Biostratigraphy

A multibiostratigraphic framework has been applied for Upper Albian-Turonian deposits, based on ammonites and calcareous nannofossils, benthic and planktic foraminifers and ostracodes. The most indicative genera and species are listed in Figure 2. Furthermore, local ranges of these taxa are illustrated and briefly described.

6.1 Ammonites

Ammonites have been determined by Z. Lewy, Geological Survey, Yerusalem/Israel.

Several ammonite bearing horizons occur within the Cenomanian to Turonian succession of the study area and among them, three ‘marker horizons’ (m1-m3, Fig.

2). Schulze et al. (2003) compare local ranges of newly sampled specimens with occurrences of adjacent areas (Israel, Egypt). Former descriptions of Mid-Cretaceous ammonites of Jordan include Taubenhaus (1920: Cenomanian-Turonian ammonites of Jordan), Nazzal & Mustafa (1993: Cenomanian ammonite assemblages from northern Jordan), and Wetzel & Morton (1959: Turonian ammonites). We follow the ammonite zonation scheme of southern Europe (Hardenbol et al., 1998) and the scheme of Israel (Freund & Raab, 1969; Lewy & Raab, 1976; Lewy, 1989; Lewy, 1990) for upper Cenomanian to middle Turonian times (Fig. 2). The distribution of the newly specified ammonites within the Cenomanian-Turonian succession is described in stratigraphic order and their local ranges are exemplarily illustrated (Figs. 6, 8, 9, 13, 16).

Specimens of Mrhiliceras lapparenti occur within the marly member c of the Naur Formation, in a section of the northern study area (RM2, Figs. 1, 13) and near Wadi Al Karak (section WK1; Figs. 1, 16). The species indicates a lower Cenomanian age (Lewy, 1990), correlative to the mantelli (and ?basal dixoni) Zone of Hardenbol et al.

(1998).

Abundant occurrences of Neolobites vibrayeanus are observed within limestones of the Fuheis and Hummar Formation in all parts of the study area (e.g. sections RM3, Fig. 1 and sections MA3, SI1+2; Figs. 1, 6, 9). N. vibrayeanus locally occurs together

with Proeucalycoceras haugi, Pseudocalycoceras harpax (section RM3, Fig. 1), or with Turrilites acutus (section TB1, Fig. 1) and these associations indicate a middle middle to (lower) upper Cenomanian age. Thus, the total range of N. vibrayeanus correlates with the rhotomagense Zone up to the lower guerangeri Zone of Hardenbol et al. (1998). An association with N. vibrayeanus and larger alveolinid foraminifers (Praealveolina cretacea, P. tenuis) is used as an indicator for late Cenomanian age (Fig. 2).

Vascoceras cauvini occurs in several sections (e.g. RM3, MA3, SI1+2) within marls, claystones or limestones of the lower Shueib Formation. Some sections from the central and southern study area (MA3, AF; Fig. 1) yield V. cauvini associated with Metoicoceras geslinianum and Burroceras transitorium. This assemblage overlies the youngest occurrence of N. vibrayeanus (mentioned above) and indicates an uppermost Cenomanian age, correlating with the geslinianum and judii zones (T1), and indicates the ‘marker bed 1’ (m1, Fig. 2). Vascoceras cauvini ranges into overlying marls or shales of the Shueib Formation (e.g. section SI1+2, Fig. 9). These exclusive occurrences of that species indicate a lower Turonian age and belong to the lower coloradoense Zone (T2, Fig. 2). Juvenile specimens of Choffaticeras pavillieri and Ch. quaasi occur within thin, platy limestones, the ‘marker bed 2’ (m2, Fig. 2) within the lower/middle Shueib Formation in several sections of the entire study area (e.g. RM4, GM2, TB, AF; Fig. 1). These occurrences correlate to those of young ontogenetic stages of Choffaticeras sp. in southern Israel (T3 Zone, Freund &

Raab, 1969). Thus, m2 coincides with the middle coloradoense Zone and indicates a lower Turonian age (Fig. 2).

Fragments of Choffaticeras securiforme were found, not in situ, but above ‘marker bed 2’ (sections TB, Fig.1). This species indicates the T4 zone in Israel (Freund &

Raab, 1969), which belongs to the upper coloradoense Zone and may therefore exhibit a lower Turonian age (Fig. 2).

An ammonite association which may contain Vascoceras durandi, Thomasites rollandi, Fagesia lenticularis, Choffaticeras quaasi and Ch. luciae, occurs within claystones and limestones of the middle and upper Shueib Formation, respectively in the entire study area (e.g. sections BH, WM, WK2, SI1+2, P; Figs. 1, 9). This ammonite bearing limestone has been defined as ‘marker bed 3’ (m3) and coincides with the Wala Limestone Member (Powell, 1989b; Fig. 2). The above mentioned assemblage correlates with the T5-6a zone ammonite association of Israel (Lewy &

Raab, 1976). In southern Israel the youngest occurrences of Ch. luciae are observed in the lower middle Turonian (Lewy, 1989). Therefore, the appearance of this species without lower Turonian ammonites such as in section RM3 (Fig. 1) defines the basal middle Turonian (beginning of woollgari Zone, T6b; Fig. 2).

Broinsonia enormis

Calcicalathina alta Calculites obscurus Broinsonia signata Broinsonia matalosa Axopodorhabdus albianus

Biozones Stage

ALBIAN CENOMANIAN TURONIAN

Substage

Upper Lower Middle Upper Lower M.

