biostratigraphy and paleoecology of cretaceous/tertiary boundary in ...
biostratigraphy and paleoecology of cretaceous/tertiary boundary in ...
biostratigraphy and paleoecology of cretaceous/tertiary boundary in ...
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Chapter Three Biostratigraphy<br />
<strong>and</strong> it is correlated with the middle part <strong>of</strong> Gansser<strong>in</strong>a gansseri Zone <strong>of</strong> (Al-<br />
Mutwali 1996), Hammoudi 2000 <strong>and</strong> Al-Mutwali <strong>and</strong> Al-Jubouri 2005), Iraq.<br />
(Chacon <strong>and</strong> Mart<strong>in</strong>-Chivelet 2005) Spa<strong>in</strong> <strong>and</strong> other different localities <strong>of</strong> the<br />
world (Robaszynski et al.,1984) <strong>and</strong> (Caron, 1985) general, (Maestas et al<br />
2003), USA. (Obaidalla 2005), Egypt. (Figs. 4.12 - 4. 13).<br />
Magnetochron records <strong>of</strong> this biozone by (Li <strong>and</strong> Keller 1998a show that the<br />
age estimation <strong>of</strong> the time span from (69.56 Ma) to (69.06Ma) 500 Ky/25meters<br />
estimat<strong>in</strong>g absolute ages based on magnetochron ages with 20 Ky/meter<br />
which <strong>in</strong>dicate higher rate <strong>of</strong> deposition than (CF7) (Fig. 5.11)<br />
Age: Late early Maastrichtian.<br />
3.2.1.4- Pseudotextularia <strong>in</strong>termedia Interval Zone (CF5)<br />
The Pseudotextularia <strong>in</strong>termedia Zone (CF5) is def<strong>in</strong>ed by the LAD <strong>of</strong> the<br />
Globotruncana l<strong>in</strong>neiana (d Orbigny) at the base <strong>and</strong> the FAD <strong>of</strong><br />
Racemiguembel<strong>in</strong>a fructicosa (Egger) at the top (plate 2, Fig 9). Nederbragt<br />
(1990), orig<strong>in</strong>ally <strong>in</strong>troduced this Biozone as the <strong>in</strong>terval from the FAD <strong>of</strong><br />
Planoglobul<strong>in</strong>a acervul<strong>in</strong>oides at the base <strong>and</strong> the FAD Racemiguembel<strong>in</strong>a<br />
fructicosa at the top. In the present study, the def<strong>in</strong>ition is constra<strong>in</strong>ed accord<strong>in</strong>g<br />
to Li <strong>and</strong> Keller (1998 a <strong>and</strong> b).The <strong>in</strong>terval <strong>of</strong> this Zone is 19 meters thick <strong>in</strong> Gali<br />
section.<br />
The recorded planktonic foram<strong>in</strong>iferal assemblages <strong>in</strong> this biozone<br />
represented by well diversified forms <strong>of</strong> Heterohelix navarroensis Loeblish, H.<br />
globulosa (Ehrenberg), H. striata (Ehrenberg), H. punctulats (Cushman), H.<br />
nauttalli (Voorwijk), H. reussi (Cyshman), H. pulchra (Brotzen), Planoglobul<strong>in</strong>a<br />
carseyae (Plummer), P. brazoensis Mart<strong>in</strong>, P. acervul<strong>in</strong>oides (Egger),<br />
Rugoglobiger<strong>in</strong>a rugosa (Plummer), R. scotti (Bronnimann), R.<br />
hexacamerata Bronnimann , R. macrocephala Bronnimann, R. milamensis<br />
Smith & Pessango, Gansser<strong>in</strong>a gansseri (Reuss), G. wiedenmayeri<br />
(G<strong>and</strong>olfi), Globotruncanita stuarti (de Lapparent), G. stuartiformis Dalbez,<br />
G. conica White, G. pettersi G<strong>and</strong>olfi, G. angulata Tilev, Globotruncana<br />
aegyptiaca Nakkady, Glt.orientalis El-Naggar, Glt. falsostuarti Sigal, Glt.<br />
dupeublie Caron et al., Glt. lapparenti Boli, Glt. arca (Cushman), Glt. rosetta<br />
Carsey, Contusotruncana contusa (Cushman), C. plicata White, C.<br />
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