56 Miss M. M. Ogikie — Coral in the '' Dolomites" 



so placed with regard to the earthy deposits below or above as to 

 look like an independent reef from the midst of sedimentary rocks 

 of its own age. Or it has been doubled upon itself, and thus, 

 apparently, attains a much greater thickness. The harder rocks of 

 Schlern and Dachstein dolomite have sometimes been pushed into 

 new positions over the slipping substratum of earthy rocks without 

 themselves undergoing much relative change of position or per- 

 ceptible evidence of strain, except when complications ai'e introduced 

 by minor thrusting and faulting along the main planes. I hope to 

 find out from specimens collected if any degree of internal change 

 in the crystallization of the rocks may be due to thrust-strain. 

 Visible signs of this strain are given by the " overcast bedding" 

 at Sasso Pitschi and on the east side of Sella. 



The appearance called " overcast bedding " is not always a con- 

 comitant of a thrust-plane, but is sometimes occasioned by the 

 outward dip of the dolomite strata from the mountain. The 

 weathering of the rock then produces a characteristic effect, e.g. on 

 the west side of Diirrenstein, where the strata dip west ; on the 

 north side of Sett Sass, where they dip north ; on the east side of 

 Sella, where they dip east, etc., etc. Another form of " overcast 

 bedding" is produced in the Cassian strata. The tufaceous or marly 

 beds surrounding Cipit Limestone are worn or washed away more 

 rapidly than the Limestones which gradually fall over and strew 

 the steep slopes below the dolomite rocks. This is also a common 

 reason why the reef-limestones predominate more, to all appearance, 

 in the neighbourhood of the cliffs than on the less steeply inclined 

 gradients of the " Alpen " or meadows. 



A curious and particularly pleasing appearance is produced where 

 a mountain slope of Schlern dolomite has been gradually denuded 

 by snow and ice, wind and weather, of its Raibl "robe of many 

 colours." Patches of greenish or reddish marls, from the size of a 

 bean to the roof of a house, are left upon the pure crystalline 

 whiteness of the dolomite. The sunlight sends its gleams upon it 

 till the cold rock is lit with life, and the shimmer that runs through 

 the leaves of an autumn forest is not more beautiful. All the more 

 strange is the contrast to the Alpine climber when he reaches the toj) 

 and finds on the other side of the mountain a giddy precipice of 

 apparently unbedded rock. We cannot wonder that the idea of 

 steep Coral cliffs facing the broad ocean and shelving inwards into 

 calm bays and lagoons has long held its own in the mind of many 

 as a fitting theory of the origin of such wonderful mountains ! 

 Beside it, any other explanation pales, and seems beset with endless 

 complications. 



For no sooner does one realize the main laws attending Tertiary 

 movement in the " Dolomites " (a series of wide folds running, 

 roughly speaking, east and west ; anticlines segmented by steep fault- 

 planes which meet and intercross as at Groden Joch, or by over- 

 thrust fault-planes as in the Buchenstein Valley ; synclines sinking 

 unequally in many detached pieces, e.g. the Tofana and Kreuzkofl 

 massif, Sett Sass, etc.), than new difficulties present themselves. 



