In Hong Kong, slope failure in weathered granite and volcanic rocks has been studied extensively, but the impact of hydrogeological conditions on slope stability has received much less attention. It is customary in Hong Kong to assume that the hydraulic conductivity (K) of weathered igneous rocks decreases with depth or as the rock mass becomes less weathered. Generally studies of groundwater f...

This chapter presents an overview of how field-based methods quantify the processes shaping upland, soil-mantled landscapes. These methods have been applied across diverse field areas, ranging from the tropical sandstones of northern Australia to the alpine granites of the Sierra Nevada in California. In all cases, the landscapes examined through such work are relatively gently sloping with a g...

The weathering of Stone Mountain Granite (adamellitc) forms kaolinite, endcllite, allophane and gibbsite of which kaolinite is the most stable. Bulk density ranges from 2.65 in fresh rock to a minimum of 1.48 in saprolite. It is a good index of weathering. Abrasion pH ranges from 5.0 in saprolite to 9.3 in fresh rock, and is direct]y related to bulk density and the amount of clay mineral. Among...

controlled by capillarity, any attempt to predict DNAPL behavior in a porous medium requires determination of Dense nonaqueous phase liquids (DNAPLs) are important subsurthe capillary pressure–saturation relationship, hereafter face contaminants. Information is lacking on DNAPL behavior in heterogeneous porous media such as weathered rock (saprolite). We denoted by w(hc), where w is the volumet...

Quantifying long-term rates of chemical weathering and physical erosion is important for understanding the long-term evolution of soils, landscapes, and Earth’s climate. Here we describe how long-term chemical weathering rates can be measured for actively eroding landscapes using cosmogenic nuclides together with a geochemical mass balance of weathered soil and parent rock. We tested this appro...

a r t i c l e i n f o chemostratigraphy of two contrasting Deccan Traps weathering profiles – an ancient, deeply weathered laterite, and a younger (Quaternary), more moderately weathered saprolite – are used to reconstruct different aspects of basalt weathering. Precision of the HFSE analyses is demonstrated through a report of the long-term concentrations and ratios determined in United States...

This study presented the first in a series of investigations currently underway to develop efficacious, cost-effective, and benign processing opportunities produce rare earth elements (REE)–rich concentrate from an Australian complex low–grade saprolite ore [1.14% total oxides (TREO) grade], which is primarily exploited for its gold copper values. work specifically preliminary flotation investi...

Meteoric waters move along pathways in the subsurface that differ as a function of lithology because effects chemical and physical weathering. To explore how this affects stream chemistry, we investigated watersheds around an igneous intrusion Luquillo Mountains (Puerto Rico). We analyzed streams on 1) unmetamorphosed country rock (volcaniclastic sedimentary strata, VC) surrounding intrusion, 2...