Transcript PHANEROZOIC TECTONIC EVOLUTION OF THE NORTH …

WESTERN-CARIBBEAN
Phanerozoic Tectonic
Deformations as Recorded in the
Cuban Foldbelt
ITURRALDE-VINENT, Manuel A.
Museo Nacional de Historia Natural, Obispo no. 61,
Plaza de Armas, La Habana 10100 Cuba,
[email protected]
Many tectonic elements which today built-up
the Cuban foldbelt, originally where part of the
Mesozoic North American passive margins
and the Proto-Caribbean and Caribbean crusts.
They are represented by the Bahamian-North
Cuban foldbelt, the Cuban Southwestern
Terranes and the Northern Ophiolites.
The North American continental margin units
crops out along the northern half of the island (Bahamian
borderland) and as the Cuban Southwestern terranes
(Mayan borderland).
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La Habana
Ma tanz as
23°N
23°N
Guaniguanico
ter r ane
Pi nar d el R io
Sa nta C lara
Ci enfue gos
22°N
22°N
Pinos
ter r ane
Nu eva Gero na
Tri nidad
Cubitas
Es cam bray
ter r ane
Ca mag uey
Cam aj‡n
Gibar a
Bahamian
margin
Bahamian
borderland
21°N
21°N
Holguin
Yucat‡n
Mayan margin
(Yucatan) borderland
As unci—n
ter r ane
Santiago de Cuba
20°N
0
85°W
100
84°W
20°N
200KM
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La Habana
Ma tanz as
23°N
23°N
Guaniguanico
ter r ane
Pi nar d el R io
Sa nta C lara
Ci enfue gos
22°N
22°N
Pinos
ter r ane
Nu eva Gero na
Tri nidad
Cubitas
Es cam bray
ter r ane
Ca mag uey
Cam aj‡n
Gibar a
Bahamian margin
21°N
21°N
Holguin
Yucat‡n margin
As unci—n
ter r ane
Santiago de Cuba
20°N
0
85°W
100
84°W
20°N
200KM
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In the sections of the Bahamian borderland there
is no record of Mesozoic tectonic deformation or
regional metamorphism.
Deformation and very low degree of
metamorphism took place only during the
Early Tertiary (Paleocene-Eocene).
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La Habana
Ma tanz as
23°N
23°N
Guaniguanico
ter r ane
Pi nar d el R io
Sa nta C lara
Ci enfue gos
22°N
22°N
Pinos
ter r ane
Nu eva Gero na
Tri nidad
Cubitas
Es cam bray
ter r ane
Ca mag uey
Cam aj‡n
Gibar a
Bahamian margin
21°N
21°N
Holguin
Yucat‡n margin
As unci—n
ter r ane
Santiago de Cuba
20°N
0
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100
84°W
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200KM
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The Mesozoic stratigraphy of both the
Guaniguanico and Escambray terranes are
very similar, but the Pinos terrane differ in
representing a more continental-ward set of
siliciclastic and carbonate rocks.
An important distinction in the Mesozoic
geological history of these terranes is the age of
their tectonic deformations and metamorphism.
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La Habana
Ma tanz as
23°N
23°N
Guaniguanico
ter r ane
Pi nar d el R io
Sa nta C lara
Ci enfue gos
22°N
22°N
Pinos
ter r ane
Nu eva Gero na
Tri nidad
Cubitas
Es cam bray
ter r ane
Ca mag uey
Cam aj‡n
Gibar a
Bahamian margin
21°N
21°N
Holguin
Yucat‡n margin
As unci—n
ter r ane
Santiago de Cuba
20°N
0
85°W
100
84°W
20°N
200KM
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In the Guaniguanico terrane there is no record of
Mesozoic tectonic deformation or regional
metamorphism. Deformation took place during
Paleocene and early Middle Eocene.
The Escambray and Pinos terranes suffered
deformation and metamorphism during the
Cretaceous. K-Ar datings in these terranes record
thermal events at the end of the Cretaceous (Pinos
78 - 65 Ma; Escambray 85 - 65 Ma). Ar-Ar and U-Pb
dating record ages around 100 Ma.
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Age of the deformations in the
continental margin areas
The deformations of the North American continental margin
took place in progression from Cretaceous to Late Eocene.
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La Habana
Ma tanz as
23°N
23°N
Guaniguanico
ter r ane
Pi nar d el R io
100
0
Sa nta C lara
200 KM
Ci enfue gos
22°N
22°N
Pinos
ter r ane
Nu eva Gero na
Tri nidad
Cubitas
Es cam bray
ter r ane
Ca mag uey
Gibar a
Cretaceous
21°N
21°N
Holguin
Paleocene-Middle Eocene
Middle to Upper Eocene
20°N
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As unci—n
ter r ane
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Santiago de Cuba
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ORIGINAL POSITION OF THE CUBAN TERRAINS
BAHAMAS
Bahamas
Gulf of Mexico
Guaniguanico
Pinos
Yucatán
Escambray
Caribbean
South America
The deformations along the continental margins of
North America have some important implications:
1. Is quite probably that these deformations record the interaction
between the North American Plate (NOAM) and the Caribbean
Plate (CARIB).
