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P a l e o g e o g r a p h i c Interpretation of a Peat Layer at T o r s o n di S o t t o ( L a g o o n of Venice, Italy) *) PAOLO A . PIRAZZOLI, NADINE PLANCHAIS, MARIE ROSSET-MOULINIER & JEAN THOMMERET **) Paleogeography, peat, stratiform deposit, lagoon, sea level, intertidal sedimentation, regression, transgression, interpretation, core cuttings, pollens (Quercus, Alnus), foraminiferal fauna, C-14 dating, Holocene, Palaeosalinity, freshwater environment, brackish water. Veneto (Lagoon o f Venice). A b s t r a c t : A 3 . 3 m long core from the central part o f the lagoon o f Venice has revealed a peat layer between 1.3 m and 2.0 m below mean sea level. Pollen analysis indicates the pre­ dominance of Quer ens and Alnus and the existence o f a transgressive phase: the base of the peat (dated 1730 + 80 y. B P ) was formed in a soft water environment, and the upper part (dated 1140 ± 80 y. B P ) in a brackish one. Foraminifera analysis indicate that transgression has preceded a regression. The whole se­ quence is, from bottom to top (Fig. 3 ) : (1) an oligohaline to mesohaline environment (from —3.3 to — 2 . 5 m) with very abundant forams; (2) a soft water environment (from —2.5 to —2.0 m ) ; (3) the 0.7 m thick peat layer, becoming gradually brackish; (4) a mesohaline environment (above —1.3 m). Correlation with neighbouring localities (Fig. 1) indicates that similar phenomena occurred at the same time in the central part of the lagoon, but not in its northern part. This regression-trans­ gression sequence is ascribed to an increased rainfall period, at about the end o f Roman times, which would have resulted in the flooding and a change in the course of several rivers; the hydrologic equilibrium in this marshy area would have been modified temporarily. Over the past 100 years, the transgression has accelerated, largely as a result of anthropic works. The "barene" are now eroding and disappearing quickly (Fig. 2 ) . T h e y are being replaced by wide sea-water basins. [Paläogeographische Interpretation einer T o r t l a g e bei T o r s o n di Sotto (Lagune v o n Venedig, Italien)] K u r z f a s s u n g : E i n 3,3 m langer Kern aus dem zentralen Bereich der Lagune von V e ­ nedig enthielt eine Torflage zwischen 1,3 und 2,0 m unter dem mittleren Meeresspiegel. Pollen­ analysen zeigen ein Vorherrschen von Quercus und Alnus und eine transgressive Phase an: der untere Teil des Torfes (nach !4C-Daten 1 7 3 0 ± 8 0 v.h.) ist in einem Süßwasser-Environment ge­ bildet worden, der obere Teil (nach n C - D a t e n 1140 + 80 v.h.) in einem brackischen. Foraminiferenanalysen zeigen an, daß der Transgression eine Regression vorangegangen ist. Die gesamte Ab­ folge enthält von unten nach oben (Abb. 3 ) : (1) ein oligohalines bis mesohalines Environment (von —3,3 bis —2,5 m) mit sehr zahlreichen Foraminiferen; (2) ein Süßwasser-Environment (von — 2 , 5 bis —2,0 m ) ; (3) die 0,7 m mächtige Torflage, die fortschreitend brackisch wird; (4) ein mesohalines Environment (oberhalb —1,3 m). *) Field-Work was supported by Centre National de la Recherche Scientifique (contrat hors convention A 6412) and was carried out in collaboration with L. Alberotanza and V. Favero. Oceanographic vessel "Umberto D'Ancona" o f the Consiglio Nazionale delle Ricerche was avail­ able for these operations. **) Adresses of the authors: P. A. P i r a z z o l i, C . N . R . S . (E.R.A. 867) and Laboratoire de Geo­ morphologie de l'E.P.H.E., 1 rue Maurice Arnoux, 92120-Montrouge, France (Field-work, geomorphology, and coordination). — N . P l a n c h a i s , C.N.R.S., Laboratoire de Palynologie de l'U.S.T.L., Place Eugene Bataillon, 34060-Montpellier Cedex, France (Pollen analysis). — M. R o s s e t - M o u l i n i e r , Laboratoire de Biologie-Geologie de l'E.N.S., 1 rue M. Arnoux, 92120Montrouge, France (Foraminifera). — J . T h o m m e r e t , Centre Scientifique de Monaco, Labora­ toire de Radioactivite appliqu^e, Avenue Saint-Martin, Principaute de Monaco (Radiometric dating).


