Category:Foraminiferal zonation: Difference between revisions
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==Overview== | |||
Foraminifera from the Chalk Group have been taxonomically described for many years and since the 1970’s biostratigraphical applications have also been discussed. It is becoming more evident that foraminiferal inceptions and extinctions can be tied in with lithostratigraphical markers (eg. marl seams, flint bands) and macrofaunal events (eg. sponge beds, ''Inoceramus''-rich beds), to provide a very detailed subdivision of the Chalk Group. Unfortunately, earlier biostratigraphical accounts often failed to record detailed stratigraphical and lithological information relating to sample positions within the succession, thus limiting their usefulness. | |||
The unpublished scheme used herein for the Chalk Group of the UK recognises a maximum of 27 foraminiferal zones, and has been compiled from a variety of published and unpublished sources (Bailey, 1978; Swiecicki, 1980; Bailey ''et al''., 1983, 1984; Hart ''et al''., 1989; Carter & Hart, 1977, Hart, 1982; Jarvis ''et al''., 1988; Mortimore, 1986). Data for offshore areas (King ''et al''., 1989) mostly relates to uncored hydrocarbon wells, and the biostratigraphical scheme for these is based on the extinction horizon (‘Last Appearance Datum’ or ‘First Downhole Occurrence’) of key taxa.; caving in these boreholes makes the first appearance uphole, or inception, an unreliable datum. | |||
In the following account | The zones, numbered 1 to 27 from oldest to youngest, are pre-fixed 'BGS' to differentiate them from previously published schemes, and where possible, they are related to the UKB zones of Hart ''et al''. (1989), macrofaunal zones and lithostratigraphical marker horizons. | ||
==Descriptions of foraminiferal biozones in the Chalk Group== | |||
In the following account the BGS foraminiferal zones of the Chalk Group are systematically described from oldest (BGS 1) to youngest (BGS 27). Alternatively, for information about a particular zone, select it from the summary table (summary correlation of foraminiferal and macrofaunal zones) | |||
[[category:Biostratigraphy of the Chalk Group | 009]] | [[category:Biostratigraphy of the Chalk Group | 009]] |
Revision as of 10:53, 1 October 2013
STAGE | STANDARD ZONE | STANDARD SUBZONE | BGS foraminiferal biozone | |||
Northern England | East Anglia | Northern England | ||||
DANIAN | ||||||
MAASTRICHTIAN | B. casimirovensis | 27 | ||||
B. junior | 26 | |||||
B. occidentalis | ||||||
25 | ||||||
B. lanceolata s.l. | 24 | |||||
CAMPANIAN | B. mucronata s.l. | 23 | ||||
22 | ||||||
21 | ||||||
G. quadrata | I. lingua | Gonioteuthis Zone | Post A. cretaceus | 20 | ||
A. cretaceus | ||||||
Hagenowia horizon | ||||||
O. pilula | Abundant O. pilula ? ? | ?D. binodosus | 19 | |||
E. depressula | ||||||
U. anglicus | 18 | |||||
SANTONIAN | M. testudinarius | |||||
U. socialis | ||||||
M. coranguinum | Upper H. rostrata | 17 | ||||
16 | ||||||
CONIACIAN | Lower H. rostrata | |||||
15 | ||||||
14 | ||||||
M. cortestudinarium | 13 | |||||
TURONIAN | S. plana | 12 | ||||
T. lata | 11 | |||||
10 | ||||||
Mytiloides spp. | ||||||
9 | ||||||
CENOMANIAN | N. juddii | S. gracile | 8 | |||
M. geslinianum | ||||||
7 | ||||||
C. guerangeri | H. trecensis | 6 | ||||
A. jukesbrownei | H. subglobosus | 5 | ||||
4 | ||||||
A. rhotomagense | T. acutus | |||||
T. costatus | ||||||
C. inerme | ||||||
M. dixoni | 3 | |||||
2 | ||||||
M. mantelli | M. saxbii | 1 | ||||
S. schluteri | ||||||
N. carcitanense |
Overview
Foraminifera from the Chalk Group have been taxonomically described for many years and since the 1970’s biostratigraphical applications have also been discussed. It is becoming more evident that foraminiferal inceptions and extinctions can be tied in with lithostratigraphical markers (eg. marl seams, flint bands) and macrofaunal events (eg. sponge beds, Inoceramus-rich beds), to provide a very detailed subdivision of the Chalk Group. Unfortunately, earlier biostratigraphical accounts often failed to record detailed stratigraphical and lithological information relating to sample positions within the succession, thus limiting their usefulness.
