98°28'30"

98°30'

29°52'30"

29°51'

29°49'30" 29°49'30"

29°51'

98°30'

29°52'30"

98°28'30"

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KENDALL COUNTY

COMAL COUNTY

Guadalupe River

Curry Creek

Honey Creek

Honey Creek

Kgrd

Kgrd

Kgrd

Kgrd

Kgrhc

Kgrd

Kgrhc

Kheh

Kcccc

Kgrhc

Kheh

Kgrhc

Kgrr

Kgrhc

Kheb

Kcccc

Kheh

Khah ?

Kcccc

Kheh

Kgrhc

Kgrhc

Kgrr

Kgrr

Kgrr

Kgrr

Kgrr

Kgrhc

MAP EXPLANATION

Informal hydrostratigraphic unit

 Doeppenschmidt 

 Rust 

 Honey Creek 

 Hensell 

 Cow Creek 

 Hammett 

Fault, type unspecified— Dashed where inferred

Fracture

Igneous dike

Contact—Between hydrostratigraphic units

Guadalupe River State Park boundary

Honey Creek State Natural Area boundary

Road

Cave or sinkhole

Hensell Sand Member 

Stratigraphic unit

Cow Creek Limestone Member

Hammett Shale Member

Kgrd

Kgrhc

Kcccc

Khah

Kheh

Glen Rose 

Limestone Kgrr

EXPLANATION OF HYDROSTRATIGRAPHIC UNITS

Pearsall

Formation

Lower member

Photograph 1. Guadalupe River, looking upstream towards the main river access point in the Guadalupe River State 

Park. Bedrock in the river is the lower part of the Cow Creek Limestone Member, Cow Creek hydrostratigraphic unit 

(Kcccc). Photograph by Robert R. Morris, USGS Volunteer for Science, November 10, 2011.

Photograph 2. Looking downstream along the right bank of the Guadalupe River in the 

northwestern part of the study area, showing the cutback in the lower part of the Cow 

Creek Limestone Member. Photograph by Robert R. Morris, USGS Volunteer for 

Science, February 16, 2012.

Photograph 3. U.S. Geological Survey geologist noting the contact between the Hensell Sand Member and the lower 

member of the Glen Rose Limestone near the western boundary of Guadalupe River State Park, Kendall County, Texas. 

Photograph by Robert R. Morris, USGS Volunteer for Science, November 9, 2011.

Photograph 4. Well-preserved hand specimen showing moldic porosity from the Honey Creek hydrostratigraphic unit (Kgrhc) 

a few feet above the contact between the Honey Creek unit and the underlying Hensell unit (Kheh). Smallest division on the 

scale along the lower portion of the image is 0.6 inch. Photograph by Robert R. Morris, USGS Volunteer for Science.

Photograph 5. Example of moldic and channel porosity in the Honey Creek hydrostratigraphic unit (Kgrhc) in Honey 

Creek State Natural Area, Comal County, Texas. Photograph by Robert R. Morris, USGS Volunteer for Science, 

November 9, 2011.

Photograph 6. Cow Creek hydrostratigraphic unit (Kcccc; Cow Creek Limestone Member) along the north side of 

Guadalupe River, Guadalupe River State Park, Kendall County, Texas. Photograph by Allan K. Clark, USGS, February 

15, 2012.

Photograph 8. USGS personnel recording details of the igneous dike in the Cow 

Creek unit (Kcccc) exposed on the north bank of Honey Creek. Photograph by 

Robert R. Morris, USGS Volunteer for Science, November 9, 2011.

Photograph 9. Igneous rock from dike and quartz geode in Honey Creek State Natural Area, Comal County, Texas. 

Photograph by Allan K. Clark, USGS, November 9, 2011.

Photograph 7. Top of the Cow Creek hydrostratigraphic unit (Kcccc; Cow Creek Limestone Member) along the south 

side of the Guadalupe River in Guadalupe River State Park, Kendall County, Texas. A part of the river can be seen near 

the middle of the left side of the photograph. Photograph by Robert R. Morris, USGS Volunteer for Science, February 

0 0.6 1.2 1.8 2.4 3.0 3.6 4.2 4.8 5.4 6.0 6.6 7.2 7.8 15, 2012. in.

