CONTENTS. 
Be GRAPH OF THE AREA No ds a a Nan dd 
HISTORICAL REVIEW OF THE GEOLOGICAL EXPLORATION OF THE 
WESTERN-BART.OR TILECPROVINGE TA RIO JA dor ses sele 000: 
PART I. 
LITHOLOGY OF THE CRYSTALLINE, GRANITE INTRUDED BASEMENT. 
A) 
B) 
C) 
D) 
E) 
THE ,PREGRANITIC* SUPERCRUSTAL ROCKS OF THE SIERRA DE 
UMANGO AREA ....... USN Te LA ES RE MIRC RG ee Ann EEE [REG 
aumlinessedimentary, SCHISTSE u ur Se ee ota) ei 
b) The basic intrusive (and effusive?) rocks (metavolcanics)........... 
NRGoncordanksills.of amphibolitese an. as en 
PPA BEndotitichtock (si). sc N ae ee ae 
Syn Basıe,ikataclastic ‚schistsen. ea a le eye 
THE FAMATINA GRANITE INTRUSION AND ITS EXOGENE PLUTO- 
NIERMEBAMORPEUSMSG er. Suse rl 
ayGraniter varities of they Pamatinay jee res. Seren 
b) Zone of abyssal mingling, brecciation and assimilation on the western 
border olthey Kamatina batholith nn causes an Se je 
en@rosseutting) peamatiticdikesı breed er stalle u eee neh lese je ei se 
d) Plutonic metamorphism in the Sierra de Umango schist-body ...... 
AN EARLY PALAEOZOIC REGIONAL METAMORPHISM, SUBSE- 
QUENT TO THE FAMATINA GRANITE INTRUSION ................ 
a) Manner of intrusion of younger granites and syenites ............. 
b) Petrographical characteristics of the yonger intrusives ............ 
KATACLASTIC STRUCTURES OF THE BASEMENT ROCKS PRO- 
DUCED PRINCIPALLY BY THE LATER (TERTIARY) OROGENETIC 
IVT ONES ES NUTS Ele Ra vate pian Te bara ShA a bode le ta SL win SAL pM cro TEEN 
Aja neacrushed’: OTANUate di STATES! en as alls a ee falla ala 
H)E Deformations in the sedimentary schists 22). 006)... eles ale eee oe 
C)ueWataclasis, in: somessdanksschisise | Su a colitis er sie le se Else! se afen ee 
GENERALITIES ON THE GEOLOGICAL POSITION OF THE SIERRA 
DE UMANGO AREA......... Apt SNS chon ORIG ER Cake iE cera Needs OF Rear 