CC 9 CC 10 CC 11

Chiastocygus litterarius Chiastozygus plathyrhetus Corollithion signum Corollithion kennedyi Cretarhabdus crenulatus

Cyclagelosphaera margerelii Eiffellithus turriseiffelii Eprolithus floralis

Microrhabdulus decoratus

Tetralithus cassianus Stoverius achylosus Gartnerago theta Gartnerago nanum

Stradneria crenulata Cribrospaerella ehrenbergii Crucicribrum anglicum

Gartnerago segmentatum Gartnerago obliquum

Prediscosphaera spinosa

Tetrapodorhabdus decorus Lithraphidites acutus

Watznaueria britannica Zeugrhabdotus embergeri Prediscosphaera columnata Manivitella pemmatoidae

Radiolithus planus Retecapsa ficula Rhagodiscus angustus

Tranolithus phacelosus Tranolithus orionatus Lithraphidites carniolensis

Watznaueria barnesae Watznaueria biporta

Zeugrhabdotus diplogrammus Zeugrhabdotus erectus Zeugrhabdotus scutula Quadrum gartneri

Fig. 3: Calcareous nannofossils (this study) are listed in alphabetical order, their ranges within the biozones CC9-CC11 are illustrated

6.2 Calcareous nannofossils

Calcareous nannofossils have been studied and determined by A. M. Marzouk, Cairo/Egypt. They are important for the biostratigraphic subdivision of the investigated sections, and abundantly occur within most argillaceous units of the Upper Albian-Turonian succession in west central Jordan. The preservation is predominantly moderate and the highest diversities are mainly observed within upper Cenomanian-lowermost Turonian deposits (Hummar and Shueib Formation). 28 genera comprising 44 species are identified after Sissingh (1977) and Perch-Nielsen (1985), including the index forms of biozones CC 9, CC 10 and CC 11 (Fig. 3).

Microphotographs of biostratigraphically indicative taxa and other abundant species are shown in Figure 4. This study mainly follows the biozonation of Sissingh (1977) and Perch-Nielsen (1985), compared to the biochronozones of the Tethyan realm according to van Salis in Hardenbol et al. (1998). Local ranges of the identified nannofossils are exemplarily illustrated by six sections from the northern (SH, Fig. 5), central (MA2+3, MD1, GM2; Figs. 6-8), and southern part (SI1+2, WB; Figs. 9, 10) of the study area.

CC 9 Zone: The first occurrence (FO) of Eiffellithus turriseiffelii marks the basis and the FO of Microrhabdulus decoratus defines the top of biozone CC 9. These taxa are observed in sections SH, MA2, MA3, MD1, GM2, SI1+2 and WB (Fig. 1). The stratigraphic range of CC 9 spans the upper Albian to middle Cenomanian and that corresponds with the Naur Formation to the middle/upper Fuheis Formation.

Preservation, abundance and diversity of calcareous nannofossils fluctuate remarkably within sediments of the CC 9 Zone without a spatial trend and apparently disconnected from the lithology. Some sections show a moderate preservation of calcareous nannofossils, while the frequency is common to abundant and the diversity is high (sections SH, MD1, SI1+2; Figs. 5, 7, 9). Other sections (MA2+3, GM2, WB; Figs. 6, 8, 10) contain in contrast a poorly preserved, low abundance and low diversity flora. However, assemblages of the CC 9 Zone are generally dominated by Watznaueria barnesae, (W. biporta) and Zeugrhabdotus erectus but Cyclage- losphaera margerelii, Eprolithus floralis, Calcicalathina alta, Eiffellithus turriseiffelii, Broinsonia enormis, Praediscosphaera spinosa, and Radiolithus planus (Figs. 5, 7, 8, 10) also abundantly occur within the investigated early Cenomanian assemblages.

c

a b d

f g h i

j k l m n

e

Fig. 4: Photomicrographs of selected calcareous nannofossils of the samples SH, MA3, MD3, GM1, AF, and SI3 (see Fig. 1). Magnification is x 3300. a: Watznaueria barnesae-sample MA3.25; b: Cribrosphaerella ehrenbergii-barnesae-sample AF1.18; c: Eiffellithus turriseiffelii-sample SI3.17; d: Radiolithus planus- turriseiffelii-sample MD3.6; e: Microrhabdulus decoratus- turriseiffelii-sample SH1.19; f: Tranolithus phacelosus- sample GM1.27: g: Zeughrabdotus embergeri- sample MA3.25; h: Manivitella pemmatoidea- sample GM1.17; i: Tetralithus cassianus- sample SH1.27; j: Quadrum gartneri- sample MA3.32; k: Eprolithus floralis- sample MD3.5; l:

Lithraphidites carniolensis- sample GM1.19; m: Zeughrabdotus erectus- sample GM1.8; n:

Prediscosphaera columnata- sample GM1.8.

Figs. 5-10 (next pages): Distribution charts of calcareous nannofossils of six original sections (SH, MA2+3, MD1, GM2, SI1+2, WB). On the left side, stratigraphy and biozones are indicated, additionally to an original section, including lithologies, sedimentary patterns and fossil occurrences. A total abundance (rare, few, common, abundant) and the level of preservation (poor, moderate, good) for each sample are illustrated, while in the right column the occurrence and abundance of each identified species is indicated. Ammonite occurrences are exemplarily illustrated on the right hand side, including marker beds (m1-m3), as well as nannofossil intervals of high-fertility indicators (intervals with Zeughrabdotus spp. and E. floralis but without R. angustus; I1-I4). For explanation of signatures in Figs. 2, 5-10, 13-17 and 18, see legend in Fig. 6.

