کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5786400 1640636 2017 35 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Stonehenge-a unique Late Cretaceous phosphatic Chalk geology: implications for sea-level, climate and tectonics and impact on engineering and archaeology
ترجمه فارسی عنوان
استون هنج - منحصر به فرد زمین شناسی کلاسیک کاسه فسفات کلسیم: مفاهیم مربوط به سطح دریا، آب و هوا و تکتونیک و تاثیر آن بر مهندسی و باستان شناسی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
چکیده انگلیسی
Ground investigations for the A303 Stonehenge Tunnels revealed a unique and complex Chalk geology including the presence of the thickest (>20 m thick), and previously unknown phosphatic chalks in England, partly filling fault controlled erosional channels. The use of natural gamma-ray borehole logs to determine the presence and thickness of the phosphatic deposits is of particular value and combined with the lithostratigraphy, macrofossil and nannofossil biostratigraphy from cores has, for the first time, accurately constrained the Coniacian to Santonian age and the lenticular geometry of such deposits. Four phosphatic chalk events between 88.5-86.5 Ma are recognised associated with synsedimentary faulting. We suggest a causal link between tectonics, subsidence and channel-formation, phosphatisation events, pulses of oceanic upwelling on a frequency of about 0.5 million years to mantle-controlled plate tectonic episodes. The implications of this geology for construction of the A303 and the archaeology of the area are discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Proceedings of the Geologists' Association - Volume 128, Issue 4, August 2017, Pages 564-598
نویسندگان
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