M ic ta w G r. N Neecckkww iicckk M M RR MM Dubuc A Arrsseennaauulltt G Gaarriinn C CBB++MMCC P Paabbooss C Cll ee mm vvii ll ll ee N NOOMM A Annssee CCaassccoonn A
Annssee àà PPiieerrrree--LLooiisseellllee
L Laa VViieellllee Gascons W Weesstt PPooiinntt Indian Point ? W Whhiittee HHeeaadd B Boonnaavveennttuurree L Laa CCoouullééee ? W Weeiirr Viséan Tournaisian Lochkovian PragianEmsian Eifelian Givetian Frasnian Famenian Pridolian Ludlow Wenlock Ll an do ve ry Rhuddanian Aeronian Telychian Cambrian Tremadoc Arenig Darriwillian Caradoc Ashgill Neo-Proterozoic O rd ov ic ia n S ilu ria n D ev on ia n CCaa rrbb oonn iiffee rroo uuss Namurian M is si ss ip pi an SEISMICMARKER 10 9 1 11 6 7 4 3 2 5 8 s s Ta Ta Ar?/Ne Ac+We SEISMOSTRATIGRAPHY
Proterozoic basement: discontinuous, parallel to undulating, medium amplitude, and low frequency reflections. MaquereauGroup: parallel, locally continuous, high amplitude, and high frequency reflections .
Non metamorphosed Ordovician: chaotic, locally parallel, discontinuous, low amplitude, and high frequency
reflec-tions, characterized by erosive truncation.
ArsenaultFormation(?): regular, parallel, continuous, high amplitude, and high frequency reflections characterized
by onlap on older Cambro-Ordovician units.
NeckwickFormation: sigmoid, discontinuous, low amplitude and high frequency reflections, characterized by toplap
and downlap.
Du Milieu River Mélange: uneven, parallel to sub-parallel, not continuous to chaotic, low amplitude and high
frequen-cy reflections.
DubucFormation: sigmoid to parallel, non-continuous, high amplitude, and high frequency reflections .
GarinFormation: chaotic reflections.
Matapedia Group (Pabos + White Head formations) and Clemville Formation: diverging, discontinuous, very low
amplitude, and high frequency reflections, up to the local absence of reflections.
Lower Siliciclastic Assembly (Weir + Anse Cascon formations): parallel, locally continuous to chaotic reflections,
characterized by a very high amplitude and low frequency.
Intermediate Calcareous Assembly (Anse à Pierre-Loiselle + La Vieille formations): sigmoidal to parallel, continuous,
low amplitude and low frequency reflections.
UpperSiliciclastic Assembly (Gascons, West Point, and Indian Point formations): chaotic reflections.
PBasement? R ES ER VO IR SO U R C E R O C K M Maaqquueerreeaauu PPoorrtt--DDaanniieell RRiivveerr M Mééllaannggee ? Proterozoic basement 0 10 km Mq 4 3 2 1 Proterozoic basement 10 km 0 Maquereau rise erosion Mictaw Arseanult 0 10 km subsidence 2 3 1 Mictaw / Arsenault Maquereau C-O Proterozoic basement 0 10 km erosion Ma Ga Ar 0 10 km Mi
Honorat (Garin) + Matapédia
DA RA GRF GPF 0 10 km Ch SJSF 0 10 km Mi Mq Ga Ar 1 2 3 4 5 7 6
Lower Chaleurs + Upper Chaleurs
DA RA GRF GPF SJSF CBS APA CVGS SSE NNW
TA
C
O
N
IC
O
R
O
G
E
N
Y
T re m a d o ci a n -A re n ig ia nQ
U
IE
SC
EN
C
E
D ar riw illi an -C ar ad oc ia n AC AD IA N SH O RT EN IN G M id dl e to La te De vo ni an A C A D IA N ST R IK E-SL IP M id dl e to La te D ev on ia nEX
TE
N
SI
O
N
C ar ad oc ia n-R hu dd an ia nQ
U
IE
SC
EN
C
E
R hu dd an ia n -P rid ol ia n1.