CENOMANIAN FuheisHLShueibWadi As SirTURONIAN Broinsonia enormis Calcicalathina alta Chiastocygus litterarius Cyclagelosphaera margerelii Eiffellithus turriseiffelii Eprolithus floralis Microrhabdulus decoratus Tetralithus cassianus

Broinsonia signata Stoverius achylosus

Axopodorhabdus albianus Prediscosphaera spinosa Tetrapodorhabdus decorus

Manivitella pemmatoidae Radiolithus planus Retecapsa ficula Rhagodiscus angustus Tranolithus orionatus

Lithraphidites carniolensis Watznaueria barnesae Watznaueria biporta Zeugrhabdotus erectus

Quadrum gartneri

Biozones

SH

Stage 2m Sample Abundance/ Preservation

Formation CC 9CC 10CC 11

Oy Oy

B B B B B

B

B

CENOMANIAN FuheisSHHFuheis

NL

NL

ShueibTURONIAN CC 9CC 9CC 10CC 10CC 11 Broinsonia enormis Calcicalathina alta Calculites obscurus Chiastocygus litterarius Chiastocygus plathyrhetus Corollithion signum Cretarhabdus crenulatus Cyclagelosphaera margerelii Eiffellithus turriseiffelii Eprolithus floralis Gartnerago segmentatum Microrhabdulus decoratus Tetralithus cassianus Tetrapodorhabdus decorus Tranolithus phacelosus

Broinsonia signata Stoverius achylosus

Prediscosphaera spinosaPrediscosphaera columnata

Manivitella pemmatoidae Radiolithus planus Retecapsa ficula Rhagodiscus angustus

Lithraphidites carniolensis Watznaueria barnesae Watznaueria biporta Zeugrhabdotus erectus

Zeugrhabdotus diplogrammus Zeugrhabdotus embergeri

Quadrum gartneri Ammonites

Zeugrhabdotus scutula Neolobites vibrayeanus Metoicoceras geslinianum Burroceras transitorium Vascoceras cauvini Choffaticeras sp. (not in situ)

Biozones

MA 2+ 3

Stage Sample Abundance/ Preservation

Formation (composite)

Oy Oy

?

?

2m

Oy Oy Oy

Legend

siltstone/ sandstone

claystone and gypsum claystone shale clayey marl

oysters bivalves echinoids

bioturbation bituminous

gastropods

B bit.

thin lamination reworked clasts Lithologies

Sedimentary patterns Fossils

Abbreviations

Wala Limestone Member Karak Limestone Member Wadi Juheira Member 'hardground' with

vertical burrows marl

marly limestone limy marls

not exposed/

not investigated

rudist 'patch reefs' planktic foraminifers orbitolinid foraminifers alveolinid

foraminifers ammonite-bearing horizons nodular limestone

limestone dolomite/

dolomitic limestone

Oy

WJ KL WL

moderate preservation good preservation poor preservation Preservation and Frequency (Calcareous nannofosils)

abundant common few rare

High-Fertility Interval Ammonite Marker Horizon

I 1

m1 (m3)

m1

Fig. 6

CC 10 Zone: The FO of Microrhabdulus decoratus and the FO of Quadrum gartneri define the basis and the top of biozone CC 10, respectively. CC 10 is evidenced in sections SH, MA2, MA3, MD1, GM2, SI1+2 and WB (Fig. 1) and covers a stratigraphic range from the middle to the upper Cenomanian. Therefore, the middle to upper Fuheis Formation to the middle Shueib Formation are included. The CC 10 Zone can be locally divided into two subzones, CC 10a and CC 10b, based on the first and last occurrence of Lithraphidites acutus, confining the CC 10a subzone (after Burnett, 1996; sections: GM2, WB; Figs. 8, 10). The preservation quality of calcareous nannofossils of the CC 10 Zone is generally moderate. Abundance and diversity are mainly high. The assemblages of the CC 10 Zone are characterised by the same species, which predominate the CC 9 Zone (mentioned above). In sections from the central and southern study area (MD1, GM2, SI1+2, WB; Figs. 7-10) Lithraphidites spp. also frequently occurs, while the indicative species for the CC 10 Zone, Microrhabdulus decoratus, occurs only rare to few in all sections.

CC 11 Zone: Biozone CC 11 is defined by the first occurrence of Quadrum gartneri (basis) and the FO of Lucianorhabdus maleformis (top). CC 11 occurs in sections SH, MA2, MA3, MD1, GM2 and SI1+2 (Fig. 1) and indicate a stratigraphic range of a lower to middle Turonian age while the base of the CC 11 Zone coincides with the Cenomanian-Turonian boundary (Robaszynski et al., 1990; von Salis in Hardenbol et al., 1998). The upper Shueib Formation and the Wadi As Sir Formation are included. The preservation of Turonian assemblages is moderate in most samples, while abundance and diversity of the assemblages strongly differ within the study area. High abundances and high diversities of the flora are just locally observed (section MA3; Fig. 6). Additionally to the dominant species, which were referred for the CC 9 Zone and the CC 10 Zone, Calculites obscurus and Stoverius achylosus frequently occur.

Bauer et al. (2001) assume a different position of the CT-boundary. Based on co-occurrences of Q. gartneri and Cenomanian ostracodes (C. algeriana, P. ziregensis, V. maghrebensis), the authors suggest that the CC11 Zone straddles the CT-boundary. Therefore, Bauer et al. (2001) follow the scheme of Burnett (1996), which defines the biozone boundary between CC10 and CC11 within the upper Cenomanian.

