Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Age deductions for STEP-1 well
| Depth (m) | Age (Ma) | Microfossil | Bioevents |
|---|---|---|---|
| 1,926 | 5.0 | Foraminifera | FDO Cyclammina cf. minima |
| 1,963 | 5.8 | Nannofossils | Maximum flooding surface (MFS) |
| 1,987 | 5.8 | Foraminifera | Peak faunal abundance (MFS) |
| 2,097 | 6.3 | Nannofossils | Sequence boundary |
| 2,316 | 7.0 | Nannofossils | MFS |
Chronostratigraphic position of STEP-1 well
| Ma | Standard chronostratigraphy | |||
|---|---|---|---|---|
| Period | Epoch | Age/stage | This study | |
| 1 | Quaternary | Holocene | Taranian | |
| 2 | ||||
| Pleistocene | Ionian | |||
| 3 | ||||
| Calabrian | ||||
| 4 | Neogene | Pliocene | Gelasian | |
| 5 | Piacenzian | |||
| 6 | Zanclean | |||
| 7 | Miocene | Messinian | STEP-1 well | |
| 8 | ||||
| 9 | Tortonian | |||
| 10 | ||||
Calcareous nannofossils biostratigraphy of STEP-1 well
| Depth (m) | Downhole occurrence of calcareous nannofossils | Age (Ma) Haq et al. (1988) | NP zones (Martini, 1971) | Inferred relative ages |
|---|---|---|---|---|
| 1,841 | First sample analysed | Late Miocene to early Pliocene | ||
| 1,902 | Presence of Ceratolithus cristatus | NN 12 | ||
| 1,914 | Presence of Ceratolithus cristatus | |||
| 1,926 | ||||
| 1,939 | FDO: Discoaster quinqueramus | 5.8 | ||
| 1,963 | Maximum flooding surface | |||
| 2,292 | FDO: Discoaster berggrenii | |||
| 2,316 | Maximum flooding surface, Presence: Discoaster quinqueramus | 7.0 | NN 11 | |
| 2,438 TD | ||||
Palynostratigraphy of STEP-1 well
| Depth (m) series | Sub-series | Gemeraad et al. (1968) | Evamy et al. (1978) | Bioevents | ||
|---|---|---|---|---|---|---|
| Zone | Sub-zone | |||||
| 1,829 | Miocene | Late Miocene | Echitricolporites Spinosus zone | P 800 | P 840 | Quantitative base occurrence of Cyperaceaepollis spp |
| 1,981 | ||||||
| 2,134 | ||||||
| 2,204 | P 830 | |||||
| 2,286 | ||||||
| 2,438 | ||||||
Foraminferal biostatigraphy of STEP-1 well
| Depth (m) | Age | Planktonic zone | Benthonic foram zone | Bioevents |
|---|---|---|---|---|
| 1,853 | Early Pliocene | N18 | Indeterminate | FDO Valvulina flexilis |
| 1,987 | Late Pliocene | N17 and older | Cyclamina cf. minina | Peak fauna abundance 5.8Ma MFS |
Harmonized biostratigraphic chart of STEP-1 well
| Depth (m) | Epoch | Age | P zone | B zone | N zone | Pa zone | Pa zone and sub-zone | Bioevents | |
|---|---|---|---|---|---|---|---|---|---|
| 1,900 | Early Pliocene | ZANCLEAN | N18 | Cyclamina minima | NN 12 | Echitricolporites Spinosus | P800 | P840 | FDO Valvulina flexilis |
| 1,950 | Presence of Ceratolithus cristatus | ||||||||
| 2,000 | Presence of Ceratolithus armatus | ||||||||
| 2,050 | FDO Cyclammina cf. minima (5.0Ma MFS) | ||||||||
| 2,100 | FDO Discoaster quinqueramus | ||||||||
| 2,150 | Late Miocene | MESSIAN | N 17 and older | NN 11 | P830 | 5.8 Ma MFS | |||
| 2,200 | Peak faunal abundance (5.8 Ma MFS) | ||||||||
| 2,250 | 6.3 Ma SB | ||||||||
| 2,300 | Quantitative base occurrence of Cyperaceaepollis spp | ||||||||
| 2,350 | Discoaster beggrenii | ||||||||
| 2,400 | 7.0 Ma MFS | ||||||||