Submarine Topography near Noto Peninsula

Abstract

This paper is a study of the features of the cultivated land, and that of the subareal and submarine topography of Noto peninsula, which is the only large peninsula that juts out on the Japan sea.
1. A Morphological Study of the Features of the Cultivated Land. (No. 6, p p. 399-411.)
This land is divided into ten part saccording to type of the feature and the patterns of both rice and dry fields.
I. Plane cultivated land.
A. The Rice field type. This spreads out as “Oti” graben in the NW part of Fig. 2.
B. The “Uti-ura” marine terrace type (see photo. 4, Fig. 5).
C. The Former salt field type (see photo. 1.) The level of the rice field is almost equal to sea level, 50 years ago they were salt fields but now rice fields.
D. The “Soto-ura” marine terrac type (see phot. 3). This type prevaids on the eastern part of the northern coast.
E. The Dry field type in the western part of the northern coast. This plane has a steep sea cliff 20-100m.
II. Massive cultivated land
F. The “Isurugi-goisi” type. This massive rice field, Fig. 2 is intimately related to a land-slide Fig. 3.
G. The Scattered type. These small massive rice field belong to “Einzeldorf” or “Weiler” on a number of upheaval planes.
H. The Corrie-like type. (see Fig. 9.) This is developed on hard rock region.
III. Linear cultivated land I. The Branching rice field type. (see Fig. 4, 5, 8.) The Valley bottom has a gentle slope, with much water and thick sediments, and the other part is not easy to irrigate, so that this type has developed.
J. The Chaining rice field type. As the result of intermittent upheavs there are many knick-points as show in Fig 10 at which point the Linear rice fields are cut or closed.
2. A Geomorphologieal Study of Subareal and Submarine Topography. (No. 7_??_8, p p. 477_??_490, 546_??_556.)
The Noto Peninsula consists of two groups of Tertiary fault blocks. The first group, which forms the main part of this peninsula, are from south to north, the “Sekidosan” block, “Oti” graben, “Bijosan” block, “Sirahama-Takahama” graben, “Musigamine” block, “Takatumeyama” block, and “Nisiura” block. Since this group is an elevated land related to the “Kaga” mountain region, which is the southern great block of the first group, these blocks have many points in common. That is, they have a marine erosion surface under 400m, and there is between the two blocks a clear fault or graben, while the trend of the blocks, and that of the fault or graben is NE-SW, which gradurally becomes NNE-SSW, and finally N-S. These changes are on account of the time that elapsed between the move-ment of the two elevations the first and second groups.
The second group, which is related to the “Hida” mountain block, lying east of the “Kaga” block, consists of two fault blocks and three submarine banks, mamely, from south to north, the “Hatibuse-” and “Suzu” blocks, “Nanatu-sima” and “Yomeguri” banks, and the “Hegura-sima” bank. The trend of this group is NE-SW. The height of the two blocks is higher than the former, and the flat plane on the top of this block mountain has a very small area, although there are many other small flat planes on the various levels. Usually, the slope is steep on the north side and gentle to the south, and both coasts have marine terraces of two or three levels, that are higher on the northern coast.
That block which situated north of the first group and west of the second group has both characteristics.
The flat planes of the first group seem to be the surfaces of a marine erosion of the same stage, while the planes at various levels of the second group seem to be the surfaces of marine erosion at several stages.