
TY  - JOUR
A1  - Kirkman, JH 
A1  - Pullar, WA 
T1  - Halloysite in late pleistocene rhyolitic tephra beds near Opotiki, coastal Bay of Plenty, North Island, New Zealand
JF  - Soil Research
JO  - Soil Res.
Y1  - 1978
VL  - 16
IS  - 1
SP  - 1
EP  - 8
KW  - 
UR  - https://doi.org/10.1071/SR9780001 
N2  - Investigation of the clay mineralogy of 14 rhyolitic tephra beds with a suggested age of 125000 to 220000 years revealed that the squat cylindrical form of halloysite is the dominant crystalline mineral. This mineral has probably crystallized from allophane over a long time period, excess silica being precipitated as a weakly hydrated phase. The squat cylindrical crystals perhaps characterize halloysite formation in rhyolitic tephras. 
ER  -