2.
3.
4.
5.
6.
7.
8.
Density contrast (g cm-3) -0.100 -0.090 -0.080 -0.070 -0.060 -0.050 -0.040 -0.030 -0.020 -0.010 0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100 -0.058 Schu -0.035 Omi/Oar -0.024 Schl -0.010 OSma -0.006 C-O 0.004 Ogn 0.040 pC bsmnt 0.078 pCMq 2001-MRN-14A 2001-MRN-14B NNNNWW S SSSEE D uv al A nt ic lin e G ra nd P ab os Fa ul t Ob se rv ed C a l c u l a t e d S ai nt -J og ue s S ud Fa ul t G a ri n R iv e r F a u lt 80 90 100 110 Proterozoic basement p pCCMMqq OOaarr O Oggnn O OSSmmaa S Scchhll S Scchhuu C C--OO C C--OO O Oaarr O Oggnn p pCCMMqq O Ommii C C--OO 3 2 1 0 -1 -2 -3 ∆ g (m G al ) 0 2 4 6 8 10 De pt h (k m )?
?
M MLLEEFFIn the model, the positive (southern)
anomaly is reproduced mainly through
tectonic stacking the high-density
greenschist facies Maquereau Group.
The negative anomaly is reproduced
mostly by the total absence of the
Maquereau Group and infilling by the
relatively low-density Upper Ordovician
Pabos Formation of the Matapedia Group.
The calculated residual gravity anomaly
curve, computed from the density
distri-bution derived from the geological
i n t erp ret at i o n , n i cel y m i m i cs t h e
observed anomaly curve. The gravity
modeling suggests: (1) the position of the
Proterozoic basement at a depth of about
10 km, (2) the presence of a tectonic
stacking of Cambrian-Ordovician units,
already suggested by the seismic
inter-pretation, and (3) the presence of a thick
succession of relatively low-density
syn-rift sedimentary rocks (Pabos Formation)
deposited during a post-Taconic
exten-sion episode.
Upper rollover and crestal collapse zone
Upper crestal collapse graben
Lower roll-over and crestal collapse zone
Syn-rift Pre-rift Unfolded ramp syncline reverse faults Ramp zone Lower crestal collapse graben A B
6. Analog Model
Figure 11. (a) Geometry and seismic velocity model of a
ramp-flat listric extensional fault system. Pre-extension
strata are shaded grey and syn-extension strata are unshaded.
(b) Migrated synthetic seismic section (with noise)
pro-duced by the Stable Beam Method (modified from McClay,
1995).
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5 6,0Mictaw Gr. Garin Fm. Matapedia Gr. Lower Chaleurs Gr. Upper Chaleurs Gr.
Pirate Cove/Escuminac Fms. Bonaventure Fm. e st im a te d vi tr in ite re fle ct a n ce (% ) Lithostratigraphic unit S SEE NNWW Immature Oil window Condensate Dry gas po st-Tacon ic buria l
M
LE
F
7. Correlations with existing
thermal maturity data
Figure 12. Variations in the average estimated vitrinite
equivalent-reflectance values in different lithostratigraphic
units of the Chaleurs Bay Synclinorium (Eastern area) and
the Aroostook-Percé Anticlinorium (modified from Roy,
2008).
