A Karst Connection model for Grand Canyon, Arizona, USA

A proposed Laramide proto-Grand Canyon

“…Over a distance of ∼ 10 km (6 mi) from recharge to discharge, this would amount to a hydraulic gradient of about 0.0127, which would have been more than sufficient to move karst groundwater under the Lone Mountain anticline/monocline and Hurricane monocline. We propose that this karst diversion directed the course of the paleocanyon river from north to east, in a similar manner as Hill et al (2008) proposed that the Colorado River changed direction from south to west across the Kaibab arch near Desert View ∼ 6 Ma (DV, Fig. 1).…”

“…Pederson (2008) studied the Muddy Creek north of Grand Canyon and concluded that these sediments did not represent terminal deposits from an ancestral Colorado River-the same conclusion as deduced by Hill et al (2008) based on Canaan Peaktype gravel distribution north of the canyon. In the southern Grand Wash fault area, near the mouth of Grand Canyon, the Muddy Creek Formation consists of three members that grade into and interfinger with each other:…”

“…8). Hill et al (2008) have headward erosion eastward from Upper Granite Gorge and along the Grandview monocline, incising into the Kaibab arch and Redwall Limestone aquifer by ∼ 6 Ma, thus effecting a karst-aquifer hydrological connection between the eastern and western Grand Canyon. Headward erosion up Marble Canyon to Hill et al's (2005Hill et al's ( , 2008) "Glen Lake" produced the "final connection" and the complete integration of the Colorado River from Colorado to the Gulf of California along a Grand Canyon similar to what exists today.…”

Erosional modification and gully formation at Meteor Crater, Arizona: Insights into crater degradation processes on Mars

“…Alternatively, an underground cavern could have existed before the impact, but opened on the crater wall because of impact excavation. For example, we observed several caves in the Kaibab Formation outside the crater, where Canyon Diablo now exists, and others (Hill et al, 2008) have reported similar caves in the Redwall Formation along the Grand Canyon section of the Colorado River. The caves are important dwelling locations for animals and microorganisms.…”

Response to Comments on the "Age and Evolution of the Grand Canyon Revealed by U-Pb Dating of Water Table–Type Speleothems"

“…Although it is true that this concept does contradict pre-early 1990s knowledge, it does not contradict more recent findings (7)(8)(9)(10)(11)(12), including a paper on the pre-Colorado River drainage in the Western Grand Canyon (5). The 16-to 6-Ma "western" canyon that we proposed is similar in both age and extent to that proposed by Young (5 (1).…”