128E0753.txt
ADMINISTRATIEVE GEGEVENS & TECHNISCHE GEGEVENS
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Kaart nr.: 128E
PLAAT: FELUY
Nr.: 0753
Type Boring: ontsluiting S.A.S. 4
Topografische kaart: 39/6
Uitgevoerd te:
Postnr.:
Adres boorplaats: Along the Brussel-Charleroi canal, between 40280 m and 40413 m (distance along E-side canal, from Charleroi to Brussels)
Opdrachtgever:
Boorfirma:
Boordatum/terreinopname:September 2001
Topografie: BGD, topo 1/10000
Stalen door:
Boormethode: ontsluiting
Lengte & doormeters:
Grondwaterstanden:
1ste maal:
Bij rust:
Tijdens pompen:
Debiet:
Waterzaaknr.:
Totale diepte:
Stalen bewaard: staalname en bewaring door auteur
Maaiveld / ref. peil: 62
X: 140375
Y: 147280
NIS code:
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LITHOLOGISCHE BESCHRIJVING
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Short description of outcrop Southern Asquempont section 4 (BGD128E0753), its immediate surroundings and its importance.
Along the Brussel-Charleroi canal, between 39246 m and 39767 m (distance along E-side canal, from Charleroi to Brussels), a more than 500 m-long, well exposed section, composed of five main outcrops, contains an asymmetric hectometre- to kilometre-scale, south-verging synform in fine-grained Upper Ordovician sediments. Legrand (1967) was the first to notice the overturned beds within this synform. Although this overturning was rejected by Martin & Rickards (1979), both Legros (1991) and Servais (1991) confirmed the reverse stratigraphic polarity of the turbidites in the core of the synform. However, the presence of these overturned beds has never been properly explained.
Three of the five main outcrops are situated along the E-side of the canal (Southern Asquempont section 1, 2 and 3) and two are situated at the W-side of the canal (Southern Asquempont section 4 and 5). Four of these outcrops (Southern Asquempont section 1 to 4) can be combined to form a section parallel to the canal, whereas the fifth outcrop (Southern Asquempont section 5) is mainly used to constrain the lateral prolongation of the beds. In order to get enough data from the central part of the area, several small new exposures were constructed along the canal by clearing the undergrowth and debris. The litho- and biostratigraphy used is based on Van Grootel et al. (1998), Samuelsson & Verniers (2000) and Verniers et al. (2001). The results of the data of the southern Asquempont section derived from Debacker (2001) and presented herein were published by Debacker et al. (2001).
1. Macroscopic observations
Lithology, sedimentology, stratigraphic polarity
Outcrops Southern Asquempont section 2 (S.A.S. 2) and 4 (S.A.S. 4; BGD128E0753), respectively situated along the E- and W-side of the canal (fig. 2.18), contain a distinct alternation of light grey fine-grained sandstones, medium grey siltstones and dark grey mudstones, interpreted as fine-grained turbidite deposits (Servais, 1991) of the middle Caradoc Ittre Formation. The turbidite sequences, predominantly Tcde-Bouma sequences (Bouma, 1962) are generally 5 to 15 cm thick, with the sandy to silty c-intervals usually comprising 20 to 35 % of the sequence thickness (Servais, 1991). Towards higher levels, in the southern part of these two outcrops, turbidites appear to become finer-grained, with less c-intervals. Locally, small-scale soft-sediment deformation is evidenced by load-casts, convolutions and small ball-and-pillow structures. Throughout the two outcrops sedimentary features, such as graded bedding, cross-bedding, truncations of older beds by younger beds and turbidite sequences, indicate a reverse stratigraphic polarity. In the sub-vertical northern limb of the synform, the beds young towards the north, towards the older core of the Brabant Massif. In the sub-horizontal southern limb the beds young downwards. Along the E-side of the Brussel-Charleroi canal, the southernmost turbidites of the Ittre Formation occur in a deformed zone at 39400 m. South of this point, the "laminites" of the Bornival Formation occur (visible in outcrop S.A.S. 1).
Cleavage/fold relationship
Outcrops S.A.S. 2 and 4, containing the synform hinge zone, essentially show the same overall structure: a large open, asymmetric, sub-horizontal to gently ESE-plunging synform with a gently to moderately NE-dipping axial surface. The hinge zone of the large south-verging synform contains several small, open, parasitic folds with a south-verging asymmetry and a step fold-like geometry (type 2D or 2C of Hudleston, 1973). The orientation of the fold hinge lines of individual small folds is sub-parallel to the fold hinge line of the large synform.