0 1000 2000 3000 Shot 200 300 400 500 600 700 800 900 1000 1100 1200 1300 T W T (m s) 2001-MRN-14A 2001-MRN-14B S SEE NNWW 0 1000 2000 3000 Shot 200 300 400 500 600 700 SJSF SHCA LMASwp DA GRF GPF Sga_silt Sga_lime Slv Slp Sac PASPÉBIAC - 1 (projeté 4,5 km) A Acc++WWee T Taa TTaa T Taa N Nee N Nee T Taa?? b bssmmnntt ???? b bssmmnntt ???? 0 5 10 km O Oaarr?? 0 1000 2000 3000 Shot CMP 200 300 400 500 600 700 800 900 1000 1100 1200 1300 T W T (m s) 2001-MRN-14A 2001-MRN-14B S SEE NNWW 0 1000 2000 3000 Shot CMP 200 300 400 500 600 700 10 8 3 10 8 7 3 4 11 6 4 11 3 10 8 11 1 3O
Om
mii
O
Om
mii
4 5O
OS
Sm
maa
O
Oaarr
O
Oggnn
O
Oggnn
O
Oaarr
C
C--O
O
ppC
CM
Mqq
SSE
E--ddiirreecctteedd T
Taaccoonniicc tthhrruussttss
U
Uppppeerr ccrreessttaall
ccoollllaappssee ggrraabbeenn
Swp Sga_silt Sga_lime Slv Slp Sac PASPÉBIAC - 1 (projected 4.5 km) 0 5 10 km SJSF SHCA MLA DA RRAA GRF GPF Proterozoic basement 2rreevveerrssee
ffaauulltt
zzoonnee
7 9 Clemville Fm. bottom 8 Garin Fm. top 6 Pabos Fm. top Neckwick/Arsenault Fm. top 4 Taconic unconformity 3 Maquereau Gr. top 2Rivière du Milieu Mélange top?
5
1 Proterozoic basement ? La Vieille Fm. top
10
Anse-Cascon Fm. top
Dextral strike-slip fault
LEGEND -40 -30 -20 -10 0 10 20 0 50 100 150 200 250 m G al km
A
A'
S hi ck sh oc ks G ro up B at hu rs tobserved gravity anomaly visually fitted regional field
2001-MRN-14A 2001-MRN-14B
Figure 9. Observed gravity profile (total anomaly) extracted from the Bouguer anomaly map and
visual estimation of the regional field.
Comparison with analog models
Decomposition Residual Bouguer anomaly modelling Seismic re-interpretation Profile B Boouugguueerr A Annoommaallyy M Maapp G
Geeoollooggiiccaall M Maapp Final model W Weellll D Daattaa P
Prroocceesssseedd 22DD sseeiissmmiicc ddaattaa
d
daa ttaa qquuaa ll ii ttyy ii ss ggoooodd
False
Additional processing
Preliminary Seismic interpretation
true
Time to depth conversion
iinntteerrpprreettaattiioonn iiss v
viiaabbllee
False True
3. Method
Figure 5. Working method used to produce the structural model ofthe study area. The seismic interpretation was constrained by the geo-logical map and formation tops penetrated by well Paspébiac No. 1. The seismic interpretation was converted into depth by using interval velocities derived from velocity analysis of prestack seismic data so it could be used as a constraint for the gravity modeling. An anomaly profile was extracted from the Bouguer anomaly map and was later decomposed into a regional and a residual component by the visual adjustment method. The gravity model was constrained by measured densities of the units. Through an iterative process, the results of the gravity modeling were used to modify the seismic interpretation and this new seismic interpretation was used to build a new geological model. The cross-section resulting from surface data analysis, seis-mic interpretation and gravity modeling was compared with pub-lished analog models in order to better understand the geometry and kinematic implications. P PAASSPPÉÉBBIIAACC -- 11 48,00 ° 48,00 ° 48,50 ° 48,50 ° -66,00 ° -66,00 ° -65,50 ° -65,50 ° -65,00 ° -65,00 ° -64,50 ° -64,50 °
0
10 km
Mictaw Gr. and Arsenault Fm. Maquereau Group
Neoproterozoic to Lower Cambrian
Garin Formation (Honorat Gr.)
