We appreciate the comments on our paper on the Post-Betze sediment-hosted disseminated gold deposit which indicate that clarification is required. Ilchik suggests alternative interpretations of our findings with regard to two main issues: the nature of the sill that we have described as "postore," and the absolute age of Post-Betze mineralization in the context of the overall spread in the dates presented in our paper. We address these issues in turn.

The postore sill, which we also loosely originally termed "dike," is important in that it brackets the timing of gold mineralization. Although Ilchik suggests that this intrusion predates mineralization, the weight of evidence is to the contrary. Whereas the postore sill is composition-ally similar to preore Goldstrike stock-equivalent rocks, it is texturally quite distinct. In fact, it was distinctive enough for us to map it out in the subsurface from drill core, something which we were unable to do for any of the other sills. Comparatively, the rock is little altered and it is the only one in the ore zone that retains primary bio-tite. Assays shown in figure 5 of Arehart et al. (1993) are the original assays done on 5-ft intervals before the core was logged; in some samples mineralized inclusions are present within the sample interval. More detailed analysis of this rock type, when clear of any inclusions of mineralized sedimentary rock, yields very low values for gold. This is true of samples from several core holes. In sharp contrast, the preore dikes and sills are all significantly altered and mineralized (i.e., well above background in areas of sedimentary rock mineralization), although they are generally of lower grade than the surrounding sedimentary rocks. We are well aware of the erratic nature of and lithologic control on gold mineralization in sediment-hosted disseminated gold deposits that are also seen at Post-Betze. Even taking this into consideration, it is clear that there is effectively no gold in the postore sill in comparison to significant gold in preore dikes and sills.

In 2001 the Dorset and east Devon Coast was inscribed on the UNESCO World Heritage List as a place of outstanding universal value on the basis of its geological succession, coastal processes and landforms and its place in the history of the development of geology (especially stratigraphy and palaeontology). Extending from Orcombe Point in the west to Studland in the east, this World Heritage Site's 85 miles of coastline contains a record of 185 million years of Earth history. At the time of the proposal being submitted to UNESCO there were discussions about whether the planned site could be extended westwards to Torquay, covering the Permian and the Devonian rocks of Teignmouth, Dawlish and Torquay or eastwards to include the Isle of Wight. For various reasons (mostly non-geological) it was decided not to expand the proposed site further, although the Isle of Wight would have been the natural extension of the site, including more of the Cretaceous succession as well as the marine Cenozoic succession of the Hampshire Basin. This excursion is, in reality, looking at what the expanded site would have included.

In August 1882, the Morgan brothers recognised a mineral deposit, now known as the Mount Morgan Gold-Copper Deposit. The final production figures for the mine were 250 tonnes of gold and 360,000 tonnes of copper from 50 million tonnes of ore, making the average grades 4.99g/t gold and 0.72% copper.

Carbonate petrography — the study of limestones, dolomites and associated deposits under optical or electron microscopes —greatly enhances field studies or core observations and can provide a frame of reference for geochemical studies. Petrography is an especially powerful tool because it enables the identification of constituent grains, the detailed classification of sediments and rocks, the interpretation of environments of deposition, and the determination of the often complex history of post-depositional alteration (diagenesis).