Marsupites testudinarius Zone - Revision history

Dbk at 12:55, 26 September 2013

2013-09-26T12:55:55Z

← Older revision		Revision as of 13:55, 26 September 2013
Line 1:		Line 1:


	'''Base''': In southern England, the base of the zone is marked by an un-named marl just above the Hawks Brow Flint (Young & Lake, 1988), and it is placed immediately below the first record of the index species in northern England, c. 0.7 m below the lower of the two Maidlands Upper Marls (Mitchell, 1994). In East Anglia, faunal records of the index are rather sparse (Woods, WH/94/90R; Jukes-Browne & Hill, 1904; Pattison ''et al''., 1993; Peake & Hancock, 1970), making precise definition problematic; it was grouped with the underlying ''U. socialis'' Zone in the BGS Trunch Borehole [TG 2933 3455] (Wood & Morter, 1994). In Northern Ireland, the base of the zone is coincident with the base of the Cloghastucan Chalk (Wilson & Manning, 1978).		'''Base''': In southern England, the base of the zone is marked by an un-named marl just above the Hawks Brow Flint (Young & Lake, 1988), and it is placed immediately below the first record of the index species in northern England, c. 0.7 m below the lower of the two Maidlands Upper Marls (Mitchell, 1994). In East Anglia, faunal records of the index are rather sparse (Woods, WH/94/90R; Jukes-Browne & Hill, 1904; Pattison ''et al''., 1993; Peake & Hancock, 1970), making precise definition problematic; it was grouped with the underlying ''U. socialis'' Zone in the BGS Trunch Borehole [TG 2933 3455] (Wood & Morter, 1994). In Northern Ireland, the base of the zone is coincident with the base of the Cloghastucan Chalk (Wilson & Manning, 1978).



	'''Top''': In southern England, the top of the zone is placed at Friar's Bay Marl 1, and in northern England, a little above marl SY 17 of Whitham (1993). In the BGS Trunch Borehole [TG 2933 3455], the top of the zone is defined by the base of a coarse, shell-rich chalk facies - the so-called 'grobkreide' facies of german successions (Wood & Morter, 1994). However, in northern England, similar coarse-grained chalk occurs within the ''M. testudinarius'' Zone (Mitchell, 1995). In Northern Ireland, the top of the zone is coincident with the top of the Cloghastucan Chalk (Wilson & Manning, 1978).		'''Top''': In southern England, the top of the zone is placed at Friar's Bay Marl 1, and in northern England, a little above marl SY 17 of Whitham (1993). In the BGS Trunch Borehole [TG 2933 3455], the top of the zone is defined by the base of a coarse, shell-rich chalk facies - the so-called 'grobkreide' facies of german successions (Wood & Morter, 1994). However, in northern England, similar coarse-grained chalk occurs within the ''M. testudinarius'' Zone (Mitchell, 1995). In Northern Ireland, the top of the zone is coincident with the top of the Cloghastucan Chalk (Wilson & Manning, 1978).



	'''Range of index species''': The index ranges through the greater part of the nominate zone in southern and northern England (Young & Lake, 1988; Mitchell, 1994), but clear data for East Anglia is lacking. In Northern Ireland, the index ranges from the base of the zone to just below the Oweynamuck Flint, a short distance below the top of the zone (Wilson & Manning, 1978).		'''Range of index species''': The index ranges through the greater part of the nominate zone in southern and northern England (Young & Lake, 1988; Mitchell, 1994), but clear data for East Anglia is lacking. In Northern Ireland, the index ranges from the base of the zone to just below the Oweynamuck Flint, a short distance below the top of the zone (Wilson & Manning, 1978).



	'''Key fauna''':		'''Key fauna''':
			{\| class="Wikitable"
			\| Brachiopoda: \|\| ''Cretirhynchia exsculpta''
			\|-
	Brachiopoda: ''Cretirhynchia exsculpta''		\| \|\|'' Terebratulina rowei''
			\|-
			\| Bivalvia: \|\| ''Acutostrea incurva''
			\|-
	'' Terebratulina rowei''		\| \|\|''Inoceramus'' (comminuted shell abundant in Northern Ireland)
			\|-
			\| \|\|''Platyceramus''
			\|-
	Bivalvia: ''Acutostrea incurva''		\| \|\|''Pseudoperna boucheroni''
			\|-
			\| \|\|''Pycnodonte vesiculare''
			\|-
	''Inoceramus'' (comminuted shell abundant in Northern Ireland)		\| \|\|''Sphenoceramus ''(''Inoceramus'') ''lingua''*
			\|-
			\| Belemnoidea: \|\|''Actinocamax versus''
			\|-
	''Platyceramus''		\| Ammonoidea:\|\| ''Parapuzosia leptophylla''
			\|-
			\| Asteroidea: \|\| ''Crateraster rotundus''*
			\|-
	''Pseudoperna boucheroni''		\| Crinoidea: \|\| ''Marsupites testudinarius''
			\|-
			\| Echinoidea: \|\| ''Conulus'' sp.
			\|-
	''Pycnodonte vesiculare''		\| \|\|''Echinocorys elevata''
			\|-
			\| \|\|''Micraster rostrata''
			\|}
	''Sphenoceramus ''(''Inoceramus'') ''lingua''*



	Belemnoidea: ''Actinocamax versus''



	Ammonoidea: ''Parapuzosia leptophylla''



	Asteroidea: ''Crateraster rotundus''*



	Crinoidea: ''Marsupites testudinarius''



	Echinoidea: ''Conulus'' sp.