Ordovician
Lower Chaleurs Group Upper Chaleurs Group Fortin Group
Bonaventure Formation
Carboniferous
Ordovician to Lower Silurian Matapédia Group
Silurian Devonian
Basalt and sediments
Chaleurs Bay
R RAA D DAA SSJJSSFFThe integration of 2D seismic interpretation, gravity
model-ing, and thermal maturity data reveals the superposition of
four different deformation styles, developed over four
deformation phases in the Chaleurs Bay area, Quebec,
Can-ada. The first deformation phase, the
Tremadocian-Arenigian Taconic Orogeny, is characterized by a
south-east-directed hinterland dipping duplex mostly involving
the Hadrynian-Lower Cambrian Maquereau Group. The
second deformation phase, the Late Ordovician
post-Taconic extension, is marked by the development of a
ramp-flat listric extensional fault system which controlled
the deposition of the Upper Ordovician Honorat and
Matapédia Groups. During the third deformation phase, the
Middle Devonian early stage of the Acadian Orogeny,
thrusts faults inherited from the Taconic Orogeny are
reacti-vated and normal faults inherited from the post-Taconic
extensional phase are inverted. Strike-slip faulting along
the Grand-Pabos and Garin River faults occurred during the
fourth deformation phase, the Middle to Late Devonian late
stage of the Acadian Orogeny.
45,0 ° 45,0 ° 50,0 ° 50,0 ° -75,0 ° -75,0 ° -70,0 ° -70,0 ° -65,0 ° -65,0 ° -60,0 ° -60,0 ° -55,0 ° -55,0 ° -50,0 ° -50,0 ° 0 200 km 0 50 100 km Devonian intrusives Carboniferous clastics
Gaspé Sandstones (Lower-Middle Devonian) Upper Gaspé Limestones (Lower Devonian) Chaleurs Group (Lower Silurian-Lower Devonian)
Honorat and Matapédia groups (Upper Ordovician-Lower Silurian) Taconic-deformed units (Cambrian-Upper Ordovician)
D Duunnnnaaggee Atlantic Ocean C CVVGGSS C CVVGGSS C CVVGGSS A APPAA A APPAA C CBBSS C CBBSS 47 ° 47 ° 48 ° 48 ° 49 ° 49 ° -71 ° -71 ° -70 ° -70 ° -69 ° -69 ° -68 ° -68 ° -67 ° -67 ° -66 ° -66 ° -65 ° -65 ° -64 ° -64 ° -63 ° -63 ° -62 ° -62 ° New Brunswick Maine Saint L awrenc e River H Huummbbeerr ++ D Duunnnnaaggee
SSTTU
UD
DYY AAR
REEAA
Figure 2. Main tectonostratigraphic domains of the Gaspé Belt
(modified from Lavoie, 2008). The Gaspé Belt has been subdi-vided into three tectonostratigraphic areas, which are from north to south: (1) the Connecticut Valley-Gaspé Synclinorium (CVGS), (2) the Aroostook-Percé Anticlinorium (APA), and (3) the Chaleurs Bay Synclinorium (CBS) (Brisebois and Brun, 1994; Bourque et al., 2001; Malo et al., 2008).
Figure 1. The Gaspé Belt and Taconic tectonostratigraphic
domains of the Canadian Appalachians (modified from Lavoie, 2008). The Gaspé Belt is the largest post-Taconic Successor
Basin of the Middle Paleozoic of Canadian Appalachians
(Williams, 1995). It includes a succession of Upper Ordovician to Upper Devonian sedimentary and volcanic rocks that overlies unconformably or are in fault contact with Cambro-Ordovician units belonging to the Humber, Dunnage and Gander (Lower Paleozoic) Zones (Brisebois and Brun, 1994; Bourque et al., 2001; Malo, 2001; Malo et al., 2008).
2. Introduction
Regional Stratigraphy and Seismostratigraphy
4. 2D Seismic
5. Gravity Data Modeling
20 01 -M R N -1 4A & B
A’
A
The Gaspé Belt
Figure 3. Geologic map showing location of
seis-mic lines 2001-MRN-14A and 2001-MRN-14B
and well Paspébiac-1, north of Chaleurs Bay. DA:
Duval Anticline; RA: Robidoux Anticline; SJSF:
Saint-Jogues Sud Fault (modified from: Pinet,
2013). The Chaleurs Bay Synclinorium contains
an assemblage of regional NE-SW-trending folds
and major E-W and NE-SW-trending faults,
most-ly involving rocks of the Upper Ordovician
Matapedia Group and the Silurian Chaleurs Group.