2. The oldest deformations are recorded in the Pinos and
Escambray terranes, suggesting that they were the first to interact
with CARIB.
3. The youngest deformations are identified along the
Guaniguanico terrane and the Bahamian borderland, recording
the so called CARIB “collision” with the Bahamas.
Cuban ophiolites
Within the Northern Cuban Ophiolites occur inclusions of
HP/LT metamorphic rocks, including metasedimentary ones,
whose K-Ar age range from 126±9.6 - 67 ±10.4 Ma.
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La Habana
Ma tanz as
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Guaniguanico
terrane
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K-Vo
lcanic
Pi nar d el R io
arc
Sa nta C lara
Ci enfue gos
Deformations
within the
Volcanic Arcs
0
Ca baig uan
22°N
Pinos terrane
Flo rida
Ca mag uey
Cretaceous arcs
Paleogene arcc
K-Volcanic arc
Bahamian borderland
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Vi ctoria de las T unas
Holguin
Northern Ophiolites
P
Volcanic arc (K-Cretaceous, P-Paleogene)
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22°N
Ci ego d e A vila
Tri nidad
Escambray terrane
21°N
K
200 KM
100
Nu eva Gero na
P-Volcanic arcSantiago de Cuba
Gu anta nam o
20°N
Yucatán borderland
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Within the sections of the volcanic arcs can be recorded a
number of regional deformational events. These deformations
took place during the Aptian, Coniacian-Santonian, late
Campanian, Maastrichtian-Paleocene and Middle Eocene.
Every deformation is associated with local hiata,
conglomerates, changes in the geochemistry of the magmas,
and with plutonite emplacement -sometimes very large as
during the latest Cretaceous and the Middle-Late Eocene.
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The deformations within the Northern Ophiolites and
the Volcanic Arcs have additional implications:
1. Is quite probably that these deformations record intraplate
tectonic events of the Caribbean (CARIB) and Proto-Caribbean
Plates (P-CARIB).
2. The fact that P-CARIB elements (Northern ophiolites)
suffered deformations since the Early Cretaceous, suggest that
this plate had had a rather complicate history.
3. The punctuated deformations recorded within the volcanic arcs
since the Aptian, imply that the Arc terranes were deformed way
before the “collision” with the Bahamas.
Paleogeographic evolution of the
continental margins
A
NORTH A MERICA
North At lant ic
rif t syst em
AFRICA
Mexican
terrains
Western Pangean
intracont inental rif t sy stem
Chortis
PACIFIC
OCEAN
SOUTH AMERICA
Andean
terrains
Land envir onments
Latest Triassic-Early Jurassic
(205-180 m.y.)
Red beds and
fr esh water sediments
Shallow mari ne
siliciclasti cs
Deep ocean
D
NORTH
ATLANTIC
Gulf of
Mexico
Florida
-Bahamas
ProtoCaribbean
PACIFIC
OCEAN
Late Jurassic
Tithonian (141-136 m.y.)
Land environments
Shallow marine
sili ciclastics
Carbonate shelf
Deep ocean
Late Cretaceous paleogeography of the continental margin
25û
Florida Platf orm
Bahamas Plat f orm
Cretaceous deformation
and metamorphism
Chix ulub
20û
Y ucatan Platf orm
NORTHERN
OPHIOLITES
Cuban Platf orm
ESCAMBRAY
TERRANE
?
PINOS
TERRANE
15û
J amaic a
Paleocene paleogeography of the continental margin
25û
Florida Platf orm
Bahamas Plat f orm
FORELAND BASINS
Chix ulub
20û
Y ucatan Platf orm
Y ucatan
Deep
ARC
PIGGY BACK BASI N
15û
-90û
-85û
-80û
-75û
Eocene deformation of the continental margin
Progressive deformation
of the continental margin
CONCLUSIONS
1. The deformations along the borderland of the Maya
block took place from SW to NE, starting in the
Cretaceous (Pinos and Escambray terranes) and lasted
until the Middle Eocene (Guaniguanico terrane).
2. The deformations along the Bahamian borderland
took place from West to East, and embrace only the
Paleocene-Late Eocene.
3. The deformations of the Northern Ophiolites took
place from South to North, and lasted since the
Cretaceous and until the Late Eocene.
4. These facts corroborate the Plate Tectonic models
which require that the present Caribbean Plate
originated West of Pangaea, to became intercalated
between North and South America since the
Cretaceous.
5. Nevertheless, the same results also represent a
problem for the most common Caribbean models,
because none of them explain why the Bahamian
borderland is deformed only during the Paleogene,
while the ophiolites for a long period of time since
the Early Cretaceous.
Project 433
Caribbea n Plate
This is a contribution to
IGCP Project 433:
"Caribbean Plate Tectonics"
Project 433
Caribbea n Plate
To learn more of this project
visit our web page
www.ig.utexas.edu/CaribPlate/CaribPlate.htm