	''Echinocorys elevata''



	''Micraster rostrata''



	(*:occur in the zone in northern England)		(*:occur in the zone in northern England)



	'''Faunal abundance & preservation''': In northern and southern England the zone is quite richly fossiliferous with a variety of fauna. However, in East Anglia, the sparsity of outcrops means that faunal records from this zone are rather limited. The index crinoid is typically preserved as dissociated calyx plates, but complete or semi-complete calices can occasionally be found. In Northern Ireland, the extreme hardness of the Chalk Group makes it difficult to collect fossils.		'''Faunal abundance & preservation''': In northern and southern England the zone is quite richly fossiliferous with a variety of fauna. However, in East Anglia, the sparsity of outcrops means that faunal records from this zone are rather limited. The index crinoid is typically preserved as dissociated calyx plates, but complete or semi-complete calices can occasionally be found. In Northern Ireland, the extreme hardness of the Chalk Group makes it difficult to collect fossils.



	'''Bio-markers''': In southern England there is a trend in the size and ormentation of ''M.'' ''testudinarius'' calyx plates through the zone.They are small and unornamented below the Brighton Marl, becoming large and ornamented just above this marl, and then becoming less ornamented but remaining large in the interval up to the Kemp Town Marl; higher in the zone they decrease in size but remain ornamented (Mitchell, 1995). A less clear trend is discernible in northern England, where the calyx plates in the lower part of the zone are either smooth or weakly ornamented, and those in the upper part of the zone generally more strongly ornamented (Mitchell, 1995). On this basis, Mitchell (1995) suggested a tentative correlation of the Brighton Marl and Danes Dyke Lower Marls. Young & Lake (1988) recorded that oysters, particularly ''Pseudoperna boucheroni'', characterise the middle and higher parts of the zone in southern England, but they in fact range through the greater part of the zone and also occur in some adjacent zones. In northern England, ''Pseudoperna boucheroni'' has numerous acmes at and above the ''U. socialis'' Zone (Whitham, 1993). An acme of ''Echinocorys elevata'' characterises the lower to middle parts of the zone in both northern and southern England, and the latter region has ''Cretirhynchia exsculpta'' ranging through the middle and upper parts of the zone (Young & Lake, 1988; Whitham, 1993). Two important bio-markers in the upper part of the zone in northern England are the restricted occurrence of the asteroid ''Crateraster rotundus'' between marls SY11 and SY 20 of Whitham (1993), and the first appearance of the long-ranging ''Sphenoceramus'' (''Inoceramus'') ''lingua'' (Mitchell, 1995).		'''Bio-markers''': In southern England there is a trend in the size and ormentation of ''M.'' ''testudinarius'' calyx plates through the zone.They are small and unornamented below the Brighton Marl, becoming large and ornamented just above this marl, and then becoming less ornamented but remaining large in the interval up to the Kemp Town Marl; higher in the zone they decrease in size but remain ornamented (Mitchell, 1995). A less clear trend is discernible in northern England, where the calyx plates in the lower part of the zone are either smooth or weakly ornamented, and those in the upper part of the zone generally more strongly ornamented (Mitchell, 1995). On this basis, Mitchell (1995) suggested a tentative correlation of the Brighton Marl and Danes Dyke Lower Marls. Young & Lake (1988) recorded that oysters, particularly ''Pseudoperna boucheroni'', characterise the middle and higher parts of the zone in southern England, but they in fact range through the greater part of the zone and also occur in some adjacent zones. In northern England, ''Pseudoperna boucheroni'' has numerous acmes at and above the ''U. socialis'' Zone (Whitham, 1993). An acme of ''Echinocorys elevata'' characterises the lower to middle parts of the zone in both northern and southern England, and the latter region has ''Cretirhynchia exsculpta'' ranging through the middle and upper parts of the zone (Young & Lake, 1988; Whitham, 1993). Two important bio-markers in the upper part of the zone in northern England are the restricted occurrence of the asteroid ''Crateraster rotundus'' between marls SY11 and SY 20 of Whitham (1993), and the first appearance of the long-ranging ''Sphenoceramus'' (''Inoceramus'') ''lingua'' (Mitchell, 1995).



	'''Age''': Santonian		'''Age''': Santonian

	[[category:Standard zonation \| 020]]		[[category:Standard zonation \| 020]]

Dbk at 12:54, 26 September 2013

2013-09-26T12:54:19Z

← Older revision		Revision as of 13:54, 26 September 2013
Line 91:		Line 91:
	'''Age''': Santonian		'''Age''': Santonian

	[[category:Standard ~~zonaton~~ \| 020]]		[[category:Standard zonation \| 020]]

Dbk: Created page with " '''Base''': In southern England, the base of the zone is marked by an un-named marl just above the Hawks Brow Flint (Young & Lake, 1988), and it is placed immediately below ..."

