809:. The deeper water deposits of stage three are represented by the Stockdale and Tranearth groups, which display a steady deepening, as expected of sediments deposited in an underfilled basin, with a sedimentation rate high enough to preserve annual variation in places. (This signal is complicated by an overprinted signature of eustatic glaciations.) The end of stage three is represented by the Coniston Group, a series of sandy turbidites, with sediment supply from the north east (and controlled by basement faulting). The group is subdivided into formations, which each represent a turbidite lobe, and are separated by anoxic background sedimentation. The Kendal Group covers the transition into stage four, with pronounced shallowing up; turbidites become thinner-bedded, and anoxic hemipelagics give way to oxygenated sediments, with storm beds becoming more and more common, and intertidal sediments topping the group. The missing Old Red Sandstone mentioned above formed the molasse sediments of stage 4.
754:). This sudden upturn in deposition rate is a result of the increasing proximity of the Avalon mountain belt, which started to depress the plate from the Ordovician, but was not close enough to increase the sedimentary input until the Silurian. The latest phase of sedimentation reflected a change in the basin's state. Instead of being underfilled, and trapping all sediment that flowed into it, it became overfilled. This was reflected by a shallowing of water depth, as the basin silted up. This culminated with a transition to terrestrial conditions in the Pลรญdolรญ.
788:
causing flexural subsidence and providing accommodation space. A "forebulge", caused by the rigidity of the crust flexing up behind the load, causes uplift and permits erosion. As the bulge moves backwards, it leaves shallow waters in its wake, which can be filled with carbonates, while hemipelagic sediments and turbidites continue to fill the deeper parts of the basin, leaving a "trinity" of facies --- this is stage 2. At a certain point, the deep water basin changes from an underfilled state, where accommodation space is created as fast as it is filled with
787:
Sinclair's model of foreland basins has remained the state of the art for over a decade, and his four-stage model provides a good match for the
Windermere supergroup. In the first stage, an orogenic wedge (here, the mountains of the Southern Uplands accretionary wedge) loads a passive margin,
766:
from a section across the
Windermere Supergroup permits an estimate to be made of its maximum burial depth. Deposits at the surface today were once covered with 5โ6 km of sediment; some of this would belong to faulted Windermere deposits, but it is postulated that the bulk of it was
804:
Stage 1 is hard to spot in the sedimentary record. The Dent Group, the oldest part of the supergroup, is a good match for the carbonate facies expected in the shallow waters of stages 2โ3; accommodation space was created through
713:, flanking the edge of the Laurentian continent, was advancing towards Avalonia. The load of the mountains formed during this collision weighed down the Avalonian plate, causing the development of
55:
675:. Compression from the south east during the later Acadian orogeny (probably caused by the closure of the Rheic ocean) buckled the strata into anticlines and synclines and caused
613:
and
Ireland, and down-dip in the Southern Uplands and Welsh Borderlands. It underlies much of north England's younger cover, extending south to East Anglia. It formed as a
740:. The rate of sediment accumulation accelerated with time; it held fairly steady at a low ~50 metres per million years (m/Ma) until the Wenlock (mid Silurian,
48:
796:
sediments, with turbidites and deltas prograding through the basin. The basin is eventually filled, and covered with fluvial and alluvial molasse (stage 4).
812:
Throughout the
Silurian, until the beginning of Old Red Sandstone deposition, sedimentation rate increases steadily, reaching a peak of 1 mm a.
1005:
41:
873:
898:
747:), when it increased greatly, eventually reaching over 1000 m/Ma when the record is terminated by erosion in the Pridoli (terminal Silurian,
618:
1010:
775:
deposits laid down by alluvial fans on the flanks of the mountain belt, and probably lower energy fluvial (river) or
936:
829:
Woodcock, N.H.; Soper, N.J.; Strachan, R.A. (2007). "A Rheic cause for the
Acadian deformation in Europe".