The area is cut by a pervasive, moderately NE-dipping cleavage. This cleavage is axial-planar to the small folds in the hinge zone of the synform and approximately axial-planar to the large synform itself. In accordance with the generally fine-grained lithology, the cleavage shows divergent cleavage fanning across the small folds. A large-scale small-angle divergent cleavage fan can also be inferred from changes in the mean cleavage orientation.
Changes in cleavage dip due to refraction and fanning allow the construction of a virtual cleavage/cleavage intersection (B-axis of cleavage planes, cleavage fan axis, cf. Debacker et al., 1999). The overall virtual cleavage/cleavage intersection or cleavage fan axis is sub-parallel to the overall fold hinge line and cleavage/bedding intersection.
The orientation of some of the structural elements changes along the canal section. Going from south to north, the trend of bedding and cleavage/bedding intersection abruptly changes from WNW-ESE to NW-SE around 39600 m (E-side canal). This is also reflected in the plunge direction of the intersection lineation. Throughout the synform, the cleavage/bedding intersection plunges towards the ESE. In contrast, north of 39600 m the cleavage/bedding intersection plunges towards the NW. The trend of the cleavage appears to remain fairly constant throughout the section.
Faults and slip planes
In several localities along the southern Asquempont section bedding- and cleavage-parallel slip zones are encountered, with a direction of slip sub-perpendicular to the trend of the fold hinge lines. In general, the sense of slip could not be determined.
The synform hinge zone (outcrops S.A.S. 2 and 4) is cut by a set of gently to moderately NE-dipping faults, post-dating cleavage development (F2a to F2f and F4a to F4c). The faults generally have a random cohesive fabric, in some cases a crush breccia or protocataclasite (e.g. F4b), in other cases a cemented breccia (e.g. F2f, F2d''). Striations indicate a movement vector sub-perpendicular to the trend of the fold hinge lines. In general, the plunge direction of the striations is oriented slightly anticlockwise to the dip direction of the faults. Because of the lack of marker horizons and the low angle to cleavage, the sense of movement could not be determined. Small, moderately to steeply NE-dipping reverse faults (F2d''') are encountered below and adjacent to F2d. Small-scale observations in the fault matrix of F2d'' also suggest a reverse movement. In contrast, however, small-scale observations in the matrix of F2b suggest a normal movement. Because there is no marked jump in stratigraphy across these faults, they are considered to have relatively small displacements. The same probably accounts for the moderately NE-dipping post-cleavage fault in outcrop S.A.S. 3 (F3a, with a crush breccia).
2. Microscopic observations
Cleavage fabric
The cleavage is a spaced cleavage, of an anastomosing disjunctive type. The microlithons, mainly consisting of quartz and chlorite-mica stacks, are generally 10 to 50 microns wide. The cleavage domains, visible as irregular zones of organic and other opaque material with cleavage-parallel white mica, are generally less than 10 microns wide. The transition between microlithons and cleavage domains is generally gradational. Chlorite-mica stacks have random orientations with respect to cleavage. Those oriented at high angles to cleavage have low aspect ratios. They are often truncated by pressure solution seams, sometimes crenulated by the cleavage and show pressure shadows. Although also predominantly present in the microlithons, the chlorite-mica stacks oriented at low angles to cleavage generally have higher aspect ratios.
Pressure shadows around opaque material and chlorite-mica stacks contain newly formed chlorite and mica. They are usually symmetrical. Of the encountered asymmetric pressure shadows, in the form of sigma structures, three indicate a reverse (top-to-the-south) shear (in samples TD021, TD031, TD035) and two a normal (top-to-the-north) shear (in TD031, TD033). There appears to be no relationship between sense of shear and bedding orientation, nor between sense of shear and position in the large synform.
Fault infill
Many of the faults in the synform hinge zone contain an infill of quartz and carbonate (probably dolomite or ankerite). As in the Ronquières area, the quartz crystals show evidence of later deformation: they are broken and truncated and sometimes show an ondulose extinction. Generally, quartz dominates the smallest fractures, whereas the practically undeformed carbonate crystals occupy the largest spaces. In several cases, the cleavage in rock fragments incorporated in the fault rock is deformed in a ductile manner, as suggested by crenulations (F2f) or drag folding (F2d'').
