126:
840:
951:
462:. These modern divisions replace numerous earlier divisions, references to which occur widely on geological maps and in other geological literature. Previously no subgroups were defined but three formations were identified; the Upper Chalk, Middle Chalk and Lower Chalk. Different formations are defined within the 'northern' and 'southern' provinces, from Norfolk northwards and south of the Thames valley respectively. A 'transitional province' between the two and covering much of
574:
418:
1280:
Across the north central and northern North Sea, the Chalk Group is a major seal unit, overlying a number of blocks of reservoir rocks and preventing their fluid contents from migrating upwards. North of the line of the Mid-North Sea - Ringkobing - Fyn structural high, the Chalk Group is still
429:
606:
The White Chalk
Subgroup includes what were formerly designated the Middle Chalk and Upper Chalk Formations, together with the Plenus Marls (topmost part of the former Lower Chalk Formation). In the southern province it is divided in the following way (youngest/uppermost at top):
1300:
areas (around 56°30' N 02°30'E, UKCS quadrants 22,23,29 and 30), the Chalk Group can be significantly overpressured. Further south in UKCS quadrant 30 and
Norwegian quadrants 1 and 2, this overpressure helps preserve porosity and enables the Chalk to be an effective reservoir.
528:, where the entire sequence is now referred to as the 'Ferriby Chalk Formation'. The thickness of the Grey Chalk Subgroup strata varies, averaging around 200 ft (61 m), depending upon the location. They often contains fossils such as the ammonites
331:. The coccolithophores lived in the upper part of the water column. When they died, the microscopic calcium carbonate plates, which formed their shells settled downward through the ocean water and accumulated on the ocean bottom to form a thick layer of
854:
The Chalk outcrops across large parts of southern and eastern
England and forms a significant number of the major physiographical features. Whilst it has been postulated that a chalk cover was laid down across just about all of England and Wales during
668:
In the southern province, the former Middle Chalk, now the
Holywell Nodular Chalk Formation and overlying New Pit Formation, averages about 200 ft (61 m) in thickness. The sparse fossils found in this sequence include the
1281:
recognisable in drilled samples, but becomes increasingly muddy northwards. North of the Beryl
Embayment (59°30' N 01°30'E), the Chalk Group is a series of slightly to moderately calcareous mudstones grouped under the name of the
914:
The broadly western margin of the Chalk outcrop is marked, from northeast to southwest, to south by the Chalk downlands of the
Yorkshire Wolds, the Lincolnshire Wolds, a subdued feature through western
1289:, this sequence has neither source potential nor reservoir capacity and is not generally considered a drilling target. Its thickness and homogeneity does make it a common target for carrying out
1407:
charge. However, when these hydrocarbons are produced, diagenesis and compaction can restart which has led to several metres of subsidence at seabed, the collapse of a number of wells, and some
509:
in its lower part (the West
Melbury Marly Chalk Formation (formerly the 'Chalk Marl') and becomes progressively purer in the 'Zig-zag Chalk Formation' (the former 'Grey Chalk'). In the central
1216:
In
Belgium, the Houthem Formation is sometimes not included in the Chalk Group because it is not a Cretaceous formation. Some stratigraphers therefore prefer to put it in the lower
482:
The Grey Chalk
Subgroup (formerly the Lower Chalk minus the Plenus Marls) is usually relatively soft and greyish in colour. It is also the most fossiliferous (especially for
1812:
973:
face one another across the Weald. For similar reasons, the Chalk is largely absent from the rather smaller area to the south of the
Purbeck-Wight Monocline, save for
702:
fossils in some nodular layers. The thickness of this sequence varies greatly, often averaging around 300 ft (91 m). Fossils may be abundant and include the
1586:
1517:
A Stratigraphical Framework for the Upper Cretaceous Chalk of England and Scotland with Statements on the Chalk of Northern Ireland and the UK Offshore Sector
1822:
1817:
1593:
1243:
was constructed by tunnelling through the West Melbury Marly Chalk (formerly the 'Chalk Marl' - a prominent sub-unit of the Grey Chalk Subgroup).
947:. In parts of the Thames Basin and eastern East Anglia the Chalk is concealed by later deposits, as is the case too within the Hampshire Basin.
