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Geothermics

(I9 7o ) - SPECIAL ISSUE 9.

U. N. Symposium on the Development and Util ization of Geothermal Resources, Pisa I97o. Vol. 2, Part 2

A Note on the Hot Spr ings o f Ecuador

A . D E

G R Y S * , ~ . V E R A * * AND P . G O O S S E N S * * *

A B ST R A CT F r o m h i s t o r i c a l r e c o r d t h e r e i s e v i d e n c e t h a t t h e

W ater s f rom severa l Ecuad or ian h o t spr in gs w ere an a- h o t sp r i n gs h av e on occa s ion s been a f f e c t ed by ea r t h -

l y z ed . O n a p r e l i m i n a r y b a s i s t h e s p r in g s m a y b e d i v i d e d i n t o

t h r e e g r o u p s : a ) c o a s t a l s p r i n g s w h i c h h a v e n o t b e e n s t u d i e d ;

q u a k e s .

I n 1 9 3 8 a n

e a r t h q u a k e i n t h e V a l l e d e l o s

b) a nor thern group of springs which are in the v icin ity of Chi l l os , near Oui to , cau se d on e set of spr ing s to d isa p-

volcanoes; and c) a southern group of springs associated with

t ravert ine deposi ts , s i tuated in an area of Pl io-Pleistocene pe ar wh i le fo r an ot he r the te m pe ra tu re ros e an d the

v o lcani sm. Th e l as t g rou p h as w a te rs w i th h igh concent ra ti on s d i sch arge i n c re ase d , a n d h as a p p are n t l y r e m ain ed t h e

o f C a , H C O3 , Na , an d C 1, besides abn o rmal amoun ts o f L i , s am e ev er s i n ce . A s a r esu l t o f t h e Pe l i l eo (n ea r Tu n -

As and B; but the SO, content is low. There may be a rela-

t ion sh ip betw een t hese w a t e r s an d t he n u merou s ep it he rmal gu rah u a ) ea r t h qu ak e i n 1 949 , acc o rd in g to ey e w i tn e ss

d epos it s i n t he a rea . acc ou n t s , t h e sp r i n gs o f B af io s (T u n gu rah u a ) d r i ed u p

a n d o n l y g a s e m a n a t e d . T h e s p r in g s r e a p p e a r e d a b o u t

I n t r o d u c t i o n f i f t e e n d a y s l a t e r .

A s u r v e y o f E c u a d o r i a n h o t s p ri n g s w a s s t a r t e d

r e c e n t l y a n d t h i s n o t e i s a p r o g r e s s r e p o r t o n t h e w o r k T h e p r e s e n t s t u d y

d o n e t o d a t e . S o f a r , o n l y a f e w o f t h e s p r i n g s i n s o m e F i g u r e 1 s h o w s t h e d i s t r i b u t i o n o f t h e k n o w n

o f t h e a r e a s h a v e b e e n v i s i te d a n d t h e w a t e r s a n a l y z e d ,

b u t w e h o p e t o e x t e n d t h i s s t u d y t o c o v e r t h e w h o l e s p r i n g s i n E c u a d o r a s i n d i c a t e d b y t h e l i t e r a t u r e , a n d

i n c l u d e s s o m e r e l e v a n t g e o l o g i c a l f e a t u r e s . R e s u l t s o f

c o u n t r y i n t h e f u t u r e .

T h e r e a r e n u m e r o u s h o t s p r i ng s i n E c u a d o r a n d t h e s p r i n g w a t e r s a n a l y z e d in t h e p r e s e n t s t u d y a r e

m a n y w e r e u s e d f o r b a t h i n g e v e n in I n c a t i m e s a s g i v e n i n T a b l e s 1 a n d 2 . M a j o r e l e m e n t s w e r e a n a l y z e d

i n d i c a t e d b y t h e Q u e c h u a n a m e s o f s o m e o f t h e s p ri n g ~ b y c o n v e n t i o n a l m e t h o d s a n d t r a c e e l e m e n t s b y c o lo r i-

a n d f r o m I n d i a n m y t h s a n d le g e n d s ( M u ~ o z 1 9 4 9) . m e t r y a n d a t o m i c a b s o r p t i o n . T a b l e 3 g i v es s o m e d e s-