References
BOUMA, A.H. 1962. Sedimentology of some flysch deposits, 168 p. Amsterdam: Elsevier
CORIN, F. 1963. Sur les roches éruptives de la tranchée d'Hasquempont, canal de Charleroi. Bulletin de la Société belge de Géologie, de Paléontologie et d'Hydrologie, 72, 55-60.
DEBACKER, T.N. 2001. Palaeozoic deformation of the Brabant Massif within eastern Avalonia: how, when and why? Unpublished Ph.D. thesis, Laboratorium voor Paleontologie, Universiteit Gent.
DEBACKER, T.N., SINTUBIN, M. & VERNIERS, J. 1999. Cleavage/fold relationships in the Silurian metapelites, southeastern Anglo-Brabant fold belt (Ronquières, Belgium). Geologie en Mijnbouw, 78, 47-56.
DEBACKER, T.N., SINTUBIN, M. & VERNIERS, J. 2001. Large-scale slumping deduced from structural and sedimentary features in the Lower Palaeozoic Brabant Massif, Belgium. Journal of the Geological Society, London, 158, 341-352.
HERBOSCH, A., VANGUESTAINE, M., DEGARDIN, J.M., DEJONGHE, L., FAGEL, N. & SERVAIS, T. 1991. Etude lithostratigraphique, biostratigraphique et sédimentologique du sondage de Lessines (bord méridional du Massif du Brabant, Belgique). Annales de la Société géologique de la Belgique, 114, 195-212.
LEGRAND, R. 1967. Ronquières, documents géologiques. Mémoires pour servir à l'explication des Cartes géologiques et minières de la Belgique, 6, 60p.
LEGROS, B. 1991. Etude structurale du Cambro-Ordovicien de la vallée de la Sennette (Massif du Brabant) - Belgique. Unpublished M.Sc.-thesis, Université Catholique de Louvain, 58p.
MARTIN, F. & RICKARDS, B. 1979. Acritarches, chitinozoaires et graptolithes ordoviciens et siluriens de la vallée de la Sennette (Massif du Brabant, Belgique). Annales de la Société géologique de la Belgique, 102, 189-197.
SAMUELSSON, J. & VERNIERS, J. 2000. Ordovician chitinozoan biozonation of the Brabant Massif, Belgium. Review of Palaeobotany and Palynology, 113, 105-129.
SERVAIS, T. 1991. Discovery of turbiditical levels in the Late Ordovician of the Sennette valley (Brabant Massif, Belgium). Annales de la Société géologique de la Belgique, 114, 247-251.
VAN GROOTEL, G., SAMUELSSON, J. & VERNIERS, J. 1998. Micropaleontologie en biostratigrafie van het Ordovicium. Unpublished final report of Project NAT/96-3.3, 103p.
VANMEIRHAEGHE ET AL. (submitted). Chitinozoan biozonation of the Upper Ordovician of the Fauquez area (Brabant Massif, Belgium). Geologica Belgica.
VERNIERS, J., HERBOSCH, A., VANGUESTAINE, M., GEUKENS, F., DELCAMBRE, B. PINGOT, J.L., BELANGER, I., HENNEBERT, DEBACKER, T., SINTUBIN, M. & DE VOS, W. 2001. Cambrian-Ordovician-Silurian lithostratigraphical units (Belgium). Geologica Belgica 4, 5-38
Timothy N. Debacker
September 2001
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STRATIGRAFISCHE INTERPRETATIE
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Ittre Formatie, Caradoc, based on Legrand (1967), Martin & Rickards (1979), Samuelsson & Verniers (2000), Verniers et al. (2001).
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AUTEUR Debacker T.N., September 2001
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Relevant documents for additional reading :
Debacker, T.N. 2001. Palaeozoic deformation of the Brabant Massif within eastern Avalonia: how, when and why? Unpublished Ph.D. thesis, Laboratorium voor Paleontologie, Universiteit Gent.
Debacker, T.N., Sintubin, M. & Verniers, J. 2001. Large-scale slumping deduced from structural and
sedimentary features in the Lower Palaeozoic Brabant Massif, Belgium. Journal of the Geological Society, London, 158, 341-352.
