Characteristics of microcracks in samples from the drill hole Noerdlingen 1973 in the Ries crater, GermanySamples from the Noerdlingen 1973 drill core contain abundant shock-induced microfractures which exhibit varying amounts of healing and sealing. Many of the microcracks resemble morphologically the open microcracks present in returned lunar samples. Data derived from petrography, scanning electron microscopy, and differential strain analysis indicate that fewer microcracks were formed at greater depths and crack sealing processes are more effective for cracks associated with planar elements. Although the microcracks in the Ries core are now sealed, they are valid analogues of the open shock-induced cracks of lunar rocks and demonstrate that open cracks do form in rocks at depth during a naturally-occurring shock event. The healing of the shock-induced cracks in the Ries core also precludes their use for laboratory measurements of physical properties intended to be used as analogue measurements of lunar samples in situ.
Document ID
19790055235
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Padovani, E. R. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Batzle, M. L. (Massachusetts Inst. of Tech. Cambridge, MA, United States)