E x a m p l e s o f O u e c h u a n a m e s a r e : C u n u n c y a c u o r h o t c r i p t iv e d a t a o f t h e h o t s p r in g s .

w a t e r ; C a c h i h u a i c o o r s a lt y c r e e k ; C u n u n c p u g y o o r

h o t s p r i n g ; a n d Y a n a y a c u o r b l a c k w a t e r . F o r t h e I n - D e s c r i p t i o n o f t h e s p r i n g s

c a s , t h e s e a r c h a n d m a i n t e n a n c e o f t h e s p r i n g s f o r T h e d i s t r i b u t i o n o f t h e s p r i n g s s h o u l d b e s e e n i n

b a t h i n g w a s a s p e c i a l i z e d t a s k a n d e n t r u s t e d t o s p e c i a l t h e g e n e r a l c o n t e x t o f t h e s t r u c t u r e , g e o l o g y a n d v o l -

w a t e r s e e k e r s . I n c o lo n i a l t i m e s s o m e o f t h e m o r e a c - c a n o l o g y o f t h e c o u n t r y . E c u a d o r c a n b e d iv i d e d i n to

c e s s i b l e s p r i n g s s u c h a s B a f io s o f T u n g u r a h u a a n d B a - t h r e e g e o g r a p h i c a l z o n e s : t h e c o a s t a l p l a i n ; s i e r r a s ;

fiG S o f C u e n c a w e r e u s e d a s s p a s b u t o n l y in t h i s c e n - a n d t h e ~ o r i e n t e ~) o r j u n g l e l o w l a n d s . B o t h th e c o a s t a l

t u r y h a v e th e s p r in g s b e e n c o m m e r c i a l i z e d f o r t h e t o u r- p l a i n a n d j u n g le l o w l a n d s ( A m a z o n b a s in ) a r e c o v e r e d

i s t i n d u s t r y , b y r e c e n t a l l u v i a l d e p o s i t s . T h e s i e r r a s o r . A n d e a n

T h e f i r st c o m p r e h e n s i v e s t u d y o f t h e t h e r m a l r a n g e s a r e b o u n d e d o n t h e e a s t a n d w e s t b y p r e - C a m -

s p r i n gs w a s b y D R ES SE L i n 1 8 7 6 w h o p u b l i s h e d a n a - b r i a n m e t a m o r p h i c a n d s e d i m e n t a r y r o c k s . R o c k s f r o m

l y se s o f s o m e o f t h e w a t e r s . O t h e r p u b l i s h e d w o r k s t h e l u ra s s i c t o t h e p r e s e n t c o n st i tu t e t h e m a i n b o d y

r e f e r p r i n c i p a l l y t o t h e m e d i c i n a l p r o p e r t i e s o f t h e w a t - o f t h e s i e r r a s a n d i n c l u d e b o t h v o l c a n i c s a n d s e d i m e n t s .

e r s (GENTEY 1 906 ; ViVA R 1 8 8 9 ; W A NDEMBERC 1 92 4) . B a th o l i t h s i n t ru d e t h e o ld e r rocks bu t t h e i r age i s u n -

M t J t~ o z ( 1 9 4 9 , 1 9 5 1 , 1 9 5 7 a n d 1 9 5 9 ) w r o t e e x t e n s i v e l y c e r t a i n . T h e m o s t r e c e n t r o c k s a r e t h e g l a c i a l a n d v o l-

o n t h e h o t s p r in g s a n d p r e s e n t e d s o m e n e w a n a l y s e s , c a n i c d e p o s i ts ( G o o s s E N S 1 9 7 0 a ) .

b u t h e a l s o s t r e s s e d t h e c u r a t i v e p r o p e r t i e s o f t h e T h e s e p a r a t i o n o f t h e s i e r r a s f r o m t h e p l a i n s i s

w a t e r s , p r o b a b l y s t r u c t u ra l l y c o n t r o ll e d . G r a b e n s w i t h i n t h e

s i e r r a s a r e b o u n d b y n o r t h - s o u t h f a u l t s . T h e r e i s e v i d -