Figure 4. Lithostratigraphy and seismostratigraphy of the Chaleurs
Bay Synclinorium and the Aroostook-Percé Anticlinorium. CB +
MC: Corner of the Beach and Murphy Creek formations; NOM:
Nadeau ophiolitic Mélange; MRM: Milieu River Mélange (modified from: Bourque et al., 2001; Jutras and Prichonet, 2002; Malo, 2004, De Souza et al., 2012; Marcil et al., 2005.)
Figure 8. Location of the gravity profile and the seismic lines MNR-14A and
2001-MRN-14B in the Bouguer anomaly map of the Gaspé Peninsula (modified from: Pinet et al.,
2005).
Figure 7. Structural interpretation of seismic lines
2001-MRN-14A and 2001-MNR-14B. DA: Duval Anticline; LMA: Lake
Ménard Anticline; RA: Robidoux Anticline; SHCA:
St-Hélène-de-la-Croix Anticline; SJSF: St-Jogues South Fault; GPF:
Grand Pabos Fault; RGF: Garin River Fault; Oar: Arsenault
Formation; Ogn: Garin Formation; Omi: Mictaw Group;
OSma Matapedia Group. pCMq: Maquereau Group. For
loca-tion, see figure 3.
Figure 6. Envelope representation of pre-stack
migrated 2001-MNR-14A and 2001-MNR-14B
seis-mic lines. Ac-We: Anse-Cascon and Weir Fms; Ar:
Arsenault Fm; Ne: Neckwick Fm. top; Ta: Taconic
unconformity. For location, see figure 3.
In our interpretation, the faults that cut across the
Silurian rocks at the surface also affect the
under-lying Cambrian-Lower Ordovician rocks. As for
the Grand Pabos and the Garin River strike-slip
faults, the interpretation suggests subvertical dips,
with a connection of both faults at depth. Low
amplitude, short wavelength folds and reverse
faults with a small throw involving
Cambro-Ordovician (sub-Taconic unconformity) units have
been interpreted as a system of partially inverted
normal listric faults (Gibbs, 1984). Reflections of
the Upper Ordovician Garin Formation (Honorat
Group) onlapping on the Taconic unconformity
mimic the syn-rift units onlap at the crest of the
roll-over anticline, illustrated by scaled analog
models of ramp-flat listric extensional fault
sys-tems (McClay, 1995). Divergent reflections
attributed to syn-rift units of the Matapedia
Group, south of the Garin River Fault, are
com-patible with an episode of post-Taconic extension.
Based on the comparison to a scaled analog
mod-el, major Acadian folds of the Chaleurs Bay
Synclinorium are interpreted as the result of
tectonic inversion of a post-Taconic upper
crestal collapse graben (McClay, 1995).
mm
aaiinn
ll
iisstt
rr
iicc
ee
xxttee
nn
ssii
oo
nnaall
ff
aa
uulltt
22 00 00 11 --MM RR NN --1144 BB 2200 0011 --MM RR NN --11 44AAG
Grr
aa
nn
dd PPaabbooss FF
aa
uulltt
G
G
aa
rrii
nn
R
R
ii
vv
ee
rr
FFaa
uull
tt
Amplitude 0 10 0 0 0 2 0 0 0 0Figure 10. Gravity data modeling. C-O: non-metamorphosed Ordovician. MLEF: Main Listric
Exten-sional Fault. pCMq: Maquereau Group. Oar: Arsenault Formation. Ogn: Garin Formation. Omi: Mictaw Group. OSma: Matapedia Group. Schi: Lower Chaleurs Group. Schu: Upper Chaleurs Group.
