminifera from these coreholes have been published. Benthic foraminifera from Grand Banks Corehole 23 have been investigated to provide information about paleoenvironment, taxonomy and stratigraphy. Corehole 23 was drilled in 87 m water depth to a depth of 423.98 m. It comprises 13 cores (Fig. 2), recovering sediments of Cenozoic and Upper Cretaceous age. Twenty-one samples (Fig. 5), collected along the entire length of the core, have been examind for micropaleontological analysis. Twenty grams of all samples were washed on a 63m sieve and examined for benthic foraminiferal analysis. A quantitative study on the distribution of benthic foraminifera led to the following results: The lower portion of the Corehole (from core 13 to core 10) is characterized by a foraminiferal microfauna rich in benthos and in a good state of preservation. The benthic foraminiferal association consists of the following Campanian-Maastrichtian taxa typical of outer neritic and upper bathyal environment: Gavelinella spp., Praebulimina spp., Pseudouvigerina spp., Globorotalites michelinianus, Bolivina incrassata, Spirobolivina rosula, Stensioeina pommerana, Lenticulina spp., Marginulina spp., Nodosaria spp. and Dentalina spp. The association recorded in core 9 corresponds to Middle Eocene and is rich in planktic foraminifera. The benthic association consists mostly of Cibicidoides spp., Siphonina spp., Bulimina spp. and Lenticulina spp., all forms characteristic of bathyal environment. Samples from cores 8 and 7 do not contain foraminifera. The foraminiferal association recorded within the uppermost part of the Corehole (core 5) consists exclusively of Pleistocene benthic foraminifera mainly belonging to the genera Cribroelphidium and Quinqueloculina, indicative of a inner neritic environment.

These faunas correspond with similar age fauna from the Scotian Shelf reported

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