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[above sketch:] (W) | * Supposed 2500 above sea 2300 | Rio del Yeso to mouth must be 25 miles or 22 or 20 | This in part to be enlarged | San [Pedro] 10,000 ft above sea one league below junction of river. | Bends up to vertical | stet | Gypseous formations | (a  (a) 70º-80º | Sections N. I & II | {The Back mountain with fainter outlines | Red section nearly vertical | Underlined 70º | 1000 ft on scale | [4 words illeg] | Small anticlinal  (b) | W | No: 5 | a | Anticline | F 200 to 400 | Supposed to be 14000 ft to 15000 | Crest of Puquenes | a | B | C | (Z) | Synclinal lines | D | 45º | E | 45º | F | H | (?) | Too narrow | E

 (C) | Shorten this | 20º | (Sect. 7) | N.B. The intermediate district of the two ranges is too low with respect to the general height of section | [3 words illeg] lines high | N.B. This whole section must be from thrice to thrice too high in proportion to breadth. | Illustration sketch-section | Porphry | Porph: breccia? | 20º to East | Portillo range | (D)

 (D) | (Sect: 8) | Mica slate | East dip | (Sketch section) (Supposed to be taken on a east & west line [up] the Cordillera). | N. B Mica slate dips eas[t] | 3 Mica slate | (shorten this five miles) (shorten this ten feet) | 200 ft | Porph: breccia | Porphry | Porph | Porph.- 3500 ft | Assumed 3300 ft above the sea

[in sketch:] (Colour) | A | B | Porph: breccia | Granite | (J Mier) his height. | 40º | ⸮ Stratification not known | Porph. breccia  Granite | Syenitic greenstone | Porphry | 2000 ft thick | Porph: breccia | Stratification not known | Gypseous formations | ⸮ & [illeg] | Porphry | 45º | Porph: breccia | Gypsum | 300 to 400 | Sandstone | Gypsum | Sandstone | Gypseous formations neither exact superposition or stratification known | Limestone | O | Sandstone  Limestone | 1 Sandstone | (Q) Bl. limestone. | Gypsum (R) | Black limestone (S) (40) | Sandstone T | Sandstone T (2) | Black limestone S (2) | R (2) Gypsum | Black limestone (Q)(2) | Sandstone P(2) | Modern conglomerate Modern conglomerate | 15,000 to 20000 ft in thickness | 45º | Colored strata ? | Laminated sandstone | Quartz | Protogine | Granite | Protogine  Protogine | 300 to 400 ft 1500 ft from bottom of valley | Lava | Mica slate | Tufa | Tufa | Lava | Talus | Pampas

[inset pencil sketch:] 2500 ft | 40º | 14000 ft | Peak of Aconcagua 23000 ft.– | 14000 assumed height of greater number of peaks | 3500 | 1 foot to 60 Road over the crest Assumed 60 nautical miles as breath of Cordilleras from mouth of valley of Maypo to edge of Pampas 3500

[below sketch:] * | Syenitic greenstone | Granite | Altered slates next to the granite | Parts porphrys within stratification | Porph: breccia | Meyen bottom of valley 2000 above plains Tollo 3600 above sea | Trachyte? Pumice | (Black colour) | Junction of rivers of Valle del Yeso & Volcan 4000 to 5000 ft. (8 or 9 leagues from this junction to that of Colorado) | (1) | Trachyte | Little narrower | (Valley of Yeso) | C[uesta][illeg] | (E)  (W. C. del Indio)* | Los Indios | F | C. | (Black limestone clay-slate vertical) [several faint pencil words illeg] | 200 to 300 ft | G F | Rock fragments of feldspathic rock. | Basin valley | Valle del of Yeso 6000 to 7000 ft? flatter more level | (H) | (no 4)  B C Valle del Yeso | (Q) | K | Peuquenes & Rio Yeso shorten 5 miles, especially I see I make basin of Yeso 10 miles | (2 | (E) P | (3)  (W) | V | (this part narrower!) | V | V | W | X | 4 | Y | Z | (E)  (W) | Z | Las Arenales | Dikes. | Erupted after country assumed present form | Lava submarine much more concol-conformable | (NB I think ⅓ of inch to mile good scale & say one inch to 6000 ft) | (5) | Mica slate must end here | Granite coverd by mica slate 30 3a | [to miles for present section] | SW 70º | One inch to mile no doubt [bed] including [gypsum] | 300-600 ft. | 65 miles | (E)

[colour key:] 1 Granite & syenitic greenstone 2 Mica slate [no number] Altered clay-slate 3 Porphry 4 Porph: breccia 5 Micaceous sandstone 6 7 Red sandstone 8 Gypsum 9 Black limestone tuffs 10 Modern conglomerate 11 Lava 12 subærial, or 11 like such

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P 36 Make total section 65 miles to W face of porphyritic conglomerate; so that in the 65 the little hillocks are excluded-

Make from mouth of Maypu to Yeso & Volcan 18 miles it is now only 5, so that 13 are to be saved Save 6 between Portillo & eastern base, & 7 seven miles between Peuquenes & junction of Yeso & Volcan 

3/70 [=] 23