Eiszeitalter
und
Gegenwart
Band 19
Seite
203-208
Öbringen/Württ.,
31. Oktober
1968
Quaternary climatic changes in t h e Caribbean and N. South-America B y J . I. S. Z O N N E V E L D , U t r e c h t
S u m m a r y . This paper gives an inventarization o f the available data concerning quater nary climatic changes in the Caribbean and the northern parts o f South America. It appears that in Colombia, N . W. Venezuela, the Leeward Islands o f the Netherlands Antilles and Barbados the pluvial periods coincided with the glacial periods in higher latitudes. The evidence for G u y a n a and Surinam is still insufficient to establish definitely the climatic evolution, altough the available data seem to indicate that during the glacial periods the climate was less humid than at present: this would correspond with a shifting o f the "arid" belt over some 10 degrees. Z u s a m m e n f a s s u n g . Es wurden in dieser kurzen Arbeit Literaturangaben über die quartären Klimaänderungen gesammelt, die aus dem karibischen Gebiet und den benachbarten Teilen Südamerikas bekannt sind. Man kann feststellen, daß in Kolumbien, Nordwest-Venezuela, Aruba, Curacao, Bonaire und Barbados pluviale Perioden etwa synchron waren mit den Glazialen in Gebieten höherer Breite. Die Daten aus Guyana und Suriname lassen zwar noch keine endgültigen Schlüsse zu, doch deutet vieles darauf hin, d a ß dort während der Glazialzeiten trockenere klimatische Bedingungen herrschten als heute. D a s würde einer Verschiebung der „ariden" Zone um etwa 1 0 ° entsprechen. R e c e n t p a l a e o c l i m a t i c research in A f r i c a h a s i n d i c a t e d t h a t o n l y p a r t o f t h e pluvials t h a t w e r e r e c o g n i z e d in different r e g i o n s o f t h e c o n t i n e n t , were s y n c h r o n o u s w i t h the g l a c i a l periods o f m o r e p o l e w a r d r e g i o n s ( c f . T R I C A R T , M I C H E L a n d V O G T , 1 9 5 7 ; BERNARD,
1 9 6 2 ; B Ü D E L , 1 9 6 3 ; F A I R B R I D G E , 1 9 6 4 ; see a l s o P E N C K , 1 9 1 3 ) .
A s a general rule i t a p p e a r s t h a t d u r i n g t h e g l a c i a l periods, the b o u n d a r i e s o f the different c l i m a t i c belts shifted towards t h e e q u a t o r . I n these periods t h e m e s o t h e r m a l zones as w e l l as t h e a r i d z o n e s o f the n o r t h e r n h e m i s p h e r e w i l l h a v e m o v e d s o u t h w a r d a n d t h e b e l t o f the e q u a t o r i a l r a i n f o r e s t n a r r o w e d . E v e n in e q u a t o r i a l r e g i o n s eolian sands w e r e deposited ( D E H E I N Z E L I N , 1 9 5 2 ) . O n l y in t h e z o n e o f the c l i m a t o l o g i c a l ( o r t h e r m a l ) e q u a t o r , some degrees s o u t h w a r d o f the a s t r o n o m i c a l one , t h e t r o p i c a l rain forest c o u l d survive. D u r i n g t h e i n t e r g l a c i a l s t h e c l i m a t i c belts shifted a g a i n t o w a r d s the poles ( c f . t h e diagram p u b l i s h e d b y F A I R B R I D G E in 1 9 6 1 a n d 1 9 6 4 ) . A l t h o u g h the shifting o f the c l i m a t i c b e l t s w a s n o t a s simple as i n d i c a t e d a b o v e , w e m a y a c c e p t t h a t in t h e N . S a h a r a the p l u v i a l periods c o i n c i d e d with t h e g l a c i a l s b u t t h a t in t h e m o r e southern r e g i o n s , pluvial p e r i o d s h a v e t o b e c o r r e l a t e d with i n t e r g l a c i a l times. F o r t h e c o r r e s p o n d i n g regions in t h e N e w W o r l d , v i z . t h e C a r i b b e a n a n d t h e a d j a c e n t p a r t o f S o u t h - A m e r i c a i t seems w o r t h w h i l e t o g a t h e r t h e e q u i v a l e n t p a l a e o c l i m a t i c i n f o r m a t i o n in order t o l o o k f o r similar c o n c l u s i o n s , a l t h o u g h a d m i t t e d l y o u r k n o w l e d g e o f t h e Q u a t e r n a r y c l i m a t i c changes in t h i s p a r t o f t h e w o r l d is rather i n c o m p l e t e . I n this p a p e r d e d i c a t e d t o t h e m a s t e r o f q u a t e r n a r y research, P r o f . D r . P . W O L D S T E D T , w e will a t t e m p t t o p r o v i d e a b r i e f i n v e n t a r i s a t i o n o n this s u b j e c t ) . 1
P a l a e o c l i m a t i c changes manifest t h e m s e l v e s b y t h e f o l l o w i n g p h e n o m e n a : A. B. C. D. E. F.
m o v e m e n t s o f the levels o f seas a n d l a k e s changes in t e m p e r a t u r e o f t h e s e a w a t e r p e d o l o g i c a l changes, i n c r u s t r a t i o n s changes i n t h e v e g e t a t i o n changes in g r o u n d w a t e r c o n d i t i o n s changes in the g e o m o r p h o l o g i c a l processes.
i) The author is much indebted to Prof. J . B . B I R D , Montreal and Dr. K. DUPHORN, Hannover, who kindly gave him some valuable references and to Mrs. M . VAN DER M A E S E N and D r . H. BOISSEVAIN, who corrected the manuscript linguistically.