UTRECHT MICROPALEONTOLOGICAL BUllETINS

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Data and conclusions from the earlier papers (Brolsma, 197 Sa, b) on the Arenazzolo and overlying Transitional interval at Capo Rossello (fig. 1) and Eraclea Minoa (fig. 2) will not be exhaustively repeated. During the seminar in Erice (1975) the marine environment in which the Arenazzolo was deposited was doubted by some of those present. The question was raised whether the faunas described by Brolsma (1975) represented reworked Tortonian faunas, incorporated in lacustrine sediments. In the latter case one might expect: 1) a rather haphazard distribution of various species in the Arenazzolo sediments, 2) a concentration of such forms in strata suggesting considerable turbulence and supply of coarser sediment, and 3) a drastic change in the quantitative distribution of all species at the transition to the overlying Trubi. 1) Samples JT 1386-1388 of section 1 at Capo Rossello (op. cit., 1975b, fig. 5) contain oligotypic assemblages in which Ammonia beccarii forms as much as 75 and 90% of the fauna in samples 1387 and 1386, respectively. Cribrononion excavatum makes up 20% of the fauna in the former sample. Sample CR 6 is almost devoid of benthonic foraminifera but it does contain abundant ostracode carapaces of Cyprideis pannonica var. agrigentina. At Eraclea Minoa 80% of the fauna of sample 14 (fig. 2, section 1) is formed by Rosalina globularis. The presence of such assemblages of very low diversity cannot be reconciled with a derivation from older deposits, but it might fit in with the assumption of restricted marine to lacustrine deposits. 2) Brolsma (1975) described small scale cross-lamination and sub-horizontal parallel lamination in the sandier strata of the Arenazzolo at Capo Rossel- 10. According to J. A. Broekman (pers. comm.) the horizontally stratified sands which sometimes show an upper part with small scale cross stratification, are very similar to the "storm-stand" layers described by Reineck and Singh (1971; see also our fig. 3). Such sands are regarded to be the result of deposition from suspension-clouds, the material of which was taken up in shallow water during storms. One of these storm layers and the directly underlying and overlying clayey sediments were sampled. The sand-bed is horizontally laminated and attains a thickness of 2 cm. Its position is 3.5 m below the Arenazzolo/Trubi contact in an exposure some 200 m SE of the proposed Miocene/pliocene boundary stratotype (Cita, 197 Sa). Sample
Fig. 3 Subhorizontally stratified and cross-laminated sandy interbeds in clayey Arenazzolo sediments at Capo Rossello. CRM 2 was taken from the storm-sand layer about 3 em above CRM 1 and 3 em below CRM 3. The latter two samples are from the adjoining clayey sediments (fig. 4). Accepting a storm-induced origin of the sandy strata we might expect higher numbers of supposedly reworked forms in sample CRM 2. The number of species per 150 specimens met with in the sand (48) is somewhat lower than the numbers collected from the clays (56 and 60). The quantitative composition of the faunas does not differ significantly, and there is no clear evidence for a difference in addition of reworked specimens (cf. fig. 4). Moreover, the assemblages make sense from an ecological point of view (Brolsma, 197 5b). 3) The numerical variation of most planktonic taxa across the Transitional interval is very small. It is hard to imagine that the faunas below the Miocene-pliocene boundary were reworked and those above the boundary were autochthonous. This would mean that after 2 million years, the newly introduced Atlantic fauna would still contain the various species in the same proportions. In addition to these faunistic considerations some lithostratigraphic data are not in accordance with a fresh-water origin of the entire Arenazzolo. Ogniben (1957) described the Arenazzolo from Sicily as a formation of variable thickness and best developed in synclinal areas. In anticlinal regions the Trubi directly overlies either the "calcare di base" of the Messinian or
Page 1 and 2: UTRECHT MICROPALEONTOLOGICAL BUllET
Page 3 and 4: QUANTITATIVE FORAMINIFERAL ANALYSIS
Page 5 and 6: The foraminifera. . . . . . . . . .
