Comparisons between marine productivity and terrestrial input records in the Gulf of California over the last 28 ka |
| |
| Authors: | Elsa Arellano-Torres Astrid J Mora-Rivera Paola Vázquez-Romero Enrique H Nava-Sánchez Juan José Kasper-Zubillaga M Socorro Lozano-García |
| |
| Institution: | 1. Facultad de Ciencias, Departamento de Ecología y Recursos Naturales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Mexico City, Mexico;2. Facultad de Ciencias, Licenciatura en Ciencias de la Tierra, Departamento de Física, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Mexico City, Mexico;3. Facultad de Ciencias, Licenciatura en Ciencias de la Tierra, Departamento de Física, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Mexico City, Mexico
Deceased.;4. Centro Interdisciplinario de Ciencias Marinas, Departamento de Oceanología, Instituto Politécnico Nacional, Av. IPN s/n, Col. Playa Palo de Santa Rita, La Paz, Baja California Sur, Mexico;5. Instituto de Ciencias del Mar y Limnología, Unidad Académica de Procesos Oceánicos y Costeros, Universidad Nacional Autónoma de México. Circuito Exterior, Ciudad Universitaria, Mexico City, Mexico;6. Instituto de Geología, Universidad Nacional Autónoma de México, Circuito de la Investigación, Ciudad Universitaria, Mexico City, Mexico |
| |
| Abstract: | We study the marine and terrestrial contributions in the Gulf of California (GC) to understand the relationship between continental climate and oceanographic variability over the last 28 ka. In Core AII125-8-JPC-20, we examine aeolian and riverine inputs as nutrients for biological productivity. We use biogenic silica (%opal), total organic carbon (%TOC) and calcium carbonate (%CaCO3) as proxies for primary productivity, and lithic fraction distributions as proxies for terrigenous transport. At the core site, biogenic and lithic components are in phase at millennial-scale in response to regional climate conditions. During the Late Pleistocene, the GC shelf area was above sea level and the western margin showed transient episodes of increased fluvial inputs. Episodic increases in %opal and reduced %TOC suggest upwelling events but ineffective C-export to the sediment. During stadial events (Heinrich 2, Heinrich 1, Younger Dryas), regional declines in %opal, but increases in %CaCO3 and TOC, suggest efficient C-export by carbonate organisms. During most of the Holocene, dust inputs are higher. Episodic increases in %TOC suggest higher C-accumulation, although this is not controlled by siliceous or calcareous organisms. In the GC, besides upwelling and current advection, nutrient inputs driven by terrestrial climate have an impact on the biological C-pump. © 2020 John Wiley & Sons, Ltd. |
| |
| Keywords: | biogenic opal calcium carbonate dust inputs fluvial inputs grain size |
|
|