Dissolution/Preservation: We assume that dissolution has strongly affected preservation and composition of the investigated nannofossil assemblages in several

CE N O M A NIA N F uhe is HL

Sh u ei b TU RO N. CC 9 CC 1 0 CC 1 1

Broinsonia enormis Calcicalathina alta Chiastocygus litterarius Crucucribrum anglicum Cyclagelosphaera margerelii Eiffelithus turriseiffelii Eprolithus floralis Gartnerago segmentatum Microrhabdulus decoratus Tetralithus cassianus

Broinsonia signata

Axopodorhabdus albianus Prediscosphaera spinosa

Manivitella pemmatoidae Radiolithus planus Retecapsa ficula Rhagodiscus angustus Tranolithus orionatus

Lithraphidites carniolensis Watznaueria barnesae Watznaueria biporta Watznaueria britannica Zeugrhabdotus erectus

Quadrum gartneri High fertility interval

B ioz on

es MD1

St a ge

Sample Abundance/ Preservation

Fo rm a tio n

B B B B

Oy Oy

Oy

Oy Oy

Oy

Oy

Oy

2m

Figure 7

Oy

I 3

I 1 I 2

units of the succession. If a time control by e.g. ammonites exists, while stratigraphically indicative nannofossils are absent, diagenetic dissolution can be assumed, although ecological restrictions also have to be considered. For example, we excluded an ecological influence on nannofossil content in section MA3 (Fig. 6).

Here, occurrences of N. vibrayeanus indicate a middle to upper Cenomanian age, but the associated poorly preserved nannofossil assemblage contains neither the index fossil for the CC9 Zone, nor for the CC10 Zone. Moreover, species that are termed as dissolution resistant forms, like Calcicalathina alta, Eprolithus floralis and Watznaueria barnesae (Thierstein, 1980; Roth & Krumbach, 1986; Erba et al., 1992) are relatively enriched within the mentioned interval (CC9, Fuheis Formation; Fig. 6).

Such an enrichment of dissolution resistant taxa is a second argument to take

Watznaueria barnesae, reflects a strong preservation bias of the assemblage which may hinder paleoenvironmental reconstructions (Roth & Krumbach, 1986). In fact, specimens of Watznaueria spp. predominate in many sections the assemblages of different time intervals, but they co-occur with other (?dissolution resistant) forms, like Calcicalathina alta, Cyclagelosphaera margerelii, Eiffellithus turriseiffelii, Eprolithus floralis and Radiolithus planus (e.g. sections MA2+3/CC9; MD1/CC11; WB/CC9;

Figs. 6, 7, 10). On the other hand, occurrences of dissolution susceptible forms (e.g.

Zeugrhabdotus spp.; Roth & Krumbach, 1986; Erba et al., 1992) should reflect a moderate or low impact of dissolution, but specimens of Z. erectus and Z. scutula (partly also Z. diplogrammus) often co-occur in our samples with the solution resistant forms, mentioned above (e.g. section SH/CC9 and CC10, GM2/CC9, WB/CC9; Figs. 5, 8, 10).

Bauer et al. (2001) studied age equivalent deposits of Sinai/Egypt and described a similar but lower diversity flora of Cenomanian to Turonian age. They assume a strong impact of dissolution and report a local enrichment of e.g. Broinsonia enormis and Calcicalathina alta within deposits of the CC10 Zone, and of e.g. Corrolithium signum, Eprolithus floralis, and Radiolithus planus within the CC11 Zone, respectively. Moreover, an ‘overlap’ of resistant and susceptible forms is described in some sections, too. A correlation between lithology and preservation of middle Cretaceous nannofossil assemblages has been assumed by Roth & Krumbach (1986). They report a positive correlation between the organic carbon content and the preservation of nannofossil assemblages, related to dissolution of carbonate by carbon dioxide that emerges during disintegration of the organic matter bearing sediments. However, such a relationship between lithology and preservation has not been observed within the present study. In contrast, bituminous dark marls or clays partly contain a well preserved and highly diverse flora (MD1/CC9, GM2/CC10, SI1+2/CT-boundary interval; Figs. 7, 8, 9).

Water depth: After Roth & Krumbach (1986), Thierstein (1980) and Hattner et al.

(1980) Broinsonia spp. and Gartnerago spp. indicate neritic environments. The prevailing shallow subtidal to intertidal environments on the upper Albian to middle Cenomanian platforms are documented by occurrences of Broinsonia enormis within

CE N O M A NIA N

Fuheis

NL

HLShueib

TU RO NI A N

CC 9CC 10CC 11 Broinsonia enormis Calcicalathina alta Chiastocygus litterarius Corollithion signum Cyclagelosphaera margerelii Eiffellithus turriseiffelii Eprolithus floralis Gartnerago nanum Gartnerago obliquum Gartnerago segmentatum Gartnerago theta Microrhabdulus decoratus Tetralithus cassianus

Broinsonia signata Stoverius achylosus Stradneria crenulata

Prediscosphaera spinosa

Manivitella pemmatoidae Radiolithus planus Rhagodiscus angustus

Lithraphidites acutus Lithraphidites carniolensis Watznaueria barnesae Zeugrhabdotus erectusZeugrhabdotus diplogrammus

Quadrum gartneri Zeugrhabdotus scutula

Biozones

GM2

St a ge

Sample Abundance/ Preservation

Formation

Oy Oy

Oy Oy

Oy bit.

Oy Oy Oy Oy

bit.

2m High fertility interval Ammonites

I 3 I 4

I 1 I 2

Choffaticeras sp. (Juvenile) Choffaticeras sp. (not in situ)

m2

(m3)

CE NOM A NI A N

FNLHLShueib

T URONI AN CC 9 CC 10 CC 1 1

Broinsonia enormis Calcicalathina alta Chiastozygus platyrhetus Corrolithion signum Cretarhabdus crenulatus Cyclagelosphaera margerelii Eiffellithus turriseiffelii Eprolithus floralis Gartnerago nanum Gartnerago obliquum Microrhabdulus decoratus Tetralithus cassianus Tetrapodorhabdus decorus

Prediscosphaera columnata

Manivitella pemmatoidae Radiolithus planus Rhagodiscus angustus Tranolithus phacelosus

Lithraphidites carniolensis Watznaueria barnesae Watznaueria biporta Zeugrhabdotus errectus Zeugrhabdotus scutula

Zeugrhabdotus diplogrammus

Quadrum gartneri

B iozones SI 1+ 2

S tage

Sample Abundance/ Preservation

Fo rma tio n

Oy Oy

?

