Potassium argon dating simplified
This article reviews currently accepted areas of knowledge, along with topics that are still the subject of ongoing research, where science does not yet have all the answers.
This basic subject was discussed more than two decades ago in (Kirkley et al., 1991); since then, there have been major advances in our understanding of diamond geology.
Localities are as follows: (1) Diavik, Ekati, Snap Lake, Jericho, Gahcho Kue, DO-27; (2) Fort a la Corne; (3) Buffalo Hills; (4) State Line; (5) Prairie Creek; (6) Wawa; (7) Victor; (8) Renard; (9) Guaniamo; (10) Juina/Sao Luis; (11) Arenapolis; (12) Coromandel, Abaete, Canasta; (13) Chapada Diamantina; (14) Boa Vista; (15) Koidu; (16) Kan Kan; (17) Akwatia; (18) Tortiya; (19) Aredor; (20) Bangui; (21) Mbuji-Mayi; (22) Camafuca, Cuango, Catoca; (23) Masvingo; (24) Mwadui; (25) Luderitz, Oranjemund, Namaqualand; (26) Orapa/Damtshaa, Letlhakane, Jwaneng, Finsch; (27) Murowa, Venetia, The Oaks, Marsfontein, Premier, Dokolwayo, Roberts Victor, Letseng-la-Terae, Jagersfontein, Koffiefontein, Monastery, Kimberley (Bultfontein, Kimberley, De Beers, Dutoitspan, Kamfersdam, Wesselton); (28) Kollur; (29) Majhgawan/Panna; (30) Momeik; (31) Theindaw; (32) Phuket; (33) West Kalimantan; (34) South Kalimantan; (35) Springfield Basin, Eurelia/Orroroo, Echunga; (36) Argyle, Ellendale, Bow River; (37) Merlin; (38) Copetown/Bingara; (39) Mengyin; (40) Fuxian; (41) Mir, 23rd Party Congress, Dachnaya, Internationalskaya, Nyurbinskaya; (42) Aykhal, Yubileynaya, Udachnaya, Zarnitsa, Sytykanskaya, Komsomolskaya; (43) Ural Mts.; (44) Arkhangelsk; (45) Kaavi-Kuopio; (46) W Alps; (47) Moldanubian; (48) Norway; (49) Rhodope; (50) Urals; (51) Kokchetav; (52) Qinling; (53) Dabie; (54) Sulu; (55) Kontum; (56) Java; (57) New England Fold Belt; (58) Canadian Cordillera; (59) Lappajärvi; (60); Ries; (61) Zapadnaya; (62) Popigai; (63) Sudbury; and (64) Chixculub. (2013), with permission of the Mineralogical Society of America. Plate tectonics is the modern unifying theory that explains the earth’s active geologic processes today, and is thought to have operated perhaps for as long as the latter half of the planet’s history.
No other planets in the solar system apparently have plate tectonics.
Within the earth, temperature always rises with depth along a path known as the Figure 3.
Recent work of the research community (summarized in Pearson and Shirey, 1999; Cartigny, 2005; Harlow and Davies, 2005; Stachel et al., 2005, 2009; Stachel and Harris, 2008, 2009; Gurney et al., 2010; Shirey et al., 2013) has been of considerable interest to economic geologists searching for natural diamonds, guiding their models of how to explore for new occurrences.
But it is also of importance to the practicing gemologist, since these are fundamental questions that a wearer of a beautiful diamond might ask.
Carbon in the earth can occur in oxidized forms, such as when bound with oxygen in CO, or in reduced forms such as diamond, graphite, or bound with hydrogen in methane and other organic molecules.
The experimentally determined pressure-temperature conditions where diamond is stable (figure 3) dictate formation pressures higher than 40 thousand atmospheres (4 GPa) and temperatures of 950–1400ºC.
Terms listed in the glossary are italicized on their first use in the text. Carbon is widely dissolved in the earth’s silicate minerals at part-per-million levels and lower.