* P r o y e c t o M i n e r o , A p a r t a d o A - 3 71 , Q u i t o , E c u a d o r . e n c e o f a m a j o r d e e p e a s t - w e s t s t r u c t u r e t h a t e x t e n d s

* * S e r v i c io N a c i o n a l d e G e o l o g l a y M i n e r i a , A p a r t a d o

A - 2 3 , Q u it o, E c ua do r. a c r o s s t h e c o n t i n e n t , b e c a u s e a p p r o x i m a t e l y i n o n e

*** United Nations P r o j e c t , B.P. 72, O u a g a d o u g o u , U p p e r l i n e a r e t o b e f o u n d t h e G a l a p a g o s I s l a n d s a n d G a l a -

V o l t a , A f r i c a . N o w a t t h e D e p t . o f G e o l o g y a n d G e o l o g i c a l

E n g i n e e r i n g . M i c h i g a n T e c h n o l o g i c a l U n i v . , H o u g h t o n , N ic h. p a g o s w r e n c h f a u l t , t h e G u l f o f G u a y a q u i l , t h e C a f i a r

4 99 31 , U S A. f a u l t a n d t h e A m a z o n r i v e r ( G o o S S E N S 1 9 7 0 b ) , T h i s

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TABLE 1. --

Major ele men ts in Ecuadorian hot springs. All values in ppm .

T °C pH Na K Ca Mg HCO3 C1 SO4 SiOz Tota l

dissolved

solids

Apuela 52 6.2 552 11 255 3 27 780 641 15 2940

Cununcyacu 26 7.0 165 17 38 2 243 16 39 1 35 660

E1 Tingo 34 7.3 340 32 29 2 506 221 5.0 [ 65 1500

La Merc ed 34 6.6 147 18 46 2 247 16 17 65 735

Bathos (Tungura hua) 42 6.7 248 46 320 14 1540 29 2892 50 6900

Los Elenes 20 7.6 327 8 254 57 468 123 995 10 2010

Cununepugyo 22 7.8 112 4 66 24 403 94 42 14 470

Guap~n 45 6.7 5600 160 363 65 3090 5160 35 42 13,000

Bafios (Cuenca) 87 7.3 2500 80 140 50 846 3540 458 23 7200

Unna med nea r Azogues 22 8.3 2360 177 850 40 3540(1) 4870 17 tad 10 ,0 00

Un name d nea r San Bartolom~ 30 ? 6.3 1930 116 208 33 2850 3740 7.0 8 7400

Portovel o Mine 50 6.7 340 3 370 240 163 182 916 17 2100

Agu as Cal iente s 50 7.1 84 22 145 0.2 19 200 288 27 780

Rio Bono 30 ? 9.1 95 nd 19 0.5 14 (o) 36 35 16 220

( L ) 1 0 9 C 0 3 - - -

( z ) 6.8 CO,---

structural line also approximately marks the southern we are aware) the springs are not depositing salts,

limit of the Plio-Pleistocene volcanoes although volcanic although there are some salt and travertine deposits

deposits are spread both north and south of this line. from springs that have disappeared. Composition of the

The volcanoes occur in roughly two belts running pa- spring waters is variable and is probably greatly in-

rallel to the coast. Four of these volcanoes are consider- fluenced by ground and river waters. Total dissolved

ed active; Reventador; Tungurahua , Cotopaxi and San- solids of the waters is from 500-3000 ppm. As the

gay (SAUER 1965). South of this structural line vol- lithium, boron, arsenic and silica concentrations are low,

canism was intense in the Pliocene. it is probable that these waters have only a very small

The structural line is also convenient for the di- magmatic component.

viding of the hot springs into two groups. Although many The springs of the southern belt are the end stages

hot springs are known in Ecuador the majority have of an active hot spring cycle and volcanism during the

temperatures between 22 and 30°C, only about ten Plio-Pleistocene. All the known springs except some

springs have temperatures above 50°C and those with outside the area of volcanic cover, are related to tra-

temperatures greater than 70°C are probably less than vertine deposits. However, the converse is not true

five. Most of the springs are found in the sierras or and some of the springs have dried up and the tra-

foothills although some have been reported on the vertine deposits have suffered erosion exposing the fis-

coast (Figure 1). The coastal springs may prove inter- sures and walls of the original plumbing of the hot

esting as their waters, besides having a possible mag- springs system and in some cases erosion has proceed-

matic component, are no doubt contaminated by the ed so far that only blocks of travertine remain in the

ocean and by petroleum brines from the nearby oil- alluvial cover. The variations of the morphology of

fields. It is possible that submarine springs exist, the travertine deposits suggest that there have been

