We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is Boundstone?

By Angela Brady
Updated Jun 04, 2024
Our promise to you
All Things Nature is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All Things Nature, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Boundstone is an indigenous deposit of limestone that was bound by algae, coral, or other unicellular organism when it was formed. Boundstone is found in areas surrounding coral reefs, and areas that were coral reefs 2.5-3 million years ago, but may be surrounded by dry land today. Depending upon the way the organic matter was arranged within the sediment when the stone was formed and what kind of organic matter it was, boundstone can be classified as either framestone, bindstone, or bafflestone.

Framestone is distinguished by a rigid framework of fossilized organic matter, usually deep-water sponges, that occur close together in a ”life position.” These sponges were bound by microbial crusts and hardened sand when living, and the spaces between gradually filled with sand, sediment, and calcite crystals. Over time, as the water receded and the structure was continuously exposed to air, the natural cementing action of the densely packed sediment preserved the remains of the organic matter as fossils. Framestone is named for the “framework” the organic matter provides, and can be found in massively large or small, dense deposits.

Bindstone is characterized by a more random dispersion of organic binding agents that may or may not be preserved. The most common binding agent in bindstone is algae, which holds together layers of mud and calcite with large “pores” caused by gas bubbles that became trapped in the sediment during formation. Stromatolites, which are fossilized mounds of layered algal mat and sediment, are the most common form of bindstone. Most bindstone deposits are oriented vertically as opposed to horizontally, due to the layering manner in which they form. The base of the stone is formed as an algal mat forms laterally, then is built upon by mud and other algae both vertically and laterally, changing with environmental conditions. Bindstone is the most commonly found type of boundstone.

Bafflestone is bound by thick-walled, parallel columns of coral, which permit only finer-grained sediment to pass through. As a result, the composition of bafflestone, other than fossilized coral, is mostly naturally-cemented sand and silt. The sand is composed of homogenous calcite and the silt consists of a mixed residue left behind after carbonate mud was filtered out. The unique structure of bafflestone means that it can only form on and around colonies of vertically-growing coral, and are therefore limited to small individual or clustered deposits. Bafflestone is named for the “baffling” action exhibited by the coral columns during the formation of the stone.

All Things Nature is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By cougars — On Oct 18, 2011

@highlighter- Boundstone in itself is a fossil. I do not know much about boundstone, but I do remember from my physical geography of energy class, it has been found alongside oil and gas reserves in various places around the globe. One area in specific that I remember hearing about boundstone is in a region of Eastern Kazakhstan.

The place in particular is the Tenzgen field along the shores of the Caspian sea. I think this is the area where geologists and petroleum engineers are currently developing as gas fields. From what I remember, this area is very rich in natural gas reserves, many of which were discovered recently. As far as where in California you might find bounstone, I am not sure, but I would assume the state is rich in boundstone because it has a significant amount of oil resources and the state is along the coast. Maybe doing a photo search online will produce some results. I know people often post location data with photos of rock specimens.

By highlighter — On Oct 18, 2011

Where can I find natural geologic deposits of boundstone? I think it would be interesting to examine these stones. I would assume that they are loaded with fossils and the likes since they are sedimentary rocks that originated in areas rich in biodiversity. I live in California, are there any areas where I can find these types of sedimentary rocks?

All Things Nature, in your inbox

Our latest articles, guides, and more, delivered daily.

All Things Nature, in your inbox

Our latest articles, guides, and more, delivered daily.