کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6427459 | 1634709 | 2016 | 15 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Rapid regional surface uplift of the northern Altiplano plateau revealed by multiproxy paleoclimate reconstruction
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The central Altiplano is inferred to have experienced â¼2.5±1km surface uplift between â¼10 and 6 Ma, while the southern Altiplano experienced a similar magnitude of surface uplift that began earlier, between â¼16 and 9 Ma. To properly constrain the along strike timing of the Altiplano plateau surface uplift, it is necessary to know how and when the northernmost part of the Altiplano plateau evolved. We reconstruct the paleoclimate and infer the corresponding paleoelevation from the Miocene-Pliocene deposits of the Descanso-Yauri basin (14-15°S) in the northernmost part of the Altiplano plateau using 4 different proxies, including carbonate clumped isotope composition (i.e., Î47 values), carbonate δ18Oc, leaf wax δDwax and pollen assemblages from paleosol, lacustrine and palustrine carbonates and organic-rich sediments. The isotopic signatures reflect past climate conditions of mean annual air temperature (Î47) and meteoric water isotope values (δ18Oc, δDwax). Our results show that the northernmost plateau remained at low elevation (0.9±0.8 to 2.1±0.9km) until late Miocene time (â¼9 Ma) characterized by â¼15â°C warmer than modern temperature (mean annual air temperature of 23±4â°C, 2Ï), low elevation vegetation and precipitation signature with reconstructed ⡠δ18Omw (VSMOW) of â8.3±2.0â°(2Ï) from carbonate (δ18Oc) and â8.6±1.8â°(2Ï) from leaf wax (δDwax). Modern elevations of 4 km were not reached until 5.4±1.0Ma, as indicated by a negative shift in δDwax (VSMOW) from â143.4±12.8â°(2Ï) to â209.2±21.1â°(2Ï) between 9.1±0.7 and 5.4±1.0Ma. The timing of surface uplift of the northernmost Altiplano is consistent with the evidence for late Miocene surface uplift of the central Altiplano (16-19°S) between 10 and 6 Ma, and indicates that regional scale uplift in the northern-central plateau significantly postdates the onset of surface uplift in the southern Altiplano (19-22°S) between â¼16 and 9 Ma. These results are consistent with piecemeal removal of the lower dense lithosphere, combined with possible lower/middle crustal flow from south to north in the plateau acting as the main mechanisms for the formation of the Altiplano plateau.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 447, 1 August 2016, Pages 33-47
Journal: Earth and Planetary Science Letters - Volume 447, 1 August 2016, Pages 33-47
نویسندگان
Nandini Kar, Carmala N. Garzione, Carlos Jaramillo, Timothy Shanahan, Victor Carlotto, Alex Pullen, Federico Moreno, Veronica Anderson, Enrique Moreno, John Eiler,