File:The Quarterly journal of the Geological Society of London (13960146853).jpg

CRYSTALLINE

 ROCKS 
 OF 
 THE 
 ALPS. 
 93 
 

then

 (about 
 3^ 
 miles 
 below 
 Zell) 
 in 
 situ, 
 a 
 cleavage-foliation 
 being 
 the 
 

dominant

 structure. 
 Similar 
 rock 
 occurs 
 a 
 little 
 way 
 above 
 Zell, 
 

where

 it 
 is 
 evidently 
 greatly 
 affected 
 by 
 pressure. 
 In 
 the 
 upper 
 

part

 of 
 the 
 valley'around 
 and 
 above 
 Maierhof, 
 crystalline 
 limestone, 
 

rather

 compacter 
 in 
 structure 
 and 
 greyer 
 in 
 colour 
 than 
 that 
 south 
 

of

 the 
 central 
 watershed, 
 is 
 well 
 developed, 
 as, 
 for 
 instance, 
 at 
 the 
 

Calvarienberg

 below 
 the 
 village, 
 and 
 about 
 a 
 mile 
 and 
 a 
 half 
 above 
 

it,

 where 
 the 
 mass 
 crosses 
 the 
 valley, 
 and 
 extends, 
 according 
 to 
 Yon 
 

Hauer,

 far 
 away 
 eastwards 
 and 
 westwards. 
 Its 
 passage 
 into 
 calc- 
 

mica-schist

 and 
 then 
 into 
 normal 
 lead-coloured 
 " 
 Thonglimmerschiefer" 
 

is

 excellently 
 seen 
 in 
 a 
 knoll 
 on 
 the 
 left 
 bank 
 of 
 the 
 valley, 
 where 
 

the

 last 
 two, 
 like 
 that 
 already 
 described, 
 exhibit 
 a 
 distinct 
 stratifica- 
 

tion-foliation

 *. 
 The 
 crystalline 
 limestone 
 often 
 has 
 a 
 platy 
 struc- 
 

ture,

 which 
 strikes 
 not 
 far 
 from 
 E. 
 and 
 W., 
 varying 
 a 
 few 
 points 
 on 
 

either

 side. 
 In 
 one 
 place, 
 above 
 Haus, 
 we 
 see 
 it 
 almost 
 in 
 contact 
 

with

 a 
 coarse 
 gneiss 
 in 
 which 
 a 
 cleavage-foliation 
 is 
 very 
 strongly 
 

marked,

 and 
 of 
 which 
 the 
 last 
 outcrop 
 is 
 only 
 about 
 10 
 feet 
 from 
 

the

 last 
 knoll 
 of 
 limestone. 
 The 
 cleavage-structures 
 in 
 the 
 two 
 

rocks

 are 
 not 
 quite 
 parallel, 
 that 
 in 
 the 
 gneiss 
 being 
 slightly 
 S. 
 of 
 

W.,

 that 
 in 
 the 
 limestone 
 a 
 little 
 N". 
 of 
 it. 
 At 
 this 
 point, 
 we 
 have 
 

either

 a 
 granite 
 intrusive 
 in 
 the 
 limestone 
 and 
 crushed 
 up 
 with 
 it, 
 

or

 a 
 natural 
 junction 
 of 
 an 
 older 
 and 
 a 
 newer 
 series 
 similarly 
 

crushed,

 or 
 a 
 faulted 
 junction 
 of 
 the 
 two 
 rocks. 
 As 
 the 
 limestone 
 

here

 is 
 exactly 
 in 
 the 
 same 
 crystalline 
 condition 
 as 
 it 
 is 
 in 
 the 
 three 
 

other

 localities 
 where 
 I 
 examined 
 it, 
 I 
 regard 
 the 
 first 
 hypothesis 
 as 
 

inadmissible.

 As 
 regards 
 the 
 third, 
 I 
 saw 
 nothing 
 to 
 suggest 
 excep- 
 

tional

 sliding 
 and 
 shearing, 
 but 
 only 
 direct 
 crushing. 
 Hence 
 I 
 do 
 

not

 think 
 there 
 has 
 been 
 an 
 overthrust-fault, 
 and 
 so 
 consider 
 it 
 on 
 the 
 

whole

 more 
 probable 
 that 
 limestone 
 and 
 other 
 members 
 of 
 the 
 

"

 Thonglimmerschiefer 
 " 
 series 
 were 
 deposited 
 upon 
 an 
 old 
 surface 
 of 
 

the

 gneiss. 
 It 
 is 
 true 
 there 
 is 
 no 
 sign 
 of 
 a 
 basal 
 conglomerate, 
 but 
 

this

 is 
 not 
 without 
 precedent. 
 

Above

 Maierhof 
 three 
 mountain-glens 
 pierce 
 deep 
 into 
 the 
 central 
 

chain

 of 
 the 
 Tyrol, 
 giving 
 the 
 traveller 
 another 
 opportunity 
 of 
 exa- 
 

mining

 the 
 " 
 Central 
 Gneiss 
 " 
 of 
 Yon 
 Hauer. 
 We 
 walked 
 several 
 

miles

 up 
 two 
 of 
 these, 
 the 
 Stillupthal 
 and 
 the 
 Floitenthal, 
 scruti- 
 

nizing

 the 
 rocks 
 in 
 situ, 
 the 
 screes 
 brought 
 down 
 by 
 lateral 
 torrents, 
 

and

 the 
 erratics 
 on 
 the 
 floor 
 of 
 the 
 glen. 
 In 
 the 
 Stillupthal 
 we 
 

noted

 a 
 porphyritic 
 gneiss, 
 with 
 occasional 
 darker 
 bands 
 of 
 lenticular 
 

outline,

 also 
 sundry 
 gneisses 
 and 
 mica-schists, 
 both 
 light 
 and 
 dark, 
 

which

 bore 
 some 
 resemblance 
 to 
 gneisses 
 of 
 the 
 Lepontine 
 type. 
 

The

 first-named 
 rocks 
 are 
 probably 
 of 
 igneous 
 origin, 
 the 
 difference 
 

in

 appearance 
 being 
 due 
 to 
 differences 
 in 
 the 
 effects 
 of 
 crushing. 
 

Some

 blocks 
 also 
 exhibited 
 junctions 
 which 
 suggested 
 an 
 intrusion 
 

of

 the 
 porphyritic 
 rock 
 into 
 the 
 " 
 Lepontine 
 " 
 gneiss, 
 anterior 
 to 
 the 
 

crushing,

 and 
 the 
 foldings 
 in 
 certain 
 of 
 the 
 schists 
 and 
 gneisses 
 are 
 

such

 as 
 would 
 be 
 most 
 naturally 
 explained 
 by 
 supposing 
 that 
 a 
 

stratification-

 foliation 
 existed 
 when 
 the 
 cleavage-foliation 
 was 
 pro- 
 

 For 
 the 
 microscopic 
 structure 
 of 
 the 
 rocks 
 of 
 this 
 district, 
 see 
 Appendix, 
 

■pp.