Diego Tovar
1
, Michel Malo
1
, Mathieu J. Duchesne
2
, and Nicolas Pinet
2
1
Institut national de la recherche scientifique, Centre Eau Terre Environnement
2
Geological Survey of Canada
Geometric and Kinematic Reconstruction of the Chaleurs Bay Synclinorium (Gaspé Belt)
through the Integration of Geological and Geophysical Data
9. Conclusions
The integration of geological data, 2D seismic reflection, gravity modeling, and thermal maturity data from the Chaleurs Bay Syn-clinorium, reveals the superposition of four different deformation styles, developed over four distinct deformation episodes. Our study lead to several new findings that bear significant implica-tions on the geological evolution model and petroleum potential of the area : (1) the existence of Taconic thrust sheets with the southeast tectonic transport suggests that the Taconic orogen in the Gaspé Peninsula is a doubly vergent orogen; (2) major Acadian folds of the Chaleurs Bay Synclinorium are interpreted as the result of tectonic inversion of a post-Taconic upper crestal collapse graben (McClay, 1995); (3) the coexistence of rock units with contrasting burial histories is interpreted as the result of post-Taconian extension normal motions along a major, previous-ly poorprevious-ly documented, fault; (4) the high organic content shales of the Mictaw Group, located in the footwall of the post-Taconian normal fault, experienced less burial than correlative rocks found in the hanging wall and preserved a significant hydrocarbon potential.
Acknowledgements
The first author acknowledges the Institut national de la
recher-che scientifique (INRS) for the financial support and Junex Inc.
for providing the reprocessed version of the seismic line 2001-MNR-14A.
Bêche, M., Kirkwood, D., Jardin, A., Desaulniers. E., Saucier, D., and Roure, F., 2007. 2D depth seismic imaging in the Gaspé Belt, a structurally complex fold and thrust belt in the Northern Appalachians, Québec, Canada. In: Thrust Belts and Foreland Basins: From Kinematics to Hydrocarbon Systems. Lacombe, O., Lavé, J., Roure, F.M., Vergés, J. (Eds.), Springer, p. 75-80.
Bourque, P.-A., Gosselin, C., Kirkwood, D., Malo, M., and St-Julien, P., 1993. Le Silurien du segment appalachien Gaspésie-Matapédia- Témiscouata: stratigraphie, géologie structurale et paléogéographie. Ministère de l’Énergie et des Ressources du Québec, MB 93-25, 115 pp.
Brisebois, D., Lachambre, G., and Piché, G., 1991. Carte géologique Péninsule de la Gaspésie. Carte 2146 - DV 91-21, Ministère de l’Énergie et des Ressources, Québec. Échelle 1:250 000.
Brisebois, D. and Brun, J., 1994. La plate-forme du Saint-Laurent et les Appalaches. In: Hocq, M. and Dubé, C. (Eds.), 1994, Géologie du Québec, Les Publications du Québec, Ministère des Ressources Naturelles, MM 94-01, 154 pp.
De Broucker, G., 1987. Stratigraphie, pétrographie et structure de la boutonnière de Maquereau - Mictaw (Région de Port-Daniel, Gaspésie). Ministère de l’Énergie et des Ressources du Québec, MM 86-03.
Gibbs, A.D., 1984. Structural evolution of extensional basin margins. Journal of the Geological Society, v. 141, p. 609-620.
Junex Inc., 2008. Junex Paspébiac #1 (C-133). Rapport de fin de forage. Projet : 3014-017. Permis : 2001PG589. Québec (Québec), 31 pp + annexes.
Kirkwood, D., 1999. Palinspastic restoration of a post-Taconian successor basin deformed within a transpressive regime, northern Appalachians. Tectonics, v. 18, p. 1027-1040.
Kirkwood, D., Lavoie, M., and Marcil, J., 2004. Structural style and hydrocar-bon potential in the Acadian foreland thrust and fold belt, Gaspé Appalachians, Canada. Dans: R. Swennen, Roure, F. and Granath, J. (Eds.), Deformation, fluid flow, and reservoir appraisal in foreland fold and thrust belts, AAPG Hedberg Series, no. 1, p. 412- 430.