1842:
1570:
315:"). Most of the fossil debris in chalk consists of the microscopic plates, which are called coccoliths, of microscopic green algae known as
690:
The former Upper Chalk by comparison is softer than the underlying sequence and the flint nodules it contains are far more abundant in the
411:
390:
1689:"Reassessment of Turonian mosasaur material from the 'Middle Chalk' (England, U.K.), and the status of Mosasaurus gracilis Owen, 1849"
1631:
988:
Some of the best exposures of the Chalk are where these ranges intersect the coast to produce dramatic, often vertical cliffs as at
125:
1737:. Actas de las IV Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno. Salas de los Infantes, Burgos, 45–74.
1480:
1274:
1528:
Martill DM, Witton MP, Gale A (2008) Possible azhdarchoid pterosaur remains from the Coniacian (Late Cretaceous) of England.
1597:
1042:
1827:
1297:
900:
1837:
1038:
319:. In addition to the coccoliths, the fossil debris includes a variable, but minor, percentage of the fragments of
859:
times, subsequent uplift and erosion has resulted in it remaining only southeast of a line drawn roughly between
280:
succession in southern and eastern England. The same or similar rock sequences occur across the wider northwest
1475:
1252:
950:
776:-aged rocks that form part of the Upper Chalk, making it the youngest known pterosaur discovered to date in
650:
Rowe Chalk Formation (formerly part of 'Upper Chalk' and the equivalent of Portsdown Chalk Formation, above)
611:
Portsdown Chalk Formation (formerly part of 'Upper Chalk' and the equivalent of Rowe Chalk Formation, below)
761:
674:
285:
1428:
from the Chalk Group have been studied for their continuous morphogical variation throughout the record.
997:
993:
506:
365:
131:
1117:) equivalents of the Chalk Group are basically continuous and crop out as a slightly northwest dipping
1187:
1290:
1198:
1172:
1070:
459:
185:
142:
1384:
1337:
1258:
573:
189:
152:
1688:
1045:
are the stratigraphical equivalents of the Chalk Group of England. They are best exposed near the
1716:
932:
876:
520:
These two formations are not recognised within the northern province i.e. the outcrop north from
1333:
age, (major reservoir in many fields including Joanne oil field (UKCS), Valhall oil field (NCS))
793:
839:
1708:
1669:
1627:
1566:
1319:
1311:
1165:
908:
578:
517:, which forms a prominent scarp in some places. There are few, if any, flint nodules present.
470:
is also recognised. A different approach again is taken as regards the succession beneath the
428:
308:
266:
1700:
1659:
1205:
1030:
989:
974:
698:
the underlying strata have the highest concentration of flints. It may contain ammonite and
691:
514:
395:
346:
335:
274:
167:
494:(formerly known as the Glauconitic or Chloritic Marl), named after the grains of the green
1734:
1445:
1013:
1001:
954:
940:
936:
928:
904:
880:
403:
316:
1652:
Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
1832:
1232:
1110:
1098:
924:
892:
884:
510:
502:
467:
381:
181:
1806:
1648:"Changes in the chalk heart-urchin Micraster Interpreted in relation to living forms"
1330:
1326:
1220:
1176:
1157:
1130:
1046:
1009:
982:
961:
Only where the Weald–Artois Anticline has been 'unroofed' by erosion i.e. within the
590:
586:
542:
530:
373:
171:
84:
46:
38:
1720:
1519:, British Geological Survey Research Report RR/05/01 (downloaded from www.bgs.ac.uk)
1465:
1453:
1150:
1062:
1034:
944:
896:
407:
320:
163:
1704:
1448:. A single partial maxillar tooth from Cenomanian aged Chalk Group described as "
1073:
is the stratigraphical equivalent of England's Chalk Group. It comprises largely
1404:
1286:
1160:, the Chalk Group succession is divided into five formations, from top to base:
1134:
1005:
970:
966:
827:
766:
743:
737:
551:
547:
521:
463:
437:
421:
399:
369:
59:
1754:. London: Proceedings of the Geologists Association, vol 86. pp. 449–535.
