the stratigraphy and structural history of the mesozoic and cenozoic ...

More documents

Recommendations

Info

$A marine wide angle reflection/refraction profile adjacent Nova ...$

deposited in the deepwater. As with previous periods of high rates of deposition into the deepwater, the increased sediment load in the Early Cretaceous initiated renewed salt motion, resulting in salt withdrawal mini-basins that formed negative relief structures on the seafloor in which turbidite channel and fan sediments were focused and deposited (Kidston et. al., 2002). Further south the Shelburne Delta became abandoned due to exhaustion and/or redistribution of the fluvial sediment supply (Kidston et. al., 2002). Deltaic sedimentation ceased along the entire Scotian margin during the Late Cretaceous and was followed by a period of slow relative sea level rise and deposition of a thick succession of coastal plain and shallow marine shelf sand and shale of the Logan Canyon Formation. No regional seismic markers are contained within the Logan Canyon Formation (MacLean and Wade, 1992). The distal equivalent of the Logan Canyon Formation is the Shortland Shale. Within the study area drilled thickness of Logan Canyon Formation (or equivalent) range from 776.3 m in well Moheida P-15 to 2220.0 m in well Evangeline H-98 (MacLean and Wade, 1993). Continued relatively high sea level conditions combined with low relief hinterland, resulted in a reduction of sediment supply to the basin during the Late Cretaceous (Kidston et. al., 2002). Marine shales, chalks and minor limestones of the Dawson Canyon Formation were deposited throughout the Scotian Basin at this time. The Petrel Member, a persistent series of thin Turonian age limestones, forms a regional lithologic and seismic marker within the Dawson Canyon Formation (Wade, 1991). The Dawson Canyon Formation was intersected in all six wells used in this study and has a 30
formation thickness consistently in the 250 ± 30 m range except for well Evangeline H- 98, where it is 809.5 m in thickness (MacLean and Wade, 1993). The Wyandot Formation overlies the Dawson Canyon Formation. It is composed of chalks, chalky mudstones, marls and minor limestones (MacLean and Wade, 1992). Within the study area the top of the Wyandot Formation is unconformably overlain by Tertiary sediments. The unconformity surface forms an easily recognizable regional seismic marker considered to mark the base of Tertiary stratigraphy. Within the study area the drilled thickness of the Wyandot Formation ranges from 19.0 m in well Oneida O-25 to 158.5 m in well Evangeline H-98 (MacLean and Wade, 1993). In the Scotian Basin the entire Tertiary sedimentary succession is included in the Banquereau Formation. An overall regression of the sedimentary systems through the Tertiary is reflected in an upward coarsening succession from marine shelf mudstones at the base of the Banquereau Formation to sandstones and conglomerates in the top. Three predominant seismic reflections within the Tertiary section are correlated with erosional surfaces within the Eocene, Oligocene and Miocene epochs (MacLean and Wade, 1992). Quaternary erosion in parts of the Laurentian Channel has removed the Tertiary section completely (MacLean and Wade, 1992). The increased deepwater Tertiary sediment load again resulted in renewed salt movement. During the past two million years, several hundred metres of glacial and marine sediments were deposited on the outer shelf and upper slope. Quaternary glacial runoff resulted in major incisions on the slope (Kidston et. al., 2002), forming the rugose water bottom seen today in the eastern portion of the study area (Figure 2-6). 31