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Korrelationen mit benachbarten Lokalitäten (Abb. 1) weisen darauf hin, daß vergleichbare E r ­ scheinungen zu gleicher Zeit im Zentralteil der Lagune, aber nicht in ihrem Nordteil, aufgetreten sind. Diese Regressions-Transgressions-Abfolge wird auf eine Periode erhöhter Niederschläge um das Ende der Römerzeit zurückgeführt, die zur Überflutung und zu einer Verlagerung des Laufes zahlreicher Flüsse geführt hat; dabei ist das ökologische Gleichgewicht dieses Marschengebietes zeitweilig verändert worden. I m Verlauf der vergangenen 100 Jahre hat sich die Transgression beschleunigt, überwiegend infolge anthropogener Eingriffe. Die „Barene" werden jetzt erodiert und verschwinden rasch (Abb. 2 ) . Sie werden durch weite Meerwasserbecken eingenommen.

Introduction T o r s o n di S o t t o ( 4 5 ° 2 0 ' 5 5 ' N — 1 2 ° 1 3 ' 4 6 " E ) is a s m a l l islet o f a b o u t 1 , 0 0 0 s q u a r e m e t e r s in t h e V e n i c e L a g o o n , p r a c t i c a l l y in t h e c e n t r e o f t h e M a l a m o c c o basin. I t s present s i t u a t i o n b e l o w t h e " b a r e n e " l i m i t ( " b a r e n e " b e i n g the l o c a l n a m e f o r t h e tidal flats) is o f somewhat recent origin. F o u r centuries a g o t h e B r e n t a R i v e r m o u t h opened i n t o t h e l a g o o n c l o s e t o t h a t l o c a l i t y . T w o centuries l a t e r t h e " C a s o n e " o f T o r s o n di S o t t o w a s e n t i r e l y s u r r o u n d e d b y t h e " b a r e n e " . A s a result o f t h e s h r i n k i n g o f this " b a r e n e " b y e r o s i o n T o r s o n di S o t t o b e c a m e an islet t o w a r d s t h e end o f t h e last c e n t u r y ; it c o u l d w e l l d i s a p p e a r in t h e c o m i n g decades.

Fig. 1: Location o f the lagoon sites mentioned in the text: (1) Fosso del Sorgo; (2) Motte di Volpego; (3) Torson di Sopra; (4) Torson di Sotto; (5) Motta del Cornio Vecchio; (6) Barena di C a ' Manzo; (7) Malamocco Pass and entrance of the oil-transport channel; (8) Laghi Teneri.


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T h e progressive e r o s i o n o f t h e „ b a r e n e " is a c o n s e q u e n c e n o t o n l y o f t h e r e d u c t i o n o f t h e r i v e r s e d i m e n t a r y supply, after t h e d e v i a t i o n o f t h e B r e n t a R . o u t o f t h e l a g o o n , b u t a l s o o f t h e d a m m i n g u p a n d t h e p r o g r e s s i v e deepening o f t h e Pass o f M a l a m o c c o , d i r e c t l y o p p o s i t t o T o r s o n di S o t t o a n d 8 k m a w a y . T h e d e p t h o f this inlet, w h i c h w a s a b o u t 4 o r 5 m e t e r s in 1 8 1 1 , i n c r e a s e d after t h e b u i l d i n g o f t h e t w o e m b a n k m e n t s t o 8 — 9 m b y 1 9 0 1 a n d , after the d i g g i n g o f t h e O i l - t r a n s p o r t channel b e t w e e n 1 9 6 6 a n d 1 9 6 9 , t o m o r e t h a n 1 5 m at the present time (Pirazzoli 1 9 7 4 ) . T h e local tidal range ( 2 H M 2 + 2 H S 2 ) was 0 . 6 5 m in 1 9 3 8 ( P o l l i 1 9 5 0 ) a n d i n c r e a s e d t o a b o u t 0 . 7 5 m in 1 9 7 3 (GOLDMAN et al. 1 9 7 5 ) .

Fig. 2 : The "barene" (local tidal flats) have almost disappeared near Torson di Sotto between 1811 and 1968. (A) man-made embankments; (4) Torson di Sotto.