1400:
1388:
1368:
965:
is the Chalk entirely absent. In this area the long north-facing scarp of the
872:
856:
821:
798:
752:
723:
712:
699:
679:
670:
560:
498:
483:
358:
332:
104:
69:
42:
1712:
1673:
1424:
1392:
1359:
1348:
1341:
1217:
1209:
1201:, consisting of alternating Campanian clays, glauconiferous sands and silts;
1191:
1142:
1118:
1082:
1074:
920:
847:
803:
773:
769:
731:
707:
695:
582:
536:
525:
471:
300:
277:
212:
109:
53:
1664:
1647:
17:
1762:
1499:
1470:
1441:
1429:
1420:
1396:
1355:
1282:
1078:
1058:
888:
864:
860:
812:
703:
556:
433:
328:
324:
293:
222:
99:
94:
79:
74:
64:
417:
341:
The Chalk Group usually shows few signs of bedding, other than lines of
1270:
1236:
1180:
1122:
1106:
1086:
978:
916:
808:
784:
777:
748:
683:
495:
487:
312:
270:
241:
114:
89:
424:, (Isle of Wight); part of southern England's extensive chalk outcrop.
1541:
Ordnance Survey 1:625,000 scale Physical Map of Great Britain sheet 2
1315:
1266:
1262:
1240:
1146:
1126:
868:
757:
594:
566:
377:
350:
304:
281:
1411:
expensive remedial work to lift the platforms and re-position them.
581:
of South England: the Chalk Group (left, white, upper unit) and the
787:. Other fossils commonly found in this formation include: solitary
637:
Holywell Nodular Chalk Formation (formerly part of 'Middle Chalk')
1626:. Millennium Atlas Co. Chapter 13, Upper Cretaceous, Chalk Group.
1444:
aged Chalk Group deposits actually are more closely allied to the
1138:
962:
949:
844:
816:
788:
572:
427:
416:
354:
342:
289:
226:
1285:
Group. With the exception of some thin sandy units in the inner
1066:
385:
631:
Lewes Nodular Chalk Formation (formerly part of 'Upper Chalk')
1016:, gives rise to similar cliff features on the French coast.
783:
The youngest beds of the sequence are found on the coast of
653:
Flamborough Chalk Formation (formerly part of 'Upper Chalk')
1374:
Chalk Unit 1 - Hidra Formation - Cenomanian (non reservoir)
1559:
Engineering Geology for Infrastructure Planning in Europe
634:
New Pit Chalk Formation (formerly part of 'Middle Chalk')
625:
Newhaven Chalk Formation (formerly part of 'Upper Chalk')
1787:. American Association of Petroleum Geologist Memoir 33.
656:
Burnham Chalk Formation (formerly part of 'Upper Chalk')
628:
Seaford Chalk Formation (formerly part of 'Upper Chalk')
617:
Spetisbury Chalk Member (formerly part of 'Upper Chalk')
614:
Culver Chalk Formation (formerly part of 'Upper Chalk')
646:
In the northern province the sequence is divided thus:
1687:
Street, Hallie P.; Caldwell, Michael W. (2014-07-29).
620:
Tarrant Chalk Member (formerly part of 'Upper Chalk')
1798:(Second ed.). The Palaeontological Association.
505:
which it contains. The remainder of the subgroup is
303:
biomicrite. A biomicrite is a limestone composed of
296:
white limestone, deposited in a marine environment.
247:
237:
232:
218:
208:
203:
195:
177:
159:
148:
138:
32:
1783:Scholle, P.A.; Bedout, D.G.; Moore, C.H. (1983).
659:Welton Chalk Formation (formerly 'Middle Chalk')
1364:Turonian shale - Early Turonian (non reservoir)
345:nodules which become common in the upper part.
1168:, consisting of Paleocene calcareous arenites;
1085:age Gribun Chalk Formation of Mull and nearby
1133:, where they join Cretaceous deposits of the
8:
1551:Hack, Robert; Azzam, Rafig; Charlier, Robert
1012:. The Chalk, which once extended across the
458:, both of which are further subdivided into
288:'. It is characterised by thick deposits of
1763:"Chalk Facts – website on everything Chalk"
338:, which eventually became the Chalk Group.
124:
29:
1663:
1587:"The Chalk play of the UK Central Graben"
969:and the longer south-facing scarp of the
490:of this subgroup usually begin with the '
155:Grey Chalk Subgroup, White Chalk Subgroup
838:
513:the two parts are separated by the hard
1813:Geological groups of the United Kingdom
1594:Department of Energy and Climate Change
1491:
1029:In the 'Ulster Cretaceous Province' of
1581:
1579:
1354:Chalk Unit 2 - Hod Formation - Middle
1273:sectors and to a lesser extent in the
1141:the Cretaceous is overlain by younger
585:(right, green, lower unit). Location:
450:The Chalk Group is now divided into a
299:Chalk is a limestone that consists of
1624:The Millennium Atlas of the North Sea
1399:can be very high when preserved from
1391:beds. These include debris flows and
372:, the southern coastal cliffs of the
7:
412:Aston Rowant National Nature Reserve
1785:Carbonate Depositional Environments
1774:Wild Flowers of Chalk and Limestone
391:Site of Special Scientific Interest
1794:Smith, A.B.; Batten, D.J. (2002).
