Orbital‐scale droughts in central‐northern Mexico during the late Quaternary and comparison with other subtropical and tropical records

Abstract

Palaeoclimate research in subtropical arid Mexico is mainly focused to infer dynamics and geographic distributions of different precipitation regimes, but droughts have received less attention. We present a new sedimentary core record indicating orbital‐scale dynamics of droughts that occurred in central‐northern Mexico during the late Quaternary. This record is reconstructed from abundances of authigenic carbonate and windblown clastic sediments in a 1026‐cm‐long sediment core from the Santiaguillo ephemeral lake. The Marine Isotope Stage (MIS) 2 lacked drought, and at least two different droughts were centred at c. 13.5 ka and at c. 7 ka during the MIS 1. The drought of c. 13.5 ka in the Santiaguillo ephemeral lake was contemporary to an interval of droughts in the Basin of Mexico (central Mexico) and stronger aeolian activity in the Baja California peninsula (northwestern Mexico). This synchronous arid condition, observed in the subtropical as well as tropical Mexico, occurred during an interval of higher spring insolation, relatively warmer but fluctuating global temperature, and stronger El Niño‐Southern Oscillation. Unsuccessful radiocarbon dating for the lower part of the sediment core led to an assignment of uncertain chronology to droughts that occurred possibly between MIS 5 and MIS 3. Copyright © 2017 John Wiley & Sons, Ltd.

Comparisons between marine productivity and terrestrial input records in the Gulf of California over the last 28 ka

“…Also, seismic profiles from the western GC show evidence of sediment bypass from the continental shelf and slope to the deepwater basins, during relative sea level low‐stands (Kluesner et al ., 2014). However, during Holocene high‐stand conditions (11.7–4 ka), the reduction in coarser sediment supply and increases in dust input (finer sediments) could have been caused by a combination of the following: (1) enhanced aeolian erosion in northwestern Mexico and California during drier periods, corresponding to increased aeolian transport (Muhs et al ., 2007; Roy et al ., 2010); and (2) increased delivery of windblown clastic sediments in northern Mexico and Baja California (Antinao et al ., 2016; Quiroz‐Jiménez et al ., 2018).…”

“…8A–F). There are also similarities between our data and regional reconstructions from neighbouring sites like the southwestern United States and northwestern Mexico, including the deserts of Chihuahua, Mojave and Sonora (Antinao et al ., 2016; Metcalfe et al ., 2015; Quiroz‐Jiménez et al ., 2018; Roy et al ., 2010). During the glacial period, between 28 and 18 ka, summer insolation was at its lowest (Laskar et al ., 2004), the sea level was ~120 m below the present (Bintanja et al ., 2005), and the Intertropical Convergence Zone (ITCZ) was in a southern position (Peterson et al ., 2000) (Fig.…”

“…Records from the southwestern United States indicate deeper lakes and forest expansion between 18 and 16 ka (Smith & Street‐Perrott, 1983). Between 14 and 11 ka, humid events have been reconstructed on land, caused by the increase in winter rain as evidenced by higher lake levels, gradation of alluvial systems and marsh pollen records in southern Baja California (Quiroz‐Jiménez et al ., 2018; Roy et al ., 2010). At 12 ka, drier conditions were found in the north of Baja California that may reflect the YD, when lakes disappeared and dust accumulation began (Ortega et al ., 1999).…”

“…During the mid‐Holocene, northwesterly winds became stronger as the North Pacific High extended to its current position (Barron et al ., 2014; McClymont et al ., 2012). The entrance of wind‐derived sediment in Bahía Kino (northwestern Mexico) at 6 ka is comparable to the removal of pine forests in the Sierra Madre Occidental coastal region, as the sea level continued to rise (Quiroz‐Jiménez et al ., 2018; Roy et al ., 2010). Current dry conditions could have been established when the scrub vegetation settled in the Sonora desert (Metcalfe et al ., 2015).…”

“…During the mid-Holocene, northwesterly winds became stronger as the North Pacific High extended to its current position (Barron et al, 2014;McClymont et al, 2012). as the sea level continued to rise (Quiroz-Jiménez et al, 2018;Roy et al, 2010). Current dry conditions could have been established when the scrub vegetation settled in the Sonora desert (Metcalfe et al, 2015).…”