. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 92 BULLETIN: MUSEUM OF COMPAEATIVE ZOOLOGY. the contrary, many of the heads lying off the central parts of the east coast of Yanua ]\Ibalavu are undoubtedly of volcanic origin, aud are merely covered with a thin veneer of growing corals. Some of the small volcanic rocks and islets oflF the east central part of the east coast of Vanua Mbalavu are deeply undercut and eroded into mushroom-shape. By far the finest example of marine erosion of volcanic rocks is seen on Plate 62, which represents an eroded shore line with m
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 92 BULLETIN: MUSEUM OF COMPAEATIVE ZOOLOGY. the contrary, many of the heads lying off the central parts of the east coast of Yanua ]\Ibalavu are undoubtedly of volcanic origin, aud are merely covered with a thin veneer of growing corals. Some of the small volcanic rocks and islets oflF the east central part of the east coast of Vanua Mbalavu are deeply undercut and eroded into mushroom-shape. By far the finest example of marine erosion of volcanic rocks is seen on Plate 62, which represents an eroded shore line with mushroom-shaped rocks oflF the shore, indicating a slight recent elevation. Plate 62 is taken from a photograph given us by Mr. E. G. Jones, and taken in Lau; unfortunately I am unable to state the exact locality. The islets of Yana Yanu forming the harbor of Lomaloma consist of a yellow volcanic mud full of rounded pebbles, and some of the spits of the east coast of Vanua Mbalavu are composed of bedded volcanic mud (soapstone) similar to that found at Suva and its vicinity. The condition of the islands and islets and rocks, both of those composed of elevated coral reefs and of volcanic rock, clearly indicates the great denudation and erosion which. VOLCANIC HILLS BACK OF LOMALOMA. have taken place, to leave only such fragmentary remains of the land •which must have once occupied the area of the lagoon. It is possible that the age of the elevated limestone found at so many points in Fiji may be comparatively great, and that the ancient limestone forming the substructure of the reef of the present day may have been deposited in late tertiary times, immediately before the present epoch.^ As has been observed, the dip of the lagoon is to the eastward, or rather, in a general way, towai'd the slopes of the deep tongue of water forming the American Passage (Plate 19). This would seem to be the natural result of the elevation of the great flat of tertiary limestones ^ See the report
Size: 3897px × 641px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorha, bookcentury1800, bookdecade1890, booksubjectzoology