The hot springs of the northern belt (except those different cycles of hot spring activity. A United Nations

along the coast) are all within 30 km of the nearest repor t describes the traver tine deposits in detail (Unit-

volcano. Most of these springs are along river banks ed Nations Development Programme, 1969).

and possibl3~ the river courses are faul t controlled. At the travert ine deposits the position of the springs

Usually a group of springs are found several kilometres is continually changing, from year to year and even

apart along the river. Near Ouito, Cuncuncyacu, E1 from month to month. A very little water bubbles

Tingo, La Merced and Alangasi, together with several through the travert ine in different places of the deposit,

other unnamed springs, are found within a distance of often accompanied by clouds of smoke. Some of the

30 km of each other along the Rio San Pedro, and en- springs are cold, but temperatures as high as 87 °C have

circle an extinct volcano Ila16. They are also within been recorded.

30 km of the volcano Pichincha. Naturally these waters have high concentrations of

Temperatures of the springs of the northern area Ca and HCO3, but Na and CI are also present in con-

are in the range 20-50°C and rarely do they exceed siderable quantit ies (Table 1). O ROURKE (1967) sug-

50°C. The hot waters emerge along the river banks and gested that the calcium carbonate of the travert ine is

algae grow in profusion on the stream sediments near derived from the San Marcos formation, the only lime-

the outflow. So far, only at Bafios (Tungurahua) has stone formation in the area. The San Marcos formation

an ochrous scum been observed, otherwise (as far as is Cretaceous in age and consists of sedimentary series

1401

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TABLE 2 . - -

Minor ele ments in Ecuadorian hot springs. All values in ppm; nd not detected; na not analyzed.

L i B A s Sb F e M n C u P b Z n A g I F

A p u e l a 1 .9 9 n d n d n d n d n a n a n a n a n d n d

C u n u n c y a c u 0 . 1 1 .2 n d n a 0 . 4 n d 0 .0 1 n a n d n a n d n d

E1 Ti n go 0 .5 5 .1 0 .04 n a 0 .4 n d 0 .002 0 .06 0 .02 n a 0 .01 n d

L a M e r c e d 0 . 2 1 .3 0 . 0 5 n a 4 n d 0 . 00 7 n a 0 . 0 08 n a 0 . 0 2 n d

B a f i o s ( T u n g u r a h u a ) 1 .4 2 . 8 n d n d 9 4 1 . 0 0 .0 01 n a 0 . 0 0 04 n a n d n d

L o s E l e n e s 0 .1 0 . 5 n d n a 1 .0 n d n d n d 0 . 0 08 0 . 0 17 n d n d

C u n u n c p u g y o 0 . 0 6 0 . 9 n d n d n d 0 . 2 n d 0 . 0 1 7 . 00 5 . 02 3 0 . 0 3 n d

Gu ap ~ i n 1 3 1 05 n d n d 0 .4 0 .8 n d 0 .05 0 .01 n d n d 5 .8

Ba f i o s (Cu en c a ) 3 .0 1 3 0 .1 2 n d 1 .2 0 .4 n d 0 .08 0 .01 n d 0 .5 4.3

U n n a m e d n e a r A z o g u e s 1 2 1 31 n d n d n d 0 .3 0 .0 2 9 0 . 06 n d n d 0 . 8 n d

U n n a m e d n e a r S a n B a r t o l o m 6 2 .6 5 2 0 . 08 n d 0 . 6 n d 0 .0 2 2 0 , 03 6 n d n d n d n d

P or t ov e l o 1 .2 4 .8 0 .02 n d 9 .3 2 .5 0 .054 0 ,04 0 ,98 0 ,2 3 3 n d 7 .2

A g u a s C a l i e n t e s 2 . 6 7 . 8 0 . 0 5 n d n d n d 0 . 0 35 0 . 0 2 4 0 . 0 3 4 n d 0 . 2 n d

R i o B o n o n d 2 . 0 0 . 0 0 4 n d 0 .1 0 . 3 n d 0 . 0 2 4 0 . 0 22 n d n d 4 . 0

TABLE 3 . - -

Description o/ Ecuadorian springs.