Debacker, T.N., Herbosch, A., Verniers, J. & Sintubin, M. 2003. Palaeozoic deformation history of the
Asquempont-Virginal area (Brabant Massif, Belgium): large-scale slumping, low-angle extensional
detachment development (the Asquempont Fault redefined) and normal faulting (The Nieuwpoort-
Asquempont fault zone). Memoirs of the Geological Survey of Belgium, 49, 1-30.
Verniers, J., Herbosch, A., Vanguestaine, M., Geukens, F., Delcambre, B. Pingot, J.L., Belanger, I.,
Hennebert, Debacker, T., Sintubin, M. & De Vos, W. 2001. Cambrian-Ordovician-Silurian
lithostratigraphical units (Belgium). Geologica Belgica, 4, 5-38.
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BIJLAGEN
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Table 1 : Orientation data of structural elements in outcrop southern Asquempont section 4 (BGD128E0753)
130 m-long outcrop of the Ittre Formation along the W-side of the Brussel-Charleroi canal, facing outcrop southern Asquempont section 2. The outcrop extends from 40280 m to 40410 m (expressed in distance along the W-side of the Brussels-Charleroi canal, from Charleroi towards Brussels). The overall stratigraphic polarity is reversed (i.e. younging downwards).
Orientations of planar elements (cleavage plane, bedding plane, fault plane,...) are given as strike/dip, followed by the azimuth direction of the dip (e.g. 025/30 SE for a plane with strike 025°, dipping 30° towards the SE) and orientations of linear elements (striation, intersection lineation,...) are given as plunge/plunge direction (e.g. 30/025 for a line plunging 30° towards 025). In all cases, an azimuth notation is used for strike and plunge direction going from 0° (N), over 180° (S) to 360° (N).
Bedding (S0)
40280-311 m:
1. 050/30SE
2. 046/24SE
3. 048/26SE
4. 049/30SE
5. 052/25SE
6. 052/23SE
7. 045/24SE
8. 046/24SE
9. 062/28SE
10. 050/30SE
11. 059/55SE
12. 055/44SE
13. 053/31SE
14. 072/29S
15. 019/16E
16. 336/25NE
17. 351/37E
18. 033/16SE
19. 344/12E
20. 336/11NE
21. 295/24NE
22. 301/16NE
23. 274/09N
24. 317/28NE
25. 021/12E
26. 346/11E
27. 008/10E
28. 076/22S
29. 063/20SE
30. 081/19S
31. 340/19E
32. 003/14E
33. 070/22S
34. 079/29S
35. 034/12SE
36. 347/17E
37. 005/25E
38. 346/21E
39. 059/17SE
40. 060/32SE
41. 039/25SE
42. 325/27NE
43. 005/24E
44. 048/42SE
45. 046/28SE
46. 065/18SE
40311- 347 m:
47. 052/29SE
48. 060/32SE
49. 059/34SE
50. 073/45S
51. 073/56S
52. 067/32S
53. 067/35S
54. 059/25SE
55. 056/24SE
56. 054/25SE
57. 063/21SE
58. 057/24SE
59. 057/21SE
60. 055/24SE
61. 058/22SE
62. 051/23SE
63. 083/31S
64. 076/28S
65. 069/21S
66. 040/18SE
67. 025/22E
68. 017/22E
69. 015/20E
70. 013/17E
71. 026/24E
72. 345/24E
73. 001/21E
74. 322/17NE
75. 087/25S
76. 095/50S
77. 088/41S
78. 084/40S
79. 346/25E
80. 055/23SE
81. 090/49S
82. 090/43S
83. 076/30S
84. 086/34S
85. 334/23NE
86. 030/15SE
87. 099/59S
88. 060/24SE
89. 027/16E
90. 071/30S
91. 023/16E
92. 054/22SE
93. 030/20SE
94. 026/21SE
95. 051/30SE
96. 004/23E
97. 048/23SE
98. 046/22SE
99. 086/40S
100. 057/21SE
101. 070/24S
102. 067/26SE
103. 065/31SE
104. 076/30S