Photograph 3. U.S. Geological Survey geologist noting the contact between the Hensell Sand Member and the lower 

Photograph 1. Guadalupe River, looking upstream towards the main river access point in the Guadalupe River State 

Photograph 6. Cow Creek hydrostratigraphic unit (Kcccc; Cow Creek Limestone Member) along the north side of 

[Stratigraphic nomenclature of the Cretaceous rocks exposed in and around the study area are from 

Mancini and Scott (2006) and Barker and Ardis (1996) and the U.S. Geological Survey National 

Geologic Map Database, GEOLEX (http://ngmdb.usgs.gov/Geolex/geolex.html). The rocks exposed 

in the study area compose a section of the middle Trinity aquifer. The middle Trinity aquifer is 

composed of the lower member of the Glen Rose Limestone, and Hensell Sand Member and Cow 

Creek Limestone Member of the Pearsall Formation. The Hammett Shale of the Pearsall Formation 

acts as a barrier between the middle Trinity aquifer and the lower Trinity aquifer. The middle 

Trinity aquifer is from 284 to 297 ft thick in the study area. The lithostratigraphy of the study area 

was mapped and combined with the porosity characteristics using the classification system 

developed by Choquette and Pray (1970) to determine the hydrostratigraphic units. Detailed 

descriptions of the Lower Cretaceous rocks exposed in the study area are the compilation of this 

report and Stricklin and others (1971), Stricklin and Smith (1973), Amsbury (1974), Inden (1974), 

Perkins (1974), and Weirman and others (2010). The descriptions below include general information about the geologic formation or member, lithologies, thickness, primary fossils present, 

porosity, type locality, and the derivation of the unit’s name. Averages and ranges of unit 

thicknesses shown below are derived from within the study area.]

Trinity Group (Lower Cretaceous)—Overlies, in the subsurface, Pennsylvanian 

shale (Imlay, 1940) in the study area. Contains shale, grainstone, sandstone, and 

fossiliferous limestone, alternating and interfingering with mudstone, wackestone, packstone, and grainstone. Upper part removed by erosion. Thickness of 

remaining Trinity Group approximately 566–579 ft

 

Glen Rose Limestone (Lower Cretaceous, lower Albian to upper Aptian)—

 Alternating beds of yellowish-tan, medium-bedded limestone and argillaceous 

limestone with minor evaporite layers. Composed of the lower and upper 

members (informal classification), separated by a regionally extensive, small 

fossil identified as Corbula sp. (Whitney, 1952). Entire upper member, corbula 

bed and upper part of the lower member, removed by erosion 

Lower member of Glen Rose Limestone (Lower Cretaceous, lower Albian to 

upper Aptian)—Massive, fossiliferous mudstone and marlstone (Clark, 2003). 

Grainstone and biostromes interbedded with thin mudstone in the lower 

two-thirds of unit. Mudstone increases in the upper parts. Regionally, unit 

approximately 260 ft thick; however, upper portion removed by erosion and only 

about 185 ft preserved. Composed of the following hydrostratigraphic units in 

descending stratigraphic order: Doeppenschmidt (Kgrd), Rust (Kgrr) and Honey 

Creek (Kgrhc)

 