N A M E L O C A T I O N G E O L O G Y S T R U CT U R E V O L C A N O L O G Y M I N E R A L I Z A T I O N

A p u e l a 8 0 k m W o f I b a r r a , W i t h i n r e c e n t v o l- P o s s i b l e f a u l t 1 5 k m W o f V n . N e a r S a n ] o s 6 d e

a l o n g R i o l n t a g c a n i c c o v e r . I n v i - C o t a c a c h i M i n a s , P b , B a , H g ,

c i n it y o f m a r b l e d e - Z n .

p o s i t s

C u n u n c y a c u 1 5 k m E o f Q u i t o , Q u a t e r n a r y 1 5 k m E o f V n .

a l o n g R i o S . P e d r o P i c h i n c h a . A l s o

n e a r e x t i n c t v o l c a -

n o l l a1 6

E 1 T i n g o 2 4 k m S E o f Q u i t o , Q u a t e r n a r y 2 0 k m S E o f V n .

a l o n g R i o S . P e d r o P i e h i n o h a . A l s o

n e a r e x t i n c t v o l c a n o

l l a1 6

L a M e r c e d 3 0 k m S E o f Q u i t o , O u a t e r n a r y 2 5 k m S E o f V n .

a l o n g R i o S . P e d r o P i c h i n c h a . A l s o

n e a r e x t i n c t v o l c a n o

l l a l 6

B a f io s ( T u n g u r a h u a ) 6 0 k m S E o f A m - W i t h i n r e c e n t v o l . 1 0 k m N o f V n .

b a t o c a n i c c o v e r , n e a r T u n g u r a h u a

c o n t a c t w i t h m e t a -

m o r p h i c s

L o s E l e n e s 1 4 k m N o f R i o - Q u a t e r n a r y 3 0 k m S E o f V n .

b a m b a C h i m b o r a z o

C u n u n c p u g y o 1 5 k m W o f R i o - O u a t e r n a r y 3 0 k m S E o f V n .

b a m b a C h i m b o r a z o

G u a p a n 3 k m N o f A z o - U p p e r C r e t a c e o u s A l o n g N - S f a u l t N o a c t iv e v o l c a n i s m N e a r H g d e p o s i t

g u e s s e d i m e n t s n e a r m e t - o f A z o g u e s

a m o r p h i e c o n t a c t .

B a f io s ( C u e n e a ) 9 k m S W o f C u e n - M i o c e n e v o l c a n i c s A l o n g N - S f a u l t, o n N o a c t iv e v o l c a n i s m A u -A g i n q u a r t z

c a e d g e o f g r a b e n v e i n 5 0 0 m f r o m

d e p o s i t

U n n a m e d n e a r I 0 k m W o f A z o - P l i o c e n e v o l e a n i e s A l o n g N - S f a u l t N o a c t i v e v o l c a n i s m N e a r H g d e p o s i t

A z o g u e s g u e s o f A z o g u e s

U n n a m e d n e a r 1 0 k m N o f S . B a r - P l i o c e n e v o l c a n i c s ? N o a c t i v e v o l c a n i s m N e a r S . B a r t o l o m 6

S a n B a r t o l o m ~ t o l o m 6 p r o s p e c t , P b , Z n ,

Ag , S b , B i , As

P o r t o v e l o I n P o r t o v e l o m i n e C r e t a c e o u s s e di - ? N o a c t iv e v o l c a n i s m M i n e A u , A g , C u ,

m e n t s P b , Z n , A s

A g u a s C a l i e n te s O n R i o A m a r i l l o C r e t a c e o u s s e d i- 9 N o a c t iv e v o l c a n i s m N e a r P o r to v e lc ,

n e a r P o r t o v el o M i n e m e n t s m i n e

R i o B o n o N e a r P o r t o v e l o C r e t a c e o u s s e di - ? N o a c t iv e v o l c a n i s m N e a r P o r t o v e l o