105. 078/34S
106. 081/39S
107. 084/38S
108. 096/58S
109. 105/69S
110. 076/31S
111. 023/21E
112. 005/18E
113. 349/16E
114. 045/15SE
115. 048/20SE
116. 040/23SE
117. 057/22SE
118. 122/74SW
119. 100/74S
120. 093/74S
121. 094/72S
122. 092/70S
123. 288/74N
124. 092/82S
125. 099/66S
126. 092/29S
40347-377 m:
127. 083/37S
128. 038/21SE
129. 062/34SE
130. 064/35SE
131. 067/37SE
132. 069/42S
133. 075/39S
134. 084/59S
135. 090/75S
136. 093/79S
137. 094/76S
138. 283/76N
139. 286/82N
140. 091/81S
141. 091/82S
142. 088/71S
143. 090/75S
144. 090/74S
145. 077/52S
146. 078/54S
147. 075/46S
148. 053/26SE
149. 020/24E
150. 005/21E
151. 086/65S
152. 280/84N
153. 271/80N
154. 094/73S
155. 093/69S
156. 093/74S
157. 094/66S
158. 091/63S
159. 089/55S
160. 083/41S
161. 064/20SE
162. 045/15SE
163. 084/49S
164. 091/62S
165. 080/39S
166. 090/64S
167. 079/45S
168. 066/30SE
169. 074/34S
170. 058/27SE
171. 053/23SE
172. 058/17SE
173. 047/12SE
174. 048/15SE
175. 054/18SE
176. 064/22SE
177. 280/79N
178. 033/15SE
179. 088/30S
180. 094/46S
181. 100/57S
182. 098/75S
183. 098/66S
184. 099/61S
185. 092/60S
186. 091/76S
187. 089/80S
188. 091/68S
189. 271/90N
190. 084/80S
191. 076/67S
192. 284/78N
193. 069/46S
194. 090/73S
195. 331/19NE
196. 010/25E
197. 343/31E
198. 338/30E
199. 342/27E
200. 328/28NE
201. 326/31NE
202. 336/26NE
203. 328/30NE
204. 088/30S
205. 280/75N
206. 283/80N
207. 281/84N
208. 099/86S
209. 106/64S
210. 101/67S
211. 104/75S
212. 108/70S
213. 102/66S
214. 100/84S
215. 050/20SE
216. 351/20E
217. 330/21NE
218. 105/51S
219. 089/33S
220. 098/48S
221. 094/31S
222. 068/26S
223. 060/28SE
224. 049/24SE
225. 020/19E
226. 326/22NE
227. 354/20E
228. 285/22N
229. 105/83S
230. 284/89N
231. 286/80N
232. 285/74N
233. 069/16S
234. 289/81N
235. 285/89N
236. 096/90S
237. 095/89S
238. 097/70S
239. 104/65S
240. 104/54S
241. 108/35S
242. 104/30S
243. 109/46S
244. 103/55S
245. 104/80S
246. 102/83S
247. 104/62S
248. 100/52S
249. 091/48S
250. 291/85N
251. 291/87N
252. 291/77N
253. 287/71N
254. 109/69S
255. 111/51S
256. 114/55SW
257. 083/19S
258. 101/18S
259. 105/24S
260. 107/31S
261. 105/38S
262. 104/19S
263. 120/69SW
264. 105/36S
265. 111/43S
266. 288/72N
267. 086/63S
268. 090/65S
269. 091/70S
270. 099/42S
271. 099/25S
272. 103/57S
273. 109/56S
274. 118/58SW
275. 110/65S
276. 283/60N
277. 283/88N
40377-410 m:
278. 283/64N
279. 106/86S
280. 281/60N
281. 283/74N
282. 281/73N
283. 283/85N
284. 269/80N
285. 281/90N
286. 096/62S
287. 098/62S
288. 089/45S
289. 087/42S
290. 071/30S
291. 089/63S
292. 101/78S
293. 096/84S
294. 090/82S
295. 080/62S
296. 094/80S
297. 002/26E
298. 270/81N
299. 097/71S
300. 096/87S
301. 282/78N
302. 092/79S
303. 081/74S
304. 104/63S
305. 103/39S
306. 097/48S
307. 103/79S
308. 101/68S
309. 085/77S
310. 266/82N
311. 062/28SE
312. 075/37S
313. 302/40NE
314. 300/35NE
315. 037/09SE
316. 330/18NE
317. 315/24NE
318. 022/10E
Cleavage (S1)
40311-347 m:
A. 007/19E
B. 343/17E
C. 336/20NE
D. 337/16NE
E. 322/23NE
F. 336/18NE
G. 343/21E
H. 315/29NE
I. 328/32NE
J. 343/22E
K. 300/22NE
L. 335/16E
M. 358/24E
N. 305/35NE
O. 329/24NE
