Evidences of active and ancient Volcanism on Mars. A review

Since t h e end of t h e last Century some observations concerning
flare-phenomena on Mars were reported by different explorers. According
to the opinion of Heuseler ( u . 1 2 . 1 3 ) , Katterfeld ("), Saheki (16),
Sato (16) and other authors, t h e respective light-phenomena might have been
t h e signs of active volcanoes on t h e planet. Grey clouds, observed b y Japanese
explorers as well as by Capen (3), may be also a t t r i b u t e d to volcanic
o u t b u r s t s . There are some observations, carried out by Dollfus (10), which
revealed the existence of relatively small, white, persistent clouds over cert
a i n Martian regions which can be i n t e r p r e t e d as w h i t e vapour-clouds emitted
by Martian volcanoes.
The author of the present s t u d y has investigated the distribution of
t h e s e phenomena over t h e Martian surface and found t h a t t h e distribution
is not random. The events occurred — in t h e overwhelming m a j o r i t y of the
cases — 011 a r e a s which are lying along t h e t r a n s i t i o n a l region between dark
and bright territories. It is i m p o r t a n t to note t h a t many of t h e lunar transient
events (probably postvolcanic phenomena) have a similar position 011
t h e lunar surface, t h a t is t h e y can be found mostly at t h e border of lunar
c o n t i n e n t s or basins respectively. On the other hand the most important
volcanic zones of t h e E a r t h are also t o be found along t h e edges of t h e Pacific
basin