2013-09-26T12:54:04Z

Created page with " '''Base''': In southern England, the base of the zone is marked by an un-named marl just above the Hawks Brow Flint (Young & Lake, 1988), and it is placed immediately below ..."

New page

'''Base''': In southern England, the base of the zone is marked by an un-named marl just above the Hawks Brow Flint (Young & Lake, 1988), and it is placed immediately below the first record of the index species in northern England, c. 0.7 m below the lower of the two Maidlands Upper Marls (Mitchell, 1994). In East Anglia, faunal records of the index are rather sparse (Woods, WH/94/90R; Jukes-Browne & Hill, 1904; Pattison ''et al''., 1993; Peake & Hancock, 1970), making precise definition problematic; it was grouped with the underlying ''U. socialis'' Zone in the BGS Trunch Borehole [TG 2933 3455] (Wood & Morter, 1994). In Northern Ireland, the base of the zone is coincident with the base of the Cloghastucan Chalk (Wilson & Manning, 1978).

'''Top''': In southern England, the top of the zone is placed at Friar's Bay Marl 1, and in northern England, a little above marl SY 17 of Whitham (1993). In the BGS Trunch Borehole [TG 2933 3455], the top of the zone is defined by the base of a coarse, shell-rich chalk facies - the so-called 'grobkreide' facies of german successions (Wood & Morter, 1994). However, in northern England, similar coarse-grained chalk occurs within the ''M. testudinarius'' Zone (Mitchell, 1995). In Northern Ireland, the top of the zone is coincident with the top of the Cloghastucan Chalk (Wilson & Manning, 1978).

'''Range of index species''': The index ranges through the greater part of the nominate zone in southern and northern England (Young & Lake, 1988; Mitchell, 1994), but clear data for East Anglia is lacking. In Northern Ireland, the index ranges from the base of the zone to just below the Oweynamuck Flint, a short distance below the top of the zone (Wilson & Manning, 1978).

'''Key fauna''':

Brachiopoda: ''Cretirhynchia exsculpta''

'' Terebratulina rowei''

Bivalvia: ''Acutostrea incurva''

''Inoceramus'' (comminuted shell abundant in Northern Ireland)

''Platyceramus''

''Pseudoperna boucheroni''

''Pycnodonte vesiculare''

''Sphenoceramus ''(''Inoceramus'') ''lingua''*

Belemnoidea: ''Actinocamax versus''

Ammonoidea: ''Parapuzosia leptophylla''

Asteroidea: ''Crateraster rotundus''*

Crinoidea: ''Marsupites testudinarius''

Echinoidea: ''Conulus'' sp.

''Echinocorys elevata''

''Micraster rostrata''

(*:occur in the zone in northern England)

'''Faunal abundance & preservation''': In northern and southern England the zone is quite richly fossiliferous with a variety of fauna. However, in East Anglia, the sparsity of outcrops means that faunal records from this zone are rather limited. The index crinoid is typically preserved as dissociated calyx plates, but complete or semi-complete calices can occasionally be found. In Northern Ireland, the extreme hardness of the Chalk Group makes it difficult to collect fossils.

'''Bio-markers''': In southern England there is a trend in the size and ormentation of ''M.'' ''testudinarius'' calyx plates through the zone.They are small and unornamented below the Brighton Marl, becoming large and ornamented just above this marl, and then becoming less ornamented but remaining large in the interval up to the Kemp Town Marl; higher in the zone they decrease in size but remain ornamented (Mitchell, 1995). A less clear trend is discernible in northern England, where the calyx plates in the lower part of the zone are either smooth or weakly ornamented, and those in the upper part of the zone generally more strongly ornamented (Mitchell, 1995). On this basis, Mitchell (1995) suggested a tentative correlation of the Brighton Marl and Danes Dyke Lower Marls. Young & Lake (1988) recorded that oysters, particularly ''Pseudoperna boucheroni'', characterise the middle and higher parts of the zone in southern England, but they in fact range through the greater part of the zone and also occur in some adjacent zones. In northern England, ''Pseudoperna boucheroni'' has numerous acmes at and above the ''U. socialis'' Zone (Whitham, 1993). An acme of ''Echinocorys elevata'' characterises the lower to middle parts of the zone in both northern and southern England, and the latter region has ''Cretirhynchia exsculpta'' ranging through the middle and upper parts of the zone (Young & Lake, 1988; Whitham, 1993). Two important bio-markers in the upper part of the zone in northern England are the restricted occurrence of the asteroid ''Crateraster rotundus'' between marls SY11 and SY 20 of Whitham (1993), and the first appearance of the long-ranging ''Sphenoceramus'' (''Inoceramus'') ''lingua'' (Mitchell, 1995).

'''Age''': Santonian

[[category:Standard zonaton | 020]]