242:. The Wagga Omeo Metamorphic Belt is a large region in the Central Lachlan between the Kancoona-Kiera Shear Zone and the Gilmore Shear Zone. Other metamorphic complexes are Kuark, Camblong, Cooma, and Jerangle in the eastern side. These zones made up the Eastern Metamorphic Belt, named by Vallance in 1969. In these high temperature belts, the temperature peaked at 700°C and the pressure was 350 MPa, with a thermal gradient of 65 °/km. This same high temperature regime produced
345:. The east Lachlan Orogen containing Adaminaby Group Turbidites is now to the east and south of the Macquarie Arc. All its boundaries with the Macquarie Arc are faults, indicating that this is a separate terrane, also known as the Adaminaby Superterrane. In the Late Ordovician the turbidites were overlaid by a black shale. The back arc region was extended at this time.
483:
Three broad subdivisions of
Lachlan Fold Belt are Western, Central and Eastern. The Western Lachlan, which lies in Victoria includes the Stawell and Melbourne Zones. The eastern boundary of the Western Lachlan is the Mount Wellington—Mount Useful Fault Zone (east of Melbourne). The Central Lachlan
366:
In the Middle
Silurian, the Pacific plate boundary moved a few hundred km to the east. A new subduction zone dipping westwards lasted from the end of the Silurian into the Late Devonian. The whole of the Lachlan Fold Belt became a back arc area with a new volcanic arc formed to the east in what is
297:
which was formed in a back arc basin or a fore arc basin. An ancient shoreline of
Australia, called the cratonic margin existed off the east coast of the Delamerian Orogen in western New South Wales, Western Victoria and Western Tasmania. In the early Ordovician there was a shallow marine shelf
370:
Deformation happened in the west 450 to 395 Mya and in the east 400 to 380 Mya. Extensional basins occur in the central and east parts of the fold belt. Oceanic subduction (or underthrusting) is evidenced for the western and central parts by slivers of
310:
formed a shallow marine connection through central
Australia to the Canning Basin in Western Australia. Sediments formed on the continental shelf of the continent from this time appear in western Tasmania and north west New South Wales. A
159:
margin of eastern
Australia. The Delamerian Orogen follows this line, and the western side of the Lachlan Orogen also follows this curve. The central and east parts of the Orogen are aligned in a north–south direction.
574:
D. R. Gray and R. A. Foster: ‘’Tectonic evolution of the
Lachlan Orogen, southeast Australia: historical review, data synthesis and modern perspectives.’’ Australian Journal of Earth Sciences (2004) vol 51 pp 773-817
225:
Benambran
Orogeny (also led to the formation of the Wagga-Omeo Zone). The Middle Devonian Tabberabberan Orogeny affected the entire LFB and terminated the precratonic stage of its development. The Carboniferous
559:
Sites within the
Lachlan Fold Belt have been associated with economically significant production of gold, copper, silver, lead, zinc and tin. There remains potential for further mineral discoveries.
319:
below the
Delamerian coast, but this subduction moved 1000 km oceanwards. An island arc was formed on the northern end of the 900 km long trench. This was the Macquarie Volcanic Arc.
213:
Other terrane subdivision have included
Melbourne, Stawell, Howqua, Girilambone Terranes, as well as Cowra, Tumut and Hill End Troughs; and Parkes and Molong Zones; and the Wagga Omeo Belt.
252:
formed by intermediate to high pressure metamorphism is found in melange at Port Sorell and the Arthur Lineament in Tasmania, and Howqua Melange and Heathcote Melange in Victoria.
210:
or older rocks thanks to the folding. In Victoria van den Berg used the terms Whitelaw Terrane for the Western Lachlan, and Benambra Terrane for the Central and Eastern Lachlan.
168:
At the present time the fold belt is about 1000 km wide. However the original width was 2000 to 3000 km wide, with the excess size absorbed by folding and thrusting.
