Seine smt

All dredgings made over the southern south-eastern flank of the smt in the 1000-200 depth range recovered vescicular and massive basalts (in two examples very fresh) with very few samples of pyroclastic rocks and one clast of an intrusive rock (gabbro ?). A "hardground-like" lithofacies, consisting of a bio-lithoclastic calcarenite, together with occasional shallow-water white foraminiferal-algal limestone were also sampled together with the benthic material (see detailed decription). Two dredges were lost during the sampling of the W-NW escarpment of the Seine.

**Figure 23:** Bioclastic fine sands (and partly silts and clays) from the flank of Seine smt
$\begin{figure}\centerline{ \epsfig{ file=IMG/s_bn_04_coarse.ps,width=8.5cm}} \end{figure}$

Table 12: Bioclastic assemblages, grabs S_BN_04 and 05.

S_BN4 Grab
Forams	Bivalves	Gastropods	others
Orbulina universa	Present but not determined	Rissoidae	Bryozoans
Globigerina bulloides		Scissurellidae
Textularidae		Pteropods	Crinoids
		(Creseis acicula; Clio piramidata;Cavolinia inflexa; Limacina inflata)
Lagenidae			Crustaceans
Uvigerina sp			otolites
S_BN5 Grab
Forams	Bivalves	Gastropods	others
Orbulina universa	Cuspidaria	Rissoidae	Echinids
Globigerina bulloides	Arcidae	Scissurellidae
Textularidae	Amusidae	Pteropods (Clio piramidata;Cavolinia inflexa;Limacina inflata)	Polychaetes
Lagenidae			Serpulidae
Uvigerina sp

**Figure 24:** Bioclastic fine sands (and partly silts and clays) from the flank of Seine smt. Grab S_BN11.
$\begin{figure}\centerline{\epsfig{ file=IMG/s_bn11.ps,width=12.5cm}} \end{figure}$

Table 13: Bioclastic assemblages, grabs S_BN_11

\|S_BN11_Grab - Depth: 614 m.
Forams	Bivalves	Gastropods	others
Orbulina universa	Nuculanidae	Rissoidae juv	Bryozoans
Globigerinoides ruber		Janthinidae	Serpulids
Globigerinella siphoniphera	Lymopsis aurita (Limacina inflata,tyliola subula)	Pteropods	Echinids
Globigerinoides sacculifer			Otolites.
Globorotalia inflata			Ophiuroids
Turborotalia truncatulinoides
Sphaeroidinellopsis sp.

**Figure 25:** Location of dredging stations over the south-eastern flank of Seine smt.
$\begin{figure}\centerline{\epsfig{ file=IMG/s_dr_nav.ps,width=15cm}} \end{figure}$

**Figure 26:** Seine smt, DR_01 dredge haul. Rocks: Vescicular and massive, microcrystalline basalt; Clast-supported bioclastic "hardgrounds" calcarenite. Benthos: Gastropods (Ranella olearia, Charonia lampas); Anthozoans (Dendrophillia sp); Solitary Corals; Echinids and small Ophiuridae.
$\begin{figure}\centerline{\epsfig{ file=IMG/s_dr_01.ps,width=15cm}} \end{figure}$

**Figure 27:** Seine smt, DR_02 dredge haul. Rocks: Clast-supported bioclastic "hardground" calcarenite. Benthos: Sponges; Anthozoans (Callogorgia verticillata); Brachiopods (Terebratulidae); Gastropods (Neosimnia s); Polychaetes.
$\begin{figure}\centerline{\epsfig{ file=IMG/s_dr_02.ps,width=15cm}} \end{figure}$

**Figure 28:** Seine smt, DR_03 dredge haul. Pyroclastic and lava rock fragments (cm size); Serpulids; weathered coral.
$\begin{figure}\centerline{\epsfig{ file=IMG/s_dr_03.ps,width=15cm}} \end{figure}$

**Figure 29:** Seine smt, DR_04 dredge haul. Rocks: Vescicular, partly glassy, basaltic scoria (several samples very fresh); porphyritic intrusive rock (gabbro?). White foraminiferal-algal limestone. Hazelnut planktonic floatstone in packestone to mudstone matrix. Clast-supported, poorly cemented, beige bio-lithoclastic calcarenite recalling hardground. Bioclasts include gastropods bivalves, echinoid fragments, corals. Benthos: wheathered Ostrea shells; Porifera; Polychaetes.
$\begin{figure}\centerline{\epsfig{ file=IMG/s_dr_04.ps,width=15cm}} \end{figure}$