On Thursday 25th of September 2014 Henk Kars (VU University Amsterdam) and Sjoerd Kluiving (VU University Amsterdam) will give a talk in the ACASASS series with the topic: Geoarchaeology: looking back and forward. The talks will be followed by a reception. *Time: Thursday 25-09-2014, 15.30-16.30 hrs. *Place: VU, Main Building, room 06A04, De Boelelaan 1105, 1081HV Amsterdam *Abstracts: Henk Kars Fifteen years of Geoarchaeology at VU: what has been reached and what is left? Geoarchaeology originally is the multi- to interdisciplinary field of study which uses geoscientific methods, methodologies and knowledge to answer archaeological questions. These questions are on level of the artifact, the site or the landscape. Examples of artifact studies are provenancing of raw materials, using mineralogical and geochemical methods. On site level, geographical and geophysical prospection techniques are used to discover and evaluate archaeological sites. Geoarchaeologists in particular investigate the relation of the site to its natural and cultural paleo-environment seen in a wider geographical and geomorphological context. With regard to archaeological heritage management, research questions are how specific artifacts will survive in soils, what are the post-depositional processes that have had effect on the preservation state of sites, and how can archaeological sites be integrated in future landscapes. It is also noticed that research questions of the earth sciences can benefit from archaeological knowledge: archaeoseismology, for instance, uses information gained from written sources and from archaeological field data to study the occurrence and magnitude of seismic activities in antiquity. All these aspects of geoarchaeology have been taught and studied at VU in the knowledge that geoarchaeology is an essential field of study to advance understanding of humanenvironment interactions in the past. Seen in light of this conclusion it is wondered why geoarchaeology is still in its infancy if compared to existing main stream geoscientific and archaeological disciplines. Sjoerd Kluiving How geoarchaeology and landscape archaeology make a contribution to Human Niche Construction (HNC) A review is given of examples of geoarchaeological and landscape archaeological research from various locations throughout Europe. Water as an example of small (and large) scale use of the natural landscape and/or topography is discussed with implications for HNC and how research in the future makes a better contribution to HNC: 1) scales of landscape research and the importance of landscape gradients, 2) are landscape gradients the starting points where organisms (humans) are altering its own selective environment (inceptive change)? 3) is it the lack of landscape gradients that initiate humans to respond to a (deteriorated) selective environment (counteractive change)? Examples of landscape gradients are: high/low, sand/clay, freshwater/seawater, land/water, loam-rich soil/loam poor soil etc. The Netherlands, North Sea Region, and case studies from the Mediterranean area are presented to illustrate the potential of geoarchaeology and landscape archaeology to HNC. Unintended consequences of human impact on large scale natural processes will be considered. In the discussion a gradient driven occupation pattern will be presented, as well as transitions of high to low attractiveness of sites of human occupation.