210 SOUTHWESTERN NEVADA AND EASTERN CALIFORNIA. 
flows at the north end of the ranee and others near Emigrant Spring 
are interbedded with the same formation. The deposition of the 
upper part of the older alluvium and the effusion of the basalt werl 
therefore contemporaneous, although the latter process continued 
after the former had ceased. The basalt is probably of the late Plio- 
cene and early Pleistocene age. 
STRUCTURE. 
The structural history of the Panamint Range has doubtless been 
as complex as that of the Ajnargosa Range, but the absence of 
Miocene formations removes the means by which the pre-Tertiary 
and middle Tertiary folding can be differentiated. It is. however, 
evident that the Paleozoic rocks were folded prior to the intrusion 
of the post-Jurassic igneous rock-. 
Tucki Mountain appears to be the northward-pitching end of a 
north-south canoe, the western side of which is buried beneath 
.Emigrant Wash or has been faulted off. The Cambrian rocks show 
well the differential folding suffered by a heterogeneous rock series. 
The schist i- typically closely folded and even crenulated: the 
limestone band- arc less strongly folded while the folds of the 
quartzite are open. 'Hie lithologic character of the series renders 
the detection of the many faults difficult. The folding of the Pogol 
nip and Pennsylvania!! limestones i- complex, although in its minor 
details less intense than that of the Amargosa Range, since over- 
turned folds and isoclinals are unusual. The major fold is an anti- 
cline, the axis of which i- situated near the western border of the 
area and trends a little west of north. The eastern arm of the fold 
is long and dips gently eastward. Superimposed upon it are many 
minor parallel folds, while cross fold- with east-wot axes cross it. 
This fold appears to die out a shorl distance south of Tin Mountain 
and here the strata are approximately horizontal. The earlier fold] 
ing was apparently accompanied by reverse strike faulting. The 
intrusion of the quartz monzonite in the southwest corner of the 
area mapped considerably disturbed the limestones in its immediate 
vicinity. They are buckled and dip steeply, usually away from the 
batholith. Faulting has occured at the contact, a- well a- in the 
quartz-monzonite mass it-elf. 
The fault between the Pogonip and Pennsylvanian limestone- is 
presumably a normal fault and i- certainly of several thousand feet 
displacement. It- position is only approximately shown on the 
map. Small normal faults of northwesterly strike are common in 
the Pennsylvanian limestone near Death Valley, and these were 
probably formed when the valley originated. Similar faults with 
2 to 4 feet displacement occur in the older alluvium, and this forma- 
tion has been uplifted and tilted toward Death Valley in places as 
much as 15°. 