Fig. 9

Ammonites

Neolobites vibrayeanus Vascoceras cauvini Choffaticeras quaasi Choffaticeras luciae

Fagesia lenticularisThomasites rollandi

m3

m1

the CC9 Zone and the CC10 Zone of several sections (e.g. SH, MD1, SI1+2). On the other hand Gartnerago spp. generally occurs rare.

Temperature/Fertility: Some species have been used as indicators for the temperature and the fertility of the surface water. Thierstein et al. (1980) and Premoli Silva et al. (1999) assume Eprolithus floralis and Zeugrhabdotus spp. to indicate cold water. Moreover, these cold water forms reflect eutrophic conditions (e.g. Roth &

Krumbach, 1986; Premoli Silva et al., 1999). In contrast, Rhagodiscus spp. indicates warm water conditions and an oligotrophic environment (Mutterlose, 1989).

Zeugrhabdotus spp. is mainly discussed as a high productivity form which is enriched during upwelling intervals (Roth & Krumbach, 1986). Therefore, the distribution of

‘eutrophic’ Eprolithus floralis, Zeugrhabdotus spp. and ‘oligotrophic’ Rhagodiscus

within the investigated sections, without exhibiting a constantly increasing or decreasing trend. Nevertheless, observed frequent Zeugrhabdotus spp. and Eprolithus floralis, and simultaneously occurring rare to few Rhagodiscus spp. in central sections, may indicate cooler water and high surface water fertility intervals (MD1/I1-I3, GM2/I1-I4; Figs. 7, 8). These distribution patterns seem to coincide with high amounts of organic carbon (I1, I2, I4; Figs. 7, 8) or with a deepening, reflected by the deposition of deeper subtidal marly deposits over shallow subtidal to intertidal limestones (I3, Figs. 7, 8). Neither north, nor south of the central sections, have comparable ‘high-fertility intervals’ been observed. Premoli Silva et al. (1999) interpret similar distribution patterns of the nannoflora within the CT-boundary interval in north and south Italy, as the onset of nutrification and the establishment of eutrophic conditions related to the oceanic anoxic event 2 (OAE2).

C E NO M A NI A N

FuheisShueibHNaur

TU R .

CC 9CC 10 Broinsonia enormisAxopodorhabdus albianus Calcicalathina alta Calculites obscurus Cyclagelosphaera margerelii Eiffellithus turriseiffelii Eprolithus floralis Gartnerago nanum Microrhabdulus decoratus Prediscosphaera spinosa Radiolithus planus Rhagodiscus angustus Stoverius achylosus Stradneria crenulata Tetralitus cassianus Tetrapodorhabdus decorus Watznaueria barnesae Zeugrhabdotus erectus Zeugrhabdotus scutula

Lithraphidites carniolensisLithraphidites acutus

Biozones

WB

St a ge

Sample Abundance/ Preservation

Formation

Oy Oy

Oy Oy

B B

?

?

Figure 10

2m

The upper Cenomanian intervals of the central sections (mentioned above) probably fit into that model. The ‘high-fertility interval’ of middle Cenomanian age (section MD1, I1; Fig. 7) may confirm the assumption of a distinct deepening before the main OAE (compare Schulze et al., 2003).

6.3 Benthic foraminifers

Benthic foraminifers have been studied in thin sections, classified after Hamaoui &

Saint-Marc (1970), Saint-Marc (1974) and Schroeder & Neumann (1985). Washed-out specimens of marly or clayey intervals have additionally been investigated and identified after Koch (1968), Basha (1979), Abdel-Kireem (1988), Weidich & Al-Harithi (1990) and Al-Rifay et al. (1993).

Stratigraphic applications follow the schemes of Saint-Marc (1974), Schroeder &

Neumann (1985), and Calonge et al. (2002), larger benthic foraminifers have been used to subdivide late Albian to late Cenomanian deposits. Occurrences of Orbitolina texana (Fig. 11a) and O. sefini (Fig. 11b) in northern sections (WS, Fig. 1) indicate an upper Albian to lower Cenomanian age. O. conica and O. corbarica (Fig. 11e) are characteristically associated with Ovalveolina crassa (Fig. 11g) in lower Cenomanian deposits of northern and central sections (WS, RM2, MA1; Figs. 1, 13). O. crassa is assigned to the lower-middle Cenomanian by Schroeder & Neumann (1985) but it is confined to the lower Cenomanian within the present study.

The ranges of Praealveolina cretacea (Fig. 11c) and Chrysalidina gradata (Fig. 11f) span the entire Cenomanian in contrast to a middle-upper Cenomanian range that is described by Schroeder & Neumann (1985). P. tenuis (Fig. 11d; sections WM, WB;

Fig. 1) and Broeckina balcanica (Fig. 11h; sections RM2, SI1+2; Figs. 13, 17) are indicative of middle to upper Cenomanian deposits, whereas an association of P.

cretacea and P. tenuis indicate an upper Cenomanian age (Hummar Formation, sections WH, WM, AF; Fig. 1).Moreover, five benthic foraminifer assemblages (BFA, Figs. 13-17) were defined and used as environmental indicators. The particular assemblages are defined either by the most frequently associated species or by those that are indicative of certain facies conditions. Some species may occur in different BFAs and although each BFA is mainly contained in one or two certain units of the upper Albian to Turonian succession, the assemblages are unusable for biostratigraphic determinations.