Page 7 and 8: Benthonic and planktonic foraminife
Page 9 and 10: and considerable lowering of the er
Page 11 and 12: topmost Messinian evaporites, chara
Page 13 and 14: literature together with Pachysphae
Page 18 and 19: 2 3 Ammonia beccarii Bolivina dente
Page 20 and 21: LITHOLOGY The new exposure to be de
Page 22 and 23: may interfinger. Evidently biogenic
Page 24: CONCLUSIONS The mediocre preservati
Page 27 and 28: 107 107G B.C 107A 106 1394 64 1393
Page 29 and 30: Fig. 9 Laterally displaced loadcast
Page 31 and 32: Orbulina, which in turn seem to dep
Page 33 and 34: 0 10 20cm. L--L--J ~II\\ :::0 if.-
Page 35 and 36: whether its assumed intermediate st
Page 37 and 38: cate that larger burrowing organism
Page 39 and 40: The foraminiferal faunas from the T
Page 41 and 42: 42 43 44 45 sa~ 3 4 4 Astrononion i
Page 43 and 44: the accumulation of silica-rich sed
Page 45 and 46: 1 1 i z 1 1 11 3 1 i ~ . 2 •• 7
Page 47 and 48: ently favoured clayey substrates bu
Page 49 and 50: The next higher part of the section
Page 51 and 52: Cibicides pseudoungerianus appears
Page 53 and 54: In the next higher interval the alt
Page 55 and 56: high. It remains equally possible t
Page 57 and 58: I 106 55 52 j 8 Ij I " ~ ~ ! I ll11
Page 59 and 60: 107A 107B 107C 107D 107E 107F 107G
Page 61 and 62: of the faunas remains practically t
Page 63 and 64: 5 -- 4 3 2 7 - - - - - - - - - - -
Page 65 and 66:
;.Monica Say(32) Todos Santos 8ay (
Page 67 and 68:
1000 m, the latter corresponding to
Page 69 and 70:
In this respect it is interesting t
Page 71 and 72:
for this interval at the three loca
Page 73 and 74:
near-absence and bloom. The level o
Page 75 and 76:
Fig. 30 Punta Piccola section, show
Page 77 and 78:
Chlorite/montmorillonite and albite
Page 79:
most of them are of the order of 15
Page 83 and 84:
The change in colour from cream to
Page 85 and 86:
The foraminiferal faunas from the M
Page 87 and 88:
, " ~ " , , . ~ . ~
Page 89 and 90:
posite- reactions with higher a-val
Page 91 and 92:
------ Cibicides lobatu(us -- Hanza
Page 93 and 94:
Bulimina inflata, Hopkinsina bononi
Page 95 and 96:
Parker, 1954). In the Andaman Sea t
Page 97 and 98:
athymetric distribution is shown in
Page 99 and 100:
in the manganese-rich interbeds (B
Page 101 and 102:
50 1~N 47 46 45 43 4 M 42 L 41 4 39
Page 103 and 104:
Emiliani (1974) analyzed core mater
Page 105 and 106:
20323, was deposited at the transit
Page 107 and 108:
it is realized that the latter two
Page 109 and 110:
FREQUENCY D ISTR I BUTION OF SOME S
Page 111 and 112:
BENTHONIC FORAMINIFERAL ASSOCIATION
Page 113 and 114:
IK < .o~
Page 115 and 116:
ed by the increase of epiphytes and
Page 117 and 118:
G. puncticulata, recorded from Aren
Page 119 and 120:
our sample 93 suddenly shows a B/P
Page 121 and 122:
loss may be due to the folding. The
Page 123 and 124:
shallowing tendency. This quiet sed
Page 125 and 126:
One of the major aims of this inves
Page 127 and 128:
anean evidently had a nutrient supp
Page 129 and 130:
A taxonomical treatment of all figu
Page 131 and 132:
Remarks: Globigerina pseudobesa (Sa
Page 133 and 134:
Remarks: Colalongo and Sartoni (196
Page 135 and 136:
30. Earland, A. (1934). Foraminifer
Page 137 and 138:
Anderson, G. ]. (1963). Distributio
Page 139 and 140:
Hsii, K. J., Cita, M. B. and Ryan,
Page 141 and 142:
Wright, R. (1977). Neogene paleobat
Page 144:
Figs. 1a-b Figs. 2a-b Figs.3a-b Fig
Page 148:
Figs. 1a-c Figs. 2a-c Figs. 3a-c Fi
Page 152:
Fig. 1 Fig. 2 Figs.3a-b Fig. 4 Fig.
Page 156:
Morphological gradation from Globor
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UTRECHT MICROPALEONTOLOGICAL BUllETINS

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