920:
737:
736:
transitions, with black shales corresponding to transgressions - these may have helped to mitigate a
699:
892:
921:"Tectonostratigraphic model for underfilled peripheral foreland basins; an Alpine perspective"
792:, to an overfilled one (stage 3). The orogenic wedge then provides a significant source of
965:
838:
709:
The
Windermere basin was formed by flexure. Prior to its formation, the Southern Uplands
8:
714:
969:
884:
842:
981:
854:
806:
710:
679:
291:
985:
858:
776:
768:
973:
932:
846:
280:
17:
732:). During the Llandovery, the Stockdale Supergroup is marked by a number of oxic-
664:
660:
591:
265:
668:
614:
320:
850:
999:
977:
703:
691:
626:
540:
311:
956:
Kneller, B.C. (1991). "A foreland basin on the southern margin of
Iapetus".
871:
733:
672:
382:
300:
698:
continental margin, composed mainly of turbidites. Between the two, the
610:
515:
828:
706:
volcanic arc, active during the subduction of the
Iapetus ocean crust.
644:
640:
560:
525:
418:
409:
355:
346:
205:
509:
Groups of the
Windermere supergroup against the geological timescale.
749:
742:
727:
656:
652:
633:
629:
596:
565:
373:
178:
695:
622:
606:
555:
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535:
530:
520:
400:
391:
364:
241:
216:
793:
772:
602:
570:
545:
427:
879:. In Budd, G. E.; Streng, M.; Daley, A. C.; Willman, S. (eds.).
789:
763:
436:
337:
874:"Deglacial anoxia in a long-lived Early Palaeozoic Icehouse."
676:
648:
937:
10.1130/0016-7606(1997)109<0324:TMFUPF>2.3.CO;2
685:
720:
690:
To the north west of the unit lies the Cambro-Ordovician
757:
725:
Sedimentation began in the
Caradoc (upper Ordovician,
872:
Page, A., Zalasiewicz, J. & Williams, M (2007).
22:
782:
594:formed during the Ordovician to Silurian periods ~
997:
16:For the Windermere group in North America, see
918:
914:
912:
910:
908:
955:
925:Bulletin of the Geological Society of America
49:
897:: CS1 maint: multiple names: authors list (
887:. Vol. 51. Uppsala, Sweden. p. 85.
905:
885:Palaeontological Association Annual Meeting
822:
702:consists of tuffs erupted by an underlying
1006:Geologic supergroups of the United Kingdom
949:
56:
42:
686:Before the Windermere: Basement terranes
647:limestones, and the overlying series of
609:and correlates along its strike, in the
865:
721:Sedimentation begins: Filling the basin
998:
507:
799:
617:, in a similar setting to the modern
34:
25:
758:Beyond the record: Postulated cover
13:
1011:Stratigraphy of the United Kingdom
511:Axis scale: millions of years ago.
14:
1022:
958:Journal of the Geological Society
831:Journal of the Geological Society
694:, a sequence that formed on the
513:
783:Modelling the basin's evolution
625:as the remains of the attached
1:
815:
762:Analysis of the clay mineral
639:The supergroup comprises the
621:, fronting the continent of
7:
601:, and exposed in northwest
508:
173:
10:
1027:
15:
851:10.1144/0016-76492006-129
738:runaway greenhouse effect
700:Borrowdale Volcanic Group
574:
978:10.1144/gsjgs.148.2.0207
881:Programme with Abstracts
66:
919:Sinclair, H.D. (1997).
752: million years ago
745: million years ago
730: million years ago
682:in some sediment beds.
599: million years ago
500:Old Red Sandstone cover
169:−400 —
159:−405 —
149:−410 —
139:−415 —
129:−420 —
119:−425 —
109:−430 —
99:−435 —
89:−440 —
79:−445 —
69:−450 —
588:Windermere Supergroup
29:Windermere supergroup
970:1991JGSoc.148..207K
843:2007JGSoc.164.1023W
715:accommodation space
807:thermal subsidence
800:Matching the model
711:accretionary prism
779:(dune) deposits.
769:Old Red Sandstone
584:
583:
27:Chronology of the
1018:
990:
989:
953:
947:
946:
944:
943:
916:
903:
902:
896:
888:
878:
869:
863:
862:
826:
753:
746:
731:
605:, including the
600:
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439:
430:
421:
412:
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367:
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58:
51:
44:
38:
23:
18:Windermere group
1026:
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1021:
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1019:
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1016:
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954:
950:
941:
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893:cite conference
890:
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870:
866:
827:
823:
818:
802:
785:
760:
748:
741:
726:
723:
688:
665:Tranearth Group
661:Stockdale Group
595:
592:geological unit
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479:Tranearth Group
478:
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472:Stockdale Group
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36:
30:
28:
21:
12:
11:
5:
1024:
1014:
1013:
1008:
992:
991:
964:(2): 207โ210.
