کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5780423 | 1635131 | 2017 | 40 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Lithostratigraphy and physical properties of lacustrine sediments of the last ca. 150 kyr from Chalco basin, central México
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Lithostratigraphy and physical properties of lacustrine sediments of the last ca. 150 kyr from Chalco basin, central México Lithostratigraphy and physical properties of lacustrine sediments of the last ca. 150 kyr from Chalco basin, central México](/preview/png/5780423.png)
چکیده انگلیسی
The recognition of past climatic fluctuations in sedimentary sequences in central Mexico is relevant for understanding the forcing mechanisms and responses of climatic system in the northern American tropic. Moreover, in this active volcanic setting the sedimentary record preserves the history of past volcanic activity. Climatic and environmental variability has been documented for the last tenths of thousands of years from the upper lacustrine sediments in Chalco basin. A series of cores drilled down to 122Â m depth in this basin offer a long, continuous and high resolution record of past climatic changes of the last ca. 150 kyr in this region. Here we present the detailed lithostratigraphy and some physical properties (magnetic susceptibility and density) of the master sequence. Sedimentary components and their abundance were identified and quantified in smear slides and direct core observations. Age model is based on 13 14C and one 230Th/U dates. Based on their facies association seven lithostratigraphic units were defined, which reflect the main stages of lake Chalco evolution. These phases closely match the marine isotopic stages. The data reveal that at the end of MIS6 Chalco was a relatively deep and stratified freshwater lake. During MIS5 the depositional environment fluctuated between low lake stands to marshy and marginal playa settings with sporadic flooding events, and severe arid periods resulted in aerial exposure of lake sediments. Low lake stands persisted during MIS4 and MIS3, with minor fluctuations towards slightly deeper phases. The Last Glacial Maximum (LGM) and the deglacial period (21-13 kyr) are characterized by intense volcanism. The early and mid-Holocene high calcareous content and alkaline-subsaline lake suggest dry conditions. The fluctuations of lake levels inferred provide the basis for future paleoclimatic works.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of South American Earth Sciences - Volume 79, November 2017, Pages 507-524
Journal: Journal of South American Earth Sciences - Volume 79, November 2017, Pages 507-524
نویسندگان
Beatriz Ortega-Guerrero, Socorro Lozano-GarcÃa, Dimitris Herrera-Hernández, Margarita Caballero, Laura Beramendi-Orosco, Juan Pablo Bernal, Esperanza Torres-RodrÃguez, Diana Avendaño-Villeda,