Doeppenschmidt hydrostratigraphic unit—Aquifer; interparticle, moldic, 

burrowed, bedding plane, fracture and cave porosity. Thickness 60 ft. Named 

for the Doeppenschmidt homestead within study area

Rust hydrostratigraphic unit—Confining unit; interparticle, fracture, and cave 

porosity. Thickness 70 ft. Named for Rust homestead in Guadalupe River State 

Park

Honey Creek hydrostratigraphic unit—Aquifer; contains interparticle, moldic, 

burrow, bedding plane, fracture, channel, and cave porosity. Contains corals 

and rudists. Forms of Trigonia sp. common. Thickness averages 55 ft. Named 

for Honey Creek Cave

Pearsall Formation (Lower Cretaceous)—Defined by Imlay (1945), contains five 

members the (bottom to top)—Hosston, Sligo, Hammett Shale, Cow Creek 

Limestone and the Hensell Sand. The Hosston member does not crop out in the 

study area; it is a dolomitic mudstone to grainstone. The Sligo member does not 

crop out in the study area, it is evaporite grading upward into mudstones to 

grainstones often dolomitc (Bebout and others, 1981). The Hammett Shale is a 

burrowed mixture of clay, terrigenous silt, carbonate mud, dolomite, and 

carbonate particles (Amsbury, 1974). According to Lozo and Smith (1956) the 

Cow Creek Limestone is a calcarenitic limestone grading upward to a 

crossbedded beach coquina with poorly sorted quartz grains and scattered chert 

pebbles. The Hensell Sand is a weakly cemented mixture of clay, quartz and 

calcareous sand with chert and dolomite pebbles (Lozo and Smith, 1956)

Hensell Sand Member (Lower Cretaceous, upper Aptian)—Limestone and 

sandstone. Weakly cemented, contains ferruginous clay, quartz, and calcareous 

sandstone. Glauconitic quartz geodes common. Exogyra sp. and oysters present. 

Thickness from 40 to 70 ft. Contains Hensell hydrostratigraphic unit

Hensell hydrostratigraphic unit—Aquifer; interparticle, moldic, and cave 

porosity. Thickness from 40–70 ft. Named for Hensell Sand lithostratigraphic 

unit

Cow Creek Limestone Member (Lower Cretaceous, Aptian)—Predominantly 

carbonate. Base shaley, transitions into fine- to medium-grained, massive, 

off-white, partly honeycombed, and fossiliferous limestone up-section. Thickness 

about 72 ft (Barnes, 1974). Contains Cow Creek hydrostratigraphic unit

Cow Creek hydrostratigraphic unit—Aquifer; interparticle, moldic, vug, 

burrow, fracture, bedding plane, channel and cave porosity. Thickness about 

72 ft

Hammett Shale Member (Lower Cretaceous, lower Aptian)—Contains 

siltstone, thin dolomite, and claystone. Lower 15 ft contains siltstone and 

dolomite. Upper part is claystone with fine-grained sandstone streaks, contains 

fossiliferous, dolomitic limestone (Lozo and Stricklin, 1956; Weirman and 

others, 2010). Total thickness 50 ft (Lozo and Stricklin, 1956). Contains 

Hammett hydrostratigraphic unit

Hammett hydrostratigraphic unit—Confining unit, contains little porosity. 

Thickness 50 ft. Named for the Hammett Shale lithostratigraphic unit

DESCRIPTION OF MAP UNITS

Kgrd

Kgrr

Kgrhc

Kheh

Kcccc

Khah

[Period, group, formation, members, and lithology modified from Stricklin and others (1971), Stricklin and Smith (1973), Amsbury (1974), Inden (1974), 

Perkins (1974), and Weirman and others (2010); aquifers from Ashworth (1983); thicknesses from outcrop and geophysical logs; hydrogeologic function 

modified from Weirman and others (2010); porosity types modified from Choquette and Pray (1970) and Lucia (1995): IP, interparticle porosity; MO, moldic 

porosity; BU, burrowed porosity; BP, bedding plane porosity; FR, fracture porosity; CH, channel porosity; VUG, vug porosity; CV, cave porosity] Period Early Cretaceous Group Trinity Group Formation Glen Rose Limestone Pearsall Formation Member Lower member Hensell Sand Member Cow Creek Limestone Member Hammett Shale Member

Approx.

thickness

(feet)