T h e s a l i n i t y w h i c h t o d a y is a b o u t 3 7 — 3 8 % o i n t h e A d r i a t i c , 3 0 °/oo in t h e o p e n l a g o o n a n d 2 0 — 2 5 % o ( o r s o m e w h a t less) in t h e " V a l l i " , must h a v e b e e n much l o w e r in f o r m e r times. I n d e e d i f t h e present f l o w o f the s m a l l r i v e r s o p e n i n g in t h e l a g o o n c o u l d reach a m a x i m u m o f 6 5 0 m s ( C a v a z z o n i 1 9 7 3 ) , f o r m e r flows o f r i v e r s in spate ( t h e P i a v e , S i l e a n d B r e n t a R i v e r s , as w e l l as some t r i b u t a r i e s o f t h e A d i g e R i v e r ) w e r e c e r t a i n l y m a n y t i m e s m o r e i m p o r t a n t . T h e area o f T o r s o n di S o t t o , in p a r t i c u l a r , w o u l d h a v e b e e n s t r o n g l y d e p e n d e n t o n t h e influence o f t h e B r e n t a R i v e r a t t h e t i m e w h e n its d e l t a discharged in this region. 3

— 1

Field work I n t h e course o f a p r e l i m i n a r y i n v e s t i g a t i o n o f t h e l a g o o n a l H o l o c e n e sediments, a c o r i n g o f 3.3 m l o n g w a s m a d e in 1 9 7 7 near t h e n o r t h e r n b o r d e r o f T o r s o n di S o t t o . A 4 0 m m d i a m e t e r D a c h n o w s k y s a m p l e r was used. T h e r e c o r e s h o w e d t h e f o l l o w i n g


Paolo A. Pirazzoli et al.

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stratigraphical succession: (depths are reported

w i t h respect t o t h e mean sea l e v e l

m.s.l.) ( F i g . 3 ) .

mean

Pollen

Foram

sea level

M

C Age

TS2 -TS 3 -TS5 TS5 - 1 ^ . 1140 ±80 BP -TS6

TS45

-

I MC -14111

-TS 7 -TS 8 -TS 9 -TS10 — 1730 ±80 BP TS11

IMC-1410 j

[ ]

TS13

TS12

[

A TS15

[

B

c

TS17-

um»

D|

-60

m

Fig. 3 : Location o f the analysed samples and stratigraphy of the Torson di Sotto core. (A) rewor­ ked silt; (B) silt; (C) peat; ( D ) continental layers.

— F r o m s u r f a c e t o — 0 . 6 m : r e w o r k e d o o z e s o f a green t o m u s t a r d - y e l l o w p r o b a b l y c o m i n g f r o m t h e n e i g h b o u r i n g c h a n n e l draggings in t h e l a g o o n .

colour,

F r o m — 0.6 to — 1 . 3 m : m u d d y clay o f grey colour with some rare vegetal remains.

F r o m — 1 . 3 t o — 2 . 0 m : peat, turning

to a dark-black colour between — 1 . 7 to

— 1 . 8 m. —

F r o m — 2 . 0 t o — 3 . 3 m : greyish c l a y e y m u d .

A n o t h e r a n d deeper c o r i n g s h o w e d t h a t t h e estuarine o r l a g o o n a l silts m i x e d with s o m e t r a c e s o f p e a t , sand a n d , o c c a s i o n a l l y , w i t h fossils, w e r e f o u n d d o w n t o a b o u t — 6 . 0 m d e p t h . A t this d e p t h t h e y w e r e r e p l a c e d b y a c l a y w h i c h a p p e a r e d t o b e o f continental origin.


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Pollen analysis S e v e n samples w e r e analysed ( F i g . 3 ) , b u t t w o o f t h e m ( T S 9 a n d T S 1 0 ) t a k e n f r o m t h e humified b o t t o m p a r t o f the p e a t c o n t a i n e d h a r d l y a n y p o l l e n s . S a m p l e s T S 3 , T S 5 , T S 7 , T S 8 were a b u n d a n t in C h e n o p o d i a c e a e a n d c a n a c c o r d i n g l y be c o n s i d e r e d as b r a c k i s h - w a t e r d e p o s i t s . S a m p l e T S 1 2 , a Phragmite m u d , m a y o n t h e o t h e r h a n d be c o n ­ s i d e r e d as a s o f t - w a t e r deposit b e c a u s e o f the i m p o r t a n t c o n t r i b u t i o n o f C y p e r a c e a e , G r a m i n a e a n d pollens o f t h e type T y p h a - S p a r g a n i u m . T h e t h e r m o p h i l e pollens o f a n t h r o p i c origin, Juglans, Olea, a n d Vitis, are c o n s i s t e n t a l t h o u g h rare. I n s a m p l e T S 1 2 t h e a b s e n c e o f some species o f a n t h r o p i c origin (Castanea, Juglans) which a r e b y c o n t r a s t f o u n d in the u p p e r levels, lead o n e t o believe t h a t this s a m p l e was deposited b e f o r e the R o m a n o c c u p a t i o n ( H o r o w i t z 1 9 6 6 — 1 9 6 7 ) .