1693:Journal of Vertebrate Paleontology
1561:, Lecture Notes in Earth Sciences
388:, (which has been classified as a
25:
1823:Upper Cretaceous Series of Europe
577:Contact between two units of the
199:over 1,500 m (4,900 ft)
1481:Southern England Chalk Formation
1275:United Kingdom Continental Shelf
1061:Chalk Province' (extending from
891:rocks of this region during the
364:Well-known outcrops include the
1622:Evans, D.; et al. (2003).
1452:" belongs to a non-Hadrosaurid
1347:Chalk Unit 3 - Hod Formation -
1257:The chalk is also an important
1212:glauconiferous sands and silts.
441:from the Chalk Group of England
1818:Geologic formations of England
1:
27:Stratigraphic Unit in England
1843:Lithostratigraphy of England
1705:10.1080/02724634.2014.846263
1658:(693): 347–437. 1959-05-28.
1502:by C. S. Harris and Scholle
1318:age (major reservoir in the
1043:Ulster White Limestone Group
945:North and South Dorset Downs
815:and fish remains (including
251:southern and eastern England
1298:Eastern Trough Area Project
935:and the western margins of
835:Chalk landscapes of England
353:also occur and are usually
1859:
1752:The Petrology of the Chalk
1733:Dalla Vecchia FM. (2009b)
1344:age (mostly non reservoir)
1250:
1039:Hibernian Greensands Group
1261:in the North Sea Central
811:, scattered fragments of
380:and motorway cuttings at
123:
37:
1476:Geology of Great Britain
1253:Geology of the North Sea
492:Glauconitic Marl Member'
130:Brass Point, one of the
1194:to Maastrichtian chalk;
909:Purbeck-Wight monocline
871:and eastwards from the
267:lithostratigraphic unit
1772:Lousley, J.E. (1969).
1750:Hancock, J.M. (1975).
1735:European hadrosauroids
1665:10.1098/rstb.1959.0007
1596:. 2006. Archived from
1383:The majority of Chalk
1305:Reservoir stratigraphy
1296:In the Shearwater and
1114:
1102:
1020:Offshore and elsewhere
958:
901:Weald–Artois Anticline
851:
598:
442:
425:
1761:Harris, C.S. (2007).
1432:remains referred to "
1179:chalk and calcareous
994:White Cliffs of Dover
977:immediately north of
953:
842:
576:
431:
420:
366:White Cliffs of Dover
361:on exposed surfaces.
273:) which contains the
269:(a certain number of
1796:Fossils of the Chalk
1291:directional drilling
1173:Maastricht Formation
1071:Inner Hebrides Group
907:and the less gentle
602:White Chalk Subgroup
452:White Chalk Subgroup
186:Hunstanton Formation
1515:Hopson, P.M., 2005
1367:Plenus Marl - Late
1351:to Middle Campanian
1259:petroleum reservoir
1227:The English Channel
1121:in a belt from the
662:Plenus Marls Member
640:Plenus Marls Member
583:Greensand Formation
478:Grey Chalk Subgroup
456:Grey Chalk Subgroup
307:debris ("bio") and
261:(often just called
190:Cambridge Greensand
153:Cambridge Greensand
39:Stratigraphic range
1828:Cretaceous England
1776:. London: Collins.
1041:and the overlying
959:
852:
599:
443:
426:
1838:Petroleum geology
1571:978-3-540-21075-7
1379:Reservoir geology
1320:Ekofisk oil field
1312:Ekofisk Formation
1166:Houthem Formation
1093:The Low Countries
933:Marlborough Downs
895:has produced the
579:lithostratigraphy
410:cuts through the
406:border where the
309:calcium carbonate
255:
254:
16:(Redirected from
1850:
1799:
1788:
1777:
1766:
1755:
1738:
1731:
1725:
1724:
1699:(5): 1072–1079.
