Physiographie forestière; physiographie des États-Unis et principes des sols en relation avec la foresterie . ley. -La tendance recnessde des digues à courte distance est directement liée à la topographie et au drainage de la ligne droite si caractéristique dans de nombreux portionsde la région de donner une apparence prononcée d'artifice à elle.Lac Temiskaming et la Rivière Profonde du drainage d'Ottawa sys-i données de Bateman, CAN. Surv. Géols. 568 LE SYSTÈME DE PHYSIOGRAPHIE FORESTIÈRE sont des exemples de lacs longitudinaux, mais leur origine peut avoir été causée par la gauchissement de la croûte ou par le blocage du type de graben. Po

• Contributeur: The Reading Room / Alamy Banque D'Images
• ID de l’image: 2AXBG75
• Taille du fichier: 7,1 MB (454,3 KB Téléchargement compressé)
• Autorisations: Modèle - non | Propriété - non
• Dimensions: 3220 x 776 px | 27,3 x 6,6 cm | 10,7 x 2,6 inches | 300dpi

Informations supplémentaires

Cette image appartient au domaine public, ce qui signifie que le droit d’auteur a expiré ou que le titulaire du droit d’auteur a renoncé à ses droits. Les frais facturés par Alamy couvrent l’accès à la copie haute résolution de l’image.

Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.

Forest physiography; physiography of the United States and principles of soils in relation to forestry . ley. -The straightnessof trend of the dikes within short distances is directly related to thestraight-line topography and drainage so characteristic in many portionsof the area as to give a pronounced appearance of artificiaUty to it.Lake Temiskaming and the Deep River of the Ottawa drainage sys-i Data from Bateman, Can. Geol. Surv. 568 FOREST PHYSIOGRAPHY tem are examples of longitudinal lakes, but their origin may have beendue to crustal warping or to block-faulting of the graben type. In stillother cases the longitudinal lakes are due to blocking of valleys by glacialmaterial. In addition to the lake types of the Laurentian that we have notedthere is another class dependent upon broader and less local conditions.These lakes lie on the border of the region and their occurrence is coin-cident with that of large isolated areas of sedimentary rock within oron the border of the crystalline area. Whether these sedimentarymasses represent downfaulted blocks of rock formerly more extensive. Fig. 227. — View on the shore of Lake St. John, Quebec. The level sky line in the background representsthe Laurentian Plateau; in the foreground is a lowland developed on limestone; in the middle distanceare alluvial terraces. than now, and preserved by downfaulting because carried below the gen-eral level of the peneplain surface, is not certainly known, but theexplanation has a high degree of plausibility, for faulted zones havebeen found about the borders of some of them and everywhere thesediments are sharply localized and extend to great depths below thelevel of the ancient peneplain. Whatever their origin they wereareas of weakness during the glacial period and indeed ever sincethe elevation of the peneplain, with the result that not only do lakebasins lie in them but the outcrop of the softer sedimentaries is alwaysmarked by the existence of a lowland whose border is sharp

Recherche dans la banque de photos par tags

• bookcentury1900
• bookdecade1910
• booksubjectforestsandforestry