# Relationship history for MSHA mine 4500939

Current hierarchy: **Imerys S A → Imerys Filtration Minerals, Inc. → Quincy WA 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

- **operator_operates_mine:** Witco Corp-Inorganics Specialties Div → Quincy WA Plant; 1950-01-01 to 1991-09-15; source msha-controller-operator-history
- **controller_controls_mine:** Denis  Andreuzzi → Quincy WA Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Denis  Andreuzzi → Witco Corp-Inorganics Specialties Div; 1950-01-01 to 1991-09-15; source msha-controller-operator-history
- **controller_controls_mine:** Alleghany Corp → Quincy WA Plant; 1991-07-26 to 2005-07-14; source msha-controller-operator-history
- **operator_operates_mine:** Imerys Filtration Minerals, Inc. → Quincy WA Plant; 1991-09-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alleghany Corp → Imerys Filtration Minerals, Inc.; 1991-09-16 to 2005-07-14; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Quincy WA Plant; 2005-07-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → Imerys Filtration Minerals, Inc.; 2005-07-15 to current/open; source msha-controller-operator-history