Eastport quadrangle notebook # 1, 1907
Page 24
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Transcription
(a) [?] Irediolopside). Nearly opposite the house there is a loose dike cutting across columnar dust like v slakes. Long “horses” of the dike are intruded into the shale & dust beds, v horses” of the latter are included in portions of the dike. The dike appears to strike N 38° E, but this may not be the real direction. Underneath the dike is a one foot layer of volcanic ash - which may also be placed on the more the point 3.W. of the house. The strike of this ash bed = N 80° E. Marine clay (stratified) occurs in a little gully as indicated on accompanying sketch map of S part of 3:44:7. The clays differ from the usual massive gray (unbedded) clays in being composed of pink seams of red clay, apparently derived from the red dust beds & Silurian shales a few rods away; these red seams interstratified with thicker layers of clay of the color of normal boulder clay. The red clay seems to “stick” well, the dark yellowish brown clays 4 miles to a foot thick about four feet are exposed dropping walls - apparently under the till. The strata of clay are thrown into minute low domes or wrinkles and are not flat, though On the nose-like point in the southern part of 3:44:7, southwest of the house shown on the map, is a fine series of dust beds & two volcanic ash beds with shales. The northern half of this nose is entirely free from red beds - so as in the strata studied Monday June 16 (see p. 35). The red beds dominate the section of Silurians from the northern half of this nose-like promontory as far north on the separate dike at the upper cliff of 3:44:7. They are entirely south of this limit in the region studied, - the lower shales being gray & flaggy; the red shales red dusts & volcanic ash like reppars on the northern end of the island just east of the railroad bridge (covered at half tide). The volcanic ash bed, apparently the same as that described above (dike 7) - yielded a few specimens, - contact 3:44. 7 ashy. A thin dike may be followed for many yards below high tide mark. The dikes are N. 22° E x S. 22° W., cracks in which runs from 6 inches to 10 inches. A specimen is labeled 1013. like = 1013 Wednesday June 14, 1907 Visitors detained beginning at Pt. Bridge toward Garden Island & parking elsewhere along it shore. Just to the southwest of the railroad on the point above - labeled 35. At this point there is an outcrop of hard white limestone - gray shales interbedded with little sandstone, about 7 feet thick with a trace a one foot layer conglomerate above & below it. A ledge and another & still smaller ones occur but a few yards to the north. The conglomerate to resemble all beds but the latter are rounded & many of them very plainly metamorphous. A couple of specimens of the lower conglomerate are dated 3:44.7a, the upper conglomerate 3:44.7b. Pt. Bridge [Silurian] exhibiting the preceding forms the first ledge now just at the house shown on the map on the north shore at the end of the rd road (this house is now no more, its site is marked by ruins & the foundations). For one a hundred yards the Silurian strata extend northeastward with a dip of 34° N. 5° E., strike W. 7° W.. The lowest beds are exposed above high water just west (a couple of yards) of the ruins of the house shown on the maps. They are gray shales which are unbedded and intact for three or four feet contain several seams with numerous numbers of bivalve, oposid lamellibranchia and ostracods; the Lingula is also common. These fossils are constant 3:44.7a. A thin seam in the middle of these 31/4 feet contains so many shells & ostracods that it is calcareous. This calcareous seam (1 inch thick) and its fossils via 3:44, 4a². Away all the rocks of the promontory (covered at three quarters tide) are gray shales & flaggs with a couple of flacher flags or sandstones. Very little red shale - if apparently little of any dust beds (truffs) occur. The red shale is confined to a few thin patches & beds 40 to 50 feet from high water (along line of dip). These red shales yielded a few lamellibranchia (modi-copoids) and a Lingula 3:44, 4b They are a couple of feet below the lower ash bed, - 3:44.4c. As the second or eastern of the two points shown on the map, - that is, the easternmost of the ledges shown on the map in 3:44. If the structure is somewhat as follows "A" (a) is a fine grained basic dike, cutting across the edge of the Silurian strata. The direction of this “A” (a) -dike is N E. 5° S., & W. 5° N. A hand specimen is numbered 1014. The dike exhibits a width of six or seven feet; its southern limit was not shown (covered with gravel). On the east side of the ledge there is another dike “B” of the sketch which is directed N. 16° W. 36 37