Calcium carbonate rocks, like limestone and marble, dissolve through a process called carbonation. This process involves a chemical reaction with carbonic acid, which is formed when carbon dioxide (CO2) dissolves in water.

Here's a breakdown of the process:

1. Formation of carbonic acid: CO2 from the atmosphere or soil dissolves in rainwater, forming carbonic acid (H2CO3):

```

CO2 (g) + H2O (l) ⇌ H2CO3 (aq)

```

2. Reaction with calcium carbonate: Carbonic acid reacts with calcium carbonate (CaCO3) in the rock, forming calcium bicarbonate (Ca(HCO3)2), which is soluble in water:

```

CaCO3 (s) + H2CO3 (aq) ⇌ Ca(HCO3)2 (aq)

```

3. Dissolution: The calcium bicarbonate dissolves in the water, leading to the breakdown and erosion of the calcium carbonate rock.

Factors influencing dissolution:

* Carbon dioxide concentration: Higher CO2 concentration in the water leads to increased formation of carbonic acid, thus accelerating the dissolution process.

* Water acidity: More acidic water (lower pH) increases the rate of dissolution.

* Temperature: Higher temperatures generally lead to faster dissolution.

* Flow rate: Moving water can remove dissolved calcium bicarbonate, encouraging further dissolution.

Consequences of dissolution:

* Cave formation: Dissolution of limestone can create caves and underground networks.

* Karst topography: Dissolution of limestone can lead to the formation of sinkholes, disappearing streams, and other karst features.

* Ocean acidification: Increased CO2 in the atmosphere leads to increased ocean acidity, affecting marine ecosystems and the dissolution of calcium carbonate structures like coral reefs.

In summary, calcium carbonate rocks dissolve due to the chemical reaction with carbonic acid, which is formed when carbon dioxide dissolves in water. This process is influenced by various factors, including CO2 concentration, water acidity, temperature, and flow rate.