Soru

Zorluk: Çok zorWeathering and Mass Wasting Processes

During field investigations in a humid tropical highland underlain by dense, jointed limestone, geologists observed both deep subterranean cave expansion and sudden downhill displacement of mud-rich regolith following torrential rains. Which statement accurately identifies the specific weathering mechanism operating on the bedrock and the distinct movement process displacing the surface material?

  1. Carbonation dissolves the limestone bedrock in situ through carbonic acid reactions, while mass wasting in the form of a mudflow displaces saturated surface regolith downslope under gravity.Cevap
  2. B
    Exfoliation peels outer rock layers off the limestone bedrock through diurnal thermal expansion, while fluvial erosion transports the loosened sediment downstream.
  3. C
    Hydrolysis chemically transforms the limestone into metamorphic slate bedrock, which then undergoes frost shattering to push debris downslope.
  4. D
    Oxidation breaks down calcium ions in situ, while running water acts as the primary mass wasting agent carrying the material as bedload.

Cevap

Carbonation dissolves the limestone bedrock in situ through carbonic acid reactions, while mass wasting in the form of a mudflow displaces saturated surface regolith downslope under gravity.
The correct answer identifies that carbonation is the in-situ chemical weathering mechanism where weak carbonic acid dissolves jointed limestone to form subterranean caverns, and that mudflow is the rapid downslope mass wasting movement triggered by water saturation reducing friction along a slope.

Adım Adım Çözüm

1
Analyze the bedrock weathering process
Limestone (CaCO3CaCO_3) reacts with rainwater containing dissolved carbon dioxide (H2CO3H_2CO_3) to form soluble calcium bicarbonate (Ca(HCO3)2Ca(HCO_3)_2). This in-situ chemical process is carbonation, which forms subterranean caves in karst landscapes.
Chemical weathering breaks down rock material in place without moving it.
2
Analyze the surface displacement process
Heavy seasonal rainfall saturates the surface regolith, reducing internal shear strength and causing the material to slide or flow downslope under the direct force of gravity as a mudflow or earthflow.
Mass wasting is strictly defined as the downslope movement of rock and soil debris under the direct influence of gravity, distinct from running water channel transport.

Anahtar Kavram

Distinction between in-situ weathering (carbonation) and gravity-driven mass wasting (mudflow)
Tahmini Süre:2m 0s
Bu soruyu puanla