Jug Rock is a natural geological formation located outside of Shoals, Indiana

Shoals, Indiana

Shoals is a town in Center and Halbert townships, Martin County, Indiana, United States. The population was 756 at the 2010 census. The city is the county seat of Martin County....

, in the valley of the East Fork of the White River

White River (Indiana)

The White River is a two-forked river that flows through central and southern Indiana and is the main tributary to the Wabash River. Via the west fork, considered to be the main stem of the river by the U.S. Board on Geographic Names, the White River is long.-West Fork:The West Fork, long, is...

. It is composed of sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

, and is the largest free-standing table rock formation (also called a "tea table

Tea table

Geologically speaking, a tea table is a rock formation that is a remnant of newer strata that have eroded away. A tea table is a type of rock column comprising discrete layers, usually of sedimentary rock, with the top layers being wider than the base due to greater resistance to erosion and...

") in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 east of the Mississippi River

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

. It is part of the Mansfield formation, laid down in the Pennsylvanian

Pennsylvanian

The Pennsylvanian is, in the ICS geologic timescale, the younger of two subperiods of the Carboniferous Period. It lasted from roughly . As with most other geochronologic units, the rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain...

 geological epoch, roughly 325 to 286 million years ago. Erosion along fracture lines separated it from a nearby cliff. A companion feature, House Rock, stands opposite Jug Rock.
In the Second Report of the Geological Survey of Indiana, published in 1871, State Geologist E. T. Cox wrote:

One of the most interesting spots to visit, for obtaining a view of this character of scenery, is near the town of Shoals, on the road to the Indian Sulphur Springs. A high ridge of millstone grit, here, terminates within a few yards of the East Fork of White river, from the top of which, there is a projecting mass of conglomerate sandstone, called the "Pinnacle," which stands one hundred and seventy feet above the level of the stream. Cyclopean blocks, that have broken off, lie around the foot of the ridge, in every conceivable position. On the north side of this ridge, the conglomerate has been cut through by disintegrating forces, which left, at some distance from the main ledge, a tall mass of rock, which has received the name of "Jug Rock," from the fancied resemblance which it bears to a jug. It is forty-two feet high and supports, on its top, a flat projecting layer, which is called the "stopper." Just above the bulge of the jug are irregular lines of stratification, known as false bedding. The lower part is thickly set with quartz pebbles. The frontispiece to this volume presents a view of the "Jug Rock" which was copied from a photograph taken by D. Allbright. For this faithful representative of a highly interesting geological scene, I am indebted to B. F. Devol, and D. Allbright, of Shoals.

Jug Rock is currently part of a nature preserve

Nature reserve

A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...

 owned by the Indiana Department of Natural Resources

Indiana Department of Natural Resources

The Indiana Department of Natural Resources is the agency of the U.S. state of Indiana charged with maintaining natural areas such as state parks, state forests, recreation areas, etc...

.

This unusual rock feature gives its name to the team of nearby Shoals High School, "Shoals Jug Rox." The Jug Rock is the school's mascot.

External links

• [ Geographic Names Information System Feature Detail Report (House Rock)]
• [ Geographic Names Information System Feature Detail Report (Pinnacle Rock)]
• Topographic map from TopoQuest (House Rock and Pinnacle Rock)
• Standing Rocks: Ancient Erosion Remnants (from Our Hoosier State Beneath Us, Indiana Geological Survey)