Tectonics of Cuba and its shelf

V.S. Shein ef a/.

The territory of the Republic of Cuba, which possesses a complicated tectonic structure, has for decades attracted the attention of geo­logists from many countries. The region under consideration has been discussed in numerous publications, in which the tectonic structure of Cuba has been considered to a certain degree. They include the classical works of Schuchert (1935), Stille (1940, 1964), Eardley (1954), King (1969), and also Pushcharovskiy et al. ( 5), Khain (8 ) , Adamovich and Chekhovich (1 ) , Meyerhoff and Hatten ( 21), etc.

Scientific interest in understanding the geologic structure of Cuba has increased even more in connection with the application of the "new global tectonics" concept to the Caribbean region. In addition, a study of the tectonic structure of the island not only is of scientific interest, but also has a practical aspect, asso­ciated with the exploration for mineral resources, including oil and gas.

Geological investigations on Cuba have been conducted for more than a century, but they have not been systematic until recently. As a result, the effectiveness of the geological-exploration work has been extremely poor. The revolution in Cuba opened the way to a se ­quential and planned study of the rock succession of the country. In 1964, a monograph on the "Geology of Cuba" was published in the Spanish language. In 1967, the first tectonic map of Cuba on a scale of 1:1,250,000, compiled by the USSR Academy of Sciences and the Cuban Academy of Sciences (under the editorship of Yu. M. Pushcharovskiy and A. M. Jimenes), was published as well as a report in the Russian language on "The Geology and Mineral Resources of Cuba."

At the present time, the Cuban Academy of Sciences and the academies of a number of

Translated from Tektonika Kuby i yeye shel'fa, Sov-etskaya Geologiya, 1978, no. 2, p. 104-119. Co­authors with Shein are S. S. Ivanov, K. A. Kleshchev, V.Ye. Khain, M. Marrero, and R. Socorro. Shein is with the Middle Asian Scientific-Research Gas In­stitute, Ivanov is with the Scientific-Research Institute of the Geology of the Arctic, Kleshchev is with the Ail-Union Scientific-Research Geological-Petroleum Institute, Khain is with Moscow State University, and Marrero and Socorro are with the Center for Geo­logical Investigations, Republic of Cuba.

countries in the socialist bloc are conducting a geological survey on a scale of 1:250,000. During 1970-1975, regional geological and geo­physical work has been conducted on the island and in its marine surroundings. The land and sea geological and geophysical investigations have been undertaken along numerous regional profiles by a group of geophysical methods, including the method of exchanged earthquake waves (MOVZ), the correlation method of r e ­fracted waves (KMPV), the method of reflected waves (MOV) and its modifications, electrical-logging, and finally, a number of parametric wells have been drilled to depths of from 3. 5 to 5. 0 km. Areal magnetometric and gravi­metric investigations have been undertakea The new data obtained, together with previous information, have been reviewed by Soviet and Cuban specialists. The principal results of these investigations, concerned with questions of the tectonics of Cuba, are presented in the present work.

GEOPHYSICAL DATA ON THE STRUCTURE OF THE CRUST

The basis for estimating the deep-seated geologic structure of Cuba and its surroundings is the result of interpreting geophysical data (MOVZ, KMPV, MOV, and gravimetry) as well as a study of the physical properties of the rocks.

A review of the data on the physical pro­perties has shown that the section of the upper part of the crust may be divided into three principal parts based on density: an upper, least dense ( average density, 2. 40-2. 45 g/cm3) portion, corresponding to the sedimentary rocks of the upper Senonian-Neogene sequence; a middle portion (density 2. 65 g/cm3), embracing Jurassic-Senonian sedimentary, magmatic, and metamorphic associations; and a lower portion, consisting of metamorphic rocks, principally amphibolites (density 2. 8-3. 0 g/cm3). The effect of the two density bound­aries (the base of the Senonian sedimentary rocks (excess density = 0. 2 g/cm3) and the surface of the basement rocks), should be predominant. The boundary velocities through the discontinuity, identified with the surface of the crystalline basement, also have greater values of 6. 4-7, and in individual cases,

Internal Geology Rev., v. 21, no„ 5 IGR is not registered with the Copyright Clearance Center, Inc„

540

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

V.S. SHEIN ET AL.

JL^.

5

&mm iM^z

FIGURE 1. Diagram showing crustal types of Cuba and surround­ing sea area.

1 - regions with continental crust; 2 - regions with crust of tran­sitional type; 4 - Main Suture; 5 - deep-seated faults; 6 - isopachs

in the crust.

7. 2-7.4 km/sec. At the same time, the deeper boundaries of the discontinuity, in density r e ­spects, are less clearly defined than normally, and the excess densities at the Conrad and Mohorovicic boundaries are in all 0.15-0.2 g/cm3.

Thus, the principal boundaries of separa­tion are confined to: a) the base of the Senonian sedimentary rocks; b) the Surface of the base­ment; and c) the base of the crust. Structural restorations have been carried out on the basis of the above geophysical discontinuities. The bases for assessing the depths of occurrence of the base of the crust are MOVZ geophysical investigations along regional profiles in the western part of Cuba (24) and gravimetry. Taking account of these data, and also results of a quantitative interpretation along 15 r e ­gional profiles within the island and published information on southeastern America, the Gulf of Mexico, and the Caribbean Sea (10, 11, 17, 18, 24), a map was constructed showing the crustal types of Cuba and the surrounding sea area (fig. 1).

Within the region indicated, we are able to recognize three types of crust: continental, oceanic, and intermediate. The continental crust is characterized by its relatively great thickness (more than 25 km) and the presence of a comparatively thick "granitic" layer (10-15 km). This type of crust is typical for the western part of the Bahamas and Florida, that

is the Bahaman and, probably, the Yucatan Platforms. Oceanic crust with a thickness of 10-15 km is developed in the Bartlett ( Cayman) Trench. The remaining part of the area under consideration, including the territory of the island of Cuba, belongs to a crust of intermediate type, which may be subdivided into suboceanic and subcontinental subtypes.

The suboceanic subtype of crust is typical of the eastern part of the Yucatan Basin, where the crustal thickness reaches 18 km. The sub­continental subtype of crust is characteristic of the island of Cuba and its shelf. It is char­acteristic that a comparatively thick crust ( 30 km) alternates with a thinned kind (down to 20 km). The greatest crustal thicknesses are confined to the central part of the island, and the least, to the region of juncture between the internal eugeosynclinal and the outer miogeo-synclinal zones. An analysis of the regional geological-geophysical profiles demonstrates that the base and the surface of the consolidated crust, in most cases, are bent conformably, forming both straight positive, and also straight negative forms. However, on individual profiles in the west of Cuba, there is a certain incon­sistency in the attitude of the base and the sur ­face of the crust. In this case, we observe complicated forms of coincidence between the relief of the Moho surface and the surface of the continental crust. The thicknesses of the "basaltic" and "granitic" layers are approxi­mately identical and vary between 10 and 15-17 km.