484:
includes the Tabberabbera Zone and the Wagga-Omeo Metamorphic Belt. The Eastern Lachlan extends to the east of the Gilmore Fault Zone, a shear zone on the edge of the WOMB.
326:
appeared in the Central Lachlan Orogen. These were derived from the western Delamerian Orogen and from the south west Ross Orogen, which is now left behind in Antarctica.
459:
Turbidites from submarine fans, trench complexes, volcanic arcs, oceanic crust and micro continents dominate lithological components. The individual rock types are mostly
367:
now the New England Orogen. Extension stretched the LFB forming rifts, and shelves, along with intrusion of granites and volcanism. This was the Tabberabberan Orogeny.
108:. These boundary orogens along with the Lachlan Orogen make up the Tasman Orogenic System In Australia, which along with the extension into the neighbouring parts of
363:, the arc collided with the back arc, ending the Benambran Cycle. The turbidites were deformed, biotite formed, and the arc was thrust over or under the turbidites.
120:
in the north east and centre of Queensland. Sometimes the Lachlan Orogen is included with the Thomson Orogen and known as the 'Lachlan-Thomson Orogen'. The
147:
rate is greater than that of plate convergence. In such a case the 'hinge', at which subduction starts, tend to move further seawards over time (rollback).
52:
274:
rose towards the surface. Granites cover 61000 km. There are 875 lithological units of granite. There are 100 volcanic units derived from the same
135:
In Victoria the western limit of the LFB is defined by the Stawell-Ararat Fault. Westwards of this fault is the Moornambool Metamorphic Complex.
402:
fossils in the Narooma Chert prove the age of the terrane to be from late Cambrian to middle Ordovician. The Narooma Terrane exposure is between
507:. The Adaminaby Group, from another terrane, was thrust northwards over the top of the Molong Volcanic Belt. The Kenyu Formation is from Late
551:
Structures in the Eastern thrust belt are oriented north–south. It has thick-skinned deformation in the west and thin-skinned in the east.
495:, formed in deep water. It is the most western part of the Arc. The Rockley–Gulgong Volcanic Belt. Budhang Chert Member is found near
270:
have formed in many parts of the LFB where there has been significant heating. They were formed at the time of extension, when hot
39:
is a geological subdivision of the east part of Australia. It is a zone of folded and faulted rocks of similar age. It dominates
417:
The western parts under New South Wales and Queensland are mostly heavily weathered and or covered in younger sediments of the
143:
The orogen is of the accretionary or 'Turkic' type. It has also been classified as a 'Carpathian' type orogen, i.e. one where
605:
Crustal structure of the Ordovician Macquarie Arc, Eastern Lachlan Orogen, based on seismic-reflection profilingabstract.htm
670:
411:
299:
334:
641:
515:. The Wagga Belt rocks are thrust eastwards over the top of the Junee-Narromine Volcanic Belt of the Macquarie arc.
425:. The underlying structure can still be explored through magnetic, gravity and seismic geophysical measurements.
394:
migrated 2500 km westwards on the moving Pacific plate and became attached to the Adaminaby Superterrane in
487:
The Macquarie Volcanic Arc formed about 1000 km off the coast. The Yarrimbah Formation is exposed west of
504:
403:
342:
181:
496:
488:
380:
330:
512:
500:
338:
124:
has been laid down over the top of the LFB in northwestern New South Wales and western Queensland and the
444:
306:
where Horn Valley Siltstone was formed, and Georgina Basin where the Coolibah Formation deposited. The
258:
has been formed in other parts of the fold belt indicating intermediate pressure and low temperature.
422:
418:
307:
125:
121:
44:
287:
97:
85:
113:
227:
177:
222:
132:
is on the top of the LFB around Sydney and Wollongong on the east coast of New South Wales.
