34:
385:
sedimentary facies and interpreted paleocurrents to the
Torridon Group. Combined with the detrital zircons that indicate a dominantly Grenvillian source, this has led to a reinterpretation that the supergroup was deposited within a foreland basin, in front of the mountains formed by the Grenville Orogeny.
226:
that are geographically or structurally isolated from each other. The certainty of the correlation between the groups is variable, with the
Torridon, Sleat and Morar groups considered as very likely to be lateral equivalents of each other, while the Iona and Tarskavaig groups and those on Shetland
384:
setting. However the scale of the interpreted river systems that deposited the
Torridon Group rocks and the consistency in the paleocurrent directions suggest that most of the sequence was deposited in a single basin. This is also true for the Morar Group, which has very similar thickness,
300:. Comparisons between the Torridon Group with areas of lower strain in the Morar Group have found many similarities in lithology, thickness and interpreted depositional environment. This group is now thought to have been deposited as part of the same depositional basin, a
354:
The
Westing, Sand Voe and Yell Sound groups on Shetland are tentatively correlated with other groups within the Wester Ross Supergroup based on lithological similarities, the ages of the youngest detrital zircons and the timing of later metamorphism.
346:, which are deformed and no sedimentological analysis has been carried out, nor have the group been sampled for detrital zircons. From its structural position it has been tentatively correlated with the lower part of the supergroup.
367:
ages are in the range 1070–1000 Ma, providing an upper bound. Metamorphic ages of 950–940 Ma have been calculated for garnets from the lower part of the Morar Group, confirming that these rocks were affected by the
241:
The
Torridon Group is the main part of what used to be termed the "Torridonian", although that also included the Stoer Group, which is now known to be a completely separate and older sequence.
342:
Rocks of the
Tarskavaig Group lie above the Tarskavaig Thrust on the southwestern end of the Sleat peninsula. The group consists of a mixture of psammites, semi-pelites and
296:
This sequence of variably metamorphosed and deformed sandstones (psammites) was originally considered as separate from the "Torridonian" and formed the lower section of the
363:
The age of this sequence is constrained by a combination of detrital zircon geochronology and by the dating of later metamorphic events. The youngest detrital zircon and
486:
210:. The contact between the Wester Ross Supergroup and the next youngest of the Neoproterozoic sequences in the Scottish Highlands, the
448:
Krabbendam, M.; Strachan, R.; Prave, T. (2022). "A new stratigraphic framework for the early
Neoproterozoic successions of Scotland".
263:, underlies the Torridon Group conformably, but the relationship with the Stoer Group is nowhere exposed. It is metamorphosed to
498:
274:, making its exact relationship to the other outcrops difficult to assess. The sequence consists of mainly coarse
532:
331:
372:(960–920 Ma) and providing a lower bound. Together these data give a depositional age range of 1000–960 Ma.
527:
326:. The group has been assigned to the Wester Ross Supergroup based on its structural position beneath the
402:
50:
223:
211:
87:
8:
406:
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175:
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98:
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64:
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24:
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179:
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developed in front of the mountain belt formed by the
Grenville Orogeny.
291:
278:
sandstones deposited in a fluvial environment with some less common grey
250:
207:
154:
102:
68:
60:
461:
33:
470:
313:
72:
380:
The Sleat and
Torridon groups have been interpreted as deposited in a
323:
275:
191:
39:
364:
343:
279:
256:
381:
319:
260:
447:
334:, which are similar to those found in the Sleat Group.
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141:
Conglomerate, mudstone (pelite where metamorphosed)
282:, probably deposited in a lacustrine environment.
484:
322:and consists of two units separated by a zone of
519:
485:Park, R.G.; Stewart, A.D.; Wright, D.T. (2003).
395:
267:and sits within the Kishorn Nappe, part of the
222:The Wester Ross Supergroup consists of several
493:. London: Geological Society. pp. 45–61.
318:The Iona Group is exposed on the island of
174:(or their metamorphic equivalents) in the
32:
469:
133:Sandstone (psammite where metamorphosed)
375:
255:The Sleat Group, which outcrops on the
520:
478:
337:
13:
166:is one of the subdivisions of the
14:
544:
450:Journal of the Geological Society
230:
214:, is everywhere a tectonic one.