185

40–70

58

14

50

Lithology

Very fine grained to fine-grained 

carbonate sand with localized 

bedding, upper part is a white, well 

sorted, fine- to medium-grained 

carbonate sand grainstone, locally 

recrystallized

Upper: claystone, with siltstone 

lentiles

Lower: siltstone and dolomite

Dolomitic oyster mudstone to 

packstone

Reddish claystone and siltstone; 

contains terrigenous sandstone, 

pelecypods, and fossil fragments

Packstone to grainstone with fossil 

fragments

Alternating beds of marl and 

mudstones, miliolid grainstone, 

grainstone, nodular bioturbated 

wackestone, and monoplurids

Thick to massive beds of a Toucasia 

sp. grainstone; contains terrigenous 

sandstone, pelecypods, and fossil 

fragments

Confining 

unit

Aquifer

Middle

Trinity

aquifer

Hydrostratigraphic

unit

Doeppenschmidt

Rust

Honey Creek

Hensell

Cow Creek

Hammett

Thickness

of outcrop in

study area

(feet)

60

70

55

40–70

72

50

Hydrogeologic 

function

Porosity

type

Aquifer

Aquifer

Aquifer

Aquifer

Confining unit

Confining unit

IP, MO, 

VUG, BU, 

FR, BP, 

CH, CV

IP (upper), 

MO, CV

IP, MO, 

BU, BP, 

FR, CH, 

CV

IP, MO, 

BU, BP, 

FR, CV

IP, FR,CV

**

* * * * * *

Hydrostratigraphy

Table 1. Summary of the geologic framework and hydrostratigraphy of the Trinity Group rock units in Guadalupe River State Park and Honey

Creek State Natural Area, Kendall and Comal Counties, Texas.

Geologic framework

** not aerially exposed in the study area

* not present in the study area

0

90

135

180

225

270

0 234 1

315 45

Figure 4. Rose diagram of fracture orientations in the Guadalupe River 

State Park and Honey Creek Natural Area, Kendall and Comal Counties, 

Texas. 

Rust

Hammett

Hensell

Honey Creek

Cow Creek

270.0

260.0

250.0

240.0

230.0

220.0

210.0

200.0

190.0

180.0

170.0

160.0

150.0

140.0

130.0

120.0

110.0

100.0

90.0

80.0

70.0

60.0

50.0

40.0

30.0

20.0

10.0

Depth

1:200ft

Gamma Hydrostratigraphic 

Members

Figure 3. Geophysical log (gamma-ray) of the Springwood groundwater 

well (DX–68–13–209) located 0.5 mile east of the study area. This log

does not include the uppermost Doeppenschmidt hydrostratigraphic unit. 

On the geophysical log, 1 foot corresponds to 200 feet of borehole. 

Neches River

Guadalupe River

Brazos River

Lavaca River

San Jacinto River

Canadian River

Trinity River

Cypress Creek

Colorado River

Red River

Nueces River

Sulphur River

Nueces

River Medina River

Brazos River

Sabine River

San Antonio River

Grand

Prairie

High

Plains

North-Central

Plains

BlacklandPrairies

Coastal Pra iri es

Interior Coastal Plains

Basin

and Range

Central

Texas Uplift

Edwards

Plateau

GULF OF MEXICO

Austin

San Antonio

95° 

100°

105°

35°

30° Study area

0 50 150 MILES 100 200

0 100 200 KILOMETERS

EXPLANATION

Physiographic province

 Basin and Range

 Central Texas Uplift

 Edwards Plateau

 Grand Prairie

 High Plains

 North-Central Plains

Gulf Coastal Plain 

physiographic subprovince

 Blackland Prairies

 Coastal Prairies

 Interior Coastal Plains

Base from U.S. Geological Survey, 1:7,000,000-scale digital data

Universal Transverse Mercator projection, Zone 14

North American Datum of 1983

Physiographic regions from Wermund, 1996 Rio Grande

Figure 2. Physiographic provinces in Texas.

