ORES OF FIVE MINOR METALS 123

Lower Trias has been thrust-faulted over the Palzozoic,
under which lies a dolomite breccia belonging to the Middle
Trias. The ores are chiefly in the Wengen beds (Upper
Trias). Fig. 38 shows that Lipold’s interpretation, established
 by 1874, has been confirmed ; the Carboniferous beds
have been thrust from the N. over the Trias by the Alpine
movements.
CALIFORNIA AND CHiNa—The mercury fields of California
(cf. Becker, U.S.G.S., Mon. No. 13, 1888) and of S.W.
China (F. R. Tegengren, G.S. China, Bull. ii, 1920, pp. 1-36)
occur in beds shattered and overthrust by the Middle

18

1g

Fo
Sais

Fig, 38.—SECTION ACROSS THE IDRIA FIELD.

Section across the Idria Field showing the thrust plane (after Bloudek).
T.S., Theresia Shaft; I.S., Insaghi Shaft; J.S., Josefi Shaft; 5, St,
Cassian Beds ;. Upper Part of Upper Trias. 4, Wengen Beds; Lower
Part of Upper Trias. Main Ore Bodies, {11}; ... Middle Trias,
Limestone and Dolomite. 2-2, Lower Trias-Werfen Beds. 1-1,
Carboniferous-Gailthal Beds (with Land plants); FFF, Faults. T.P.,
Thrust Plane. According to one interpretation the rock at the base
of the Theresia Shaft is a Cretaceous Limestone and the ore-body
and adjacent beds have been overthrust on to the limestone.

Kainozoic mountain-forming movements. Minor deposits of
Mercury are known in many parts of the world, especially
along the Alpine-Himalayan mountain system and on the
western mountains of North and South America. The de-Posits
 are sometimes of very recent date; thus the Pleistocene
 lake deposits at Ohzawai in the Bay of Islands, New
Zealand, contain veinlets of cinnabar with marcasite and
traces of gold, silver, and antimony, which are being deposited
by hot water in fissures (A. P. Griffiths, Tr. N.Z IM.E., ii,
1898, p. 52).
ASSOCIATION oF Ores with Kawozorc Mountain Move-MENTS—The
 mercury ores are therefore geologically young and