Abstract:

Abstract:  In the rheological experiments for natural mafic rock samples  there will be semibrittle deformation under lower temperature ranges, in contrast, there will appear melts at grain boundaries in the  sample under higher temperatures, and this could greatly effect  the rheological behaviors of samples.  In the literature, the stress exponent n is mostly reliable and with high recurrence rate, the activation energy Q is, in some extent, reiterative, however, the coefficient  A is poorly reiterative .  We performed creep tests using 6 kinds  of samples with different mineral components. The mechanical data show that it is more complicated for the effect of mineral component on rheology of rocks than physical models based on   flow laws of two phase and polyphase aggregates determined by endmember components. For the sample consisted of plagioclase, clinopyroxene and hornblende, rheological behaviors are controlled by plagioclase and clinopyroxene when the content of hornblende is less than 10%, however,  the role of hornblende could become significant for deformation of samples when the content of hornblende is higher than 10%. For the sample with major mineral of plagioclase, quartz and hornblende, rheological behaviors are dependent on plagioclase and hornblende when content of quartz is less than 10%, but  when plagioclase content is near 70% it will decide the deformation behaviors of  the  samples. In contrast to that, quartz could  completely control the creep of samples when its content  is higher than 20%.   The most effective method to study rheology of mafic granulite is  to perform creep tests using natural gabbro (or diabase) as well as using hot pressed  synthetic samples prepared from the major mineral components extracted from  mafic granulite.

Key words:

Key words: mafic rock;   rheology;   mineral component;   complexity