The benthic foraminifer assemblage one (BFA 1) is characterised by an association of larger agglutinated and calcareous foraminifers. Abundant taxa are e.g. Orbitolina spp., Buccicrenata hedbergi, Ovalveolina sp., Praealveolina spp., Pseudolituonella reicheli, Chrysalidina gradata, Biplanata peneropliformis, and Biconcava bentori, often associated with Cuneolina pavonia, Nezzazata conica and smaller miliolids.

Fig. 11: Photographs of biostratigraphically indicative benthic foraminifers; a: Orbitolina texana- sample WS3.3 (axial section, scale bar=250 µm), ?Aptian-middle Albian; b:

Orbitolina sefini- sample WS3.6 (axial section, scale bar=500 µm), upper Albian-lower Cenomanian; c: Praealveolina cretacea- sample WK1.16 (axial section, scale bar=500 µm), middle-upper Cenomanian; d: Praealveolina tenuis- sample WM2.7 (axial section, scale bar=500 µm), middle-upper Cenomanian; e: Orbitolina corbarica- sample WS3.10 (axial section, scale bar= 500 µm), upper Albian-lower Cenomanian; f: Chrysalidina gradata- sample WB1.8 (axial section, scale bar=500 µm), middle-upper Cenomanian; g: Ovalveolina crassa- sample WS3.6 (axial section, scale bar=500 µm), upper Albian-middle Cenomanian;

h: Broeckina balcanica- sample RM2.11 (oblique equatorial section, scale bar=25 µm),

Amphicytherura distincta Amphicytherura sexta

Stage CENOMANIAN TURONIAN

Formation Substage

L M U L M U

Naur Fuheis HL Shueib

Amphicytherura cf. yakhiniensis Bairdia sp.

Bythocypris sp.

Cytherella sp.

Cytherella aff. gambiensis Cytherella gigantosulcata Cytherella aegyptiensis

Cytherella gr. parallela Cytherella gr. C. ovata Cythereis algeriana Cythereis mdaouerensis Cythereis namousensis Dolocytheridea crassa Dolocytheridea atlasica Metacytheropteron berbericum Neocyprideis vandenboldi

Nigroloxoconcha naqaensis n. sp.

Ovocytheridea cf. reniformis Ovocytheridea crassa

Paracypris mdaouerensis Paracypris dubertreti Paracypris bremani

Parakrithe sp.

Parakrithe andreni Peloriops ziregensis Peloriops elassodictyota Perissocytheridea gr. sohni Phlytocythere citreum

Reticulocosta rawashensis Reticulocosta kanaanensis Spinoleberis israeliana

Veeniacythereis maghrebensis Veeniacythereis streblolophata

Veeniacythereis streblolophata schista Veeniacythereis jezzineensis

Fig. 12: The stratigraphical ranges of all identified ostracodes (this study, listed in alphabetical order) are illustrated.

BFA 1 predominantly occurs within bioclastic limestones. Moreover, specimens of Orbitolina spp. and Ovalveolina sp. have exclusively been found in the north and the northern central part of the study area (including Wadi Abu Kusheiba; Fig. 1).

High diversities and abundances characterise BFA 1 and indicate open shallow subtidal environments with ‘normal’ oxygen content and well-lit water. Associations that are dominated by larger, agglutinated forms (Orbitolina spp., Chrysalidina gradata, Pseudolituonella reicheli) additionally reflect higher water energy within these shallow subtidal environments.

BFA 2 predominantly consists of agglutinated species, e.g. Haplophragmoides rugosa, H. kirki, Ammobaculites impexus, A. turonicus, A. agglutinans, Hemicyclammina sigali, Flabellammina cf. alexanderi, Pterammina israelensis, Marssonella oxycona, M. trochus, Triplasia ?murchinsoni. Few calcareous forms may also occur (e.g. Gavelinella spp.). BFA 2 mostly occurs within marly intercalations of transgressive phases. Weidich & Al-Harithi (1990), interpreted comparable lower diversity assemblages with predominating agglutinated taxa as indicators for unfavourable life conditions in a stress environment, probably with hampered circulation and decreased oxygen content. These observations coincide with those of BFA 2 occurrences, yielding nearly monospecific Hemicyclammina sp. or associated Ammobaculites sp. and Haplophragmoides sp. (e.g. section MA2, Shueib Formation;

Fig. 14) and seem to reflect restricted environments. However, in other cases, a relatively diverse BFA 2 co-occurs with abundant and diverse benthic micro- and macrofossils (ostracodes, echinoids, bivalves; e.g. section MA2, lower Fuheis Formation; Fig. 14). Here, we interpret BFA 2 as an indicator for open, relative deeper water conditions and therefore for a different environment, compared to BFA 1 (decreased carbonate production, ?substrate containing enriched siliciclastics).

Indicative taxa of BFA 3 are calcareous forms like Lenticulina sp., Astacolus sp., Frondicularia sp., Vaginulina sp. and Dentalina spp.. Additionally, agglutinated foraminifers (e.g. Haplophragmoides spp., Sculptobaculites sp. and Reophax sp.) may be associated.

Figs. 13-17 (next pages): Local ranges of benthic foraminifers and ostracodes are illustrated. Five original sections (RM2, MA2, MA3, WK1, SI1+2) include stratigraphy, lithological and sedimentological informations, and fossil occurrences. The distribution of benthic foraminifer associations (BFA 1-5) and occurrences of ostracode assemblages (OA1, 2) are indicated. Ammonite occurrences are exemplarily marked on the right hand side. For explanation of signatures see legend in Fig. 6 and Fig. 13.

Bairdia sp.

Cytherella sp.

