![Anais Salazar 2008 H Extremo Anais Salazar 2008 H Extremo](https://i.ytimg.com/vi/PwY5pxU8a7A/maxresdefault.jpg)
The southern samples are characterized by the presence of polycrystalline quartz and plutonic lithic fragments (see fig. ( c ) Monocrystalline quartz (Qz) and sedimentary lithic fragments (Ls and arrows) distinguish the samples from the northern depocentre from those of the southern depocentres.
![Anais Salazar 2008 H Extremo Anais Salazar 2008 H Extremo](https://3.bp.blogspot.com/-J1PrP_l_rfc/XVsWyczgr3I/AAAAAAAAUMg/fkjURu9zd5ALnP8UL_ecPBG3oZH_x84cACK4BGAYYCw/s640/anais-salazar-instagram-sexy-pies-edad%2B%252843%2529.jpg)
( b ) Cuspate and pumice shards (arrows) provide evidence of active volcanism during sedimentation (sample TOR-02). ( a ) Metamorphic lithic fragments are common in the base of the column (sample TOR-02, Loncopu ́ section). Photomicrographs of the Tordillo Formation. Sample coordinates, values of the sandstone compositional framework and U–Pb (LAM-MC-ICP-MS) age measurements of zircons grains are available at This younger age represents a discrepancy of at least 7 Ma from the absolute age of the Kimmeridgian and Tithonian boundary (from the chronostratigraphic timescale accepted by the International Commission of Stratigraphy, IUGS), and has strong implications for the absolute age of the Jurassic–Cretaceous boundary. The results permit a statistically robust estimation of the maximum deposition age for the Tordillo Formation at c.
![Anais Salazar 2008 H Extremo Anais Salazar 2008 H Extremo](https://pbs.twimg.com/media/BtFvTAfCAAETA1H.jpg)
In the former, the arc region played a considerable role as a source region, but this is not identified in the latter. The comparison between provenance patterns of the Tordillo Formation and of the Avilé Member (Agrio Formation) showed some differences. Towards the top, the data suggest that the Andean arc becomes the main source region. Temporal variation in the provenance indicates that at the beginning of the sedimentation, Carboniferous to Lower Jurassic magmatic rocks and Lower Palaeozoic metamorphic rocks were the most important sources. 144, 153 and 178 Ma), although two secondary sources were defined at c. The ages indicate that the most important source region of sediment supply was the Jurassic Andean arc (peaks at c. New U–Pb detrital zircon ages are presented for the Tordillo Formation.