HENBUEY METEORITE CEATEES ALDERMAN 



225 



There is one extremely useful point which greatly aids in the 

 locating of the smaller craters, and also in their identification in 

 cases when the crater walls have been removed by erosion. That is 

 the presence of mulga trees. Mulgas are, in this area, practically 

 confined to the watercourses, which, although generally dry, occa- 



FiGORB 2.- 



-Plan showing the general distribution of the craters and of the meteorite 

 fragments around them 



sionally flow after rain. The craters, however, almost invariably 

 contain a clump of mulgas. This is due to the concentration in the 

 center of the crater of any rain water falling within the crater walls. 

 The inward wash of rain has naturally filled up a great deal of the 

 central depression and the finer sediment has formed a highly im- 

 pervious surface after the nature of a " clay pan." Water is thus 

 preserved in the crater for a much longer period than outside the 

 walls. 



The greatest interest was attached to the two largest craters, 

 which may be called the Main Crater and the Water Crater (Nos. 7 

 and 6). Viewed from the outside, a very gentle slope rises up to 



