# Relationship history for MSHA mine 4405046

Current hierarchy: **Imerys S A → Imerys Norfolk, Inc. → Chesapeake Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Lone Star Industries Inc → Chesapeake Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lone Star Cement Inc → Chesapeake Plant; 1978-03-09 to 1984-06-17; source msha-controller-operator-history
- **controller_controls_operator:** Lone Star Industries Inc → Lone Star Cement Inc; 1978-03-09 to 1984-06-17; source msha-controller-operator-history
- **operator_operates_mine:** Lone Star Lafarge Inc → Chesapeake Plant; 1984-06-18 to 1985-11-19; source msha-controller-operator-history
- **controller_controls_mine:** Lone Star Indus Inc & Lafarge Fondu International → Chesapeake Plant; 1984-06-18 to 1985-11-19; source msha-controller-operator-history
- **controller_controls_operator:** Lone Star Indus Inc & Lafarge Fondu International → Lone Star Lafarge Inc; 1984-06-18 to 1985-11-19; source msha-controller-operator-history
- **operator_operates_mine:** Imerys Norfolk, Inc. → Chesapeake Plant; 1985-11-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Chesapeake Plant; 1985-11-20 to 2003-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Imerys Norfolk, Inc.; 1985-11-20 to 2003-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Materis SA → Chesapeake Plant; 2003-11-01 to 2014-03-25; source msha-controller-operator-history
- **controller_controls_operator:** Materis SA → Imerys Norfolk, Inc.; 2003-11-01 to 2014-03-25; source msha-controller-operator-history
- **controller_controls_mine:** Astorg Partners → Chesapeake Plant; 2014-03-26 to 2019-07-08; source msha-controller-operator-history
- **controller_controls_operator:** Astorg Partners → Imerys Norfolk, Inc.; 2014-03-26 to 2019-07-08; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Chesapeake Plant; 2019-07-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → Imerys Norfolk, Inc.; 2019-07-09 to current/open; source msha-controller-operator-history