541

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

INTERNATIONAL GEOLOGY REVIEW

The crust of Cuba has been cut by deep -seated faults into a number of blocks. The most important fault is the Main Suture, where the thickness of the crust is sharply reduced, being 13-20 km. Some of the boundary and inter-block deep-seated faults also pass into the mantle. The presence of seismic bound­aries in the upper mantle, and also calculations of the pressures below the base of the crust, carried out by S. S. Ivanov, indicate that the material of the upper mantle is not uniform. Below the base of the crust, at a depth of 32 km, pressures are 950-1060* 104 g/cm2, whereas in the surrounding blocks with oceanic and sub-oceanic crust, the pressure at this same depth is 930-104 g/cm2. Therefore, it is logical to suggest that the difference in pressure is equal­ized at significantly greater depths than 32 km, and that the upper mantle here has an anoma­lous character, with the presence of regions of decompaction. Other regions with a crust of intermediate type may also have a mantle of similar structure.

THE STRUCTURAL ZONATION OF CUBA

Based on new geological and geophysical data, we compiled a Tectonic Map of Cuba on a scale of 1:500, 000 (V. S. Shein, K. A. Kleshch-ev, S. S. Ivanov, V. N. Smirnov, M. Marrero, Ye. V. Khakhalev, S.Yu. Bankovskiy, S. Pas, G. Hernandes, M. M. Bogdanov, and the chief editor, S. P. Maksimov). On this map, dia-grammatically reproduced in Figure 2, are shown the tectonic elements of the Laramide and older fold complexes, the superimposed tectonic structures, and the allochthonous tec -tonic units.

Within the area of Cuba and its marine surroundings, several structural complexes have been recognized on the basis of the com -position of the component rocks, the degree of deformation, and the manifestation of meta-morphism andmagmatism (fig. 3): the c rys­talline basement, the early and late geosynclinal fold complexes, the complex of sedimentary rocks resting on the crystalline basement of the miogeosyncline, and the superimposed early and late orogenic complexes. In addition, tec -tonically displaced, allochthonous complexes of both eugeosynclinal and miogeosynclinal rocks are recognized.

The age of the rocks of the above complexes is variable. Evidently the crystalline basement universally consists of the oldest, pre-Jurassic formations. The early geosynclinal folded com­plex in the western and central regions of Cuba consists of Jurassic-Albian rocks.

Age of the rocks of the late geosynclinal complex is Cenomanian-Santonian, of the early orogenic complex, Campanian-Paleocene, and

of the late orogenic complex, Eocene-Quater­nary. In the extreme southeast of Cuba, rocks of the late geosynclinal complex have a Paleo-cene (possibly Late Cretaceous) — Middle Eo­cene age, those of the early orogenic complex are middle Eocene — Oligocene, and those of the late orogenic complex, Neogene-Quaternary in age.

In Cuba and its marine surroundings, the following major structural units are recognized: the Bahama-Yucatan Platform (plate) and its peripheral depressions, the North Cuban frontal foredeep, the Laramide fold system of Cuba, and a system of Late Cretaceous - Cenozoic epi-eugeosynclinal troughs (fig. 2).

The Bahama-Yucatan Platform. The Baha-man portion of this platform is located with the northern, and the Yucatan portion, within the southwestern marine surroundings of Cuba. The platform is characterized by the presence of two structural complexes: a pre-Jurassic crystalline basement, consisting of metamorphic and magmatic rocks, and a sedimentary cover, consisting of Mesozoic and Cenozoic formations. Thickness of the sedimentary cover reaches 4-6 km. In the south, the Bahaman portion of the platform forms a zone of pericratonic sink­ing, which passes into the North Cuban mio­geosyncline. The North Cuban frontal foredeep has been superimposed on the zone of per icra­tonic sinking and the northern part of the mio­geosyncline.

The Laramide fold system of Cuba. This system consists of miogeosynclinal and eugeo­synclinal zones, forming a monovergent meg-anticlinorium in the latest ( orogenic) structure.

The miogeosynclinal zone is located within the northern littoral and northern marine sur ­roundings of the island. Jn the north, it abuts along a deep-seated fault (the outer, marginal suture) with the pericratonic sinking of the Bahaman portion of the platform, and on the south, it is separated from the eugeosyncline by the inner, or Main, suture. On the land, the Upper Jurassic — Turonian miogeosynclinal formations are often overlain by Maastrichtian-Neogene deposits, which fill the North Cuban marginal foredeep, and also by a tectonically displaced ( allochthonous) eugeosynclinal com -plex. In individual blocks, rocks of the mio­geosyncline have been intensely uplifted, eroded, and crop out on the surface (Pinar del Rio, Santa Clara, Camaguey, and Holguiri). The length of the miogeosynclinal zone in the Cuban meganticlinorium exceeds 1000 km, and its width varies from 50 to 100 km.

The tectonic structure of the miogeosyncline has involved two principal structural complexes: a lower (pre-Jurassic crystalline basement), and an upper ( a complex of Jurassic-Turonian

542

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

V.S. SHEIN ET AL.

FIG

UR

E 2

. D

iagr

am o

f te

cton

ic z

onat

ion

of C

uba.

1 -

mio

geos

yncl

ine;

2

-

euge

osyn

clin

e;

3

- de

ep-w

ater

bas

ins

wit

h oc

eani

c cr

ust

; 4

- B

atab

ano

Mas

sif

(cen

tral

arc

h zo

ne);

o

utc

rop

s of

roc

ks o

f:

5 -

cry

s­ta

llin

e (m

elan

ocra

tic)

bas

emen

t w

ithi

n th

e eu

geos

yncl

ine,

6

- J

ura

ssic

-Neo

com

ian

met

acar

bona

te-t

erri

geno

us c

ompl

ex o

f th

e fo

lded

bas

emen

t 7

- A

pUan

-T

uron

ian,

pr

edom

inan

tly

volc

anog

enic

, in

ear

ly L

aram

ide

fold

ed c

ompl

exes

, 8

- l

ate

Sen

onia

n -

earl

y E

ocen

e in

lat

e L

aram

ide

fold

eclc

ompl

exes

9

-"l

ate

Eoc

ene

volc

anog

enic

-sed

imen

tary

tra

nsi

tional

(pr

e-or

ogen

ic)

com

plex

in

lat

e L

aram

ide

com

plex

es,

10 -

ter

rige

nous

-car

bona

te c

ompl

ex o

f The

mio

geos

yncl

ine,

Je

stin

g o

n th

e cr

yst

alli

ne

base

men

t;

11 -

zon

e of

tec

toni

c ov

erla

p (e

ugeo

sync

lina

l al

loch

thon

);