The unpublished scheme used herein for the Chalk Group of the UK recognises a maximum of 27 foraminiferal zones, and has been compiled from a variety of published and unpublished sources (Bailey, 1978; Swiecicki, 1980; Bailey et al., 1983, 1984; Hart et al., 1989; Carter & Hart, 1977, Hart, 1982; Jarvis et al., 1988; Mortimore, 1986). Data for offshore areas (King et al., 1989) mostly relates to uncored hydrocarbon wells, and the biostratigraphical scheme for these is based on the extinction horizon (‘Last Appearance Datum’ or ‘First Downhole Occurrence’) of key taxa.; caving in these boreholes makes the first appearance uphole, or inception, an unreliable datum.
The zones, numbered 1 to 27 from oldest to youngest, are pre-fixed 'BGS' to differentiate them from previously published schemes, and where possible, they are related to the UKB zones of Hart et al. (1989), macrofaunal zones and lithostratigraphical marker horizons.
Descriptions of foraminiferal biozones in the Chalk Group
In the following account the BGS foraminiferal zones of the Chalk Group are systematically described from oldest (BGS 1) to youngest (BGS 27). Alternatively, for information about a particular zone, select it from the summary table (summary correlation of foraminiferal and macrofaunal zones)
Subcategories
This category has only the following subcategory.
The number of included categories (C), pages (P) and files (F) is stated in brackets.
Pages in category "Foraminiferal zonation"
The following 27 pages are in this category, out of 27 total.
- BGS Zone 1 (=UKB1 and 2 of Hart et al., 1989)
- BGS Zone 2 (UKB3 of Hart et al., 1989)
- BGS Zone 3 (=UKB4 of Hart et al., 1989)
- BGS Zone 4 (=UKB 5 of Hart et al., 1989)
- BGS Zone 5 (=UKB6 of Hart et al., 1989)
- BGS Zone 6 (=modified UKB7 of Hart et al., 1989)
- BGS Zone 7 (=lower UKB 8 of Hart et al., 1989)
- BGS Zone 8 (=upper UKB8 and basal UKB9 of Hart et al., 1989)
- BGS Zone 9 (=modified UKB9 of Hart et al., 1989)
- BGS Zone 10 (=basal UKB10 of Hart et al., 1989)
- BGS Zone 11 (=lower and middle UKB10 of Hart et al., 1989)
- BGS Zone 12 (=upper UKB10 of Hart et al., 1989)
- BGS Zone 13 (=UKB11 of Hart et al., 1989)
- BGS Zone 14 (=lower and middle UKB12 of Hart et al., 1989)
- BGS Zone 15 (=upper UKB12 of Hart et al., 1989)
- BGS Zone 16 (=UKB13 of Hart et al., 1989)
- BGS Zone 17 (=lower and middle UKB14 of Hart et al., 1989)
- BGS Zone 18 (=uppermost UKB14 and lower UKB15 of Hart et al., 1989)
- BGS Zone 19 (=upper UKB15 of Hart et al., 1989)
- BGS Zone 20 (=UKB16 of Hart et al., 1989)
- BGS Zone 21 (=UKB17 and lower UKB 18 of Hart et al., 1989)
- BGS Zone 22 (=uppermost UKB18 of Hart et al., 1989)
- BGS Zone 23 (=UKB19 of Hart et al., 1989)
- BGS Zone 24 (=UKB20 of Hart et al., 1989)
- BGS Zone 25 (=UKB21 of Hart et al., 1989)
- BGS Zone 26(=UKB22 of Hart et al., 1989)
- BGS Zone 27