Abstract The Oligocene–Miocene Catahoula Formation occurs along the length of the Gulf of Mexico coastal plain from the Rio Grande to the state of Mississippi. In Starr County, in South Texas, the formation is typified by the 20 m-thick Catahoula Volcanic Ash, interpreted to represent a single caldera eruption. The massive ash fall is the main source of the uranium that has been mined in South Texas since the late 1950s. It is also the origin of massive amounts of petrified wood, which was used in prehistory for making projectile points and continues to be used for landscaping. Diagenetic alteration of the volcanic ash produced the distinctive El Sauz Chert, which was used by native Americans for 10 000 years to make projectile points. More recently, the Catahoula Volcanic Ash was used as pozzolanic aggregate with Portland cement for the construction of Falcon Dam. The outcrop of the Catahoula Volcanic Ash in Starr County is the centrepiece of a geoheritage initiative, titled ‘ Ancient Landscapes of South Texas at the Nexus of Natural and Cultural History ’, whose goal is to connect the earth and social sciences to educate residents, students and visitors in how the region's geology has played a significant role in its social history.

Abstract Kibbanahalli is an important Lower Palaeolithic site-complex in southern Karnataka, a state in the southern region of Peninsular India. This region is crucial as it is somewhat centrally located between areas to the north, east and south, where decades of systematic Palaeolithic research has led to the establishment of firm cultural stratigraphy(ies) and even, in some cases, of chronology(ies). However, in stark contrast to these regions, southern Karnataka is often ignored in prehistoric research. Over 90 years of (intermittent) investigations at this site-complex have laid the foundations of our understanding of the Palaeolithic occupation of this region. It is of utmost importance to continue Palaeolithic research in this area as it is one of the fastest-growing industrializing and urbanizing zones of the world, with large population centres such as Bangalore (Bengaluru), Mysore (Mysuru) and others located here. Documenting the rich Palaeolithic heritage in this region before its eventual surrender to the forces of ‘development’ is thus a priority. Further, it is also necessary, if possible, to qualify and quantify the impact of these developmental processes on the visibility and preservation of the archaeological record, in general, and the Palaeolithic record, in particular, which might serve as a model for future research in similar regions. These recent investigations have led to the identification of many new Palaeolithic localities, and a secure identification of the technological attribution of their lithic assemblages. The presence of a uniform stratigraphic association of the archaeological horizon and similarities in their lithic collections has led to the reclassification of the many localities at Kibbanahalli and its vicinity into a site-complex. This paper reports on a series of field observations and remotely sensed data collected to understand the distribution pattern of the various Palaeolithic localities of this site-complex. Results of this study highlight the critical role played by modern-day land-use patterns on the observed distribution of the archaeological record, as well as its visibility. This observation challenges previous interpretations regarding the settlement patterns and strategies suggested for the Palaeolithic occupation of this region. Further, this study draws attention to the need and necessity to understand the role of various site formation processes, especially modern-day land-use activities, on the observed and observable patterns in the archaeological record, as well as the visibility, or lack thereof, of the archaeological record.