Abstract
A buried Holocene marine bed was discovered upon drilling a water well in Algarrobo (33°22'S), located on the coast of central Chile. Radiocarbon dating of a wood fragment found within the deposit indicates an age of 6450 cal yr BP. The top of this bed, 0.25 m-thick, was reached at an elevation of 3.8 m above mean sea level. This bed contains abundant monospecific faunas of foraminifers (Ammonia tepida) and ostracodes (Cyprideis beaconensis), indicative of deposition in a very shallow, transitional marine environment. Palynologic analysis reveals a Chenopodiaceae-dominated (~70%) assemblage, indicating a relatively arid and warm climate.
Highlights
Pleistocene terraces are widespread along the coast of Chile and have been a subject of study since the 19th century (e.g., d'Orbigny, 1842; Darwin, 1846; Domeyko, 1848; Herm, 1969; Paskoff, 1970, 1977; Leonard and Wehmiller, 1992; Ota et al, 1995; Ortlieb et al, 1996; Marquardt et al, 2004)
Drilling of a water well in the San Jerónimo Creek, near Algarrobo, led to the casual discovery of a buried Holocene marine bed within fluvial deposits. We consider this finding important because there is no prior record of marine Holocene deposits in this part of central Chile. This discovery implies the possibility of new Holocene findings in the area, which would permit the calculation of coastal uplift rates and to determine if these rates are enhanced by the nearby aseismic Juan Fernández Ridge, which is subducted 30 km north of Algarrobo
The Algarrobo marine bed was discovered by chance upon examining sediments unearthed during the excavation of a water well on the southern bank of the San Jerónimo Creek
Summary
Pleistocene terraces are widespread along the coast of Chile and have been a subject of study since the 19th century (e.g., d'Orbigny, 1842; Darwin, 1846; Domeyko, 1848; Herm, 1969; Paskoff, 1970, 1977; Leonard and Wehmiller, 1992; Ota et al, 1995; Ortlieb et al, 1996; Marquardt et al, 2004). Drilling of a water well in the San Jerónimo Creek, near Algarrobo, led to the casual discovery of a buried Holocene marine bed within fluvial deposits. We consider this finding important because there is no prior record of marine Holocene deposits in this part of central Chile. This discovery implies the possibility of new Holocene findings in the area, which would permit the calculation of coastal uplift rates and to determine if these rates are enhanced by the nearby aseismic Juan Fernández Ridge, which is subducted 30 km north of Algarrobo
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
