Botswana Update

16 May 2007 07:03

Petra Diamonds Ld16 May 2007 For release 16 May 2007 Petra Diamonds Limited Exploration Update - Botswana Petra Diamonds Limited ("Petra" or "the Company"), the AIM-quoted diamond mininggroup, announces an update with regards to the exploration programme inBotswana. Highlights • Drilling results from the 600 metre diameter gravity negative anomaly (previously reported by Petra) confirm that the surface area of the diamondiferous kimberlite within the anomaly is likely to be significantly larger than previously accepted • A new kimberlite (X25) has been identified within Petra's licence areas - this discovery is highly significant as the area has been explored thoroughly by other exploration companies in the past, yet new technologies and methodologies employed by Petra have now led to this important discovery • Petra has acquired new prospecting licences in the Jwaneng area - these new licences hold two known diamondiferous kimberlites (DK4 and DK6) • 20 highly encouraging targets have been identified in Petra's Orapa North licence block Drilling at large gravity anomaly The 600 metre diameter gravity negative anomaly (reported on in Petra'squarterly report to 31 December 2006) has now been drill-tested. Twostrategically placed holes (relative to the gravity anomaly) both intersectedkimberlite beneath approximately 40 metres of Kalahari sand cover. Geophysicalmodeling suggests the body, previously described as inconclusive (and small) interms of size, is likely to be "champagne" glass shaped with a surface area(interpreted from geophysics) of approximately 25 hectares. The target is alsopotentially much larger than previously believed. Material for the above twoholes has been submitted to Petra's Helam laboratory and indicator mineralsrecovered from the samples will be probed by an outside facility for diamondbearing prospectivity. This kimberlite has the potential to be a substantialdeposit, although the grade over the majority of it is at this time untested. Kimberlite X25 The ground follow up on the 700km(2) low-level Xcalibur horizontal gradientmagnetic survey previously flown by Petra has resulted in the discovery of a newkimberlite, X25. The area in the vicinity of this kimberlite has beenintensively explored by reputable exploration companies since the early 1980's,but new technologies are now available enabling Petra to successfully deploy anXcalibur high resolution gradient magnetic survey. Targeting a magnetic anomalypicked from the Xcalibur dataset, a drilling campaign resulted in the discoveryof the X25 kimberlite. Kimberlite was intersected from 79 metres to a depth of125 metres; initial geophysical interpretation suggests a smaller kimberlite. Inthe light of this significant discovery, more exploration work is being plannedfor the locality, although no further work will be carried out on thiskimberlite due to its small size. Jwaneng Licences Petra has recently been granted prospecting licences in the vicinity of theJwaneng diamond mine. These licence areas hold two previously identifiedkimberlites, DK4 and DK6, both of which are diamondiferous. Petra will undertakefurther work to ascertain the prospectivity of these kimberlites as well as puttogether a work programme to explore these new licence areas. Xcalibur survey A large 12,673 line kilometre high resolution magnetic gradiometer Xcalibursurvey has been successfully completed over the Orapa North sections of Petra'slicence areas. This approach, which entails collecting data at a flight heightof 20 metres, is able to detect kimberlites with enough detail to allow fordrilling without geophysical ground follow-up. Interpretation of the datareceived has resulted in a minimum of twenty high priority targets that requirefurther investigation. Ends Notes 1. The information in this update that relates to Exploration Results, MineralResources or Ore Reserves is based on information compiled by Jim Davidson, Pr.Sci Nat (reg No 400031/06), who is a Member of the Geological Society of SouthAfrica, a 'Recognised Overseas Professional Organisation' ('ROPO'), included ina list promulgated by the ASX from time to time. Jim Davidson is a full-timeemployee of the Company and has sufficient experience which is relevant to thestyle of mineralisation and type of deposit under consideration and to theactivity which he is undertaking to qualify as a Competent Person as defined inthe 2004 Edition of the 'Australasian Code for Reporting of Exploration Results,Mineral Resources and Ore Reserves'. Jim Davidson has given his written consentto the inclusion in this announcement of the matters based on his information inthe form and context in which it appears. Jim Davidson is the Qualified Personfor the purposes of the AIM Guidance Note on Mining, Oil and Gas Companies datedMarch 2006 2. It should be noted that the potential quantity in this report is conceptualin nature, there has been insufficient exploration to define a Mineral Resourceand it is uncertain if further exploration will result in the determination of aMineral Resource. For further information, please contact: Cathy Malins / Annabel Leather Telephone: +44 (0) 20 7851 7480 Parkgreen Communications, London This information is provided by RNS The company news service from the London Stock Exchange