الوصفNorth america and scandinavia basement rocks.png
North Americancratons and basement rocks. As radiometric ages were determined for the shield-like rocks on the continents which were either exposed at the surface, underlay the flat rocks, or were within the interior of the mountain belts, patterns of age intervals were determined. These old rocks have been called the "basement". This has been interpreted to mean that the continents had somehow grown by development of rock assemblages with these characteristic age parameters. The expanding continental nuclei are part of the "craton" which consist of both exposed and buried basement rocks.
هذا رسمٌ مُعَدَّلٌ رقميَّاً من النسخة الأصليَّة. التعديلات هي: Change of colours to match some geological map colour templates. يُمكن الاطلاع على النسخة الأصليَّة هنا: North america basement rocks.png: . المُستخدم الذي أجرى التعديلات هو: Bjoertvedt.
نسب العمل إلى مُؤَلِّفه – يلزم نسب العمل إلى مُؤَلِّفه بشكل مناسب وتوفير رابط للرخصة وتحديد ما إذا أجريت تغييرات. بالإمكان القيام بذلك بأية طريقة معقولة، ولكن ليس بأية طريقة تشير إلى أن المرخِّص يوافقك على الاستعمال.
الإلزام بترخيص المُشتقات بالمثل – إذا أعدت إنتاج المواد أو غيرت فيها، فيلزم أن تنشر مساهماتك المُشتقَّة عن الأصل تحت ترخيص الأصل نفسه أو تحت ترخيص مُتوافِقٍ معه.
2005-09-16T15:47:59Z Saperaud 484x429 (13371 Bytes) [[North America]]n [[craton]]s and basement rocks. As radiometric ages were determined for the shield-like rocks on the continents which were either exposed at the surface, underlay the flat rocks, or were within the interio
{{Information |Description=North Americancratons and basement rocks. As radiometric ages were determined for the shield-like rocks on the continents which were either exposed at the surface, underlay the flat rocks, or were within the interior o