Hong Kong Geology Guide Book Geotechnical Engineering Office ...

Study of the rock outcrops, particularly at the northern and southern ends of Ping
Chau, provides an opportunity to understand shallow freshwater lake-type
sedimentation processes. At the northern end of the island, the rock layers are inclined
towards the southeast, whereas at the southern end, they tilt towards northwest. Thus,
the island is arcuate in shape. The dip angle of the rock layers varies from 11 o to 21 o
(see
figure above).
Convolute bedding in the Ping Chau
Formation
Careful observation will enable identification of sedimentary structures, such as low-
angle inclined bedding and convolute structures. Other structures, such as mud cracks,
ripple marks, rain prints, hieroglyphs/scolite, should also be searched for as additional
evidence of the depositional environment.
In general, fossils can be found in the well-sorted and fine-grained sedimentary rocks,
such as the siltstone and mudstone. Patience is required for fossil hunting. However,
please do not destroy the natural environment by haphazardly splitting rocks
searching for fossils.
Comments
Angular fragment and calcite cement
infilled along a tensional fault
The Yanshanian mountain-building period, which
had a major influence in the coastal
region in southeast China, concluded in the Late Cretaceous. The subsequent
Himalayan mountain-building period, during the Tertiary period, mainly affected the
western part of China. Consequently, the coastal area of southern China has remained
fairly stable since the Late Cretaceous. Although some local earth movement has
occurred along faults, it is thought that the post-Cretaceous sedimentary sequence in
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