m e n t s m i n e

1 4 0 2

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o f w h i ch th e p r i n c i p a l ro ck t y p e i s a b l a ck fo s s i l i fero u s ea r l y m i n era l s , a n d a f ter cry s ta l l i z a t i o n a l b i t i z a t i o n of

a rg i l li t e w h i ch g ra d es i n to b l a ck sh a l es a n d i s i n t er - th e p l a g i o c l a se ca n en r i ch th e res i d u a l f l u i d s i n ca l c i u m ,

ca l a t ed w i th l i m es to n e b a n d s • I t i s p o ssi b l e~ h o w ev e r , b u t i t i s u n cer ta i n h o w th is f l u i d ca n b e sep a ra ted f ro m

t h a t t h e c a l c i u m c a r b o n a t e i s n o t d e r i v e d f r o m t h e s o l u - a c o o l i n g m a g m a c h a m b e r . S i m i l a r t o t h e E c u a d o r i a n

t i o n o f th e sed i m en ta ry l i m es to n es b u t i s re l a t ed to sp r i n g s a re so m e sp r i n g s i n C a l i fo rn i a w h ere , d esp it e

m a g m a t i c a c t i v i t y . W H ITE ( 1 9 6 7 ) p o i n t s o u t th a t d u r i n g th e a b sen ce o f l i m es to n e b ed s i n th e a rea , th e sp r i n g

m a g m a t i c d i ff eren t i a t io n , ca l c i u m i s t a k en u p b y th e w a ters ca rry l a rg e a m o u n ts o f ca l c i u m ca rb o n a te .

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5/5

S u l f a t e c o n t e n t o f t h e w a t e r s i s l o w , a n d t h i s 2 . T h e d i f f e r e n c e b e t w e e n t h e n o r t h a n d s o u t h

t o g e t h e r w i t h t h e h i g h c o n c e n t r a t i o n s o f N a , C a , C 1 a n d s p r i n g s i s p r o b a b l y r e l a t e d to t h e v o l c a n i c h i s t o r y o f t h e

H C O ~ s u g g e s t a s i m i l a r i t y w i t h o r e f o r m i n g f l u i d s. F u r - t w o a r e a s , I n t h e n o r t h e r n b e l t , t h e h o t w a t e r s , w h i c h

t h e r m o r e , t h e c o n c e n t r a t i o n s o f K , L i, A s a n d B a r e m a y b e o n l y h e a t e d g r o u n d w a t e r s , h a v e t r a v e l le d f u r t h e r

t h o s e w h i c h m a y b e e x p e c t e d f r o m t h e s e t y p e s o f f l ui d s, f r o m t h e m a g m a c h a m b e r a n d t h e or i g in a l m a g m a t i c

E x a m p l e s o f t h e f l u id s r e l a t e d t o o r e d e p o s i t s a r e a m p l y c o n s t i tu e n t s h a v e b e c o m e e x t r e m e l y d i lu t e . B y c o n t r a s t,

d e m o n s t r a t e d i n t h e l i t e r a t u r e ( W H I T E 1 9 5 5 , 1 9 6 7 ; i n t h e s o u t h e r n b e l t , t h e v o l c a n i c s a r e o l d e r a n d e r o s i o n

WHITE, H E M , W A R I N I 3 1 9 6 3 ; E L L I S 1 9 67 ; RO E DD E R h a s e x p o s e d p a r t o f t h e h o t s p r i n g p l u m b i n g s y s t e m

1 9 6 7) a n d e v i d e n c e i s n o t o n l y d e r i v e d f r o m h o t s p r in g s w h i c h i n c l u d e d t h e t ra v e r t i n e a n d m i n e r a l d e p o s it s . I f

b u t a l s o f r o m f l u i d i n c l u s i o n s i n m i n e r a l s , m i n e r a l d e p o s i t s a r e p r e s e n t i n t h e n o r t h e r n a r e a s , t h e y

N u m e r o u s v e i n d e p o s i ts a r e f o u n d i n t h e s o u t h e r n a r e p r o b a b l y a t d e p t h a n d s o f a r r e m a i n u n e x p o s e d .