12 -

co

nto

urs

of

regi

ons

of e

pi-e

ugeo

sync

hnal

dow

nwar

ping

; I3

cln

tou

rS

ep

-eu

geos

yncl

inal

tro

ughs

and

bas

ins;

14

- s

outh

ern

boun

dary

of

the

Nor

th C

uban

fro

ntal

fo

red

eep

; 15

- M

ain

Sut

ure;

16

- m

ter-

bloc

k (t

ran

s-cr

ust

aTtr

ansc

urr

ent

faul

ts;

17 -

int

er-b

lock

(cr

ust

al)

tran

scu

rren

t fa

ults

; 18

- s

peci

al t

ran

scu

rren

t fa

ult

s;

19 -

eug

eosy

ncli

nal

oy

erth

rust

; 2

0 -

Sout

h C

uban

zo

ne o

f^^d

eep-

seat

ed f

ault

s;

21 -

bur

ied

boun

dary

of

earl

y an

d la

te L

aram

ide

fold

com

plex

es;

22 -

str

ike

of

stru

ctu

res

of

fold

com

plex

es;

23 -

tec

toni

c w

indo

ws;

24

- k

lipp

e.

543

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

sedimentary rocks). The crystalline basement has not been reached by drill holes, and its structure within the Cuban area has been studied by geophysical methods (MOV, gravimetry, and mag -netometry). The basement surface has been depressed southward along sys­tems of faults, forming a series of large blocks which extend in a north­westerly direction. Depth to the crys -talline basement varies within the mio-geosyncline from 6 to 12 km. The most uplifted sectors of the basement are the Pinar del Rio and Cayo Rom­ano blocks, where depth to basement is respectively 5 and 7 km. On the basis of depths to basement, the fea­tures of the composition and structure of the sedimentary rock complex of the miogeosyncline may be subdivided into two portions: inner and outer.

The outer zone of the miogeosyn­cline has a significantly greater width (up to 50-70 km) than the inner zone. It is characterized by smaller depths to the surface of the crystalline base­ment ( 6-9 km). The section in the sedimentary formations consists mainly of shallow-water carbonate rocks; near the boundary with the inner zone, reefal structures, form­ing a barrier reef, developed during the Upper Jurassic, Lower and basal Upper Cretaceous sequence. The in­tensity of folding is much weaker than in the inner zone of the miogeosyn­cline. However, here also there are steep dips of strata (50-60°) and the steep reverse - overthrusts.

The inner zone of the miogeosyn­cline directly abuts against the Main Suture and is characterized by the deep position of the crystalline base­ment ( 9-12 km) and the extreme in­tensity of folding. Its width is ap­proximately 30 km. The sedimentary rocks rest on the crystalline basement and consist of terrigenous-carbonate formations (Jurassic-Neocomian) in the lower part and chert-carbonate, relatively deep-water material (Ap-tian-Turonian) in the upper part, with a southward increase in the con­tent of cherty rocks. All these rocks have been crumpled into linear north­westerly striking folds, often with a northerly vergence, and almost every­where they are overlain along over-thrusts by allochthonous eugeosynclinal formations.

The miogeosynclinal zone of North Cuba is broken by young faults into a

FIG

UR

E 3

. D

iagr

amm

atic

sec

tion

of

tect

onos

pher

e in

Cub

a an

d it

s m

arin

e su

rro

un

din

gs.

1 -

wat

er;

2 -

Eoc

ene-

Qua

tern

ary,

pr

edom

inan

tly

carb

onat

e,

wea

kly

defo

rmed

str

uct

ura

l co

mpl

ex;

3 -

uppe

r S

enon

ian

- P

aleo

cene

te

rrig

enou

s-ca

rbon

ate

stru

ctu

ral

com

plex

: a)

fly

scho

id w

ithi

n re

gion

s of

epi

-eug

eosy

ncli

nal

dow

nwar

ping

, b

- lo

wer

mol

asse

in

zone

of

fro

nta

l fo

rede

ep;

4 -

Jura

ssic

-San

toni

an,

pred

omin

antl

y ca

rbon

ate,

st

ruct

ura

l co

mpl

ex:

a- f

olde

d m

ioge

osyn

clin

al,

b -

wea

kly

defo

rmed

pla

tfo

rmal

; 5

- C

reta

ceou

s fo

ld-o

ver

thru

st e

ugeo

sync

lina

l co

m­

plex

; 6

- Ju

rass

ic-N

eoco

mia

n m

etam

orp

hic

com

plex

(m

eta-

terr

igen

ou

s an

d m

eta-

carb

onat

e);

7 -

hype

rbas

ites

; 8

- se

rpen

tini

zed

hype

rbas

ites

; 9

- al

loch

thon

­ou

s o

ccu

rren

ce o

f ro

cks

of o

phio

lite

ass

ocia

tion

(te

cton

ic m

elan

ge a

nd o

list

ostr

ome

sequ

ence

s in

zon

e of

tec

toni

c o

ver

lap

);

10 -

su

rfac

e of

cry

stal

line

ba

sem

ent

wit

hin

the

mio

geos

yncl

ine

and

the

zone

of

per

icra

ton

ic s

inki

ng o

f th

e B

aham

an P

latf

orm

; 11

- b

ase

of c

rust

; 12

- b

asem

ent

wit

hin

the

pres

ent

geos

yncl

ine

(3rd

la

yer

of o

cean

ic c

rust

);

13 -

geo

phys

ical

lay

ers:

a

- g

ran

itic

, b

- bas

alti

c;

14 -

bas

emen

t w

ithi

n th

e eu

geos

yncl

ine;

15

- s

upra

-ast

heno

sphe

re l

ayer

of

man

tle;

16

- a

sthe

nosp

here

; 17

- b

ound

arie

s of

geo

phys

ical

lay

ers;

18

- d

eep-s

eate

d f

ault

s;

19 -

fau

lts

in t

he c

over

and

the

upp

er p

art

of t

he c

rust

; 20

- s

ole

of m

ajor

dee

p-s

eate

d o

vert

hrus

ts;

21 -

sol

e of

reg

iona

l na

ppes

; 22

- s

pec

ial

over

thru

sts.

INTERNATIONAL GEOLOGY REVIEW

544

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

V.S. SHEIN ET AL.

system of transverse blocks. The transverse faults, which led to the formation of the blocks, cut the folded or fold-overthrust rock complexes and as result, not simply blocks, but horst-anticlinoria and graben-synclinoria have been formed, recognized on the map by Pushcharov-skiy et al. (5 ) . The most typical of them is the Pinar del Rio horst-antic linorium, the structure of which involved Mesozoic sediment­ary rocks, beginning with the Lower-Middle Jurassic sequence, which crops out in its cen­tral part. The small outcrops of volcanic and intrusive rocks occurring here are, in our opinion, klippen (preserved from erosion by fragments of the eugeosynclinal allochthon). In many cases, the Lower Jurassic-Oxfordian rocks and the overlying sequence form a com -plex combination of nappes, which were subse­quently (at the end of Eocene time and later) broken up* into a series of blocks of different size.