Page 1 and 2: THE STRATIGRAPHY AND STRUCTURAL HIS
Page 3 and 4: The integration of seismic stratigr
Page 5 and 6: leaving his door open and helping m
Page 7 and 8: 3.3.4 Tr2 Sequence Boundary 57 3.3.
Page 9 and 10: List of Figures (Short Titles) 1-1
Page 11 and 12: 3-22 Time structure map of the T1 S
Page 13 and 14: 5-17 End member geometries of alloc
Page 15 and 16: Chapter 1 Introduction 1.1 Introduc
Page 17 and 18: developed in the western part of th
Page 19 and 20: Areomagnetic surveys of the North A
Page 21 and 22: y Mukhopadhyay and Wade (1990), Wil
Page 23 and 24: 9 Figure 1-2: Comparative stratigra
Page 25 and 26: Naskapi N-30 Figure 1-3: Map showin
Page 27 and 28: SE NW 0 6 12 Kilometers 13 Figure 1
Page 29 and 30: converted using velocity informatio
Page 31 and 32: to date the effects of salt tectoni
Page 33 and 34: A 19 A’ Figure 2-1: Bathymetry an
Page 35 and 36: Within the area of the Scotian Basi
Page 37 and 38: 23 Figure 2-3: Generalized lithostr
Page 39 and 40: the landward extensions of regularl
Page 41 and 42: marine shales of the Misaine Member
Page 43: and positive relief structures on t
Page 47 and 48: 2.4 Structural Styles and Geometry
Page 49 and 50: and igneous rocks of the Meguma Ter
Page 51 and 52: approximately 6 to 7 kilometers bel
Page 53 and 54: 4.2.3 Halotectonics In addition to
Page 55 and 56: 41 Figure 2-10: Scotian Margin base
Page 57 and 58: NW SE 6126 m 43 Figure 3-1: Represe
Page 59 and 60: TGS Base Tertiary Unconformity 45 T
Page 61 and 62: 47 Figure 3-3: Lithoprobe seismic r
Page 63 and 64: (Member Good DS9 Good Good Excellen
Page 65 and 66: NW SE Onlap Downlap 0 6 12 Kilomete
Page 67 and 68: 3.3.1. Top Basement Marker Within t
Page 69 and 70: 3.3.2. Tr1 Sequence Boundary The Tr
Page 71 and 72: 3.3.3 Depositional Sequence 1 Depos
Page 73 and 74: Glooscap C-63 E Moheida P-15 D TWT
Page 75 and 76: NW SE D D’ Eurydice Figure 3-9: S
Page 77 and 78: Formation consists of a series of m
Page 79 and 80: These reflections may represent int
Page 81 and 82: Anomalous highs Sequence boundary i
Page 83 and 84: in shape, 1 to 12 kilometers in dia
Page 85 and 86: Intersection with salt structure Fa
Page 87 and 88: 62, also intersected the Abenaki Fo
Page 89 and 90: marker in a landward direction (Fig
Page 91 and 92: south (slope-parallel) direction. T
Page 93 and 94: 3.3.13 Depositional Sequence 5 Depo
Page 95 and 96:
Thickness TWT (ms) D D’ Thick Int
Page 97 and 98:
NW SE Quaternary Miocene - Oligocen
Page 99 and 100:
Due to the consistently high amplit
Page 101 and 102:
Correlation with the Shubenacadie H
Page 103 and 104:
3.3.17 Depositional Sequence 7 Depo
Page 105 and 106:
3.3.18. T2 Sequence Boundary The T2
Page 107 and 108:
Reflections within DS8 are commonly
Page 109 and 110:
3.3.20 T3 Sequence Boundary The T3
Page 111 and 112:
3.3.21 Depositional Sequence 9 Depo
Page 113 and 114:
3.3.22 Water Bottom The uppermost r
Page 115 and 116:
4.1 Introductory Remarks Chapter 4
Page 117 and 118:
A (TWT ms) Basin-Bounding Fault Fam
Page 119 and 120:
A A’ NW SE 105
Page 121 and 122:
4.2.1 Slope Basin-Bounding Fault Fa
Page 123 and 124:
Figure 4-3: Seismic Profile B-B’
Page 125 and 126:
Wernicke (1981) or “second-order
Page 127 and 128:
a) 2.0 3.0 4.0 5.0 6.0 7.0 8.0 b) D
Page 129 and 130:
T3 T2 T1 T0 K1 J2 J1 Tr2 Tr1 NW SE
Page 131 and 132:
thickening, resulting in distinct w
Page 133 and 134:
Tertiary. In the northwest some maj
Page 135 and 136:
SE NW Minor Faults 3076 m Major Fau
Page 137 and 138:
NE SW 3075 m Pock-Marks ? Erosion E
Page 139 and 140:
Chapter 5 Salt Tectonics 5.1 Mechan
Page 141 and 142:
as a pressurized fluid with differe
Page 143 and 144:
shales related to rapid progradatio
Page 145 and 146:
131 Figure 5-3: Tectono-stratigraph
Page 147 and 148:
Shelf N 0 15 30 Kilometers Moheida
Page 149 and 150:
Shelf N 0 15 30 Kilometers Upper Sl
Page 151 and 152:
A) NW SE B) Swells Normal basement-
Page 153 and 154:
Salt Detachment Association includi
Page 155 and 156:
formed shortly after autochthonous
Page 157 and 158:
and Vendeville (1994) shows that th
Page 159 and 160:
Allochthonous Stock “Finger” Di
Page 161 and 162:
A’ SE A Folding of strata from T0
Page 163 and 164:
Diapirs commonly intersect the K1 S
Page 165 and 166:
D’ SE NW D 0 3 6 Strata folded fr
Page 167 and 168:
Figure 5-14: Diapir rejuvenation du
Page 169 and 170:
5.3.4 The Secondary Weld Associatio
Page 171 and 172:
NW SE 0 3 6 Kilometers Inclined Sec
Page 173 and 174:
An allochthonous salt structure is
Page 175 and 176:
Salt Stocks A salt stock is charact
Page 177 and 178:
F’ NE SW F 0 6 12 Kilometers Coal
Page 179 and 180:
G (A) (B) G’ Figure 5-20: (A) Nor
Page 181 and 182:
Figure 5-21: Schematic evolution of
Page 183 and 184:
listric fault, causing the developm
Page 185 and 186:
egardless of depositional setting a
Page 187 and 188:
growth will continue until the sour
Page 189 and 190:
Salt structures with onlapping syn-
Page 191 and 192:
the base of post-kinematic stratigr
Page 193 and 194:
SE NW 4093 m 179 Offset of paleo-de
Page 195 and 196:
NE SW 6 km 181 Turtle Structure Pos
Page 197 and 198:
NE SW 183 0 3 6 Turtle Structure Ki
Page 199 and 200:
Figure 6-1: Seismic profile from th
Page 201 and 202:
Figure 6-2: Tectono-stratigraphic c
Page 203 and 204:
Ordovician metasedimentary rocks of
Page 205 and 206:
191 Figure 6-3: Schematic block dia
Page 207 and 208:
etween the location of salt swells
Page 209 and 210:
On the slope, the Late to Middle Ju
Page 211 and 212:
Listric growth faults typically tip
Page 213 and 214:
this diapiric region. However, it w
Page 215 and 216:
characteristically concordant with
Page 217 and 218:
typical of passive margins modified
Page 219 and 220:
Slope Basin: Kidston et al. (2002)
Page 221 and 222:
~ Present day 100 C ~ Present day 1
Page 223 and 224:
area can be divided into three slop
Page 225 and 226:
Pre-Mesozoic structures are not con
Page 227 and 228:
eservoir. The well locations were c
Page 229 and 230:
7.2 Key Conclusions Geological Evol
Page 231 and 232:
exclusively deform Late Triassic to
Page 233 and 234:
• A reservoir of Cretaceous to Te
Page 235 and 236:
References Alsop, G. I., Brown, J.P
Page 237 and 238:
Gauley, B. J., 2001, Lithostratigra
Page 239 and 240:
Keen, C. E., and Potter, D. P., 199
Page 241 and 242:
Scotian Rise, Geological Survey of
Page 243:
Welsink, H.J., Dwyer, J.D., and Kni
show all

the stratigraphy and structural history of the mesozoic and cenozoic ...

Create successful ePaper yourself

Delete template?

Save as template?