Palaeoenvironmental record of the last 70 000 yr in San Felipe Basin, Sonora desert, Mexico: preliminary results
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| Format: | Artículo científico |
| Language: | en |
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Universidad Nacional Autónoma de México
1999
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| author | Beatriz Ortega Guerrero |
| author_facet | Beatriz Ortega Guerrero |
| contents | Palaeoenvironmental record of the last 70 000 yr in San Felipe Basin, Sonora desert, Mexico: preliminary results Beatriz Ortega Guerrero Margarita Caballero Miranda Socorro Lozano García Margarita De la O Villanueva Ciencias de la Tierra lake sediments Baja California Magnetic properties Quaternary paleoclimates Preliminary results of a palaeoenvironmental research which includes particle size analyses, diatom and rock-magneticanalyses for a 9.5 m long core from Laguna Seca de San Felipe (LSSF), Baja California, are presented. AMS 14C dating gives anextrapolated age of ca. 70 kyr for the sequence analysed. Rock-magnetic measurements (including c, cfd%, ARM, SIRM, hysteresisparameters and S ratios), organic content (LOI) and particle size distribution show highly contrasting conditions between glacialand late glacial-Holocene sediments. Dry conditions prevailed between 70 000 and 45 000 yr ago. The full glacial, between 34 000and 19 000 yr ago, is characterized by moist conditions. The late glacial-Holocene sediments display a five-fold increment in mostof the magnetic parameters and in sedimentation rate. This change is interpreted as an increment in runoff waters. At ca. 7000 yrB.P., a dry period is recorded, which probably spans until 6000 yr B.P., when moist conditions return. The onset of the actual aridcharacteristics occurred around 4000 yr B.P. 1999 artículo científico 0016-7169 https://www.redalyc.org/articulo.oa?id=56838303 en http://www.redalyc.org/revista.oa?id=568 Geofísica Internacional application/pdf Universidad Nacional Autónoma de México Geofísica Internacional (México) Num.3 Vol.38 |
| format | Artículo científico |
| id | redalyc_56838303 |
| institution | Redalyc |
| language | en |
| publishDate | 1999 |
| publisher | Universidad Nacional Autónoma de México |
| spellingShingle | Palaeoenvironmental record of the last 70 000 yr in San Felipe Basin, Sonora desert, Mexico: preliminary results Beatriz Ortega Guerrero Ciencias de la Tierra lake sediments Baja California Magnetic properties Quaternary paleoclimates Palaeoenvironmental record of the last 70 000 yr in San Felipe Basin, Sonora desert, Mexico: preliminary results Beatriz Ortega Guerrero Margarita Caballero Miranda Socorro Lozano García Margarita De la O Villanueva Ciencias de la Tierra lake sediments Baja California Magnetic properties Quaternary paleoclimates Preliminary results of a palaeoenvironmental research which includes particle size analyses, diatom and rock-magneticanalyses for a 9.5 m long core from Laguna Seca de San Felipe (LSSF), Baja California, are presented. AMS 14C dating gives anextrapolated age of ca. 70 kyr for the sequence analysed. Rock-magnetic measurements (including c, cfd%, ARM, SIRM, hysteresisparameters and S ratios), organic content (LOI) and particle size distribution show highly contrasting conditions between glacialand late glacial-Holocene sediments. Dry conditions prevailed between 70 000 and 45 000 yr ago. The full glacial, between 34 000and 19 000 yr ago, is characterized by moist conditions. The late glacial-Holocene sediments display a five-fold increment in mostof the magnetic parameters and in sedimentation rate. This change is interpreted as an increment in runoff waters. At ca. 7000 yrB.P., a dry period is recorded, which probably spans until 6000 yr B.P., when moist conditions return. The onset of the actual aridcharacteristics occurred around 4000 yr B.P. 1999 artículo científico 0016-7169 https://www.redalyc.org/articulo.oa?id=56838303 en http://www.redalyc.org/revista.oa?id=568 Geofísica Internacional application/pdf Universidad Nacional Autónoma de México Geofísica Internacional (México) Num.3 Vol.38 |
| title | Palaeoenvironmental record of the last 70 000 yr in San Felipe Basin, Sonora desert, Mexico: preliminary results |
| topic | Ciencias de la Tierra lake sediments Baja California Magnetic properties Quaternary paleoclimates |
| url | https://www.redalyc.org/articulo.oa?id=56838303 |