Lachambre, G. and Brisebois, D., 1990. Géologie de la Gaspésie / compilé par G. Lachambre et D. Brisebois à partir des travaux inédits de D. Brisebois et A. Slivitzky. Gouvernement du Québec, Ministère des Ressources naturelles, Secteur des mines. Échelle 1:50,000.
McClay, K.R., 1995. 2D and 3D analogue modelling of extensional fault struc-tures: templates for seismic interpretation. Petroleum Geoscience, v. 1, p. 163-178.
Pinet, N., Lavoie, D., Brouillette, P., Dion, D.-J., Keating, P., Brisebois, D., Malo, M., and Castonguay, S., 2005. Gravimetric and aeromagnetic atlas of the Gaspé Peninsula. Geological Survey of Canada, Open File 5020, 68 pp.
Pinet. N., Keating, P., Brouillette, P., Dion, D.-J., and Lavoie, D., 2006. Produc-tion of a residual gravity anomaly map for Gaspésie (northern Appalachian Mountains), Quebec, by a graphical method. Geological Survey of Canada, Current Research 2006 -D 1, 8 pp.
Pinet, N., 2013. Gaspé Belt subsurface geometry in the northern Québec Appa-lachians as revealed by an integrated geophysical and geological study: 2 - Seis-mic interpretation and potential field modelling results. Tectonophysics, v. 588, p. 100-117.
Roy, S., 2008. Maturation thermique et potentiel pétroligène de la ceinture de Gaspé, Gaspésie, Québec, Canada. Thèse. Québec, Université du Québec, Institut national de la recherche scientifique, 459 pp.
St-Julien, P. et Hubert, C., 1975. Evolution of the Taconian Orogen in the Québec Appalachians. American Journal of Science, v. 275A, p. 337-362.
References
8. Kinematics and Timing of Deformation
Figure 13. Structural evolution of the Chaleurs Bay Synclinorium and the Aroostook-Percé
Anti-clinorium. APA: Aroostook-Percé Anticlinorium; Ar: Arsenault Formation; CBS: Chaleurs Bay Synclinorium; Ch: Chaleurs Group; C-O: non-metamorphosed Cambro-Ordovician; CVGS: Con-necticut Valley-Gaspe Synclinorium. DA: Duval Anticline; Ga: Garin Formation; GPF: Grand Pabos Fault; GRF: Garin River Fault; Mi: Mictaw Group. Mq: Maquereau Group; Mt: Matapedia Group; RA: Robidoux Anticline; SJSF: Saint-Jogues Sud Fault.
1. Summary
In t h e C h a l e u r s B a y S yn c l i n o r i u m , m o s t o f
outcropping rock units are in the condensate to dry gas
windows and exhibits a constant decrease in the
aver-age estimated vitrinite equivalent-reflectance values
from the base to the top of the stratigraphic column. A
notable exception corresponds to the Mictaw Group, at
the base of the stratigraphic succession, which is still
in the oil-window (Roy, 2008). This contrasting history
is compatible with the development of a major
unmapped post-Taconic listric extensional fault,
locat-ed between the Mictaw Group (Port-Daniel area) and
the Matapédia Group (Duval Anticline). According to
our model, rocks of the Mictaw Group, in the footwall
(southeast) of this fault, were preserved from
signifi-cant post-Taconic burial, while syn-extension strata
were deposited during the post-Taconic extension
phase, in the hanging wall (northwest) of this fault. For
the CBS, the Ordovician Mictaw Group (Dubuc
Formation) is a potential source rock of hydrocarbons,
reaching TOC values higher than 3.0% with organic
matter type II (Malo et al., 2008; Roy, 2008).
A Acc++WWee
C
C--O
O
? ? 9 OphioliteHigh-grade metamorphics Nearshore sandstones
Terrestrial conglomerate Mélange
Deep water limestones
Platformal limestones Fine-grained siliciclastics Volcanics
Deep water mudstones and sandstones
M at ap éd ia G r. Lo w er C ha le ur s G r. U .C ha le ur s G r.