Field Notebook: Texas 1957b
Page 71
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Transcription
7/31/58/3 - King's bed 8, section 22. 7/31/58/4 - about 15' above 7/31/58/2 on same hill, different anthill however. This is in the silicified thin bedded limestone and reddish to yellowish siltstone facies like the lower Leonard on the Decie Ranch above the Hess ledge - Clouded over at 4:00 Thin beds grade north into Leonard shale lithology. PG. 106 8/1/58 Hess Ranch The canyon through the Leonard Ridge at the east end of the Hess Horst is formed by a flexure at the escapement. Here the fold is monoclinical with about 30' of offset. This same fold increases in magnitude NE and forms the steeply dipping ridge of Lower Leonard just S of the Intrusive mass. The valley is formed because of a zone of step faults 6" to several feet apart. This is a "shear" zone in which the shear strikes about N50E and are vertical +-. 8/1/58/1 - Coll. of Bryozoan from lowest Word limestone on Road to Old Word Ranch. Also a member of brachs and a pelvic bone of something. One brach looks like Pentisporifer pulcher [?] but can't get it out - the darn Rock is too big to move. This is about 150' below Word #1 limestone. Sent pelvic bone to John Wilson U. of Texas. 23 August. PG. 107 8/1/58/2 - Loc. 86. 50 yards WSW of top of limestone at southeastern side of intrusion in Hess Horst. Anthill in a limestone about 15' below highest limestone exposed on this ridge. ie. King's Map is wrong here. Schwagerina guemblei. PG. 108 8/2/58 Leonard Mt. 8/2/58/1 - same as 7/23/58/1 8/2/58/2 - 30' above base of Wolfcamp conglomerate SW Leonard Mt., one frag of a cobble containing fusulines included. U. of Texas Field Camp came up to look at the SW face of Leonard Mt., I gave them the Ross interpretation. It is about 250' up through folded rocks of probably Haymond equivalent, before getting to the lowest conglomerate. The SE dipping Gaptank beds are near conformable on top of the this lowest conglomerate, and thicken towards the SE. There were gently folded and truncated so suggests fluxes rather than more or less continuous movement. In my section 35, there are a few more feet of brown siltstone above the "Dimple" limestone than shown. PG. 109 8/2/58/3 - 10' above massive conglomerate unit at Hess Horst. This is about 2/3 of the way up the slope at the east side of the saddle separating the 2 main ridges of the Horst. Free specimens, mostly loose in the slope but many beds of fusulinid limestone in place in this interval.