Parakrithe sp.

Cytherella aff. gambiensis Cytherella aegyptiensis Cytherella gigantosulcata Cytherella gr. parallela Cytherella gr. C. ovata Cythereis namousensis Dolocytheridea atlasica Dolocytheridea crassa Ovocytheridea crassa Paracypris mdaouerensis Paracypris dubertreti

Peloriops ziregensis Peloriops elassodictyota Perissocytheridea gr. sohni Reticulocosta rawashensis Spinoleberis israeliana Veeniacythereis maghrebensis Veeniacythereis streblolophata V. streblolophata schista Veeniacythereis jezzineensis Mrhiliceras lapparenti

CENOMANIAN Naur

Stage RM2

Formation

Sample Biconcava bentori Biplanata peneropliformis Broeckina balcanica Buccicrenata hedbergi Chrysalidina gradata Cuneolina pavonia Flabellammina sp.

Merlingina cretacea Nezzazata conica Nummoloculina regularis Orbitolina spp.

Ovalveolina crassa Praealveolina cretacea Pseudonummoloculina sp.

Pseudedomia drorimensis Pseudolituonella reicheli Pseudorhapidionina dubia Quinqueloculina sp.

Trochospira avnimelechi Valvulammina sp.

Pterammina israelensis Flabellammina cf. alexanderi Marssonella sp.

Triplasia sp.

Ammobaculites sp.

Haplophragmoides sp.

Dentalina sp.

Lenticulina sp.

Ostracodes

Ammonites OA 1

OA 1

BFA 2 BFA 1

BFA 1

Benthic foraminifers

Oy Oy Oy OyOy

WJ b c d _2m

Fig. 13foraminifer occurrences in thin sectionsBenthicForaminiferAssemblage

OstracodeAssociationforaminifer occurrences in washed residuesostracode occurrencesinwashedresidues BFA 3 BFA 1

Biconcava bentori Chrysalidina gradata Cuneolina pavonia Nezzazata spp. Orbitolina spp. Ovalveolina cassa Praealveolina sp. Pseudolituonella reicheli Quinqueloculina sp. Trochospira avnimelechi Valvulammina sp. Ammobaculites sp. Flabellammina sp. Haplophragmoides sp. Hemicyclamminasp. Marssonella sp. Pterammina sp. Triplasia sp. Bairdia sp. Cytherella sp. Cytherella aff. Gambiensis Metacytheropteron berbericumCytherella gr. Parallela Spinoleberis israeliana Veeniacythereis maghrebensis. Veeniacythereis jezzineensis

Sample Benthic foraminifers Ostracodes

Shueib Hummar

Naur bcdFuheisHL

CENOMANIAN

MA2 Wadi Abu Kusheiba

Stage Formation 2m OA 1

BFA 1BFA 2BFA 2BFA 2BFA 1 Oy

Oy Oy Oy

B B

BFA 3 mainly occurs in clayey intervals, often alternating withmarls, clays or limestones, yielding abundant planktic foraminifers (e.g. Figs. 13, 15). Epifaunal genera (Lenticulina sp.) and shallow infaunal forms of BFA 3 (e.g. Dentalina spp.)

reflect normal life conditions on the sediment surface and within the uppermost sediment layers (aerobe/intermediate assemblage, compare Coccioni et al., 1993).

Within the studied sections, BFA 3 characterises the initial stage of platform flooding and represents therefore, an assemblage of (beginning) platform crisis.

BFA 4 is characterised by low diversity small calcareous benthic foraminifers.

Specimens of Gabonita spp. and Neobulimina spp. (Kuhnt, oral communication, 2001) predominate but agglutinated taxa (e.g. Ammobaculites spp., Hemicyclammina sp.) are associated. BFA 4 exclusively occurs in clayey (bituminous) deposits (e.g.

Figs. 15, 17). The buliminid taxa mark deeper water environments and dysoxic conditions (Holbourn et al., 1999). Moreover, BFA 4 occurs coeval with calcareous nannofossils, indicating high fertility intervals. Therefore, a sea-level rise/sea-level

ShueibFuheisHLNL

Upper Cen.Lower TuronianMiddle Cenomanian

Wadi Abu Kusheiba

MA3

Substage Formation 2m Sample Ammobaculites sp. Flabellammina cf. alexanderi Haplophragmoides sp. Hemicyclammina sigali Marssonella sp.. Triplasia sp. Dentalina sp. Frondicularia sp. Gabonita obesa Neobulimina spp.

Benthic foraminifersBFA 2BFA 2BFA 3BFA 4 Amphicytherura distincta Amphicytherura cf. yakhiensis Cytherella sp. Parakrithe sp.

Paracypris bremani

Cytherella aff. gambiensis Cytherella aegyptiensis Metacytheropteron berbericum Neocyprideis vandenboldi Nigroloxoconcha naqaensis n. sp. Reticulocosta kanaanensis Veeniacythereis jezzineensis OstracodesOA 2OA 1

Fig. 15

highstand, and probably increased productivity rates, resulting in a platform crisis, may be reflected.

BFA 5 is often dominated by miliod forms (e.g. Quinqueloculina sp.), but other taxa, like Valvulammina sp., Cuneolina pavonia, Pseudedomia drorimensis, Nezzazata conica, N. simplex, Pseudorhapydionina dubia and Pseudorhipidionina carsertana co-occur. BFA 5 chiefly occurs in massive, dolomitic limestones and is characterised by relatively low diversities and a predominance of mostly large and thick walled miliolid specimens, restricted intertidal to shallow subtidal (lagoonal) facies belts (e.g.

Fig. 14).

