West East EXPLANATION M E E’ M Line intersection w/ B-B’ S M Upper Pan Glen Rose M 11-1 STRATIGRAPHIC CROSS SECTION E-E’ Geophysical Log & Samples (Kgru) S M Blanco River Dip Cross Section # # # Alex S. Broun, P.G., Douglas A. Wierman, P.G. # # and Wesley Schumacher M S F Wyn M Line intersection Geophysical Log Lower w/ C-C’ BLANCO CO. HAYS CO. Glen Rose M (Kgrl) S M M S G F Hensel (Khe) BLANCO RIVER Ap SB PR2 Upper Glen Rose: M Upper Trinity G G Upper Trinity Cow Creek ft LasM3 Upper Glen Rose (Kcc) 400 Limited Aquifer Geophysical Log & Samples Hammett Wall1 BLANCO (Kha) Ap SB PR1 Cie Sey Stl Nar Nel Arr Samples S G RIVER S M Geophysical Log Geophysical Log Geophysical Log Shell Core Geophysical Log Geophysical Log Sligo (Ksl) BLANCO RIVER 300 Lithology from Lederman Well S M Upper Aptian - Lower Albian Aptian - Lower Upper Stratotype Surface Sec. Offline one mile NW # Upper Glen Rose # Lower-Upper Sycamore/ “CA” Regional Marker Upper Glen Rose Glen Rose (1) Hosston Contact (Ksy/Kho) M 200 S F S KarstKarst Dinosaur tracks Little Blanco S F M measured section S F B. Hunt & S Lower Glen Rose BLANCO RIVER Burnet Ranch #1 S. Musick Shell core S Explanation M S Limestone (micr) Figure modified from Stricklin & S S F Lozo, 1971 and R.W. Scott, 2007 100 Limestone (skel) Lower Glen Rose Stratigraphic notes: Lower Glen Rose S Lower Glen Rose: Middle Trinity Aquifer LOWER CRETACEOUS Limestone (reef) 1- Edwards Group, Kainer Fm, as defined by Rose (1972). S F S Dolomite M Shale/marl G = grains Hensel Khe facies Middle Trinity Gypsum/anhydrite F = frame builders change S = skeletal Hensel: Confining Unit & Minor Aquifer Siliciclastic (silt, clay) = micritic limestone Hensel M # = gypsum/anhydrite Ap SB PR2 Siliciclastic (sand, silt) # 0 DATUM Hensel DATUM = springs S G S G Conglomerate ApSBPR1 Cow Creek = Sequence boundaries Cow Creek Cow Creek: Middle Trinity Aquifer 11 Plate Upper Aptian Upper Cow Creek -100 Hammett Hamm. Hammett: Confining Unit Ap SB PR1(1)(2) Hamm. SLIGO S G S Stratigraphic & Structure Cross Sections Pinchout E - E’ Sligo Hosston Sligo: Lower Trinity ft -200 Sligo Carbonate Aquifer 100 Barremian Lowerr Aptian Lowerr Sycamore / Hosston 50 VE = 50 X (1) Lower Trinity -300 (2) Sequence boundaries & ages (1)After Scott et al. 2007 Lithology from Brushy Top W3A 0.5 1 mi Hosston: after Scott et al., (2007) Offline five miles North Hinge Datum top of Cow Creek Lower Trinity Clastic Aquifer After W. F. Wilson; Fm. Tops and line Hosston PALEOZOIC Interpretation A. S. Broun -400 Valanginian - Hautervian Valanginian PALEOZOIC West E Cie East Geophysical Log EXPLANATION E’ ft msl 11-2 STRUCTURE CROSS SECTION E-E’ ft msl CieF Qal Alluvium 1600 Geophysical Log 1600 Sey Stl Nar Nel Pan Geophysical Log Geophysical Log Shell Core Geophysical Log Wall1 Geophysical Ked Edwards Samples Log & Samples Kgru Upper Glen Rose 1400 1400 Arr Mane2 LasM3 Wyn Kgrl Lower Glen Rose BLANCO Geophysical Log Samples Geophysical Log & Samples Geophysical Log BLANCO Shel RIVER Khe Hensel RIVER Geophysical Log 1200 Qal BLANCO 1200 TOM CREEK FAULT ZONE WIMBERLEY FAULT ZONE RIVER Kcc Cow Creek BLANCO Hinge line RIVER Kha Hammett 1000 BLANCO 1000 TRINITY GROUP RIVER Kgrl Ksl Sligo Khe Kho/Ksy Hosston/ Sycamore 800 800 Kcc Pz Paleozoic Normal fault, Kha down-to-the-west Cross Section E-E’ (Blanco River Dip Section): The Ksl 600 600 Hwy 290 - A-A' section is 25 miles long. Trinity-age rocks increase in Hwy 12 - B-B' Lakeway Hwy 281 - C-C' thickness to the southeast, from an estimated 700 feet A Travis Cypress Creek - D-D' C Blanco to over 1000 feet at the Pan well. The Hosston con- Scattered biostromes at this level are intermittent Normal fault, Kho Blanco River - E-E' Johnson Hays tains thick conglomerate with sands and silts in an allu- along the line of section. Well-developed upper mound down-to-the-west City B 400 vial fan/delta-plain facies proximal to the Llano Uplift. facies reefs are observed at the outcrop and in the sub- 400 Pz The Sligo pinches out near the Blanco - Hays County surface at Arr, Wall1, LasM3, and Pan wells. The Wyn Austin line. It is overlain by transgressive, quiet water, marine well, drilled close to the Blanco River, west of Wimber- 1986). The karst may be associated with the Wimberley Dripping Springs Hammett shale that onlap, but do not cover the uplift. ley, is missing the reef section (possibly due to karst fault and the Blanco River, where meteoric water and D A’ The Cow Creek, 70-90 feet thick, becomes increas- development). Over a 20-30 foot interval the gamma surface water, following fracturing, move down gradient to Blanco 200 ingly carbonate to the southeast with an upper grain curve indicates shale and the resistivity curves show the porous reef. The Wall1 well also has a missing upper 200 E Buda limestone and a well-developed dolomite section. The low resistivity. Samples from a nearby well, at the same reef section although a mid-section mound is well devel- Early Miocene-age Faulting C’ ft Kyle Hensel sand facies covers the uplift. The facies change stratigraphic interval, have cuttings of red clay, red- oped. Silty, dolomitic, and micritic limestone sediment fill 200 Comal Woodcreek D’ with the Lower Glen Rose occurs between the StI well brown pisolites, breccia and incrusted limestone frag- the basin in the Upper Glen Rose and cover the Llano E’ Wimberley and the Narrows outcrop. The Narrows biostrome ments. The clay is interpreted as terra rossa, washed Uplift. A basal Upper Glen Rose anhydrite bed was 0 100 VE= 25 X 0 B’ (Scott, 2007) is limited to about 5 miles along section. down and into the cave in the post-Pleistocene (Young, described at the LasM3 well. San Marcos 0 5,000 10,000 ft.