Foraminifera analysis S i x samples w e r e a n a l y s e d ( t w o a b o v e and f o u r b e n e a t h t h e p e a t l a y e r ) . T h e results follow. T S 2 — F e w f o r a m s were f o u n d . T h o s e o b s e r v e d w e r e Ammonia tepida, Protelphidium paralium (= Nonion depressulum for C i t a and P r e m o l i - S i l v a 1 9 6 7 ) and Buccella (= Ammonia) perlucida. C i t a a n d P r e m o l i - S i l v a consider t h a t this association c o r r e ­ s p o n d s t o a t y p i c a l l a g o o n a l e n v i r o n m e n t , w h e r e a s L e v y ( 1 9 7 1 ) c o n s i d e r s it m e s o h a l i n e . T h e presence o f s o m e M i l i o l i d a e suggests t h a t t h e t r a n s p o r t o f l i t t o r a l m a r i n e m a t e r i a l is i n v o l v e d . T S 4 — F o r a m s r a r e : Ammonia tepida, Protelphidium paralium and Trochammina inflata. T h i s last species is t y p i c a l o f a h a l o p h i l e v e g e t a t i o n z o n e ( L U T Z E 1 9 6 8 , M U R R A Y 1971). T S 11 and T S 13 — N o forams. T S 1 5 — V e r y a b u n d a n t f o r a m s : Ammonia tepida lium ( a b o u t 3 0 °/o) a n d some r a r e Buccella perlucida mesohaline environment. T S 1 7 — V e r y a b u n d a n t f o r a m s : Ammonia Ammobaculites agglutinans, Elphidium decipiens haline environment.

( a b o u t 7 0 % ) , Protelphidium para­ a n d Elphidium decipiens. O l i g o to

tepida ( 9 0 ° / o ) , Protelphidium paralium, a n d Buccella perlucida. Oligo to meso­

Radiometric datations 1 4

W e were able t o d a t e the u p p e r a n d l o w e r p a r t o f t h e p e a t l a y e r using the C m e t h o d . A combination of samples T S 5 a n d T S 6 , collected between — 1 . 3 m and — 1 . 4 m, yielded a n a p p a r e n t age o f 1 1 4 0 ± 8 0 y . B P ( M C - 1 4 1 1 ) . S a m p l e T S 1 0 , c o l l e c t e d at a b o u t — 1 . 9 0 / — 1 . 9 5 m, y i e l d e d an age o f 1 7 3 0 ± 8 0 y . B P ( M C - 1 4 1 0 ) ( n o c o r r e c t i o n f o r age was applied). S o m e correlations A change in t h e p a l e o g e o g r a p h i c c o n d i t i o n s o f T o r s o n di S o t t o , c h a r a c t e r i z e d b y a r e g r e s s i v e f o l l o w e d b y a t r a n s g r e s s i v e m a r i n e p h a s e , m a y be i n f e r e d f r o m pollens a n d f o r a m s found f r o m T S 1 7 to T S 2 . T h i s oscillation is in n o w a y a n i s o l a t e d p h e n o m e n o n . ( 1 ) A t M o t t a del C o r n i o V e c c h i o ( F i g . 1, L o c . 5 ) our c o r i n g - d e v i c e e n c o u n t e r e d b e t ­ w e e n — 1 . 8 and — 2 . 0 m a peat l a y e r s i m i l a r to t h a t o f T o r s o n di S o t t o . 17