948:
931:(3): 324โ346.
904:
864:
820:
819:
817:
814:
801:
798:
784:
781:
759:
756:
722:
719:
687:
684:
669:Coniston Group
615:foreland basin
582:
581:
575:
569:
564:
559:
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353:
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318:
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309:
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288:
278:
277:
263:
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238:
237:
213:
212:
202:
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175:
174:
172:
167:
162:
157:
152:
147:
142:
137:
132:
127:
122:
117:
112:
107:
102:
97:
92:
87:
82:
77:
72:
67:
64:
63:
61:
60:
53:
46:
35:
32:
31:
26:
9:
6:
4:
3:
2:
1023:
1012:
1009:
1007:
1004:
1003:
1001:
987:
983:
979:
975:
971:
967:
963:
959:
952:
938:
934:
930:
926:
922:
915:
913:
911:
909:
900:
894:
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882:
875:
868:
860:
856:
852:
848:
844:
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836:
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821:
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797:
795:
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778:
774:
770:
765:
755:
751:
744:
739:
735:
729:
718:
716:
712:
707:
705:
704:calc-alkaline
701:
697:
693:
692:Skiddaw Group
683:
681:
678:
674:
670:
666:
662:
658:
654:
650:
646:
642:
637:
635:
631:
628:
627:Iapetus ocean
624:
620:
616:
612:
608:
604:
598:
593:
589:
572:
567:
562:
557:
552:
547:
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522:
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438:
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420:
411:
402:
393:
384:
375:
366:
357:
348:
339:
330:
313:
304:
293:
284:
273:
258:
257:
233:
232:
208:
207:
197:
196:
65:
59:
54:
52:
47:
45:
40:
39:
33:
24:
19:
961:
957:
951:
940:. Retrieved
928:
924:
880:
867:
834:
830:
824:
811:
803:
786:
771:, including
761:
724:
708:
689:
673:Kendal Group
638:
619:Ganges basin
587:
585:
486:Coniston Gr.
383:Sheinwoodian
240:
215:
204:
177:
837:(5): 1023.
611:Isle of Man
37:This box:
1000:Categories
942:2008-02-13
816:References
657:greywackes
645:turbiditic
641:Dent Group
493:Kendal Gr.
465:Dent Group
419:Lochkovian
410:Ludfordian
356:Rhuddanian
347:Hirnantian
986:128947549
859:140681911
696:Avalonian
634:Laurentia
630:subducted
374:Telychian
680:cleavage
623:Avalonia
607:Pennines
401:Gorstian
392:Homerian
365:Aeronian
966:Bibcode
839:Bibcode
794:molasse
777:aeolian
773:molasse
659:of the
603:England
428:Pragian
312:Pridoli
164:–
154:–
144:–
134:–
124:–
114:–
104:–
94:–
84:–
74:–
984:
857:
790:flysch
764:illite
734:anoxic
649:shales
632:under
459:
454:
449:
444:
437:Emsian
338:Katian
982:S2CID
877:(PDF)
855:S2CID
677:slaty
653:grits
590:is a
899:link
671:and
655:and
586:The
516:Pre๊
57:edit
50:talk
43:view
974:doi
962:148
933:doi
929:109
847:doi
835:164
750:419
743:424
728:455
643:of
597:450
1002::
980:.
972:.
960:.
927:.
923:.
907:^
895:}}
891:{{
883:.
853:.
845:.
833:.
717:.
667:,
663:,
651:,
636:.
566:Pg
988:.
976::
968::
945:.
935::
901:)
861:.
849::
841::
576:โ
571:N
561:K
556:J
551:T
546:P
541:C
536:D
531:S
526:O
521:๊
329:y
327:l
325:r
323:a
321:E
303:u
301:L
292:W
283:l
281:L
272:e
270:t
268:a
266:L
256:n
254:a
252:i
250:n
248:o
246:v
244:e
242:D
231:n
229:a
227:i
225:r
223:u
221:l
219:i
217:S
206:O
195:c
193:i
191:o
189:z
187:o
185:e
183:l
181:a
179:P
20:.
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