The inner, eugeosynclinal zone of the Lara­mide fold system occupies a significant area of the island and part of the southern marine surroundings. In the north, as noted previously, it was separated by the Main Suture from the miogeosynclihe, and in the south by a zone of deep-seated faults from the present geosyn-clinal system of the Caribbean Basin. The floor of the eugeosyncline is the crystalline basement, intensely altered by geosynclinal processes, evidently of pre-Jurassic age. It consists of metamorphic rocks, mainly amphi-bolites, which crop out near Escambraya. Its surface may be traced by seismic-exploration to a depth of from 1. 0 to 7. 5 km.

The next structural complex of this zone consists of Jurassic-Neocomian terrigenous and carbonate rocks, metamorphosed to the greenschist and partly to the amphibolite facies. It shows up on the surface on Isla de Pinos south of the western part of Cuba, in the Es -cambray Mountains to the north of the town of Trinidad, and in the Sierra de Purial in the ex­treme eastern part of the island. This meta­morphic complex has been studied in detail by Somin and Mil'yan (6, 7 ) , who have proved its Mesozoic age, which was earlier suggested on the basis of similarity to the San Cayetano Suite of the Pinar del Rio region.

The Jurassic-Neocomian metamorphic complex possesses a complicated structure, normal for metamorphic sequences, consisting of small, intensely crumpled folds; however, its non-metamorphosed equivalents in the Or-ganos Mountains reveal a similar structure. On the whole, the outcrops of the complex in the inner zone of Cuba have the nature of large domes, which is particularly evident in Pinos and Escambray.

Surrounding these domes, as has been shown for the Escambray area by Somin and Mil'yan, and for the Sierra de Purial by Cobi-ella (13), there are rocks of the ophiolite complex ( serpentinized hyperbasites, amphi-bolites, e t c . ) . The upper part of the complex is formed by a typical spilite-diabase associa­tion, usually dated as Aptian-Albian. However, its age may be older, beginning at the end of Jurassic time. The equivalents of this asso­ciation on Haiti are considered to be pre-middle Aptian in age, on Puerto Rico and the Virgin Islands, pre-Albian, and on Desirade ( Lesser Antilles), they are older than 142 m. y . , that is, not younger than Late Jurassic ( 12).

The ophiolite complex is overlain by a Cenomanian-Turonian andesite association; in the literature, there is information about the presence in the basal portions of this associa­tion, of ophiolite clasts, which may indicate a break and significant movements prior to the beginning of its deposition. The thickness of the association reaches 1. 5 km.

The andesite volcanogenic association is spatially and evidently genetically associated with intrusive bodies of rocks of the quartz diorite and granodiorite type. Outcrops of this volcanic-plutonic complex extend through the central axial part of Cuba to the south of the Main Suture, reaching its greatest development in the provinces of Las Villas (region of Santa Clara) and Camagiiey. As we shall see later, they may be interpreted as a Late Cretaceous volcanic arc.

The Coniacian-Santonian deposits, which have a volcanogenic-clastic composition, in associational and structural respects occupy an intermediate position between the Cenomanian-Turonian andesite association and the Maas-trichtian-Cenozoic orogenic formations.

All that has been said about the age of the late geosynclinal complex applies to that sig­nificant major portion of Cuba where the main zone of tectonic deformations occurs in the Senonian sequence, that is , it is early Laramide in age. The culmination phases of this epoch were sub-Hercynian(pre-Coniacian) and spec­ifically early Laramide (pre-Maastrichtian). Deposition of the orogenic complex of sediments, which fill the epi-eugeosynclinal downwarps, began in Maastrichtian time.

The zone of early Laramide folding extends along the length of Cuba for more than 800 km, with a width of about 100 km. In the west, it branches and extends around the Batabano Mas­sif.

545

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

INTERNATIONAL GEOLOGY REVIEW

The buried Batabano Massif embraces a large area of the Gulf of the same name within the southwestern shelf and the neighboring land area. Its maximum length is 200 km, and width 130 km. From geophysical data, the section of the massif consists of crystalline basement and a sedimentary cover from 1. 5-2. 0 up to 5.0 km thick. Between the basement and the cover there may be Cretaceous ( ?) volcanogenic rocks present, the thickness of which does not exceed 1. 5 to 2. 0 km. The most deeply depressed part is the northern and western edge of the massif, where the depth to basement is 4.0-6. 0 km.

The zone of late Laramide folding embraces the southeastern part of Cuba (the Sierra Maestra Range and its slopes). Deformation also took place in two phases ( a preliminary, Havanan phase, on the Paleocene-Eocene bound­ary, and a principal, Oriente, phase, on the early-middle Eocene boundary. Deposition of the andesite association continued here during the course of late Senonian and the beginning of Paleogene time until early Eocene inclusive. The rocks of this association have been cut by granitoid plutons and less frequently by basic intrusions. The principal structures of the zone of late Laramide folding are the Sierra Maestra horst-anticlinorium and the accom­panying East Cuban synclinorium to the north (5) . The inner structure of the Sierra Maestra anticlinorium is of the fold-overthrust type; it has been complicated by young vertical faults, which have broken the anticlinorium into blocks.

Orogenic epi-eugeosynclinal downwarps have been superimposed on the Laramide fold structures of the eugeosynclinal complex and the Batabano Massif. Two of them (the West Cuban and Central Cuban) are located in the zone of early Laramide folding and have conse­quently been filled with a Senonian-Neogene orogenic complex. A third downwarp (the East Cuban) already lies in the zone of late Laramide folding; its sequence includes mo-lasse formations, beginning only from middle Eocene time.

The East Cuban downwarp, or more p r e ­cisely, its most easterly Cauto Basin, is a centricline of a geosynclinal basin developing at the present time with a suboceanic crust (the Yucatan Basin of the Caribbean Sea). The Sierra Maestra anticlinorium, in its turn, ex -tends westward along the Cayman Submarine Ridge, which terminates the islands of the same name. The unity of these structures is empha­sized by the large positive magnetic anomaly which joins them and by the results of dredging, carried out both by American and by Soviet expeditions (2 ) .

In the south, the Cayman - Sierra Maestra r i se abuts along a major fault with the Bartlett

(Cayman) Deepwater Trench. Attention is drawn to the fact that all these three structures are younger than the main portion of Cuba, and have a near-latitudinal (WSW-ENE) strike, which forms a significant angle with the north­westerly strike of the main structures of the island. However, the latter all reach its east­ern end, the Sierra Maestra anticlinorium being separated from the eastern pericline by the Guantanamo Basin.