b e l t a n d o n l y s p o r a d i c a l l y i n t h e n o r t h e r n a r e a . E p i - T h e p o r p h y r y c o p p e r d e p o s i t p r o b a b l y d a t e s f r o m t h e

t h e r m a l d e p o s i ts a re t h e m o s t c o m m o n a n d c o n si s t o f U p p e r C r e ta c e o u s a n d it s r e l a ti o n to t h e re c e n t c y c le

c o m p l e x s u l f i d e s o f Z n , P b , A g , C u , A s , S b , B i a n d H g , o f v o l c a n i c a c t i v i t y i s n o t k n o w n .

t h o u g h n o t a l l t h e s e m e t a l s a r e p r e s e n t i n o n e d e p o s i t .

O t h e r m i n e r a l i z a t i o n i n c l u d e s g o l d - q u a r t z v e i n s , d i s s e m - A c k n o w l e d g e m e n t s

i n a t e d p y r i t e i n v o l ca n i c rock s , a n d on e p o rp h y ry W e than k IoLIO G~ m A an d ROOER DU POls fo r co ll ec ti ng

co p p er p ro sp e c t . I t i s m os t l i ke ly t h a t t h e ep i t h e rm al some o f t h e samples . Th is a rt ic le w as r ev iew ed by PET~

FozzA aa and CARLOs MOSQUERA and we appreciate their crit-

d ep o s i t s a r e r e l a t ed t o t h e r ece n t h o t sp r i n g ac t i v i t y , i ca l comment s.

d a t i n g f r o m t h e P l i o -P l e i st o c e n e , w h i l e t h e p o r p h y r y

c o p p e r d e p o s i t m a y b e o l d e r . W e h a v e n o d e f i n it e p r o o f R E FE R EN C ES

of t h e con n ec t i on o f t h e h o t sp r i n g s w i th m in era l i za - D~ ,~ssm . . 1 8 76 - - Estud io s sobre a lgu nas aguas minera les d e l

Ecuador. An. Univ . Cen tra l Oui to , 4 , 136 , 179 , 292 , 350 ,

t i on bu t t h e n a tu re o f t h e o re d ep o s i t s an d t h e co rn - 409, 458 , 6o6.

po si t io n of the wa ter s sugg ests tha t th is m ig ht be so . ELLIS A. J . 1967 - - The chemist ry of some explored geothermal

I n t h e P o r t o v e l o m i n e , h o t w a t e r s a r e e m e r g i n g a l o n g s ys te m s, in : • Geoc hemis try o] Hy drothermal Depos i t s J ,

H o l t , R i n e h a r t , W i n s t o n , N e w Y o r k . 4 6 5 .

o n e o f t h e u n d e r g r o u n d l e v e l s . T h e s u l f a t e c o n c e n t r a t i o n G ~ N r ~ v . 1 90 6 - - A na ly sis d e

las aguas

minerales de Tesalia.

i s h i g h a n d a l s o C u , Z n , P b , A g a n d F e a r e p r e s e n t i n An. Univ . Cen tra l Oui to , 22, 148.

Goossmss P. 1970 a - -

T h e g e o l o g y o f

Ecuador, an explicative

ab n o rm al am ou n t s . Th i s i s t h e on ly w a t e r kn o w n to n o t e fo r t h e geolog ica l map o f t he Rep ub li c o f Ecuad or

be d i r ec t l y r e l a t e d t o m in e ra l d ep os i t i n t h i s a r ea . (1:500 ,000) . Ann . Soc. g ol . Belg, in press.

C,OOSSE~rs P. 1970 b m A pr op os d'un e tectonique transversale

en Ecuador (Amerique du Sud).

Con/. sol id Earth Prob-

C o n c l u s i o n s Ictus, Buenos Aires.

Mugloz I . E. 19 49 -- A gu as minerales de Ecuador .

Oui to ,

B e c a u s e o f t h e l i m i t e d n a t u r e o f t h is s t u d y w e c a n Ecuador.

on ly g ive so m e ten tat ive con clu sio ns: Mtri~oz 1 . E. 1951 - - ln forme anali tico de las fuen tes de

aguas

minerales de la Provincia de Cotopaxi.

Latacunga,

1 . T h e h o t s p r i n g s o f E c u a d o r m a y b e b r o a d l y Ecuador.