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(2) N e a r t h e n o r t h e r n l i m i t o f C a ' M a n z o ( L o c . 6 ) a p e a t l a y e r is f o u n d b e t w e e n — 2 . 0 a n d — 2 . 5 m . J u s t a b o v e a n d b e l o w this l a y e r t h e f o r a m s a r e r a r e ( s o m e Ammonia tepida, Protelphidium paralium, Buccella perlucida) o r absent. (3) I n a c o r e f r o m M o t t e di V o l p e g o ( L o c . 2 ) , A s c o l i ( 1 9 6 6 — 1 9 6 7 ) o b s e r v e d b e t w e e n — 5 . 0 9 a n d — 5 . 6 5 m , w i t h respect t o m.s.L, t h e p r e s e n c e o f blackish c l a y s o f high o r g a n i c c o n t e n t a n d v e g e t a l r e m a i n s b u t e n t i r e l y free o f fossil r e m a i n s . T h e s e layers w e r e inter­ p r e t e d b y A s c o l i as e v i d e n c e o f a v e r y short c o n t i n e n t a l phase o f a l a c u s t r i n e e n v i r o n m e n t t y p e . I n t h e same c o r e , a m a r i n e shell f o u n d at 0.5 m b e n e a t h t h e c l a y l a y e r w a s dated at 1 7 0 8 ± 85 y. B P (Bonatti 1 9 6 8 ) . (4) A t F o s s o del S o r g o ( L o c . 1 ) , M a r c e l l o a n d S p a d a ( 1 9 6 8 ) m e n t i o n the e x i s t e n c e o f p e a t l a y e r s f r o m — 1 . 3 5 t o — 1 . 8 5 m r e l a t i v e t o m.s.l. T h e s e deposits, which represent a c o n t i n e n t a l m a r s h e n v i r o n m e n t , c o v e r s o f t - w a t e r sediments a n d a r e themselves t o p p e d by a " b a r e n e " f o r m a t i o n . T r e e s t u m p s (Alnus, Fraxinus) w e r e o b s e r v e d close b y at a b o u t 1 m d e p t h . O t h e r t r e e stumps, p r o b a b l y a p a r t o f t h e same forest, w e r e d a t e d a t 1 1 4 0 ± 4 5 y. B P at T o r s o n di S o p r a ( L o c . 3 ) a n d a t 1 5 1 5 ± 8 5 y . B P at L a g h i T e n e r i ( L o c . 8 ) . It appears t h a t these p e a t l a y e r s , situated a t v a r i o u s depths, d o n o t differ much from t h e p e a t o f T o r s o n di S o t t o in t h e i r

1

4

C ages.

Discussion and conclusion T h e p e r i o d b e t w e e n 4 5 0 a n d 6 5 0 A D a p p e a r s t o h a v e b e e n v e r y r a i n y in V e n e t i a ( M A R C E L L O 1 9 6 3 ) . I t w a s m a r k e d b y a n i m p o r t a n t h y d r o l o g i c e v e n t : t h e flooding o f 5 8 9 A D , described b y P a u l u s D i a c o n u s . T h i s changed the course o f s e v e r a l rivers, a m o n g t h e m the B r e n t a a n d A d i g e ) . Such p o w e r f u l w a s the i n t e n s i t y o f t h e flooding t h a t the t o w n o f J u l i a C o n c o r d i a , 3 0 k m t o t h e N - E o f t h e V e n e t i a n l a g u n a w a s d e s t r o y e d en­ t i r e l y a n d w a s left c o v e r e d b y a soft w a t e r m a r s h ( M A R C E L L O a n d C O M E L 1 9 6 3 ) . 1