As noted previously, the eugeosynclinal and miogeosynclinal zones of Cuba throughout their extent have been separated by the Main Suture. The latter is clearly associated with a marginal overthrust, along which the mio-geosyncline was overlain by eugeosynclinal rocks, which formed a zone of tectonic overlap over a significant area (fig. 4). It extends for more than 1000 km and has a width (equal to the amplitude of the horizontal displacements) of from 10-25 km in the central regions up to 40-80 km in the west and east of the island. The thickness of the overthrust sequences is up to 4 km. The existence of this zone has been demonstrated by geological observations, drilling, and geophysical data.

In the sequence of the zone of tectonic over­lap, two stages (plates) have been identified above the autochthon: a lower, Camarioca* stage, and an upper, Bacuranao * stage. The autochthon consists of Upper Jurassic-Neocom-ian miogeosynclinal deposits, on which Maas­trichtian-Paleocene rocks rest with intense stratigraphic unconformity. The Camarioca tectonic plate includes an Aptian-Turonian carbonate-chert miogeosynclinal (leptogeosyn-clinal) sequence, also unconformably overlain by Maastrichtian-Paleocene clastic sediments. Drilling has established that the tectonic plate under consideration has been overthrust onto the Maastrichtian-Paleocene rocks of the autoch­thon. The Bacuranao tectonic plate consists of Cretaceous eugeosynclinal rocks with a transgressive Maastrichtian-Paleocene sequence in the roof. This plate rests both on the rocks of the Camarioca tectonic unit and also on older rocks. The Camarioca (miogeosynclinal) and Bacuranao (eugeosynclinal) plates have been partially buried under younger Eocene-Quaternary rocks, which have already partici­pated in the fold-overthrust processes, forming a neo -autochthon.

The zone of tectonic overlap is cut by transverse faults (transcurrent faults, normal faults, e t c . ) , forming frequent nappes: Pinar del Rio, Bahia Honda, Havana-Matanzas, Mo-tembo, Santa Clara, Moron, Gloria, Hibara, * and Moa. The length of these nappes is mea­sured in hundreds of kilometers, its width is

* Names not verified.

546

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

V.S. SHEW ET AL.

10-80 km, and its thickness ranges from hund­reds of meters up to 4 km (Bahia Honda and Havana-Matanzas). The nappes have, in turn, been broken up into smaller portions (blocks).

The North Cuban ( Cis-Cuban) frontal fore-deep separates the Cuban fold system from the Bahama Platform and occupies the northern littoral with its adjoining sea areas. The fore-deep has been filled mainly with carbonate, clastic-carbonate, and evaporite, and less fre­quently terrigenous deposits of late Senonian -Neogene age, with a thickness up to 5 km. These molasse formations are underlain in a normal stratigraphic sequence by a Jurassic -Santonian rock complex, belonging in part (to the south) to the miogeosyncline, and in part (to the north) to the southern margin of the platform. The length of the North Cuban fore-deep is 1200 km, and its width 45-60 km. In transverse section, the foredeep consists of southern (near-geosynclinal or folded) and northern ( near-platform) margins and a central zone. Along strike, the foredeep is divided by transverse r ises into three principal sectors: western, central, and eastern. The near-geo­synclinal margin of the foredeep extends for 1200 km and has a width of 20-45 km, and the thickness of the infilling sediments is 1-2 km. During pre-Eocene time, the Maastrichtian-Paleocene rocks developed within it underwent intense fold-overthrust deformations, as a r e ­sult of which they were crumpled into linear folds along with the underlying miogeosynclinal formations of Late Jurassic-Turonian age. In individual places (the Haruco* region, e tc . ) , the Aptian-Turonian rocks of the miogeosyncline have been overthrust onto Maastrichtian-Paleo-cene rocks. In other cases (Moron region), the near-geosynclinal margin of the foredeep has been buried below the eugeosynclinal plate. The northern boundary of the folded margin, which separates it from the central zone, is quite marked and is confined to regional normal-fault and flexural-fracture zones.

The central, axial zone of the foredeep extends parallel to the folded margin, and has a width of 30-75 km. The thickness of the sedi­mentary filling here is 4-5 km, and the depth to basement is up to 6. 5 km. At the present time, this zone is undergoing non-compensated sinking, in connection with which, the depth of the sea reaches 2 km. The zone under consider­ation is distinguished from the folded margin of the frontal foredeep primarily by the marked decrease in deformation of the sequences. Here, gentle folds of platformal type are de­veloped, complicated in individual cases by normal faults.

* Names not verified.

The near-platform margin of the frontal foredeep extends in the sea area for a distance of 60-150 km from Cuba. Rocks of this zone, without significant structural unconformity, rest on deposits of the pericratonic trough of the Bahama Platform. The folds here j^ce of the platform type.

One of the most important problems of Cuban geology is the nature of the Main Suture and the origin of the ophiolite complex. In the modern structure of Cuba, the Main Suture, which bounds the eu- and miogeosynclinal zones and extends throughout the entire island for a distance of 1300 km, a width of 35-40 km, and is inclined southward at 60-70°, borders the main zone of distribution of the ophiolite complex which occurs northeast of this suture in a clearly allochthonous attitude. Magmatic rocks of the complex are assumed to have penetrated from the mantle either in the form of intrusions, or, as is most likely, in the form of protrusions (19) along this deep-seated fault, and were dis­tributed tectonically to the northeast, having covered the miogeosynclinal formations.

The decisive role of the Main Suture is emphasized by geophysical data, which indicate an uprise of the Moho surface along it, and that it borders a region with a significantly different crust (typically continental in the northeast and subcontinental in the southwest). This fault controls the distribution of rocks of differ­ent composition. Thus, to the north of it, not taking account of the allochthon of the zone of overlap, sedimentary rocks of the miogeosyn­cline are developed, and to the south, essen­tially magmatic eugeosynclinaL formations. An important consideration is also the confinement of glaucophane-lawsonite schists, eclogites, and eclogitic rocks to the Main Suture, or more precisely to its southeastern limb and the ophio­lite allochthon (7, 12).

