Which test result indicates high clay content by forming a long thread?

Which test result indicates high clay content by forming a long thread?

• A. Snake test yields a long thread
• B. Shake test indicates shock absorption
• C. Patty test yields high water holding capacity
• D. Sieve analysis shows particle distribution

Answer: (A)

Forming a long thread is a direct cue to high clay content because clay minerals create a very cohesive, plastic paste when moist. In the snake-type test, you roll a soil sample into a thin, elongated strip. If it can be pulled into a long, continuous thread without cracking or breaking, that shows strong cohesion and plasticity typical of clays. The longer the thread, the greater the clay content and plasticity of the soil. Other tests measure different properties, not the amount of clay indicated by thread length. A shake-type test relates to how material handles vibration or impact (not its clay-driven cohesiveness). The patty test looks at how much water the soil can hold, which can be influenced by texture but isn’t a direct measure of clay content via thread formation. Sieve analysis evaluates particle sizes and distribution, which again doesn’t assess plasticity or clay content by forming threads.

Forming a long thread is a direct cue to high clay content because clay minerals create a very cohesive, plastic paste when moist. In the snake-type test, you roll a soil sample into a thin, elongated strip. If it can be pulled into a long, continuous thread without cracking or breaking, that shows strong cohesion and plasticity typical of clays. The longer the thread, the greater the clay content and plasticity of the soil.

Other tests measure different properties, not the amount of clay indicated by thread length. A shake-type test relates to how material handles vibration or impact (not its clay-driven cohesiveness). The patty test looks at how much water the soil can hold, which can be influenced by texture but isn’t a direct measure of clay content via thread formation. Sieve analysis evaluates particle sizes and distribution, which again doesn’t assess plasticity or clay content by forming threads.