M t~ oz 1. E. 1957 - - Compendio de hidrologia general y apli-

d i v i d e d i n t o t h r e e g r o u p s : c ad a. Impren ta Munic ipa l , Oui to . Ecuador .

M tn~ z I . E. 1 9 5 9 - lnventar io de las aguas minero-medici-

a ) Th e coas t a l sp r i n gs w h ich w e re n o t s t u d i ed h a les d e Ecuad or . Editorial Universitaria, Ouito. Ecuador.

an d o f w h ich n o fu r t h e r d e t a i l s a r e av a i l ab l e . O 'RotmK E 1. E . 1 967 - - Trav er ti n e d epos it s o f southe rn Ecua-

dor. U. N. Minera l Projec t Ecuador , unpub l . Rep .

b) T h e sp r i n gs o f t h e n o r th e rn be l t a s so c i a t ed w i t h Ro Etm s~ . 1 967 ~ F lu id in c lu s ion s as samples o f o re f lu id s .

in : • Geoc hemis try o f Hydro thermal Depo s i t s J , H ol t ,

r e c e n t v o l c a n i c a c t i v i t y . T h e w a t e r s a r e v a r i a b l e i n c o r n -

R i n e h a r t , W i n s t o n , N e w Y o r k , 5 1 5 .

p os i t i o n an d ap p ea r t o be r eh e a t ed mete o r i c w a t e r s be - SAUr_~ W . 1 965 - - Geo log ia de l Ecuad or .

Edi t . Min is ter io

Educaci6n, O,zi to, Ecuador.

cau se o f t h e l ow con cen t r a t i o n s o f L i , A s , an d B . Th ese U .N . D~W LOPM~rr PROO~'MME 1 969 - - Tech n ica l Rep o r t

spr i ngs usu al ly do not de pos i t sal t s . N ° 3 , Clays and Traver tine, (Operat ion N O 3 , Cuenca) .

U n i t e d N a t i o n s . N e w Y o r k .

¢) Th e sp r i n gs o f t h e sou th e r n be l t a r e i n an a r ea v w ~ I . M. 18 8 9 - - Observae ion es sob re e l a rt icu lo ~ A p li -

caciones m6dicas de algunas aguas minerales del Ecuador J.

w h e r e v o l c a n i c a c ti v i ty w a s i n t e n s e d u r i n g t h e P l i o -

An. Univ. Central , Ouito, 3 , 18.

Ple i s t oc en e . T h e sp r i n gs a r e as so c i a t e d w i th t r av er t i n e W ^~ Ms L~O 1 . B . 1 924 - - E l agua minera l d e Tesa li a. A n .

d e p o s i t s , b u t t h e r e a r e a l s o t r a v e r t i n e d e p o s i t s w h e r e t h e Univ. Central , Ouito, 32, 215 .

wn rrE D. E. 1955 ~ Therm al sprin~s and epithermal depo-

s p r i n g s h a v e d r i e d u p . T h e w a t e r s a r e h i g h i n C a , H C O .~ , s its . Eeon Geol . , 50 th Anniv . , 99 .

N a, C I bu t l o w in SO~ a n d a l so h av e c on s id e r ab l e W n rm D. E . 1 967 ~ Mercu ry an d base -metal d epos it s a s so -

ciated with thermal and mineral waters,

in : • Geochemis try

a m o u n t s o f L i , A s a n d B . I t i s s u g g e s t e d t h a t t h e s e

o / H y d r o t h e r m a l D e p o s i t s ~ , H o l t , R i ne h a r t, W i n s t o n , N e w

s p r i n g s a r e r e l a t e d t o t h e n u m e r o u s e p i t h e r m a l d e p o s i t s

Y o r k , 5 7 5 .

o f Z n , P b , A g , C u , S b , A s , a n d H g p r e s e n t i n t h e a r e a , W n r r~ D , E ., H EM

] .

D., WARrinG G. A. 1963 - - Chemical

composition of sub-surface waters. Pro[. Pap. U.S. geol .

a n d t h i s s h o u l d b e t h e s u b j e c t o f f u r t h e r i n v e s t i g a t i o n s . Surv . , 440-F.

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