However, the distribution of the ophiolite complex is not limited to the Main Suture alone. It is also invariably distributed in the form of a melange over a considerable distance from this suture toward the south, in particular in the region of Santa Clara (Las Villas Province), reaching here the northern slopes of the Escam-bray Massif, where it lies in tectonic contact with the metamorphic rocks of the core of the massif. In the extreme eastern part of Oriente Province, ophiolites are known not only on the northern but also on the southern slope of the Sierra de Purial Massif and near the Cayman Trench. The hyperbasites ( serpentinized lherzolites) have been exposed by dredging in this same trench, 160 km west of Great Cayman Island (25), at the base of the Cayman - Sierra MaestraRidge. These data suggest the existence of yet another, southerly ophiolite trough or that all the ophiolites have a southern extension and occur in allochthonous attitude ( 9), but over a

547

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

INTERNATIONAL GEOLOGY REVIEW

^ j ^ r r v ^ ^

5 E3* E3' d FIGURE 4. Diagrammatic geological profile from Camarioca* to Chapelin* (Matanzas Province).

1 - surface of crystalline basement; 2 - rocks of eugeosynclinal allochthon; 3 - Upper Jurassic-Turonian miogeosynclinal formations; 4 - Maastrichtian-Paleocene early orogenic formations; 5 Eocene-Miocene late orogenic formations; 6 - eugeosynclinal overthrust; 7 - overthrusts (intra-

miogeosynclinal); 8 - reverse and normal faults.

significant part of the island they have been buried below younger formations or have been eroded away ( in the region of projections of the metamorphic basement — Pinos, Escam-bray, e tc . ) . The best conditions for the p r e ­servation of the rocks of the ophiolite complex in the form of melange or in redeposited form ( a s olistostromes) arose in the zone of the Main Suture and in front of it, where the ophio­lite material was seemingly a filler of an un­compensated Cretaceous (Tithonian-Turonian) trough.

In completing the description of the modern structure of Cuba, we must take note of a sys­tem of young sinistral transcurrent faults with northeasterly strike. Total displacement of these transcurrent faults is about 350 km; this means that the southeastern end of the Cuban meganticlinorium was displaced by this amount relative to the northwestern end, and on the whole the island has undergone tension along strike. In the west of Cuba, it has evidently been separated by a large sinistral transcurrent fault from the Yucatan Peninsula and its shelf, which sinks stepwise into the Yucatan Basin.

PROBLEMS OF THE TECTONIC HISTORY OF CUBA

The tectonic history of Cuba as a whole may be quite confidently reconstructed only

* Names not verified.

from the beginning of middle Cretaceous time, and for the miogeosyncline, we may start with Jurassic time. One of the fundamental problems that must be clarified in order to throw light on the earlier history, is the age and nature of the crystalline basement. The latter, as has been noted, is different in its physical properties in the two blocks, which meet along the Main Suture. In the northern (northeastern) block, the basement is common to the basement of Yucatan and Florida, revealed by drilling, and is probably of Precambrian age (8 ) , although it is possible that metamorphosed lower and middle Paleozoic formations also participated in its construction, especially in the south, that is, in the vicinity of Cuba. The thickness of the consolidated crust within this block is 25-30 km.

The southern block corresponds to the inner zone of Cuba. The thickness of the consolidated crust within it is 20-32 km; calculations suggest an increased density for its component rocks (2. 8-3. 0), beginning with the upper parts; the Conrad and Moho discontinuities are vaguely defined. All this shows that the crust within the Cuban block consists mainly of rocks either intensely metamorphosed, or predominantly of basic composition ("melanocratic basement, " according to M. S. Markov). In the first case, we may be dealing with lower Precambrian formations which approached the surface during pre-Jurassic time as a result of lengthy uplifts (the granulite belt of the Grenville type in North America). In the second case, the crust

548

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

V.S. SHEIN ET AL.

may be significantly younger, up to early Meso-zoic in age, and may primarily represent a crust, close to oceanic in type, not having been subjected to complete "continentalization. " The first hypothesis is favored in part by the presence of clasts or tectonic fragments of gneisses and crystalline schists at several points, concentrated near the zone of the Main Suture (G. Mil'yan). In any case, the Cuban block is an independent block of continental crust which may probably be regarded as a median massif. However, it may originally have been associated with the Central American Massif, the eastern extension of which is r e ­presented by the Nicaraguan Rise (8) .

The cover of this massif consists of the San Cayetano Lower-Middle terrigenous asso­ciation arid an Upper Jurassic carbonate asso­ciation, represented in metamorphosed form in Isla de Pinos and in Escambray. The San Cayetano Series, in its association aspect, is similar to the marginal, pericontinental sub-association of the sand-shale association of the Lower and Middle Jurassic of the Northern Caucasus, that is , it represents deposits of the inner part of the shelf and the continental slope. The source of supply of its constituent terrigenous material could have lain either within the North American continent (transport by a large river of the Mississippi type), or within the Nicaraguan Rise, with the essentially quartzose composition of the silt-psammites indicating erosion of a granite-gneiss basement. Significant opposition to the first variant (sup­ply from the north) is seen in the development of deposits of similar age in the form of eva­porites in the vicinity of the Gulf of Mexico, the Bahama plate, and the Cuban miogeosyn-cline, if only these evaporites did not commence on a higher stratigraphic level, corresponding already to the carbonate association.

The next, strictly geosynclinal stage of development began in the vicinity of Cuba, as throughout the entire Caribbean region, at the end of the Jurassic Period, probably in Tithon-ian time. To the south of the Bahama-Yucatan plate (southern margin of the North American plate), a geosynclinal system developed, ex­tending westward through the region of the Gulf of Honduras into Honduras, Guatemala, and Southern Mexico. This system evidently r e ­presented the southwestern extension of the North Atlantic, and not the Pacific Ocean (20).

The southern part of the northern miogeo­synclinal zone of Cuba, from Tithonian to Turonian time, was a deepwater trench with deposition of chert-carbonate sediments, which did not compensate the sinking. This trench could have been underlain by a thin crust s imi­

lar to the oceanic type and could have been bounded on the south by the Central Cuban median massif, a relict of which at the present time is the buried Bataband Massif. The trench possibly comprised only the northern margin of a larger basin with oceanic crust, which sub­sequently also gave rise to the ophiolite flows in the northeastern limb of the Main Suture. It is more likely, however, that the main eugeo-synclinal basin lay somehwere to the south of the Central Cuban Massif, in the band of the present-day Cayman - Sierra Maestra Rise or even farther south.

At the end of Early Cretaceous time, prior to Albian or Cenomanian time, this early geo­synclinal phase, characterized, especially at the beginning, by intense tension, was replaced by the late geosynclinal phase with predominance of compression. Along the northern margin of the Central Cuban Massif, in the band of the present Main Suture, a Benioff zone developed, sloping below the massif. It evidently follows that its formation must be associated with over-thrusting of the ophiolite masses, converted into a melange, from the southern basin onto the median massif, the formation of an andesitic volcanic arc along its northern edge in the hanging wall of the Main Suture, the injection of granitoid intrusions, and the regional meta-morphism of the Jurassic - Lower Cretaceous sequences as far as the formation of glauco-phane-lawsonite schists and eclogites in the band of the Main Suture. The fact that this metamorphism is even more clearly defined in the northeastern part of Haiti (22), proves the decrease in the angle of slope of the Benioff -zone surface in this direction. On the other hand, near the western end of Cuba, the Benioff zone was probably broken by a transform fault, and its continuation should be sought even in Central America.

