Illuminating the lack of consensus among descriptions of earth history data in the North American deserts: A resource for biologists

Abstract

Understanding the timing of mountain building and desert formation events in western North America is crucial to understanding the evolutionary history of the diverse arid-adapted biota that is found there. While many different, often conflicting descriptions exist regarding geobiotic change in western North America, little work has been done to synthesize these various viewpoints. In this paper we present several case studies that illustrate the differences in the various explanations, based on geological and paleobiological data, detailing mountain uplift and desertification in western North America. The majority of the descriptions detailing mountain building in this area fall into two major periods of uplift, the Laramide uplift (∼70—50 Ma) and the Neogene uplift (∼15—2 Ma), yet it remains unclear which of these events was responsible for the formation of the modern mountains. Like the descriptions of mountain building, various accounts exist detailing the timing of desert formation. Some authors suggest that the deserts existed as far back as 15 Ma while others propose that desert formation occurred as recently as 10,000 years ago. Based on this review of the literature, we suggest that the data on Cenozoic geomorphological evolution of the North American desert landscape is still too coarse and filled with gaps to allow for the development of a robust model of landscape evolution. Instead, this work demonstrates the need for biologists studying the North American biota to realize just how problematic some of the earth history data and models are so that they can build this uncertainty into biogeographic reconstructions.

The Cuatro Ciénegas Basin in Coahuila, Mexico: An Astrobiological Precambrian Park

“…The biological data suggest a continual presence of water in this oasis in northern Mexico, first as a sea and then as subterranean hydrologic systems. Evaporites (mineral sediments that result from evaporation) of different ages indicate that aquatic environments have always been present at the CCB (Minckley and Jackson, 2008;Szynkiewicz et al, 2010;Wilson and Pit, 2010). Consistent with our research efforts and those of others, it might appear that, over time, the chemistry of the ancient subterranean continental waters changed from sodium chloride to calcium, magnesium, sulfate, and carbonate ions that dominate the current chemistry (Minckley and Cole, 1968;Forti et al, 2003).…”

“…Reviewed extensively by Minckley (1969) and Wilson and Pit (2010), mountain building and subsequent desertification of northern Mexico and the southwestern United States was significant in creating ecosystems that led to the evolution and isolation of desert-adapted taxa along the entire North American continent. From the late Triassic to the early Cretaceous, all of northern Mexico was covered by seawater, and it is likely that the Laramide Uplift [70-50 Ma before present (BP); one of two major mountain-building events in North America] initiated a progressive regression of the Western Interior Seaway, which began to regress in the late Cretaceous due to the uplift caused by the Laramide Orogeny (Minckley, 1969;Ferrusquía-Villafranca, 1998).…”

“…The final regression of the sea occurred during the late Paleocene, and the complete isolation of the CCB from the Gulf of Mexico happened with the uplift of the Sierra Madre Oriental in the mid Eocene (Ferrusquía-Villafranca, 1998) with the close of the Western Interior Seaway. There is still debate (Wilson and Pit, 2010) as to whether the Laramide event or the more recent Neogene Uplift (15-2 Ma BP) was responsible for the severe deformation that produced the land surfaces now evident in the modern mountain ranges of North America. However, the majority of paleontological evidence supports the progressive desertification of the Chihuahuan Desert (thereby the CCB) by 15 Ma BP.…”

“…However, the majority of paleontological evidence supports the progressive desertification of the Chihuahuan Desert (thereby the CCB) by 15 Ma BP. Hence, the region has largely been geologically and climatically stable since that time (Axelrod, 1979;Wilson and Pit, 2010). With regard to the CCB specifically, there is palynological evidence that during the late Quaternary (2.5 Ma BP) the area experienced climatic changes that include the migration of woodland-type vegetation upslope as the climate warmed (Meyer, 1973;Metcalfe et al, 2000;Minckley and Jackson, 2008).…”

As Old as the Hills: Montane Scorpions in Southwestern North America Reveal Ancient Associations between Biotic Diversification and Landscape History

“…Agreement on a cohesive geohistorical framework for mountain formation across southwestern North America remains elusive despite decades of research [69]. Ecologically specialized ‘living fossils’, like the scorpions of the vorhiesi group, represent model organisms for tracking orogeny, as evidenced in the present study by the amount of genetic structure observed across the relatively small distances between adjacent mountain ranges.…”