I am looking for a specific [matroid](https://en.wikipedia.org/wiki/Matroid). I found a source that claimed to discuss these matroids, but then, only discusses [geometric lattice](https://en.wikipedia.org/wiki/Geometric_lattice). Even more, in that paper, the geometric lattice that seems to be the right one was described as > ... the lattice associated with the [Steiner system](https://en.wikipedia.org/wiki/Steiner_system) $S(3,6,22)$. It might be clear to some, how to translate between all these different constructs, but I have a hard time finding any source explaining to me (in short) how these concepts are linked. I suppose, that the matroid of the geometric lattice $\mathcal L$ is defined on the set of atoms of $\mathcal L$, and independence of atoms $a_1,...,a_n\in\mathcal L$ means that the supremum $a_1\vee \cdots \vee a_n$ has rank $n$. But this is just a guess. Furthermore, the lattice that comes from $S(3,6,22)$ is said to be of rank 3, but there is not much more said about this. Can someone tell me how to obtain the matroid from $S(3,6,22$)? --- There are actually two papers I am talking about: - [Basis Transitive Matroids](https://link.springer.com/content/pdf/10.1023%2FA%3A1022411901450.pdf), by A. Delandtsheer, H. Li., which discusses matroids purely in terms of geometric lattices and dimensional linear spaces (DLS). - [Homogeneous Designs and Geometric Lattices](https://reader.elsevier.com/reader/sd/pii/0097316585900226?token=97090CC92B3E729C65E22D6EACE74C5E72BD01CFD609BB19D7B88AE952A540A3FA10D898DD584A899A074FB911CE653D), by W. M. Kantor (Theorem 2), which lists $S(3,6,22)$ as a Steiner system associated with a lattice.