The next phase of intense compression took place in the region under consideration duringpre-Coniaciantime (the sub-Hercynian phase). This phase included the beginning of fold deformations of the miogeosynclinal complex and overthrusting of the ophiolite allochthon along with material of younger andesitic volcanics onto the southern margin of the miogeosynclinal zone. This material has in part been converted into olistostromes under the influence of gravity, and these have been buried in the base of the orogenic upper Senonian complex. Thus, the ophiolite, melange-olistostrome material ope­rates as a filler of an uncompensated downwarp, developed since Tithonian time. This indeed may explain the great thickness of the ophiolite nappe, which reaches 3-4 km. The pre-Conia­cian phase probably also includes the beginning of nappe-transport of the Jurassic-Neocomian sequences of the cover of the Central Cuban Massif into the area of the future Sierra de los Organos.

549

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

INTERNATIONAL GEOLOGY REVIEW

During the next phase of compression dur­ing pre-Campanian time, the ophiolite allochthon was crumpled into folds along with the underly­ing rocks of the miogeosynclinal zone. The melange-olistostrome sequence, unconformably overlain later by the upper Senonian-lower Paleogene molasse and again gently crumpled along with it, was converted into a collector, enclosing the oil pools in Cuba. In Central Cuba, the ophiolite complex was preserved in structures of synformal type and was eroded in the antiforms (the granite-gneiss domes).

Beginning with the pre-Campanian, early Laramide phase, the central part of Cuba be­gan to undergo a general uprise; the Central Cuban geanticline developed, the axis of which became the Late Cretaceous volcanic -plutonic belt ( a r c ) . Farther north, formation of the North Cuban frontal foredeep began, being filled with decomposition products of this arc, and posteriorly, the formation of epi-eugeosyn-clinal downwarps begaa This same process, as a result of rifting and mantle diapirism, led to the development of the Yucatan Basin, r epre ­senting an inter-arc basin since to the south of it, and ranging in time from Senonian up to Middle Eocene, a second younger arc (Cuba — Cayman - Sierra Maestra) developed. Its o r i ­gin in the ophiolite substrate is considered more likely than in continental crust, which has been suggested by some American investigators. This arc intersects the trend of the Central Cuban arc, beginning in Campanian time. The Main Suture evidently ceased to play the role of a Benioff zone, and the latter was displaced to the south of the Cayman - Sierra Maestra band, whereas its eastern extension, beginning in Haiti, retained its original position.

Compression along the Main Suture was manifested on the Paleocene-Eocene boundary, during the Havanan phase of tectogenesis, and was expressed in crumpling of the inner margin of the North Cuban trough into folds. Almost simultaneously or somewhat later, movements began along transcurrent faults, which dissected the entire structure of Cuba into a large number of blocks. They led to the advance of the Cuban island arc in a northerly direction; this is e s ­pecially significant on the western flank where it must have been accompanied by displacement along the East Yucatan fault. Accompanying these movements, there may also have been further opening of the Yucatan Basin, the width of which is commensurate with the total amplitude of the transcurrent displacements, and also the above-noted fold deformations of the North Cuban downwarp. The beginning of Paleogene time was the principal epoch of formation of olistostromes in Cuba (also known in the upper Senonian sequence), which had earlier been recognized as independent stratigraphic sub -

divisions (e . g. the Manacos * in Pinar del Rio, and La Picota in Oriente) and described as "wildflysch" (Hatten et a l . ) .

The last major phase of compression and tangential deformations occurred at the end of middle Eocene time (locally referred to as the Oriente phase). In practice, it affected only the south of Oriente Province, mainly the Sierra Maestra, the present structure of which is due to this phase of diastrophism. In the remaining area of Cuba and in its surroundings at this time, only block-wave movements took place. Toward the end of the Oriente phase, there was yet another important event — sinis­tral movements along a transform fault to the south of the Cayman - Sierra Maestra Rise, along which the deepwater Bartlett ( Cayman) Trench was subsequently formed. It is actively developed in the present epoch in contrast to the Yucatan Basin, the aseismicity of which suggests only a relatively smooth downwarping.

After the movements of the Oriente phase, we observe a gradual decrease in tectonic activ­ity, which had reached its culmination during Miocene time. This is indicated by the com­plete cessation of volcanic activity, a gradual decrease in the role of coarse and very coarse clastic rocks and their replacement by carbon­ate rocks and even evaporites, and also by a marine transgression onto the planated land area. Indeed, this process was not smooth, and it was interrupted, in particular, at the Oligocene-Miocene boundary, and before the late Miocene and Pliocene by separate phases of uplift, but no significant deformations took place in this case. The south part of Oriente retained its mobility longest of all and ended its geosynclinal development later than the other regions.

With respect to the previous Campanian-Eocene orogenic stage, the present stage could be regarded as post-orogenic. However, such a definition is scarcely valid. At the end of Pliocene time ( during Quaternary time), Cuba, like the whole of the Caribbean region, entered a phase of active orogeny with reconstruction of the mountain relief (the so-called Caribbean phase of diastrophism). This phase of develop­ment of Cuba and the Caribbean region may be classified as late orogenic, in contrast to the early orogenic Campanian-Eocene phase. So far as the Oligocene-Neogene "inter-orogenic" period is concerned, in tectonic activity it represents quite a normal phenomenon, r e ­flected in the development of a regional planation surface, which cuts across the earlier folded structure and has later undergone intense block-wave deformations during the late orogenic phase. But the specific feature of Cuba and

*Name not verified.

550

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

V.S. SHEIN ET AL.

the Caribbean region as a whole is the lingering nature of this "inter-orogenic" period, reflected in the predominance of carbonate rocks in the sequence of the North Cuban downwarp.

Such is the possible model of the tectonic evolution of Cuba. There still remain in it many unsolved problems, which may be answered only during a process of further investigations, in particular, the completion of a detailed geo­logical map and the drilling of deep wells of the parametric type not only in the basins, but also in the present uplifts.

REFERENCES

1. Adamovich, A. F . , and Chekhovich, V. D., 1964, FUNDAMENTAL FEATURES OF THE GEOLOGIC STRUCTURE OF EAST­ERN CUBA: Moskov. Obshch. Ispytateley Prirody Byull., Otdel. Geol., v. 39, no. 1, p. 10-21.

2. Valyashko, G.M., El'tsina, G. N., Litvin, V. M., et aL , 1975, GEOLOGICAL AND GEOPHYSICAL CHARACTERISTICS OF THE PRINCIPAL STRUCTURAL ELE­MENTS OF THE MEXICAN-CARIBBEAN REGION: AN SSSR Inst. Okeanolog. TrUdy, v. 100, p. 18-39.

