Alunite minerals occur as white powdery lumps  and laminated coloured deposits within cavity and solution  channel infill of the palaeokarst zone of the Upper Eocene  Dammam Formation. This formation is exposed in a quarry  located on the Al Ahmadi ridge within the Greater Burgan oil  field in southern Kuwait. Field occurrences and sedimentary  structures of the alunite deposits were described. Collected  samples were petrographically described, and their mineralogy  and geochemistry were determined using X-ray diffraction  and X-ray fluorescence, respectively. Microfabrics were investigated  using SEM, revealing that they are primarily composed  of fibrous alunogen (hydrous aluminium sulphate) and  pseudo-cubical K-alunite (hydrous potassium aluminium sulphate).  Their mode of occurrence suggests a hypogenetic  origin, where sulphide gases associated with hydrocarbon  gases reacted with an Al-rich solution leached from clay  minerals and feldspars of the cavity-fill muddy sand sediments.  The hydrocarbon gases may have seeped from subsurface  petroliferous formations within the Greater Burgan oil  field along vertical fractures. This study suggests that these  acidic seeps may have played a role in the development of the  palaeokarst zone of the Dammam Formation.

Folia are an unusual speleothem type resembling inverted cups or bracket fungi. Themechanismof folia formation is not fully understood and is the subject of an ongoing debate. This study focuses on an occurrence of folia present in Santa Catalina Cave, a non-thermal epigenic cave located close to Matanzas (Cuba). The sedimentology, morphology, petrology, permeability and geochemistry of these folia have been studied to gain new insight on the processes leading to their development. It is concluded that folia in Santa Catalina Cave formed at the top of a fluctuating water body, through CO2-degassing or evaporation, which may have been enhanced by the proximity to cave entrances. Two observations strongly support our conclusions. (1) When compared to other subaqueous speleothems (e.g. cave clouds) present in the same rooms, folia occur exclusively within a limited vertical interval that likely represents an ancient water level. Folia occur together with calcite rafts and tower cones that developed, respectively, on top of and below the water level. This suggests that a fluctuating interface is required for folia formation. (2) The measured permeability of the folia is too high to trap gas bubbles. Thus, in contrast to what has been proposed in other studies, trapped bubbles of CO2 cannot be invoked as the key factor determining the genesis and morphology of folia in this subaqueous environment.

Hermeneutics is the theory of interpretation. One of its major components is recognizing prejudgments, or forestructures, that we bring to our objects of study. In this paper, we construct a historical narrative of the evolution of thinking about the role of caves in relation to groundwater flow in limestone, and we tabulate forestructures as they appear in the story. This account consists of three overlapping time periods: the before and after of an incident that repelled hydrogeologists and students of karst from each other in the middle of the 20th century; a period, up to around the turn of this century, when karst science and mainstream hydrogeology were on different tracks; and a period of convergence, now intertwining, beginning roughly in the last quarter of the 20th century. Two influential players in our story are M.K. Hubbert, whose introduction of the Eulerian perspective of flow was a force for divergence, and R.M. Garrels, whose founding of the field of sedimentary geochemistry was a force for convergence. Other key players include F.T. Mackenzie, J.E. Mylroie, V.T. Stringfield, the U.S. Geological Survey, the Bermuda Biological Station, and the Gerace Research Center in the Bahamas, along with the historical accounts of W.B. White. Our narrative ends with the broader acceptance of the concept of multiple-permeability karst aquifers. We flag in our construction a total of 43 forestructures distributed amongst the categories of hermeneutic theory: 14 in the category of preconceptions; 9 in goals; 14 in tools such as skills; and 6 in tools such as institutions. These counts are an example of the concept of social construction of statistics, and we discuss the implications in terms of the huge number of potential combinations of forestructures that could shape alternative historical narratives of this subject over this time frame.