411:BGS Lexicon of named rock units
217:
38:Torridon Group sandstones near
285:
244:
1:
388:
307:
7:
349:
227:are likely but not proven.
10:
549:
487:"3. The Hebridean terrane"
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289:
248:
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403:British Geological Survey
206:sedimentary rocks of the
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145:
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129:
124:
116:
108:
94:
79:
56:
46:
31:
23:
18:
489:. In Trewin N.H. (ed.).
407:"Wester Ross Supergroup"
332:ages of detrital zircons
182:on medium to high-grade
491:The Geology of Scotland
533:Geological supergroups
358:
164:Wester Ross Supergroup
19:Wester Ross Supergroup
112:Northwestern Scotland
51:Geological supergroup
376:Depositional setting
212:Loch Ness Supergroup
202:or locally over the
88:Loch Ness Supergroup
528:Geology of Scotland
462:10.1144/jgs2021-054
25:Stratigraphic range
370:Renlandian Orogeny
265:greenschist facies
176:Scottish Highlands
90:(tectonic contact)
75:, Tarskavaig Group
500:978-1-86239-126-0
328:Moine Thrust Zone
184:metamorphic rocks
172:sedimentary rocks
160:
159:
540:
512:
511:
509:
507:
482:
476:
475:
473:
445:
422:
421:
419:
417:
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338:Tarskavaig Group
298:Moine Supergroup
200:Lewisian complex
196:Paleoproterozoic
99:Lewisian complex
36:
16:
15:
548:
547:
543:
542:
541:
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518:
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316:
310:
294:
288:
253:
247:
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204:Mesoproterozoic
186:and associated
42:
12:
11:
5:
546:
536:
535:
530:
514:
513:
499:
477:
423:
393:
392:
390:
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360:
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339:
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312:Main article:
309:
306:
302:foreland basin
290:Main article:
287:
284:
249:Main article:
246:
243:
237:Torridon Group
235:Main article:
232:
231:Torridon Group
229:
219:
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168:Neoproterozoic
158:
157:
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147:
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131:
127:
126:
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96:
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84:Ardvreck Group
81:
77:
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65:Torridon Group
58:
54:
53:
48:
44:
43:
37:
29:
28:
21:
20:
9:
6:
4:
3:
2:
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531:
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259:peninsula on
258:
252:
242:
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228:
225:
215:
213:
209:
205:
201:
197:
193:
189:
188:igneous rocks
185:
181:
180:unconformably
177:
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132:
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59:
55:
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45:
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30:
27:: 1000–960 Ma
26:
22:
17:
504:. Retrieved
490:
480:
453:
449:
414:. Retrieved
410:
397:
379:
362:
353:
341:
317:
295:
254:
240:
221:
218:Stratigraphy
170:sequence of
163:
161:
146:Type section
471:10023/24155
292:Morar Group
286:Morar Group
276:feldspathic
272:thrust belt
251:Sleat Group
245:Sleat Group
208:Stoer Group
155:Wester Ross
103:Stoer Group
69:Morar Group
61:Sleat Group
522:Categories
389:References
314:Iona Group
308:Iona Group
269:Caledonian
178:. It lies
73:Iona Group
151:Named for
125:Lithology
117:Thickness
80:Underlies
57:Sub-units
506:June 23,
350:Shetland
330:and the
324:mylonite
192:Archaean
95:Overlies
344:pelites
190:of the
130:Primary
40:Diabaig
497:
416:31 May
365:rutile
280:shales
224:groups
120:6–9 km
257:Sleat
138:Other
508:2010
495:ISBN
418:2024
382:rift
320:Iona
261:Skye
198:age
194:and
162:The
109:Area
47:Type
466:hdl
458:doi
454:179
359:Age
101:or
86:or
524::
464:.
456:.
452:.
426:^
409:.
405:.
71:,
67:,
63:,
510:.
474:.
468::
460::
420:.
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