60:
391:
188:
93:
40:
616:
439:
started to form by seafloor spreading. This split off a segment of the coast to form the
322:
Between the continent and the island arc or trench, deep water sediments in the form of
440:
117:
664:
316:
303:
294:
271:
535:
527:
472:
384:
376:
239:
129:
92:(550 to 470 Mya). On the east side is found the Narooma Accretionary Complex (or
531:
448:
407:
156:
508:
436:
356:
312:
249:
144:
101:
89:
64:
56:
17:
329:
The Ordovician volcanoes of the arc are now found around Parkes, Wellington,
492:
460:
372:
323:
243:
399:
395:
360:
350:
291:
207:
109:
105:
48:
451:
was extended moving Tasmania away from the rest of Australian Mainland.
184:. Other faults separate the different terranes making up the orogen.
267:
430:
298:
called the Gnalta Shelf, over the top of the Koonenberry Belt near
468:
464:
275:
255:
198:
The concept of terranes has been applied to the LFB with the term
379:, and Honeysuckle Beds east of Tumut; The Kiandra Beds north of
230:
was the terminal event and converted the LFB into a neocraton.
221:
Most of the LFB was greatly affected by the Late Ordovician to
383:
and the Tumut Pond Serpentinite Belt on the west side of
375:
and blueschist metamorphism. These are known as Coolac
238:
There are two high temperature low pressure regions of
206:. Geomagnetic poles cannot be reliably determined for
84:
The Lachlan Fold Belt is bordered on the west by the
595:
Granites of the Lachlan Fold Belt Ishihara Symposium
523:
The upper crust contains chevron folded turbidites.
410:and also between Burewarra Point and Durras around
302:. At the same time there were marine conditions in
246:and S-type granite from the Ordovician sediments.
642:"The Lachlan Fold Belt: A Legacy of exploration"
128:covers the southwest of New South Wales. The
8:
584:AGCRC Project No: 1060AO The Lachlan Orogen
191:was accepted, the LFB was described as the
499:. The Molong Volcanic Belt lies between
116:. North of the Lachlan Fold belt is the
71:. It covers an area of 200,000 km.
567:
555:Economically significant mineralisation
414:on the south coast of New South Wales.
7:
615:Australia, Geoscience (2016-04-08).
640:Eastwood, Alexandra (2022-12-16).
25:
53:the Australian Capital Territory
421:or Great Australian Basin and
1:
155:The Tasman Line outlines the
491:. It consists of siliceous
617:"Lachlan Fold Belt Project"
67:. It was earlier known as
687:
526:The lower crust contains
176:Rock beds are folded in
96:) from 445 Mya, and the
59:. It was formed in the
433: million years ago
547:Eastern Lachlan Orogen
542:Central Lachlan Orogen
519:Western Lachlan Orogen
187:Before the concept of
47:, also extending into
575:GrayFoster_AJES_1.pdf
671:Geology of Australia
621:Geoscience Australia
423:Murray-Darling Basin
419:Great Artesian Basin
351:447 to 443
200:Lachlan Superterrane
182:thin skinned thrusts
126:Murray-Darling Basin
122:Great Artesian Basin
202:being used for the
193:Lachlan Geosyncline
180:. They are cut by
69:Lachlan Geosyncline
467:interbedded, with
315:zone consumed the
98:New England Orogen
646:Australian Mining
353:million years ago
278:as the granites.