1684:
1678:
1677:
1667:
1644:
1638:
1637:
1619:
1613:
1612:
1610:
1608:
1603:on 18 April 2015
1602:
1591:
1583:
1574:
1552:
1548:
1542:
1539:
1533:
1526:
1520:
1513:
1507:
1498:As discussed in
1496:
1387:are redeposited
1208:, consisting of
1206:Aachen Formation
1190:, consisting of
1188:Gulpen Formation
1175:, consisting of
1149:deposits of the
1031:Northern Ireland
1025:Northern Ireland
990:Flamborough Head
957:, Chiltern Hills
756:, and the small
692:South of England
515:Totternhoe Stone
396:Stokenchurch Gap
317:coccolithophores
275:Upper Cretaceous
168:Thanet Formation
128:
119:
56:
30:
21:
1858:
1857:
1853:
1852:
1851:
1849:
1848:
1847:
1803:
1802:
1793:
1782:
1771:
1760:
1749:
1746:
1744:Further reading
1741:
1732:
1728:
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1545:
1540:
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1527:
1523:
1514:
1510:
1497:
1493:
1489:
1462:
1450:Iguanodon hilli
1446:Russellosaurina
1419:Fossils of the
1417:
1381:
1371:(non reservoir)
1336:Chalk Unit 4 -
1325:Chalk Unit 5 -
1310:Chalk Unit 6 -
1307:
1277:sector (UKCS).
1255:
1249:
1229:
1199:Vaals Formation
1129:to the city of
1103:Krijtkalk-Groep
1095:
1089:is recognised.
1055:
1027:
1022:
1014:English Channel
1002:Old Harry Rocks
955:Ivinghoe Beacon
941:Cranborne Chase
937:Salisbury Plain
929:Berkshire Downs
905:Hampshire Basin
881:Yorkshire Wolds
837:
801:tubes (such as
604:
480:
448:
404:Buckinghamshire
349:of the mineral
134:
118:
117:
112:
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97:
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15:
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11:
5:
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1726:
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1575:
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1534:
1532:B 28: 209–218.
1521:
1508:
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1473:
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1461:
1458:
1416:
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1372:
1365:
1362:
1352:
1345:
1334:
1323:
1306:
1303:
1248:
1245:
1233:Channel Tunnel
1228:
1225:
1214:
1213:
1202:
1195:
1184:
1169:
1094:
1091:
1054:
1051:
1026:
1023:
1021:
1018:
1004:(Purbeck) and
925:Chiltern Hills
893:Alpine orogeny
836:
833:
819:teeth such as
772:is known from
694:, although in
666:
665:
664:
663:
657:
654:
651:
644:
643:
642:
641:
635:
632:
629:
626:
623:
622:
621:
618:
612:
603:
600:
486:fossils). The
479:
476:
468:Chiltern Hills
447:
444:
382:Blue Bell Hill
253:
252:
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234:
230:
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206:
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182:Selborne Group
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1633:1-86239-119-X
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1398:
1394:
1390:
1389:allochthonous
1386:
1378:
1373:
1370:
1366:
1363:
1361:
1357:
1353:
1350:
1346:
1343:
1339:
1338:Hod Formation
1335:
1332:
1331:Maastrichtian
1328:
1327:Tor Formation
1324:
1321:
1317:
1313:
1309:
1308:
1304:
1302:
1299:
1294:
1292:
1288:
1284:
1278:
1276:
1272:
1268:
1264:
1260:
1254:
1247:The North Sea
1246:
1244:
1242:
1238:
1234:
1226:
1224:
1222:
1221:Hesbaye Group
1219:
1211:
1207:
1203:
1200:
1196:
1193:
1189:
1185:
1182:
1178:
1177:Maastrichtian
1174:
1170:
1167:
1163:
1162:
1161:
1159:
1158:Low Countries
1154:
1152:
1148:
1144:
1140:
1136:
1132:
1128:
1124:
1120:
1116:
1112:
1108:
1104:
1100:
1092:
1090:
1088:
1084:
1080:
1076:
1072:
1068:
1064:
1060:
1052:
1050:
1048:
1044:
1040:
1036:
1032:
1024:
1019:
1017:
1015:
1011:
1010:Isle of Wight
1007:
1003:
999:
998:Seven Sisters
995:
991:
986:
984:
983:Isle of Wight
980:
976:
972:
968:
964:
956:
952:
948:
946:
942:
938:
934:
930:
926:
922:
918:
912:
910:
906:
902:
898:
894:
890:
886:
882:
878:
874:
870:
866:
862:
858:
849:
846:
841:
834:
832:
830:
829:
824:
823:
818:
814:
810:
806:
805:
800:
796:
795:
790:
786:
781:
779:
775:
771:
768:
765:. A possible
764:
763:
759:
755:
754:
750:
746:
745:
740:
739:
734:
733:
728:
725:
721:
717:
716:Terebratulina
714:
710:
709:
705:
701:
697:
693:
688:
686:
685:
681:
677:
676:
675:Terebratulina
672:
661:
660:
658:
655:
652:
649:
648:
647:
639:
638:
636:
633:
630:
627:
624:
619:
616:
615:
613:
610:
609:
608:
601:
596:
592:
591:West Lulworth
588:
587:Lulworth Cove
584:
580:
575:
571:
569:
568:
563:
562:
558:
554:
553:
549:
545:
544:
543:Mantelliceras
539:
538:
533:
532:
531:Schloenbachia
527:
523:
518:
516:
512:
508:
504:
500:
497:
493:
489:
485:
477:
475:
473:
469:
465:
461:
457:
453:
445:
440:
439:
435:
430:
423:
419:
415:
413:
409:
405:
401:
397:
394:) and at the
393:
392:
387:
383:
379:
375:
374:Isle of Wight
371:
367:
362:
360:
356:
352:
348:
344:
339:
337:
334:
330:
326:
322:
318:
314:
310:
306:
302:
297:
295:
291:
287:
283:
279:
276:
272:
268:
264:
260:
250:
246:
243:
240:
236:
231:
228:
224:
221:
217:
214:
211:
207:
202:
198:
194:
191:
187:
183:
180:
176:
173:
172:Lambeth Group
169:
165:
162:
158:
154:
151:
147:
144:
141:
137:
133:
132:Seven Sisters
127:
122:
116:
111:
106:
101:
96:
91:
86:
81:
76:
71:
66:
61:
55:
48:
47:Maastrichtian
44:
40:
36:
31:
19:
1795:
1784:
1773:
1751:
1729:
1696:
1692:
1682:
1655:
1651:
1642:
1623:
1617:
1605:. Retrieved
1598:the original
1565:, Springer,
1562:
1558:
1554:
1546:
1537:
1529:
1524:
1516:
1511:
1503:
1494:
1466:Chalk stream
1454:Hadrosauroid
1449:
1437:
1433:
1423:
1418:
1408:
1382:
1295:
1293:manoeuvers.
1279:
1265:, mainly in
1256:
1230:
1215:
1155:
1151:Landen Group
1096:
1056:
1028:
987:
960:
919:, including
913:
897:London Basin
877:Lincolnshire
853:
826:
820:
802:
792:
782:
760:
751:
742:
736:
730:
726:
719:
715:
706:
689:
682:
673:
667:
645:
605:
565:
559:
550:
541:
535:
529:
519:
507:argillaceous
491:
481:
455:
451:
449:
446:Subdivisions
436:
408:M40 motorway
389:
363:
340:
321:foraminifera
298:
262:
258:
256:
164:unconformity
52:100–66
1500:Chalk Facts
1405:hydrocarbon
1322:and others)
1287:Moray Firth
1137:. North of
1135:Paris Basin
1115:Krijt-Groep
1097:The Dutch (
1081:though the
1037:-dominated
1006:The Needles
971:North Downs
967:South Downs
828:Squalicorax
799:marine worm
767:azhdarchoid
762:Porosphaera
744:Tylocidaris
738:Echinocorys
727:Sternotaxis
720:Gibbithyris
713:brachiopods
552:Actinocamax
522:East Anglia
464:East Anglia
438:Echinocorys
422:The Needles
400:Oxfordshire
370:Beachy Head
271:rock strata
259:Chalk Group
33:Chalk Group
18:Upper Chalk
1807:Categories
1530:Zitteliana
1487:References
1434:Mosasaurus
1401:diagenesis
1397:Porosities
1385:reservoirs
1369:Cenomanian
1251:See also:
1075:sandstones
857:Cretaceous
822:Cretolamna
794:Parasmilia
753:Marsupites
671:brachiopod
597:, England.
