Textural characterization of beach sands from the Gulf of California, Mexico: implications for coastal processes and relief

Abstract

Grain size determinations were carried out for 54 beach-sand samples from the western (n = 25) and eastern (n = 29) coasts of the Gulf of California, Mexico, in order to establish the relationship among coastal processes, relief, and grain size parameters for both areas based on grain size distributions. This was done because both coastal areas are controlled by marine processes and the geomorphology of the coast, since fluvial discharges are negligible in the distribution of sands. In general, sands from the western coast are mainly coarse, moderately sorted, near-symmetrical with leptokurtic and very leptokurtic distributions. Correlations between grain-size parameters for the western coast are controlled by less selectivity in the coastal processes to concentrate fractions in a specific range of sizes, a narrow coastal plain, and compositional differences in the sands due to the heterogeneous lithology and the presence of carbonate shells. Eastern coast beach sands are medium, moderately well sorted, near-symmetrical with mesokurtic to leptokurtic distributions. Correlations between grain size parameters for the eastern coast are controlled by longshore current drifts in a northwestern direction and a wider coastal plain compared to the western coast.

Effect of temperature on photosynthesis, growth and calcification rates of the free-living coralline alga Lithophyllum margaritae

“…Unlike other macroalgal-based ecosystems there is little organic material and low turnover. However, coralline debris or biocalcarinite from broken rhodoliths generates large amounts of carbonate material, contributing to coastal sediments, large beach berms and fossil beds along the Baja California Peninsula (Johnson et al 2007, Kasper-Zubillaga et al 2007, Sewell et al 2007. Though coralline algae are critical for sustaining beach sediment, most studies of Baja California rhodoliths have focused on their taxonomy and ecology with little work on their growth and calcification physiology.…”

Petrographic and geochemical analyses of dune sands from southeastern Mexico, Oaxaca, Mexico

“…It is essential to highlight that medium-to fine-grained dune sands in the Oaxaca region are similar to those observed in coastal dune sands worldwide (Abuodha, 2003;Kasper-Zubillaga, Carranza-Edwards, & Morales De la Garza, 2007;Lopez, Hegy, & Missimer, 2020). Dune sands are texturally linked to the longshore transport of aeolian sands, the wind regime, as well as the grain size availability by river input (Noda, 2005).…”

“…Point counting results were recalculated to percentages for each category. Ternary diagrams were constructed with the following poles: Q-F-L; Q-K-P; Lm-Ls-Lv and Amp-Op-Grt based on the standard main compositional framework and subordinate components of the river and dune sands (Garzanti et al, 2012(Garzanti et al, , 2015Garzanti, Padoan, et al, 2013;Kasper-Zubillaga, Carranza-Edwards, & Morales De la Garza, 2007;Mendieta-Lora et al, 2018) (Tables 1 and 2).…”

“…When the sand samples dryness was achieved, we added a solution of HNO 3 (2%). (Garzanti, 2019;Garzanti et al, 2013,b;Garzanti & Resenti, 2016;Kasper-Zubillaga, Carranza-Edwards, & Morales De la Garza, 2007;Mendieta-Lora et al, 2018;Nesbitt & Young, 1982). The CaO* is part of the silicate fraction determined in the plagioclase sands content (see Honda & Shimizu, 1992).…”

“…Several factors possibly control dissimilarities in dune features. For instance, wind velocity impact, direction and frequency on the dune sands, and regional geomorphology have been identified as controlling factors in several dune systems around the world (Garzanti et al, 2012;Garzanti et al, 2015;Kasper-Zubillaga, Carranza-Edwards, & Morales De la Garza, 2007;Kasper-Zubillaga & Zolezzi-Ruiz, 2007;Lancaster, 1985Lancaster, , 2009Muhs, 2017;Zimberlman & Williams, 2007). Little research regarding dune sands evolution and provenance studies for the southeastern dune sands in Oaxaca are reported in the literature.…”