CENOMANIAN

WK1

Chrysalidina gradata Cuneolina pavonia Nezzazata spp. Nummoloculina regularis Praealveolina cretacea Pseudolituonella reicheli Pseudorhipidionina casertana Quinqueloculina sp. Valvulammina sp. Pterammina israelensis

Flabellammina cf. alexanderi Marssonella sp. Tritaxia sp. Ostracodes Ammonites

OA 1

BFA 1

BFA 2

BFA 1BFA 2Benthic foraminifers Lenticulina sp.Hemicyclammina sigali

Orbitolina sp.

Naur bcdFuheis

Stage Formation 2m Sample

Oy Oy

Oy

Oy OyOy

Bythocypris sp.Amphicytherura sexta Cytherella sp. Cytherella aegyptiensis Cythereis algeriana Cythereis namouesis Metacytheropteron berbericum Parakrithe sp. Parakrithe andreni Peleriops ziregensis Phlytocythere citreum Veeniacythereis streblolophata V. streblolophata schista Veeniacythereis jezzineensis Mrhiliceras lapparenti

Veeniacythereis maghrebensis

Fig. 16

OA 1

Paleogeographical comparisons: For Sinai/Egypt Shahin & Kora (1991) defined

‘biozones’, comprising benthic and planktic foraminifers and also ostracodes. The authors established four zones for Cenomanian to Turonian times. However, the characteristic benthic foraminifers of these zones (e.g. Thomasinella aegyptia, Daxia

cenomana, Discorbis turonicus) are not observed within age-equivalent material from west central Jordan.

Bauer et al. (2003) described benthic foraminifer assemblages from Sinai that are similar to those of the present study: an association, containing e.g. Nummoloculina sp., Cuneolina sp., Pseudolituonella sp., Biconcava ?bentori, Nezzazata sp., Praealveolina sp. and Chrysalidina gradata, characterises open shallow subtidal facies belts on the Cenomanian platform. This assemblage is very similar to BFA 1 of this study. Another Cenomanian assemblage of Bauer et al. (2003) consists of few miliolids and undifferentiated benthic foraminifers and probably characterises a restricted (lagoonal) environment, like BFA 5 of the present scheme. Turonian assemblages of Bauer et al. (2003) exhibit a decrease in abundance and diversity

Stage

SI1+2

2m

CENOMANIANT FormationShueibFNaur abcdHL Sample Benthic foraminifers

Oy Oy Oy

Oy

Oy

B B

Biplanata peneropliformisBiconcava bentori Dicyclina sp. Broeckina balcanica Chrysalidina gradata Cuneolina pavonia Nezzazata spp. Nummoloculina regularis Praealveolina cretacea Pseudolituonella reicheli Pseudorhapidionina dubia Pseudorhapidionina laurensis Pseudorhipidionina casertana Quinqueloculina sp. Valvulammina sp. Ammobaculites sp. Flabellammina cf. alexanderi Haplophragmoides sp. Marssonella sp. Pterammina israelensis Gabonita obesa Neobulimina ?albertensis Cytherella sp. Metacytheropteron berbericum Nigroloxoconcha naqaensis n. Sp. Paracypris bremani Reticulocosta rawashensis Veeniacythereis jezzineensis

OstracodesOA 1

BFA 2BFA 1BFA 4

Fig.17

OA 2

and are predominated by miliolids, Cuneolina sp., Valvulammina sp. and Pseudorhapydionina sp., which coincides again with the faunal content of BFA 5.

Biozones of Hamza et al. (1994) from northern Sinai exhibit also many similarities, compared to the Jordanian assemblages: the Flabellammina alexanderi /Flabellammina aegyptiaca Zone of Hamza et al. (1994) is similar to BFA 2 of Jordan and the Hedbergella-Heterohelix Zone, contains also benthic taxa, like Dentalina spp.

and Lagena sp. and is therefore comparable with BFA 3 of the present study.

Saint-Marc (1974) subdivided the Cenomanian to Turonian succession of Lebanon into several units. The benthic foraminifer content of the units c41-c51 (lower Cenomanian to lower Turonian) predominantly coincides with the Jordanian assemblages BFA 1, BFA 2 and BFA 5. An exception is the occurrence of Pseudolituonella reicheli (Saint-Marc, 1974) within lower Turonian deposits, whereas in west central Jordan this species only occurs within Cenomanian deposits. The benthic foraminifer assemblage within Cenomanian shallow marine limestones of Lebanon and Israel (Hamaoui & Saint-Marc, 1970) exhibits many taxa that are also observed in Jordanian limestones of Cenomanian age: Biconcava bentori, Biplanata peneropliformis, Pseudolituonella reicheli, Nummofallotia apula, Nezzazata, Valvulammina, Chrysalidina and Miliolidae also occur in BFA 1 of the present study.

Moreover, Lipson-Benitah (1990) observed a less diverse benthic assemblage of predominating lenticulinids and gavelinids within the CT-boundary interval and interpreted it as an indicator for oxygen-poor water during transgression. This assemblage approximately coincides with our BFA 3.

To sum up, the species content of upper Albian to Turonian benthic foraminifers in Jordan and adjacent areas is very similar. Mainly the described platform assemblages (comparable to BFA 1, (2) and 5) and their paleoecological interpretations coincide, but assemblages that characterise transgressive phases (like BFA 3) are also widespread. BFA 4 has no direct equivalent, probably due to a hiatus in Egypt, comprising the platform flooding deposits of the CT-boundary interval (Bauer et al, 2001), and related to differing paleoceanographic conditions on the shelf (e.g. deeper water facies in Israel; Lipson-Benitah, 1990).

6.4 Ostracodes

Marly deposits of lower and middle Cenomanian age (Naur Formation, Fuheis Formation) locally yield an abundant and relatively diverse ostracode assemblage,