561:Inoceramus
555:, and the
499:glauconite
460:formations
359:iron oxide
333:calcareous
43:Cenomanian
1713:0272-4634
1674:2054-0280
1440:from the
1438:gracillis
1425:Micraster
1409:extremely
1403:by early
1393:turbidite
1360:Coniacian
1349:Santonian
1342:Campanian
1267:Norwegian
1218:Paleogene
1210:Santonian
1192:Campanian
1143:Paleocene
1119:monocline
1083:Santonian
1079:mudstones
975:the downs
943:and the
921:Breckland
883:. Gentle
848:Anticline
809:bryozoans
804:Rotularia
791:(such as
774:Coniacian
770:pterosaur
732:Micraster
724:echinoids
708:Spondylus
700:gastropod
696:Yorkshire
548:belemnite
537:Scaphites
526:Yorkshire
511:Chilterns
472:North Sea
357:to brown
325:ostracods
301:coccolith
292:, a soft
278:limestone
265:) is the
263:the Chalk
213:limestone
204:Lithology
196:Thickness
160:Underlies
149:Sub-units
1721:84392980
1607:18 April
1573:, p. 491
1471:Downland
1460:See also
1442:Turonian
1430:Mosasaur
1421:echinoid
1356:Turonian
1283:Shetland
1235:linking
1181:arenites
1125:city of
1059:Scottish
1057:In the '
1053:Scotland
899:and the
889:Mesozoic
865:Lyme Bay
861:The Wash
813:starfish
680:echinoid
678:and the
557:bivalves
503:chlorite
496:minerals
484:ammonite
466:and the
434:echinoid
378:quarries
376:and the
355:oxidized
329:mollusks
286:province
282:European
233:Location
223:mudstone
178:Overlies
1415:Fossils
1395:flows.
1340:- Late
1237:England
1156:In the
1107:Belgian
1087:Morvern
1049:coast.
1035:clastic
1008:on the
981:on the
979:Ventnor
917:Norfolk
887:of the
885:folding
875:of the
845:Wealden
785:Norfolk
778:England
749:crinoid
704:bivalve
684:Conulus
589:, near
432:Fossil
398:on the
347:Nodules
313:micrite
284:chalk '
242:England
238:Country
209:Primary
1719:
1711:
1672:
1630:
1569:
1506:(1983)
1504:et al.
1316:Danian
1271:Danish
1263:Graben
1241:France
1147:Eocene
1127:Aachen
1123:German
1105:) and
1069:) the
1047:Antrim
992:, the
927:, the
923:, the
903:, the
873:scarps
869:Dorset
789:corals
758:sponge
747:, the
741:, and
722:, the
711:, the
595:Dorset
567:Ostrea
546:, the
540:, and
488:strata
454:and a
351:pyrite
311:mud ("
305:fossil
294:porous
248:Extent
1833:Chalk
1717:S2CID
1601:(PDF)
1590:(PDF)
1139:Namur
1111:Dutch
1099:Dutch
963:Weald
817:shark
343:flint
290:chalk
227:flint
219:Other
143:Group
1709:ISSN
1670:ISSN
1628:ISBN
1609:2015
1567:ISBN
1555:2004
1269:and
1239:and
1231:The
1204:the
1197:the
1186:the
1171:the
1164:the
1145:and
1131:Mons
1077:and
1067:Skye
1063:Mull
1033:the
939:and
879:and
863:and
843:The
825:and
718:and
564:and
501:and
386:Kent
336:ooze
327:and
257:The
139:Type
60:PreꞒ
1701:doi
1660:doi
1656:242
1563:104
1358:to
1065:to
867:in
831:).
807:),
797:),
524:to
45:to
1809::
1715:.
1707:.
1697:34
1695:.
1691:.
1668:.
1654:.
1650:.
1592:.
1578:^
1557::
1553:;
1456:.
1436:"
1329:-
1314:-
1223:.
1153:.
1113::
1101::
1000:,
996:,
985:.
931:,
911:.
780:.
735:,
729:,
687:.
593:,
570:.
534:,
474:.
414:.
384:,
368:,
323:,
225:,
188:,
184:,
170:,
166:,
110:Pg
54:Ma
49:,
41::
1765:.
1723:.
1703::
1676:.
1662::
1636:.
1611:.
1183:;
1109:(
850:.
402:/
115:N
105:K
100:J
95:T
90:P
85:C
80:D
75:S
70:O
65:Ꞓ
20:)
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