3. Knipper, A. L . , and Puig-Rifa, M., 1967, TECTONIC POSITION OF THE PRO­TRUSIONS IN THE NORTHWESTERN PART OF ORIENTE PROVINCE. In GEOLOGY AND MINERAL RESOURCES OF CUBA: p. 42-57, Izd-vo Nauka, Mos­cow.

4. Laverov, N. P . , Shanin, L. L., and Cobrera-Ortega, R., 1967, ABSOLUTE AGE OF SOME ROCKS IN CUBA. In GEOLOGY AND MINERAL RESOURCES OF CUBA: p. 188-190, Izd-vo Nauka, Moscow.

5. Pushcharovskiy, Yu.M., Knipper, A. L . , and Puig-Rifa, M., 1967, TECTONIC MAP OF CUBA ON A SCALE OF 1:1, 250, 000. In GEOLOGY AND MIN­ERAL RESOURCES OF CUBA: p. 7-30, Izd-vo Nauka, Moscow.

6. Somin, M. L . , and Mil'yan, G., 1972, METAMORPHIC COMPLEXES OF PINOS, ESCAMBRAY, AND ORIENTE IN CUBA AND THEIR AGE: AN SSSR Izvestiya, ser. geol., no. 5, p. 48-58.

1976, SOME FEATURES OF THE STRUCTURE OF THE MESOZOIC META­MORPHIC SEQUENCES IN CUBA: Mos­kov. Obshch. Ispytateley Prirody Byull., otd. geol., v. 51, no. 5, p. 73-94.

8. Khain, V. Ye., 1975, PROBLEMS OF THE TECTONICS OF THE MEXICAN-CARIB-BEAN REGION. In TECTONICS, SEIS-MICITY, AND GEODYNAMICS OF THE SOUTHEASTERN SURROUNDINGS OF THE PACIFIC OCEAN: p. 20-60, Soviet Radio Press , Moscow.

9. Shaposhnikova, K.I . , 1974, TECTONICS OF CENTRAL CUBA: Geotektonika, no. 1, p. 29-44.

10. Echchevaria, G., Shablinskaya, N. V., and Shatsilov, V. I . , 1974, NEW DATA ON THE STRUCTURE OF THE CRUST OF THE WESTERN PART OF CUBA: AN SSSR Doklady, v. 215, no. 3, p. 673-676.

11. Ewing, J . , Ewing, M., and Ley den, R., 1970, SEISMIC-PROFILE SURVEY OF THE BLAKE PLATEAU. In CONTINENTAL MARGINS AND ISLAND ARCS: p. 165-180, Izd-vo Mir. [Translation of idem, 1966, Am. Assoc. Petroleum Geologists Bull., v. 50, p. 1948-1971.]

12. Boiteau, A., and Saliot, Michard P . , 1972, METAMORPHISME DE HAUTE PRESSION DANS LE COMPLEXE OPHIO-LITIQUE DU PURIAL (ORIENTE, CUBA): Acad. Sci. Comptes Rendus, Paris , v. 274, p. 2137-2140.

13. Cobiella, I. L. , 1974, ALGUNOS RASGOS DE LA ESTRATIGRAFIA DE IMIAS Y CAJOBABO, PROVINCE DE ORIENTE: Primera hornado cientifico tectonica, Habana, p. 18.

14. Judoley, C M . , Soloviov, O.N., Skidan, I.K., e t a l . , 1964, COMMENTARIOS SOBRE EL MAPA GRAVIMETRICO DE LA ISLA DE CUBA: Revista Tecnologica, v. 2, no. 2, p. 8-19.

15. Furrazola-Bermudez, G., Judoley, C. M., Mijailovskaya, M., e t a l . , 1964, GEO-LOGIA DE CUBA: 350 p.

16. Hatten, C. W., 1967, PRINCIPAL FEA­TURES OF CUBAN GEOLOGY. DISCUS­SION: Am. Assoc. Petroleum Geologists Bull., v. 51, no. 5, p. 780-789.

17. Ipatenco, S., Copnin, M., and Shijov, S., 1971, EMPLES DE LA EXPLORACION GRAVIMETRICA PARA ESTUDIAR LA ESTRUCTURA DE LA CORTESA TER-RESTRA DE LA ISLA DE CUBA Y LOS TERRITORIAS ADIACENTES: Revista Tecnologica, no. 2, p. 18-19.

18. Ipatenco, S., and Sagina, N., 1974, SOBRE DE LA VANTAMIENTO GRAVI­METRICO EN CUBA: La Habana, Min­ister io de Mineria Combustible y Metal-lurgia, p. 8-14.

551

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013

INTERNATIONAL GEOLOGY REVIEW

Knipper, A. L. , and Cabrera, R., 1972, TECTONIC POSITION OF ULTRAMAFIC BODIES OF CUBA: VI Confer, del Caribe, Mem., 5 pp.

Malfait, B. T. , and Dinkelman, M.G., 1972, CTRCUM-CARIBBEAN TECTONIC AND IGNEOUS ACTIVITY AND THE EVO­LUTION OF THE CARIBBEAN PLATE: Geol. Soc. Am. Bull., v. 83, no. 2, p. 251-271.

Meyerhoff, A. A. , and Hatten, C.W., 1974, BAHAMAS SALIENT OF NORTH AMERICA, TECTONIC FRAMEWORK, STRATIGRAPHY AND PETROLEUM POTENTIAL: Am. Assoc. Petroleum Geologists Bull., v. 58, no. 6, p. 1211-1239.

Nagle, F . , 1960, CARIBBEAN GEO­LOGY: Marine Sci. Bull., v. 21, no. 2, p. 375-439.

23. Piotrowska, K., 1975, THE NAPPE DE­VELOPMENT ON THE SIERRA DE LOS ORGANOS (WESTERN CUBA): Ac. Pol. Sci. Bull., ser . Sciences de la Terre, v. 23, no. 1, p. 43-52.

24. Sherbacova, B . , Bovenko, K., and Hernandes, G., 1974, UTILIZACION DEL METODO DE LAS ONDAS DE CAMBIO DE LOS TERREMOTOS PARA EL ESTUDIO DE LA ESTRUCTURA GEOLOGICA PROFUNDA DE CUBA: Primera Jornada cientifica tectonica, T. H. La Habana, p . 91.

25. Eggler, D.H. , Fahlquist, D.A., Pequeg-nat, W.E . , e t a l . , 1973, ULTRA-BASIC ROCKS FROM THE CAYMAN TROUGH, CARIBBEAN SEA: Geol. Soc. Am. Bull., v. 84, no. 6, p. 2133-2138.

552

Dow

nloa

ded

by [

Tem

ple

Uni

vers

ity L

ibra

ries

] at

20:

46 0

7 M

ay 2

013