98°30'

98°00'

30°00'

29°40'

29°20'

98°45'

98°15'

DX–68–13–209

San Antonio

International 

Airport

Honey Creek State

Natural Area

Guadalupe River

State Park

BEXAR 

KENDALL COUNTY

COUNTY

COMAL COUNTY

Creek

Creek

River

Medina

Guadalupe

Creek

Leon

Salado

River

Cibolo

Creek

Honey

CANYON LAKE

Study area

TEXAS

LOCATION MAP

Figure 1. Location of the Guadalupe River State Park and Honey Creek State Natural Area, Bexar, Comal, and Kendall Counties, Texas.

0 1 5 1 0 5 20 MILES

0 5 1 10 5 20 KILOMETERS

EXPLANATION

Trinity aquifer outcrop and Edwards aquifer 

 catchment area (Maclay, 1995)

Edwards aquifer outcrop (Ashworth and Hopkins, 1995)

Edwards aquifer subcrop (Ashworth and Hopkins, 1995)

DX–68–13–209

City limit

Honey Creek cave

Well and State Well number

National Weather Service station

90

281

35

10

410

Hydrostratigraphic map of the Guadalupe River State Park and 

Honey Creek State Natural Area, Kendall and Comal Counties, Texas

Geology and Hydrostratigraphy of the Guadalupe River State Park 

and Honey Creek State Natural Area, Kendall and Comal Counties, Texas

By

Allan K. Clark, Charles D. Blome, and Robert R. Morris

2014

Base modified from U.S. Geological Survey, 

Spring Branch, Bergheim, and Anhalt, Texas, 

1:24,000-scale digital data (contour data, 1999)

North American Datum of 1983 (NAD 83)

Universal Transverse Mercator projection, Zone 14

Park boundaries modified from 2011 Texas Parks 

and Wildlife Department dataset 

Any use of trade, firm, or product names is for descriptive purposes only and 

does not imply endorsement by the U.S. Government.

Although this information product, for the most part, is in the public domain, 

it also may contain copyrighted materials as noted in the text. Permission to 

reproduce copyrighted items must be secured from the copyright owner.

This database, identified as SIM 3303, has been approved for release and 

publication by the U.S. Geological Survey (USGS). Although this database 

has been subjected to rigorous review and is substantially complete, the 

USGS reserves the right to revise the data pursuant to further analysis and 

review. Furthermore, it is released on condition that neither the USGS nor the 

U.S. Government may be held liable for any damages resulting from its 

authorized or unauthorized use.

For more information concerning this publication, contact:

Director, USGS Texas Water Science Center

U.S. Geological Survey

1505 Ferguson Lane

Austin, Texas 78754–4501

(512) 927-3500

Or visit the Texas Water Science Center Web site at:

http://tx.usgs.gov/

Publishing support provided by: 

Denver Publishing Service Center

Edit and digital layout by C.F. Chan

Manuscript approved for publication June 3, 2014

To learn about the USGS and its information products visit

http://www.usgs.gov/ 

1-888-ASK-USGS

This report is available at:

http://pubs.usgs.gov/sim/3303

Suggested citation: Clark, A.K., Blome, C.D., and Morris, R.R., 2014, 

Geology and hydrostratigraphy of Guadalupe River State Park and 

Honey Creek State Natural Area, Kendall and Comal Counties, Texas: 

U.S. Geological Survey Scientific Investigations Map 3303, 8 p., 1 sheet, 

scale 1:24,000, http://dx.doi.org/10.3133/sim3303. 

ISSN 2329-132X (online)

http://dx.doi.10.3133/sim3303

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Map 3303

Pamphlet accompanies map

Mapping was completed by A.R. Clark, with the 

help of C.D. Blome and R.R. Morris. D.E. Pedraza 

prepared the digital compilation and GIS 

database of the hydrostratigraphic map. 

1 1/ 2 0 1 MILE

SCALE 1: 24 000

1000 1000 0 2000 3000 4000 5000 6000 7000 FEET

1 0 1/ 2 1 KILOMETER

APPROXIMATE MEAN

DECLINATION, 2014 TRUE NORTH

MAGNETIC NORTH

4°