P. 306/25NE
Q. 292/41N
R. 320/31NE
S. 306/19NE
T. 315/25NE
U. 306/30NE
V. 284/36N
W. 312/26NE
X. 307/52NE
Y. 299/44NE
Z. 312/24NE
A'. 312/31NE
B'. 320/45NE
C'. 310/46NE
D'. 316/45NE
E'. 298/38NE
F'. 321/24NE
G'. 326/28NE
H'. 308/31NE
I'. 313/29NE
J'. 322/24NE
40347-377 m:
K'. 302/30NE
L'. 281/62N
M'. 283/75N
N'. 324/15NE
O'. 288/65N
P'. 301/32NE
Q'. 293/31NE
R'. 317/50NE
S'. 312/26NE
T'. 280/54N
U'. 283/71N
V'. 284/80N
W'. 288/74N
X'. 289/61N
Y'. 325/49NE
Z'. 298/39NE
A². 327/38NE
B². 285/45N
C². 276/56N
D². 289/58N
E². 290/45N
F². 286/57N
G². 291/58N
40377-410 m:
H². 306/48NE
I². 291/56N
J². 289/29N
K². 284/48N
L². 300/38NE
M². 286/54N
N². 278/50N
O². 303/46NE
P². 298/50NE
Q². 284/47N
R². 272/53N
S². 302/27NE
T². 286/56N
U². 314/26NE
V². 314/22NE
W². 288/40N
X². 325/40NE
Y². 307/35NE
Z². 333/50NE
A³. 312/30NE
B³. 311/34NE
C³. 308/26NE
D³. 314/23NE
E³. 331/24NE
F³. 302/38NE
G³. 303/18NE
H³. 320/24NE
Cleavage/bedding intersection
40311-347 m:
19/106 (54)
17/100 (54)
16/095 (55)
15/092 (55)
17/095 (56)
14/105 (57)
12/087 (S)
15/091 (55)
16/099 (55)
14/106 (63)
21/112 (69)
13/098 (93)
23/085 (96)
11/104 (75)
14/105 (80)
11/101 (87)
12/101 (104)
16/105 (105)
13/109 (114)
19/109 (115)
19/098 (116)
16/108 (118)
16/107 (124)
09/118 (126)
40347-377 m:
17/103 (131)
24/096 (138)
20/097
24/111
21/100
24/096 (139)
16/096
21/107
22/096
20/098 (147)
15/100
13/107
18/101
20/103
10/098
15/108
20/102
14/110 (176)
06/104 (184)
16/115
14/104
25/083 (196)
30/082 (204)
04/105 (209)
20/116 (216)
16/103
20/101(224)
08/104
21/103
09/101
22/110 (Y')
20/096 (266)
40377-410 m:
29/104 (H²)
18/106
17/106
24/113
18/094 (F³)
(54) : close to bedding plane 54 (S) : close to cleavage plane S
Faults and slip planes
Sense of movement is unknown.
F4a (S to N):
1. 290/38N
2. 290/50N*
3. 286/49N*
4. 304/43NE
5. 300/40NE
6. 297/49NE
7. 309/24NE
Striations F4a:
46/345 (2)
44/335 (3)
40/006 (3)
F4b (S to N):
1. 311/50NE*
2. 307/36NE*
3. 301/49NE*
4. 306/64NE
5. 291/36N*
6. 287/46N*
7. 294/47NE
Striations F4b:
45/006 (1)
32/005 (2)
48/011 (3)
35/001 (5)
42/353 (6)
F4c (N to S):
1. 301/44NE
2. 309/31NE*
3. 285/24N*
4. 299/29NE*
5. 302/35NE*
6. 281/39N*
7. 312/27NE
8. 310/40NE
9. 320/39NE
10. 321/38NE
Striations F4c:
29/016 (2)
21/007 (3)
24/020 (4)
30/000 (5)
37/001 (6)
Striations on bedding planes:
16/029 (4~9)
25/210 (33)
22/210 (48)
17/212 (49)
34/213 (50)
25/210 (53)
14/211 (54)
11/216 (88)
(S to N), (N to S) : measured from S to N, respectively from N to S
* : fault plane with striations
(1) : striations measured on fault plane 1/bedding plane 1
(4~9) : striations between bedding plane 4 and 9
Sedimentary ripples
40280-40311 m:
1. 15/076 on 053/25SE
1'. 16/087 on 053/25SE
1². 18/092 on 053/25SE
1³. 11/079 on 053/25SE
2. 14/092 on 065/26SE (46)
3. 12/080 on 024/14SE (46)
40311-40325 m:
4. 16/094 on 055/24SE
5. 17/097 on 056/25SE
5'. 17/105 on 056/25SE
5². 21/107 on 056/25SE
5³. 16/098 on 056/25SE
54. 13/089 on 056/25SE
6. 16/093 on 055/21SE
7. 08/097 on 084/29S
40350-40370 m:
8. 09/110 on 104/54S (240)
8'. 05/110 on 104/54S (240)