P e a t deposits seem t o h a v e d e v e l o p e d m a i n l y in the c e n t r a l a n d s o u t h e r n p a r t o f the V e n e t i a n l a g o o n , at the f o r m e r m o u t h o f t h e B r e n t a R i v e r . I n t h e n o r t h e r n p a r t o f the l a g o o n , o n t h e o t h e r h a n d , t h e rush o f soft w a t e r appears to h a v e b e e n less a b u n d a n t than in c e n t r a l o r southern p a r t . T h e l i t h o l o g y o f 3 5 cores ( A l b e r o t a n z a et a l . 1 9 7 7 ) does not s h o w t h e regressive-transgressive o s c i l l a t i o n o b s e r v e d in the a r e a o f T o r s o n di S o t t o , even t h o u g h t h e r e is e v i d e n c e t h a t b r a c k i s h w a t e r s w e r e present as f a r back as t h e R o m a n epoch. T h i s regressive-transgressive o s c i l l a t i o n is n o t therefore o f e u s t a t i c origin. T a k i n g a c c o u n t o f all a v a i l a b l e d a t a , an i n t e r p r e t a t i v e sketch o f t h e successive events m a y be o u t l i n e d . T o w a r d s t h e end o f t h e R o m a n epoch, t h e lack o f m a i n t e n a n c e a n d , p r o b a b l y , an i n c r e a s e in t h e r a i n f a l l , p r o v o k e d in V e n e t i a s o m e h y d r o g r a p h i c disorders a r o u n d the l a g o o n a l outlets. T h e level o f t h e soft w a t e r l a y e r must h a v e risen, p a r t i c u l a r l y in the v i c i n i t y o f t h e w a t e r streams. T h e p a l u d a l marshes w e r e t h a n a b l e t o e x t e n d ; t h e in­ fluence o f t i d a l a c t i o n d o w n - s t r e a m w a s l i m i t e d , fluvial sediments w e r e t r a p p e d , thus g i v i n g rise t o t h e f o r m a t i o n a n d d e p o s i t o f t h e l i t t o r a l peats. A t t h e same t i m e , t h e c o m p a c t i o n o f l a g o o n a l H o l o c e n e s e d i m e n t s , a l r e a d y some m e t r e s thick, w a s c o n t i n u i n g s l o w l y . T h i s c o m p a c t i o n w a s p a r t i c u l a r l y i m p o r t a n t f o r p e a t l a y e r s , a l t h o u g h it v a r i e d f r o m p l a c e t o p l a c e . I t p r o b a b l y h a d t h e a d d e d effect o f a slight !) H i s t . L a n g o b . , I l l , 2 3 : " E o tempore fuit aquae diluvium in finibus Venetiarum et Liguriae, seu ceteris regionibus Italiae, quale post Noe tempus creditur non fuisse. Factae sunt lavinae possessionum, seu villarum, hominumque pariter et animantium magnus interitus. Destricta sunt itinera, dissipatae sunt viae . . .".


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rising o f t h e sea-level, w h i c h in this a r e a does n o t a p p e a r t o h a v e reached a l e v e l higher t h a n t h a t which exists a t present (PIRAZZOLI 1 9 7 3 ) . N a t u r e w a s o n l y o v e r c o m e a t t h e e n d o f t h e 1st m i l l e n n i u m o f o u r e r a , w h e n t h e rising S t a t e o f V e n i c e o r d e r e d t h e d i g g i n g o f channels f o r d r a i n a g e o r n a v i g a t i o n a n d w h e n t h e p r i n c i p a l r i v e r streams w e r e p r o g r e s s i v e l y d e v i a t e d a w a y f r o m t h e L a g o o n . B r a c k i s h e n v i r o n m e n t s s l o w l y gained t h e u p p e r h a n d a n d s t a g n a n t soft w a t e r s disappe­ a r e d ; t h e p e a t was r e c o v e r e d b y a v e g e t a t i o n m o r e a n d m o r e h a l o p h i l e . After t h e i m p r o v e m e n t o f t h e pass o f M a l a m o c c o , o n e c e n t u r y ago, t h e transgressive phase a c c e l e r a t e d n e a r T o r s o n di S o t t o . O v e r several d e c a d e s t h e transgression b e c a m e m o r e a n d m o r e rapid, a s a result o f s u b s i d e n c e s o f a n t h r o p i c o r i g i n a n d o f t h e progressive d e e p e n i n g o f t h e c h a n n e l inlet. T h e r e s u l t i n g increase o f t h e t i d a l range, t h e c o n c o m i t a n t i n c r e a s e i n t h e tidal c u r r e n t power, a n d t h e polluting a c t i o n o f M a n (PIRAZZOLI 1 9 7 8 ) h a v e a c c e n t u a t e d t h e e r o s i o n a l p h e n o m e n a . T h e present transgressive s t a g e leads t o a r a p i d r e t r e a t o f t h e " b a r e n e " , a n d l e a v e s i n their p l a c e w a t e r basins which, w h e n they a r e n o t obscured b y p o l l u t i o n , a r e less a n d less l a g o o n a l a n d m o r e a n d m o r e m a r i n e in their characteristics.

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Manuscript received on 1 4 . 1 . 1 9 8 0 . 17


Quaternary Science Journal - Paleogeographic Interpretation of a Peat Layer at Torson di Sotto ...  

Ein 3,3 m langer Kern aus dem zentralen Bereich der Lagune von Venedig enthielt eine Torflage zwischen 1,3 und 2,0 m unter dem mittleren Mee...