228:Kanimblan Orogeny
86:Delamerian Orogen
29:Lachlan Fold Belt
16:(Redirected from
678:
656:
655:
653:
652:
637:
631:
630:
628:
627:
612:
606:
603:
597:
593:Chappell, B.W.,
591:
585:
582:
576:
572:
434:
354:
63:from 450 to 340
61:Middle Paleozoic
21:
686:
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544:
534:, and magmatic
521:
481:
457:
447:. Around then,
429:
392:Narooma Terrane
349:
308:Larapintine Sea
290:of the belt is
284:
264:
236:
219:
204:Lachlan Mudpile
189:plate tectonics
174:
166:
153:
141:
94:Narooma Terrane
88:from the early
82:
77:
75:Characteristics
41:New South Wales
23:
22:
15:
12:
11:
5:
684:
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632:
607:
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548:
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540:
520:
517:
480:
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456:
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441:Lord Howe Rise
283:
280:
263:
260:
235:
232:
223:Early Silurian
218:
215:
173:
170:
165:
162:
152:
149:
140:
139:Classification
137:
118:Thomson Orogen
81:
78:
76:
73:
37:Lachlan Orogen
24:
18:Lachlan Orogen
14:
13:
10:
9:
6:
4:
3:
2:
683:
672:
669:
668:
666:
647:
643:
636:
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622:
618:
611:
608:
602:
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590:
587:
581:
578:
571:
568:
562:
560:
554:
552:
546:
541:
539:
537:
533:
529:
524:
518:
516:
514:
511:and contains
510:
506:
502:
498:
494:
490:
485:
478:
476:
474:
473:metavolcanics
470:
466:
462:
454:
452:
450:
446:
442:
438:
432:
426:
424:
420:
415:
413:
409:
405:
401:
397:
393:
388:
386:
382:
378:
374:
368:
364:
362:
358:
352:
346:
344:
340:
336:
332:
327:
325:
320:
318:
317:Pacific crust
314:
309:
305:
304:Amadeus Basin
301:
296:
295:oceanic crust
293:
289:
281:
279:
277:
273:
272:asthenosphere
269:
261:
259:
257:
253:
251:
247:
245:
241:
233:
231:
229:
224:
216:
214:
211:
209:
205:
201:
196:
194:
190:
185:
183:
179:
178:chevron folds
171:
169:
163:
161:
158:
150:
148:
146:
138:
136:
133:
131:
127:
123:
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72:
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66:
62:
58:
54:
50:
46:
42:
38:
34:
30:
19:
649:. Retrieved
645:
635:
624:. Retrieved
620:
610:
601:
594:
589:
580:
570:
558:
550:
536:underplating
525:
522:
513:conglomerate
486:
482:
479:Subdivisions
458:
427:
416:
412:Batemans Bay
389:
385:Talbingo Dam
377:serpentinite
369:
365:
347:
333:and east of
328:
321:
285:
265:
254:
248:
240:metamorphism
237:
234:Metamorphism
220:
212:
203:
199:
197:
192:
186:
175:
167:
154:
142:
134:
130:Sydney Basin
112:make up the
83:
68:
36:
32:
28:
26:
532:lithosphere
449:Bass Strait
408:Eurobodalla
300:Broken Hill
157:Precambrian
651:2023-12-11
626:2023-12-11
563:References
509:Ordovician
493:siltstones
443:, part of
437:Tasman Sea
357:Ordovician
335:Condobolin
324:turbidites
313:subduction
250:Blueschist
145:subduction
114:Tasmanides
102:Palaeozoic
100:from late
90:Palaeozoic
57:Queensland
461:sandstone
455:Lithology
445:Zealandia
373:ophiolite
262:Plutonism
244:migmatite
217:Orogenies
172:Structure
104:to early
665:Category
530:oceanic
528:duplexed
400:Conodont
396:Silurian
361:Silurian
348:Between
292:Cambrian
288:basement
266:Granite
208:Devonian
110:Gondwana
106:Mesozoic
80:Location
49:Tasmania
45:Victoria
505:Boorowa
404:Narooma
398:times.
355:in the
343:Boorowa
282:History
268:plutons
497:Oberon
489:Parkes
471:, and
428:About
381:Batlow
331:Molong
501:Cowra
469:chert
465:shale
339:Cowra
276:magma
256:Slate
151:Shape
35:) or
503:and
463:and
435:The
406:and
390:The
341:and
286:The
164:Size
55:and
43:and
27:The
359:to
65:Mya
33:LFB
667::
644:.
619:.
538:.
475:.
431:84
387:.
337:,
195:.
51:,
654:.
629:.
31:(
20:)
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