The Use of Chemistry of Garnets and Heavy Minerals Around Lalago Kimberlite Pipe in Deciphering Diamond and Non-Diamond Bearing Kimberlite Pipes in Tanzania

More than three hundred kimberlite pipes have been reported in Tanzania. Only a few are diamond–bearing. A prospecting criteria to outline the diamond and non-diamond bearing kimberlites has been proposed. Bulk rock chemical analyses and chemistry of garnets and black minerals (picroilmenite, magnetite, rutile and titanite) collected around one kimberlite pipe in Tanzania were studied using Atomic Absorption Spectrophotometer (AAS) and Electron Microprobe (EMP). Although chromite and zircons occur in kimberlite pipes, they were not used in this study because they also characterize other surrounding rocks. Electron microprobe analysis of heavy minerals indicate that the ilmenites (picroilmenite) are poor in MgO contents (0.03 – 0.6 wt.%); but are rich in MnO (9.94 – 12.27wt.%). The garnets are poor in Cr2O3 with pronounced almandine content which has led to the conclusion of having a barren kimberlite source. It is suggested that combination of the chemistry of garnet and heavy minerals may be used as an exploration tool for deciphering diamond and non-diamond bearing kimberlites.Keywords: Electron microprobe, black minerals, mineral and fluid inclusions, kimberlites, garnets

Hybrid apes in the Anthropocene: burden or asset for conservation?

1. Conservationists often view hybrid animals as problematic, at least if anthropogenic influence caused the intermixing to occur. However, critics propose that humans should respect nonhuman autonomy, reject essentialism, and accept the creatures they have helped create. 2. Based on two case studies of our own ethological, genetic, and ethnographic research about chimpanzee and orangutan subspecies hybrids, we assess what, if anything, should be done about such animals. We consider problems posed by cross-bred apes relating to: 1) Breeding—Do hybrids really experience reduced reproductive success? How are population-level concerns and welfare of individual animals balanced in conservation breeding? 2) Essentialism—Are anti-hybrid arguments based on essentialist or purist thinking? Does essentialism vary by conservation context? 3) Pragmatism—How do socio-economic circumstances influence whether hybrids are embraced or ignored? Does the erosion of ‘untouched nature’ render hybrids more important? 3. We show that answers to these questions are complex and context-specific, and that therefore decisions should be made on a case-by-case basis. For example, we find that anti-hybrid arguments are essentialist in some cases (e.g. ape management in zoos) but not in others (e.g. ape reintroduction). Thus, rather than present recommendations, we conclude by posing nine questions that conservationists should ask themselves when making decisions about taxonomic hybrids