In 2007, Windy L. Jaeger, Lazlo P. Keszthelyi, Alfred McEwen, Patrick S. Russell and Colin S. Dundas (University of Arizona) examined very high resolution images from HiRISE and reassessed earlier interpretations of the Athabasca Valles system in light of the new available data. The researchers found that all the flood features in the Athabasca Valles are draped by lava flows, and concluded that the valley was most likely carved not by floodwaters but by low-viscosity lava erupting from Cerberus Fossae. They re-interpreted all putative glacial features observed both in the Athabasca Valles and downstream in Cerberus Palus as volcanic in nature, directly challenging the periglacial hypothesis claimed by David Page and co-workers. David Page directly disputed the authors' volcanic interpretations of the pitted mounds and polygonal terrains in a later publication, noting that these features occasionally are found to superpose impact craters. A volcanic interpretation does not permit this later resurfacing. Page criticized the researchers for cherry-picking observations to suit their hypothesis. The authors responded to Page's criticisms by pointing out that secondary impact craters are not always energetic enough to completely erase pre-existing landforms, and that his assertions about polygonal terrain are analogized from a region of Elysium Planitia that is very far and that is structurally distinct from the polygons observed within the Athabasca Valles. Jaeger and her co-workers also noted GRS, SHARAD and CRISM interpretations strongly suggesting that water ice has not been a major reshaping force in the geologic history of the Athabasca Valles.