WEATHERING OF GRANITE AND ASSOCIATED EROSIONAL FEATURES IN HONG KONG

Abstract

Research Article| October 01, 1957 WEATHERING OF GRANITE AND ASSOCIATED EROSIONAL FEATURES IN HONG KONG BRYAN P RUXTON; BRYAN P RUXTON DEPARTMENT OF GEOGRAPHY AND GEOLOGY, UNIVERSITY OF HONG KONG, HONG KONG Search for other works by this author on: GSW Google Scholar LEONARD BERRY LEONARD BERRY DEPARTMENT OF GEOGRAPHY AND GEOLOGY, UNIVERSITY OF HONG KONG, HONG KONG Search for other works by this author on: GSW Google Scholar GSA Bulletin (1957) 68 (10): 1263–1292. https://doi.org/10.1130/0016-7606(1957)68[1263:WOGAAE]2.0.CO;2 Article history received: 05 Jul 1956 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation BRYAN P RUXTON, LEONARD BERRY; WEATHERING OF GRANITE AND ASSOCIATED EROSIONAL FEATURES IN HONG KONG. GSA Bulletin 1957;; 68 (10): 1263–1292. doi: https://doi.org/10.1130/0016-7606(1957)68[1263:WOGAAE]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The granite in Hong Kong is frequently weathered to a depth of more than 60 m (200 feet). The soil (or A and B horizons of pedology) is only a few feet thick. The very thick C horizon is considered as the weathering profile and is divided into four zones roughly parallel to the surface. Division is based on the percentage of solid rock and the character of the residual debris.Local variations in the weathering profiles are due to conditions of slope, subsurface water, vegetation, structure, and type of granite. Widespread modifications are the result of a varied climatic and geomorphological history.At Lai Chi Kok a wave-cut platform truncates a complete weathering profile. A Han tomb, discovered in the terrace, provides evidence of considerable subsurface eluviation in the upper weathering zone. Eluviation is shown to be important in the differentiation of local weathering debris and may give rise to a well-sorted residue.Studies in three areas show that thick, complete profiles were formed on gently sloping surfaces and are now variably dissected. Adjustment to structure has taken place within the weathering profiles in a small vertical range of denudation. Large pockets of core stones in residual debris of the upper zones are explained as abandoned portions of the weathering profile.Most gullying in Hong Kong occurs on slopes from 10°–40° in the region of deep weathering. It is due to instabilities in the upper weathering zones after partial dissection and deforestation. Surface erosion bares the subsoil to drying winds, which with partial eluviation from available free faces causes a contraction of the debris. Deep cracks are formed, and accelerated eluviation aided by storm runoff develops these into gullies. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.