Seasonal and interannual variation of sterols in macrophytes from the Pacific coast of Baja California Peninsula (Mexico)

2020 ◽  
Author(s):  
Serviere‐Zaragoza Elisa ◽  
Hurtado‐Oliva Miguel Angel ◽  
Mazariegos‐Villarreal Alejandra ◽  
Arjona Olivia ◽  
Palacios Elena
2014 ◽  
Vol 27 (3) ◽  
pp. 1297-1306 ◽  
Author(s):  
Elisa Serviere-Zaragoza ◽  
Miguel Angel Hurtado ◽  
Marlenne Manzano-Sarabia ◽  
Alejandra Mazariegos-Villarreal ◽  
Mónica Reza ◽  
...  

2005 ◽  
Vol 15 (3) ◽  
pp. 259-269 ◽  
Author(s):  
Milagros López-Mendilaharsu ◽  
Susan C. Gardner ◽  
Jeffrey A. Seminoff ◽  
Rafael Riosmena-Rodriguez

1980 ◽  
Vol 13 (3) ◽  
pp. 346-364 ◽  
Author(s):  
Alan J. Woods

AbstractThree emergent marine terraces are prominent between Playa El Marron and Arroyo El Salinito and comprise the most extensive Pleistocene planation surfaces in central Baja California, Mexico. The deposits of the lowest terrace, the Tomatal, are 120,000 ± 20,000 yr old (Sangamonian?) while the absolute ages of the two higher and older terraces, the Andrés and Aeropuerto, are unknown. The Tomatal terrace is particularly well developed and comprises degraded sea cliffs, paleodunes, and lagoonal sequences. Shingle paleobeach ridges also occur locally and reflect shore progradation and tombolo formation. The Tomatal shoreline is nearly horizontal at 7 ± 1 m above present mean sea level, whereas the older Aeropuerto terrace has been tilted so that it decreases in elevation toward the southeast. Nonetheless, coastal tilting is not nearly as great as at many other localities in California and Baja California. This is despite the fact that the entire Baja California peninsula has been assumed to be tectonically unstable during the Pleistocene, primarily because of the forces generated by plate motion.


2015 ◽  
Vol 82 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Juan Antonio De Anda-Montañez ◽  
Susana Martínez-Aguilar ◽  
Eduardo F. Balart ◽  
Tania Zenteno-Savín ◽  
Lía Méndez-Rodríguez ◽  
...  

2010 ◽  
Vol 26 (1) ◽  
pp. 118-119 ◽  
Author(s):  
G. Ruiz-Campos ◽  
A. Ramírez-Valdez ◽  
S. González-Guzmán ◽  
A. F. González-Acosta ◽  
D. Acosta Zamorano

2002 ◽  
Vol 74 (2) ◽  
pp. 121-131 ◽  
Author(s):  
P. Ramı́rez-Garcı́a ◽  
J. Terrados ◽  
F. Ramos ◽  
A. Lot ◽  
D. Ocaña ◽  
...  

2021 ◽  
Author(s):  
Daniel R. Muhs

Abstract. The primary last interglacial, marine isotope substage (MIS) 5e records on the Pacific Coast of North America, from Washington (USA) to Baja California Sur (Mexico), are found in the deposits of erosional marine terraces. Warmer coasts along the southern Golfo de California host both erosional marine terraces and constructional coral reef terraces. Because the northern part of the region is tectonically active, MIS 5e terrace elevations vary considerably, from a few meters above sea level to as much as 70 m above sea level. The primary paleo-sea level indicator is the shoreline angle, the junction of the wave-cut platform with the former sea cliff, which forms very close to mean sea level. Most areas on the Pacific Coast of North America have experienced uplift since MIS 5e time, but the rate of uplift varies substantially as a function of tectonic setting. Chronology in most places is based on uranium-series ages of the solitary coral Balanophyllia elegans (erosional terraces) or the colonial corals Porites and Pocillopora (constructional reefs). In areas lacking corals, correlation to MIS 5e can sometimes be accomplished using amino acid ratios of fossil mollusks, compared to similar ratios in mollusks that also host dated corals. U-series analyses of corals that have experienced largely closed-system histories range from ~124 to ~118 ka, in good agreement with ages from MIS 5e reef terraces elsewhere in the world. There is no geomorphic, stratigraphic, or geochronology evidence for more than one high-sea stand during MIS 5e on the Pacific Coast of North America. However, in areas of low uplift rate, the outer parts of MIS 5e terraces apparently were re-occupied by the high-sea stand at ~100 ka (MIS 5c), evident from mixes of coral ages and mixes of molluscan faunas with differing thermal aspects. This sequence of events took place because glacial isostatic adjustment processes acting on North America resulted in regional high-sea stands at ~100 ka and ~80 ka that were higher than is the case in far-field regions, distant from large continental ice sheets. During MIS 5e time, sea surface temperatures (SST) off the Pacific Coast of North America were higher than is the case at present, evident from extralimital southern species of mollusks found in dated deposits. Apparently no wholesale shifts in faunal provinces took place, but in MIS 5e time, some species of bivalves and gastropods lived hundreds of kilometers north of their present northern limits, in good agreement with SST estimates derived from foraminiferal records and alkenone-based reconstructions in deep-sea cores. Because many areas of the Pacific Coast of North America have been active tectonically for much or all of the Quaternary, many earlier interglacial periods are recorded as uplifted, higher elevation terraces. In addition, from southern Oregon to northern Baja California, there are U-series-dated corals from marine terraces that formed ~80 ka, during MIS 5a. In contrast to MIS 5e, these terrace deposits host molluscan faunas that contain extralimital northern species, indicating cooler SST at the end of MIS 5. Here I present a standardized database of MIS 5e sea-level indicators along the Pacific Coast of North America and the corresponding dated samples. The database is available in Muhs (2021)  [https://doi.org/10.5281/zenodo.5557355].


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