Sedimentary facies, mineralogy, and geochemistry of the sulphate-bearing Miocene Dam Formation in Qatar

Miocene diagenetic and epigenetic strontium mineralization in calcareous series from Cyprus and the Arabian Gulf: Metallogenic perspective on sub- and suprasalt redox-controlled base metal deposits

“…Sr isotopic ratios were normalized to 86 Sr/ 88 Sr = 0.1194. Because of the young age of the investigated sediments and their very low Rb/Sr ratio as indicated by XRF analysis (Dill et al, 2005), no age correction of the 87 Sr/ 86 Sr ratio for decay of 87 Rb was applied. Ca isotope ratios were calculated from mass spectrometric raw data.…”

“…The Dam formation rests on an unconformity capping the Eocene Rus formation below and is itself unconformably overlain by siliciclastic rocks of the Hofuf formation (Table 3). The Miocene and Eocene formations along the southern shoreline of the Arabian Gulf are almost entirely made up of shallow marine limestones with only a few evaporitic and marly intercalations (e.g., ''Midra Shales") (Cavelier, 1970;Weijermars, 1999;Whybrow et al, 1999;Dill et al, 2003Dill et al, , 2005.…”

“…They form part of a Neogene belt of calcareous-evaporitic series, extending from the Iberian Peninsula through the Mediterranean area into the Arabian Gulf (Dill et al, 2005). The celestite deposits in the eastern Mediterranean region and in the Arabian Gulf have not yet been investigated and hence, except from some unpublished company reports, no scientific paper has been published on their origin.…”

“…In Cyprus, Miocene evaporites are mined for local cement production, while in the Gulf area, they are mined to manufacture plaster gypsum. Further eastward, in stratigraphically equivalent Neogene sequences, gypsum-strontium deposits were found along the Trucial Coast of the Arabian Gulf in Qatar (Dill et al, 2005;Dill and Henjes-Kunst, 2007) and, to a lesser extent, in the United Arab Emirates (Peebles, 1999) (Figs. 1b and 2).…”

Paleontological, mineralogical and chemical studies of syngenetic and epigenetic Pb–Zn–Ba–P mineralizations at the stratotype of the K/P boundary (El Kef area, Tunisia)

“…Among the phyllosilicates kaolin-group minerals prevail over illite-smectite and may be taken as proximity indicators sensu Schutter (1998). Kaolinite is known to be the prime alteration product during continental weathering of silicates, mainly feldspar, whereas illitesmectite developed off-shore (Dill et al 2005). Resedimentation with dominantly quartz at the base is gradually passing into an environment where argillaceous suspended material was delivered from a low-relief hinterland represented by the Kasserine Island into a proximal shelf environment.…”