8². 07/108 on 104/54S (240)
8³. 11/114 on 104/54S (240)
9. 04/116 on 104/30S (242)
9'. 05/115 on 104/30S (242)
10. 01/115 on 105/24S (259)
10'. 06/115 on 105/24S (259)
10². 03/114 on 105/24S (259)
(46) : nearest bedding measurement
Samples
TD021
TD022
TD023
TD024
TD025
TD026
TD027
TD028
TD030
TD031
TD032
TD033
TD034
TD035
TD036*
TD037*
TD038*
* : sample taken north of 40.410 km
Timothy N. Debacker
September 2001
-------------------------------------------------------
Table 2 - Samples taken at outcrop southern Asquempont section 4 (BGD128E0753)
Apart from sample number (column 1), position of sample (column 2) and sample orientation (column 3), also the date of sampling (column 4), the number of thin sections made (column 5) and some remarks are given (column 6). The remarks concern the formation name to which the sample belongs, particular structural, lithological or sedimentological observations, sometimes the purpose for sampling. Orientations of planar elements (cleavage plane, bedding plane, fault plane,...) are given as strike/dip, followed by the azimuth direction of the dip (e.g. 025/30 SE for a plane with strike 025°, dipping 30° towards the SE) and orientations of linear elements (striation, intersection lineation,...) are given as plunge/plunge direction (e.g. 30/025 for a line plunging 30° towards 025). In all cases, an azimuth notation is used for strike and plunge direction going from 0° (N), over 180° (S) to 360° (N).
TD021
Southern Asquempont section 4; ( 40.285 km, middle part
056/22SE
06/08/98
1
Ittre Fm.; sedimentology, lithology; reverse polarity, load casts and cusps, burrow-like soft-sediment deformation
TD022
Southern Asquempont section 4; ( 40.285 km, middle part
035/39SE
06/08/98
Ittre Fm.; sedimentology, lithology; reverse polarity
TD023
Southern Asquempont section 4; ( 40.2895 km, middle part
047/25SE
06/08/98
1
Ittre Fm.; sedimentology, lithology
TD024
Southern Asquempont section 4; ( 40.292 km, middle to upper part
065/30SE
06/08/98
1
Ittre Fm.; sedimentology, lithology; deformation: small fold, normal cleavage/fold relationships but reverse polarity
TD025
Southern Asquempont section 4; ( 40.2925 km, middle to upper part
016/28E
06/08/98
Ittre Fm.; sedimentology, lithology.
TD026
Southern Asquempont section 4; ( 40.293 km, middle
017/28E
06/08/98
1
Ittre Fm.; sedimentology, lithology; reverse polarity
TD027
Southern Asquempont section 4; ( 40.302 km, middle
096/38S
06/08/98
Ittre Fm.; sedimentology, lithology; post-cleavage deformation, striations: 25/210, 45/030
TD028
Southern Asquempont section 4; ( 40.310 km, middle to upper part
286/36N
06/08/98
2
Ittre Fm.; deformation: fault rock: crush breccia to protocataclasite; striations: 35/001
TD030
Southern Asquempont section 4; ( 40.370 km, upper part
296/65NE
27/08/98
1
Ittre Fm.; sedimentology, lithology;
intraformational breccia
TD031
Southern Asquempont section 4; ( 40.371 km, lower part
Indication of up and N
27/08/98
4
Ittre Fm.; sedimentology, lithology; reverse polarity, load cast and ball-and-pillow structure, or burrow?
TD032
Southern Asquempont section 4; ( 40.3595 km, upper part
210/76NW
27/08/98
Ittre Fm.; sedimentology, lithology; small fold; reverse polarity
TD033
Southern Asquempont section 4; ( 40.346 km, upper part
327/30NE
27/08/98
1
Ittre Fm.; sedimentology, lithology; reverse polarity
TD034
Southern Asquempont section 4; ( 40.348 km, upper part
093/81S
27/08/98
1
Ittre Fm.; sedimentology, lithology; reverse polarity
TD035
Southern Asquempont section 4; ( 40.406 km, upper part
281/20N
03/09/98
2
Ittre Fm.; sedimentology, lithology; reverse polarity
TD036, (TD036')
Small outcrop north of southern Asquempont section 4, ( 40.4365 km, lower part
306/41NE, 280/47N
04/05/99
Ittre Fm.; sedimentology, lithology; reverse polarity (?)
TD037
Small outcrop north of southern Asquempont section 4, ( 40.464 km, lower part
296/35N
04/05/99
Ittre Fm.; sedimentology, lithology; normal polarity?
TD038
Small outcrop north of southern Asquempont section 4, ( 40.488 km, lower part
124/90SW
04/05/99
Ittre Fm.; sedimentology, lithology; normal polarity
Timothy N. Debacker
September 2001
------------------------
Table 3 - Table showing interpreted bedding, cleavage and fracture data from outcrop southern Asquempont section 4 (BGD128E0753).
The B-axis (Beta-axis) corresponds to the fold axis in the case of bedding and to the cleavage fan axis in the case of cleavage. Orientations of planar elements (cleavage plane, bedding plane, fault plane,...) are given as strike/dip, followed by the azimuth direction of the dip (e.g. 025/30 SE for a plane with strike 025°, dipping 30° towards the SE) and orientations of linear elements (striation, intersection lineation,...) are given as plunge/plunge direction (e.g. 30/025 for a line plunging 30° towards 025). In all cases, an azimuth notation is used for strike and plunge direction going from 0° (N), over 180° (S) to 360° (N).
Outcrop
Bedding (S0)
Cleavage (S1)
S1/S0 intersection
Fractures
40280-40410 m**
southern Asquempont section 4
n = 318; B-axis: 16/102
n = 86; mean: 303/36 NE ( 019°; B-axis: 18/096
n = 61; mean: 17/102 ( 007°
/
8 small tectonic folds in the synform hinge zone, outcrop southern A. section 4, 40340-40370 m. These data are incorporated in **
n = 131; B-axis: 15/103
n = 23; mean: 293/50 NE; B-axis: 18/097
n = 32; mean: 18/102 ( 007°
/
Extreme values of plunge direction are 21/095 (n = 12, antiform at 40344m) and 14/110 (n = 13, antiform at 40348m), extreme plunge values 01/106 (n = 30, antiform at 40362 m) and 22/102 (n = 12, antiform at 40345 m)
Timothy N. Debacker
September 2001
-------------------------------------
Table 4 - Table of mean fault and slip plane data from outcrop southern Asquempont section 4 (BGD128E0753 ).
Orientations of planar elements (cleavage plane, bedding plane, fault plane,...) are given as strike/dip, followed by the azimuth direction of the dip (e.g. 025/30 SE for a plane with strike 025°, dipping 30° towards the SE) and orientations of linear elements (striation, intersection lineation,...) are given as plunge/plunge direction (e.g. 30/025 for a line plunging 30° towards 025). In all cases, an azimuth notation is used for strike and plunge direction going from 0° (N), over 180° (S) to 360° (N).
Outcrop
Faults and slip planes
40280-40410 m
southern Asquempont section 4
Three moderately NE-dipping faults, sub-parallel to cleavage. Sense of slip is unknown, but probably reverse, with a small dextral component. The faults are very similar to those observed in outcrop southern Asquempont section 2.
In several places, striations on bedding planes are observed.
F4a: 296/42NE (n = 7); striations: 44/349 ( 013° (n = 3)
F4b: 300/47NE (n = 7); striations: 41/003 ( 006° (n = 5)
F4c: 305/34NE (n = 10); striations: 28/009 ( 008° (n = 5)
All faults: 300/40NE (n = 24); B-axis: 05/114
Striations: 37/003 ( 012° (n = 13)
Striations on bedding planes: 17/211 ( 002° (n = 8)
Timothy N. Debacker
September 2001
BELGISCHE GEOLOGISCHE DIENST
128E/753 KAARTBLAD: FELUY
p. 1/8
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